Science.gov

Sample records for zwitterionic hybrid polymer

  1. Conjugated polymer zwitterions and solar cells comprising conjugated polymer zwitterions

    DOEpatents

    Emrick, Todd; Russell, Thomas; Page, Zachariah; Liu, Yao

    2018-06-05

    A conjugated polymer zwitterion includes repeating units having structure (I), (II), or a combination thereof ##STR00001## wherein Ar is independently at each occurrence a divalent substituted or unsubstituted C3-30 arylene or heteroarylene group; L is independently at each occurrence a divalent C1-16 alkylene group, C6-30arylene or heteroarylene group, or alkylene oxide group; and R1 is independently at each occurrence a zwitterion. A polymer solar cell including the conjugated polymer zwitterion is also disclosed.

  2. Novel sulfonated polyimide/zwitterionic polymer-functionalized graphene oxide hybrid membranes for vanadium redox flow battery

    NASA Astrophysics Data System (ADS)

    Cao, Li; Kong, Lei; Kong, Lingqian; Zhang, Xingxiang; Shi, Haifeng

    2015-12-01

    Hybrid membranes (SPI/ZGO) composed of sulfonated polyimide (SPI) and zwitterionic polymer-functionalized graphene oxide (ZGO) are fabricated via a solution-casting method for vanadium redox flow battery (VRB). Successful preparation of ZGO fillers and SPI/ZGO hybrid membranes are demonstrated by FT-IR, XPS and SEM, indicating that ZGO fillers is homogeneously dispersed into SPI matrix. Through controlling the interfacial interaction between SPI matrix and ZGO fillers, the physicochemical properties, e.g., vanadium ion barrier and proton transport pathway, of hybrid membranes are tuned via the zwitterionic acid-base interaction in the hybrid membrane, showing a high ion selectivity and good stability with the incorporated ZGO fillers. SPI/ZGO-4 hybrid membrane proves a higher cell efficiencies (CE: 92-98%, EE: 65-79%) than commercial Nafion 117 membrane (CE: 89-94%, EE: 59-70%) for VRB application at 30-80 mA cm-2. The assembled VRB with SPI/ZGO-4 membrane presents a stable cycling charge-discharge performance over 280 times, which demonstrates its excellent chemical stability under the strong acidic and oxidizing conditions. SPI/ZGO hybrid membranes show a brilliant perspective for VRB application.

  3. Integrated antimicrobial and nonfouling zwitterionic polymers.

    PubMed

    Mi, Luo; Jiang, Shaoyi

    2014-02-10

    Zwitterionic polymers are generally viewed as a new class of nonfouling materials. Unlike their poly(ethylene glycol) (PEG) counterparts, zwitterionic polymers have a broader chemical diversity and greater freedom for molecular design. In this Minireview, we highlight recent microbiological applications of zwitterionic polymers and their derivatives, with an emphasis on several unique molecular strategies to integrate antimicrobial and nonfouling properties. We will also discuss our insights into the bacterial nonfouling performance of zwitterionic polymers and one example of engineering zwitterionic polymer derivatives for antimicrobial wound-dressing applications. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Conjugated Polymer Zwitterions: Efficient Interlayer Materials in Organic Electronics.

    PubMed

    Liu, Yao; Duzhko, Volodimyr V; Page, Zachariah A; Emrick, Todd; Russell, Thomas P

    2016-11-15

    Conjugated polymer zwitterions (CPZs) are neutral, hydrophilic, polymer semiconductors. The pendent zwitterions, viewed as side chain dipoles, impart solubility in polar solvents for solution processing, and open opportunities as interfacial components of optoelectronic devices, for example, between metal electrodes and organic semiconductor active layers. Such interlayers are crucial for defining the performance of organic electronic devices, e.g., field-effect transistors (OFETs), light-emitting diodes (OLEDs), and photovoltaics (OPVs), all of which consist of multilayer structures. The interlayers reduce the Schottky barrier height and thus improve charge injection in OFETs and OLEDs. In OPVs, the interlayers serve to increase the built-in electric potential difference (V bi ) across the active layer, ensuring efficient extraction of photogenerated charge carriers. In general, polar and even charged electronically active polymers have gained recognition for their ability to modify metal/semiconductor interfaces to the benefit of organic electronics. While conjugated polyelectrolytes (CPEs) as interlayer materials are well-documented, open questions remain about the role of mobile counterions in CPE-containing devices. CPZs possess the processing advantages of CPEs, but as neutral molecules lack any potential complications associated with counterions. The electronic implications of CPZs on metal electrodes stem from the orientation of the zwitterion dipole moment in close proximity to the metal surface, and the resultant surface-induced polarization. This generates an interfacial dipole (Δ) at the CPZ/metal interface, altering the work function of the electrode, as confirmed by ultraviolet photoelectron spectroscopy (UPS), and improving device performance. An ideal cathode interlayer would reduce electrode work function, have orthogonal processability to the active layer, exhibit good film forming properties (i.e., wettability/uniformity), prevent exciton

  5. Facile surface modification of glass with zwitterionic polymers for improving the blood compatibility

    NASA Astrophysics Data System (ADS)

    Zhang, Lingling; Chen, Xiaojuan; Liu, Pingsheng; Wang, Jing; Zhu, Haomiao; Li, Li

    2018-06-01

    A facile procedure to modify glass film with zwitterionic polymers for improving the blood compatibility was introduced. The glass slides were first silanized with 3-methacryloxypropyltrimethoxysilane (MPT) to generate methacrylate groups on the surface. Then, N, N’-dimethyl-N-methacryloxyethyl-N-(3-sulfopropyl) ammonium (DMMSA), a sulfobetaine zwitterionic monomer, was polymerized on the silanized glass substrates by free-radical polymerization in order to graft the zwitterionic polymers onto the substrates. X-ray Photoelectron Spectroscopy (XPS), water contact angle, scanning electron microscope (SEM) and atomic force microscopy (AFM) were utilized to analyze the surface properties of the grafted glass. The blood compatibility of the grafted glass was verified by whole blood contacting and platelet adhesion experiments in vitro. The results showed that the zwitterionic polymers were successfully grafted on the glass surface, and consequently significantly inhibited the platelet adhesion and whole blood cell attachment.

  6. Molecular level studies on interfacial hydration of zwitterionic and other antifouling polymers in situ.

    PubMed

    Leng, Chuan; Sun, Shuwen; Zhang, Kexin; Jiang, Shaoyi; Chen, Zhan

    2016-08-01

    Antifouling polymers have wide applications in biomedical engineering and marine industry. Recently, zwitterionic materials have been reported as promising candidates for antifouling applications, while strong hydration is believed to be the key antifouling mechanism. Zwitterionic materials can be designed with various molecular structures, which affect their hydration and antifouling performance. Although strong hydration has been proposed to occur at the material surfaces, probing the solid material/water interfaces is challenging with traditional analytical techniques. Here in this review, we will review our studies on surface hydration of zwitterionic materials and other antifouling materials by using sum frequency generation (SFG) vibrational spectroscopy, which provides molecular understanding of the water structures at various material surfaces. The materials studied include zwitterionic polymer brushes with different molecular structures, amphiphilic polymers with zwitterionic groups, uncharged hydrophilic polymer brushes, amphiphilic polypeptoids, and widely used antifouling material poly(ethylene glycol). We will compare the differences among zwitterionic materials with various molecular structures as well as the differences between antifouling materials and fouling surfaces of control samples. We will also discuss the effects of pH and biological molecules like proteins on the surface hydration of the zwitterionic materials. Using SFG spectroscopy, we have measured the hydration layers of antifouling materials and found that strong hydrogen bonds are key to the formation of strong hydration layers preventing protein fouling at the polymer interfaces. Antifouling polymers have wide applications in biomedical engineering and marine industry. Recently, zwitterionic materials have been reported as promising candidates for antifouling applications, while strong hydration is believed to be the key antifouling mechanism. However, zwitterionic materials can be

  7. Water-soluble polymers bearing phosphorylcholine group and other zwitterionic groups for carrying DNA derivatives.

    PubMed

    Lin, Xiaojie; Ishihara, Kazuhiko

    2014-01-01

    Water-soluble polymers with equal positive and negative charges in the same monomer unit, such as the phosphorylcholine group and other zwitterionic groups, exhibit promising potential in gene delivery with appreciable transfection efficiency, compared with the traditional poly(ethylene glycol)-based polycation-gene complexes. These zwitterionic polymers with various architectural structures and properties have been synthesized by various polymerization methods, such as conventional radical polymerization, atom-transfer radical-polymerization, reversible addition-fragmentation chain-transfer polymerization, and nitroxide-mediated radical polymerization. These techniques have been used to efficiently facilitate gene therapy by fabrication of non-viral vectors with high cytocompatibility, large gene-carrying capacity, effective cell-membrane permeability, and in vivo gene-loading/releasing functionality. Zwitterionic polymer-based gene delivery vectors systems can be categorized into soluble-polymer/gene mixing, molecular self-assembly, and polymer-gene conjugation systems. This review describes the preparation and characterization of various zwitterionic polymer-based gene delivery vectors, specifically water-soluble phospholipid polymers for carrying gene derivatives.

  8. Antifouling Thin-Film Composite Membranes by Controlled Architecture of Zwitterionic Polymer Brush Layer.

    PubMed

    Liu, Caihong; Lee, Jongho; Ma, Jun; Elimelech, Menachem

    2017-02-21

    In this study, we demonstrate a highly antifouling thin-film composite (TFC) membrane by grafting a zwitterionic polymer brush via atom-transfer radical-polymerization (ATRP), a controlled, environmentally benign chemical process. Initiator molecules for polymerization were immobilized on the membrane surface by bioinspired catechol chemistry, leading to the grafting of a dense zwitterionic polymer brush layer. Surface characterization revealed that the modified membrane exhibits reduced surface roughness, enhanced hydrophilicity, and lower surface charge. Chemical force microscopy demonstrated that the modified membrane displayed foulant-membrane interaction forces that were 1 order of magnitude smaller than those of the pristine TFC membrane. The excellent fouling resistance imparted by the zwitterionic brush layer was further demonstrated by significantly reduced adsorption of proteins and bacteria. In addition, forward osmosis fouling experiments with a feed solution containing a mixture of organic foulants (bovine-serum albumin, alginate, and natural organic matter) indicated that the modified membrane exhibited significantly lower water flux decline compared to the pristine TFC membrane. The controlled architecture of the zwitterionic polymer brush via ATRP has the potential for a facile antifouling modification of a wide range of water treatment membranes without compromising intrinsic transport properties.

  9. Dispersing Zwitterions into Comb Polymers for Nonviral Transfection: Experiments and Molecular Simulation.

    PubMed

    Ghobadi, Ahmadreza F; Letteri, Rachel; Parelkar, Sangram S; Zhao, Yue; Chan-Seng, Delphine; Emrick, Todd; Jayaraman, Arthi

    2016-02-08

    Polymer-based gene delivery vehicles benefit from the presence of hydrophilic groups that mitigate the inherent toxicity of polycations and that provide tunable polymer-DNA binding strength and stable complexes (polyplexes). However, hydrophilic groups screen charge, and as such can reduce cell uptake and transfection efficiency. We report the effect of embedding zwitterionic sulfobetaine (SB) groups in cationic comb polymers, using a combination of experiments and molecular simulations. Ring-opening metathesis polymerization (ROMP) produced comb polymers with tetralysine (K4) and SB pendent groups. Dynamic light scattering, zeta potential measurements, and fluorescence-based experiments, together with coarse-grained molecular dynamics simulations, described the effect of SB groups on the size, shape, surface charge, composition, and DNA binding strength of polyplexes formed using these comb polymers. Experiments and simulations showed that increasing SB composition in the comb polymers decreased polymer-DNA binding strength, while simulations indicated that the SB groups distributed throughout the polyplex. This allows polyplexes to maintain a positive surface charge and provide high levels of gene expression in live cells. Notably, comb polymers with nearly 50 mol % SB form polyplexes that exhibit positive surface charge similarly as polyplexes formed from purely cationic comb polymers, indicating the ability to introduce an appreciable amount of SB functionality without screening surface charge. This integrated simulation-experimental study demonstrates the effectiveness of incorporating zwitterions in polyplexes, while guiding the design of new and effective gene delivery vectors.

  10. Surface modification of silicon wafer by grafting zwitterionic polymers to improve its antifouling property

    NASA Astrophysics Data System (ADS)

    Sun, Yunlong; Chen, Changlin; Xu, Heng; Lei, Kun; Xu, Guanzhe; Zhao, Li; Lang, Meidong

    2017-10-01

    Silicon (111) wafer was modified by triethoxyvinylsilane containing double bond as an intermedium, and then P4VP (polymer 4-vinyl pyridine) brush was "grafted" onto the surface of silicon wafer containing reactive double bonds by adopting the "grafting from" way and Si-P4VP substrate (silicon wafer grafted by P4VP) was obtained. Finally, P4VP brush of Si-P4VP substrate was modified by 1,3-propanesulfonate fully to obtain P4VP-psl brush (zwitterionic polypyridinium salt) and the functional Si-P4VP-psl substrate (silicon wafer grafted by zwitterionic polypyridinium salt based on polymer 4-vinyl pyridine) was obtained successfully. The antifouling property of the silicon wafer, the Si-P4VP substrate and the Si-P4VP-psl substrate was investigated by using bovine serum albumin, mononuclear macrophages (RAW 264.7) and Escherichia coli (E. coli) ATTC25922 as model bacterium. The results showed that compared with the blank sample-silicon wafer, the Si-P4VP-psl substrate had excellent anti-adhesion ability against bovine serum albumin, cells and bacterium, due to zwitterionic P4VP-psl brush (polymer 4-vinyl pyridine salt) having special functionality like antifouling ability on biomaterial field.

  11. Probing the weak interaction of proteins with neutral and zwitterionic antifouling polymers.

    PubMed

    Wu, Jiang; Zhao, Chao; Hu, Rundong; Lin, Weifeng; Wang, Qiuming; Zhao, Jun; Bilinovich, Stephanie M; Leeper, Thomas C; Li, Lingyan; Cheung, Harry M; Chen, Shengfu; Zheng, Jie

    2014-02-01

    Protein-polymer interactions are of great interest in a wide range of scientific and technological applications. Neutral poly(ethylene glycol) (PEG) and zwitterionic poly(sulfobetaine methacrylate) (pSBMA) are two well-known nonfouling materials that exhibit strong surface resistance to proteins. However, it still remains unclear or unexplored how PEG and pSBMA interact with proteins in solution. In this work, we examine the interactions between two model proteins (bovine serum albumin and lysozyme) and two typical antifouling polymers of PEG and pSBMA in aqueous solution using fluorescence spectroscopy, atomic force microscopy and nuclear magnetic resonance. The effect of protein:polymer mass ratios on the interactions is also examined. Collective data clearly demonstrate the existence of weak hydrophobic interactions between PEG and proteins, while there are no detectable interactions between pSBMA and proteins. The elimination of protein interaction with pSBMA could be due to an enhanced surface hydration of zwitterionic groups in pSBMA. New evidence is given to demonstrate the interactions between PEG and proteins, which are often neglected in the literature because the PEG-protein interactions are weak and reversible, as well as the structural change caused by hydrophobic interaction. This work provides a better fundamental understanding of the intrinsic structure-activity relationship of polymers underlying polymer-protein interactions, which are important for designing new biomaterials for biosensor, medical diagnostics and drug delivery applications. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  12. Amino acid-based zwitterionic polymers: antifouling properties and low cytotoxicity.

    PubMed

    Li, Wenchen; Liu, Qingsheng; Liu, Lingyun

    2014-01-01

    A group of five amino acid containing zwitterionic vinyl monomers, based on serine, lysine, ornithine, glutamic acid, and aspartic acid, respectively, were proposed and developed for potential antifouling applications. Their polymer brushes were grafted on gold chips by surface-initiated photoiniferter-mediated polymerization. We then compared their performance in resisting protein adsorption from full human serum and plasma. All five polymers can reduce protein adsorption by more than 90% compared to the unmodified gold. The ornithine-based and aspartic acid-based poly(methacrylamide) can most strongly resist protein adsorption from serum and plasma, compared to the other three. The ability of surfaces to suppress bacterial adhesion is another criterion in evaluating antifouling properties of materials. Our results show that the five polymer-grafted surfaces can significantly suppress Escherichia coli K12 adhesion to 99% compared to the bare gold surface. The zwitterionic structure of amino acids, with homogenously distributed and balanced positive and negative charges, is responsible for the outstanding antifouling properties. Considering multiple potential applications (e.g. medical devices and drug delivery) of the antifouling materials, we further systematically evaluated the cytotoxicity of both monomers and polymer nanogels for all five materials at various concentrations. Very low cytotoxicity was observed for all tested amino acid-based monomers and nanogels, which is comparable or even lower than the traditional and some newly developed antifouling materials, which might be related to the biomimetic nature of amino acids.

  13. Zwitterionic sulfobetaine polymer-immobilized surface by simple tyrosinase-mediated grafting for enhanced antifouling property.

    PubMed

    Kwon, Ho Joon; Lee, Yunki; Phuong, Le Thi; Seon, Gyeung Mi; Kim, Eunsuk; Park, Jong Chul; Yoon, Hyunjin; Park, Ki Dong

    2017-10-01

    Introducing antifouling property to biomaterial surfaces has been considered an effective method for preventing the failure of implanted devices. In order to achieve this, the immobilization of zwitterions on biomaterial surfaces has been proven to be an excellent way of improving anti-adhesive potency. In this study, poly(sulfobetaine-co-tyramine), a tyramine-conjugated sulfobetaine polymer, was synthesized and simply grafted onto the surface of polyurethane via a tyrosinase-mediated reaction. Surface characterization by water contact angle measurements, X-ray photoelectron spectroscopy and atomic force microscopy demonstrated that the zwitterionic polymer was successfully introduced onto the surface of polyurethane and remained stable for 7days. In vitro studies revealed that poly(sulfobetaine-co-tyramine)-coated surfaces dramatically reduced the adhesion of fibrinogen, platelets, fibroblasts, and S. aureus by over 90% in comparison with bare surfaces. These results proved that polyurethane surfaces grafted with poly(sulfobetaine-co-tyramine) via a tyrosinase-catalyzed reaction could be promising candidates for an implantable medical device with excellent bioinert abilities. Antifouling surface modification is one of the key strategy to prevent the thrombus formation or infection which occurs on the surface of biomaterial after transplantation. Although there are many methods to modify the surface have been reported, necessity of simple modification technique still exists to apply for practical applications. The purpose of this study is to modify the biomaterial's surface by simply immobilizing antifouling zwitterion polymer via enzyme tyrosinase-mediated reaction which could modify versatile substrates in mild aqueous condition within fast time period. After modification, pSBTA grafted surface becomes resistant to various biological factors including proteins, cells, and bacterias. This approach appears to be a promising method to impart antifouling property on

  14. Quantitative fabrication, performance optimization and comparison of PEG and zwitterionic polymer antifouling coatings.

    PubMed

    Xing, Cheng-Mei; Meng, Fan-Ning; Quan, Miao; Ding, Kai; Dang, Yuan; Gong, Yong-Kuan

    2017-09-01

    A versatile fabrication and performance optimization strategy of PEG and zwitterionic polymer coatings is developed on the sensor chip of surface plasma resonance (SPR) instrument. A random copolymer bearing phosphorylcholine zwitterion and active ester side chains (PMEN) and carboxylic PEG coatings with comparable thicknesses were deposited on SPR sensor chips via amidation coupling on the precoated polydopamine (PDA) intermediate layer. The PMEN coating showed much stronger resistance to bovine serum albumin (BSA) adsorption than PEG coating at very thin thickness (∼1nm). However, the BSA resistant efficacy of PEG coating could exceed that of PMEN due to stronger steric repelling effect when the thickness increased to 1.5∼3.3nm. Interestingly, both the PEG and PMEN thick coatings (≈3.6nm) showed ultralow fouling by BSA and bovine plasma fibrinogen (Fg). Moreover, changes in the PEG end group from -OH to -COOH, protein adsorption amount could increase by 10-fold. Importantly, the optimized PMEN and PEG-OH coatings were easily duplicated on other substrates due to universal adhesion of the PDA layer, showed excellent resistance to platelet, bacteria and proteins, and no significant difference in the antifouling performances was observed. These detailed results can explain the reported discrepancy in performances between PEG and zwitterionic polymer coatings by thickness. This facile and substrate-independent coating strategy may benefit the design and manufacture of advanced antifouling biomedical devices and long circulating nanocarriers. Prevention of biofouling is one of the biggest challenges for all biomedical applications. However, it is very difficult to fabricate a highly hydrophilic antifouling coating on inert materials or large devices. In this study, PEG and zwitterion polymers, the most widely investigated polymers with best antifouling performance, are conveniently immobilized on different kinds of substrates from their aqueous solutions by

  15. Combining Fullerenes and Zwitterions in non-Conjugated Polymer Interlayers to Raise Solar Cell Efficiency.

    PubMed

    Liu, Yao; Sheri, Madhu; Cole, Marcus D; Emrick, Todd; Russell, Thomas P

    2018-06-12

    Polymer zwitterions were synthesized by nucleophilic ring-opening of 3,3'-(but-2-ene-1,4-diyl)bis(1,2-oxathiolane 2,2-dioxide) (a bis-sultone) with functional perylene diimide (PDI) or fullerene monomers. Integration of these polymers into solar cell devices as cathode interlayers boosted efficiencies of fullerene-based organic photovoltaics (OPVs) from 2.75% to 10.74%, and of non-fullerene-based OPVs from 4.25% to 10.10%, demonstrating the versatility of these interlayer materials in OPVs. The fullerene-containing polymer zwitterion (C60-PZ) showed a higher interfacial dipole (∆) value and electron mobility than its PDI counterpart (PDI-PZ), affording solar cells with high efficiency. The power of PDI-PZ and C60-PZ to improve electron injection and extraction processes when positioned between metal electrodes and organic semiconductors highlights their promise to overcome energy barriers at the hard-soft materials interface of organic electronics. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Highly Specific Binding on Antifouling Zwitterionic Polymer-Coated Microbeads as Measured by Flow Cytometry.

    PubMed

    van Andel, Esther; de Bus, Ian; Tijhaar, Edwin J; Smulders, Maarten M J; Savelkoul, Huub F J; Zuilhof, Han

    2017-11-08

    Micron- and nano-sized particles are extensively used in various biomedical applications. However, their performance is often drastically hampered by the nonspecific adsorption of biomolecules, a process called biofouling, which can cause false-positive and false-negative outcomes in diagnostic tests. Although antifouling coatings have been extensively studied on flat surfaces, their use on micro- and nanoparticles remains largely unexplored, despite the widespread experimental (specifically, clinical) uncertainties that arise because of biofouling. Here, we describe the preparation of magnetic micron-sized beads coated with zwitterionic sulfobetaine polymer brushes that display strong antifouling characteristics. These coated beads can then be equipped with recognition elements of choice, to enable the specific binding of target molecules. First, we present a proof of principle with biotin-functionalized beads that are able to specifically bind fluorescently labeled streptavidin from a complex mixture of serum proteins. Moreover, we show the versatility of the method by demonstrating that it is also possible to functionalize the beads with mannose moieties to specifically bind the carbohydrate-binding protein concanavalin A. Flow cytometry was used to show that thus-modified beads only bind specifically targeted proteins, with minimal/near-zero nonspecific protein adsorption from other proteins that are present. These antifouling zwitterionic polymer-coated beads, therefore, provide a significant advancement for the many bead-based diagnostic and other biosensing applications that require stringent antifouling conditions.

  17. Highly Specific Binding on Antifouling Zwitterionic Polymer-Coated Microbeads as Measured by Flow Cytometry

    PubMed Central

    2017-01-01

    Micron- and nano-sized particles are extensively used in various biomedical applications. However, their performance is often drastically hampered by the nonspecific adsorption of biomolecules, a process called biofouling, which can cause false-positive and false-negative outcomes in diagnostic tests. Although antifouling coatings have been extensively studied on flat surfaces, their use on micro- and nanoparticles remains largely unexplored, despite the widespread experimental (specifically, clinical) uncertainties that arise because of biofouling. Here, we describe the preparation of magnetic micron-sized beads coated with zwitterionic sulfobetaine polymer brushes that display strong antifouling characteristics. These coated beads can then be equipped with recognition elements of choice, to enable the specific binding of target molecules. First, we present a proof of principle with biotin-functionalized beads that are able to specifically bind fluorescently labeled streptavidin from a complex mixture of serum proteins. Moreover, we show the versatility of the method by demonstrating that it is also possible to functionalize the beads with mannose moieties to specifically bind the carbohydrate-binding protein concanavalin A. Flow cytometry was used to show that thus-modified beads only bind specifically targeted proteins, with minimal/near-zero nonspecific protein adsorption from other proteins that are present. These antifouling zwitterionic polymer-coated beads, therefore, provide a significant advancement for the many bead-based diagnostic and other biosensing applications that require stringent antifouling conditions. PMID:29064669

  18. Mitigation of Biofilm Development on Thin-Film Composite Membranes Functionalized with Zwitterionic Polymers and Silver Nanoparticles.

    PubMed

    Liu, Caihong; Faria, Andreia F; Ma, Jun; Elimelech, Menachem

    2017-01-03

    We demonstrate the functionalization of thin-film composite membranes with zwitterionic polymers and silver nanoparticles (AgNPs) for combating biofouling. Combining hydrophilic zwitterionic polymer brushes and biocidal AgNPs endows the membrane with dual functionality: antiadhesion and bacterial inactivation. An atom transfer radical polymerization (ATRP) reaction is used to graft zwitterionic poly(sulfobetaine methacrylate) (PSBMA) brushes to the membrane surface, while AgNPs are synthesized in situ through chemical reduction of silver. Two different membrane architectures (Ag-PSBMA and PSBMA-Ag TFC) are developed according to the sequence AgNPs, and PSBMA brushes are grafted on the membrane surface. A static adhesion assay shows that both modified membranes significantly reduced the adsorption of proteins, which served as a model organic foulant. However, improved antimicrobial activity is observed for PSBMA-Ag TFC (i.e., AgNPs on top of the polymer brush) in comparison to the Ag-PSBMA TFC membrane (i.e., polymer brush on top of AgNPs), indicating that architecture of the antifouling layer is an important factor in the design of zwitterion-silver membranes. Confocal laser scanning microscopy (CLSM) imaging indicated that PSBMA-Ag TFC membranes effectively inhibit biofilm formation under dynamic cross-flow membrane biofouling tests. Finally, we demonstrate the regeneration of AgNPs on the membrane after depletion of silver from the surface of the PSBMA-Ag TFC membrane.

  19. Simple Protein Modification Using Zwitterionic Polymer to Mitigate the Bioactivity Loss of Conjugated Insulin.

    PubMed

    Xie, Jinbing; Lu, Yang; Wang, Wei; Zhu, Hui; Wang, Zhigang; Cao, Zhiqiang

    2017-06-01

    Polymer-protein conjugation has been extensively explored toward a better protein drug with improved pharmacokinetics. However, a major problem with polymer-protein conjugation is that the polymers drastically reduce the bioactivity of the modified protein. There is no perfect solution to prevent the bioactivity loss, no matter the polymer is conjugated in a non-site specific way, or a more complex site-specific procedure. Here the authors report for the first time that when zwitterionic carboxybetaine polymer (PCB) is conjugated to insulin through simple conventional coupling chemistry. The resulting PCB-insulin does not show a significant reduction of in vitro bioactivity. The obtained PCB-insulin shows two significant advantages as a novel pharmaceutical agent. First, its therapeutic performance is remarkable. For PCB-insulin, there is a 24% increase of in vivo pharmacological activity of lowering blood glucose compared with native insulin. Such uncommonly seen increase has rarely been reported and is expected to be due to both the improved pharmacokinetics and retained bioactivity of PCB-insulin. Second, the production is simple from manufacturing standpoints. Conjugation procedure involves only one-step coupling reaction without complex site-specific linkage technique. The synthesized PCB-insulin conjugates do not require chromatographic separation to purify and obtain particular isoforms. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Antifouling Properties of a Self-Assembling Glutamic Acid-Lysine Zwitterionic Polymer Surface Coating.

    PubMed

    Ziemba, Christopher; Khavkin, Maria; Priftis, Dimitris; Acar, Handan; Mao, Jun; Benami, Maya; Gottlieb, Moshe; Tirrell, Matthew; Kaufman, Yair; Herzberg, Moshe

    2018-04-23

    There is a need for the development of antifouling materials to resist adsorption of biomacromolecules. Here we describe the preparation of a novel zwitterionic block copolymer with the potential to prevent or delay the formation of microbial biofilms. The block copolymer comprised a zwitterionic (hydrophilic) section of alternating glutamic acid (negatively charged) and lysine (positively charged) units and a hydrophobic polystyrene section. Cryo-TEM and dynamic-light-scattering (DLS) results showed that, on average, the block copolymer self-assembled into 7-nm-diameter micelles in aqueous solutions (0 to 100 mM NaCl, pH 6). Quartz crystal microbalance with dissipation monitoring (QCM-D), atomic force microscopy (AFM), and contact angle measurements demonstrated that the block copolymer self-assembled into a brush-like monolayer on polystyrene surfaces. The brush-like monolayer produced from a 100 mg/L block copolymer solution exhibited an average distance, d, of approximately 4-8 nm between each block copolymer molecule (center to center). Once the brush-like monolayer self-assembled, it reduced EPS adsorption onto the polystyrene surface by ∼70% (mass), reduced the rate of bacterial attachment by >80%, and inhibited the development of thick biofilms. QCM-D results revealed that the EPS molecules penetrate between the chains of the brush and adsorb onto the polystyrene surface. Additionally, AFM analyses showed that the brush-like monolayer prevents the adhesion of large (> d) hydrophilic colloids onto the surface via hydration repulsion; however, molecules or colloids small enough to fit between the brush polymers (< d) were able to be adsorbed onto the surface via van der Waals interactions. Overall, we found that the penetration of extracellular organelles, as well as biopolymers through the brush, is critical for the failure of the antifouling coating, and likely could be prevented through tuning of the brush density. Stability and biofilm development

  1. Modification of Silicone Elastomer Surfaces with Zwitterionic Polymers: Short-Term Fouling Resistance and Triggered Biofouling Release.

    PubMed

    Shivapooja, Phanindhar; Yu, Qian; Orihuela, Beatriz; Mays, Robin; Rittschof, Daniel; Genzer, Jan; López, Gabriel P

    2015-11-25

    We present a method for dual-mode-management of biofouling by modifying surface of silicone elastomers with zwitterionic polymeric grafts. Poly(sulfobetaine methacrylate) was grafted from poly(vinylmethylsiloxane) elastomer substrates using thiol-ene click chemistry and surface-initiated, controlled radical polymerization. These surfaces exhibited both fouling resistance and triggered fouling-release functionality. The zwitterionic polymers exhibited fouling resistance over short-term (∼hours) exposure to bacteria and barnacle cyprids. The biofilms that eventually accumulated over prolonged-exposure (∼days) were easily detached by applying mechanical strain to the elastomer substrate. Such dual-functional surfaces may be useful in developing environmentally and biologically friendly coatings for biofouling management on marine, industrial, and biomedical equipment because they can obviate the use of toxic compounds.

  2. Zwitterionic polymer functionalization of polysulfone membrane with improved antifouling property and blood compatibility by combination of ATRP and click chemistry.

    PubMed

    Xiang, Tao; Lu, Ting; Xie, Yi; Zhao, Wei-Feng; Sun, Shu-Dong; Zhao, Chang-Sheng

    2016-08-01

    The chemical compositions are very important for designing blood-contacting membranes with good antifouling property and blood compatibility. In this study, we propose a method combining ATRP and click chemistry to introduce zwitterionic polymer of poly(sulfobetaine methacrylate) (PSBMA), negatively charged polymers of poly(sodium methacrylate) (PNaMAA) and/or poly(sodium p-styrene sulfonate) (PNaSS), to improve the antifouling property and blood compatibility of polysulfone (PSf) membranes. Attenuated total reflectance-Fourier transform infrared spectra, X-ray photoelectron spectroscopy and water contact angle results confirmed the successful grafting of the functional polymers. The antifouling property and blood compatibility of the modified membranes were systematically investigated. The zwitterionic polymer (PSBMA) grafted membranes showed good resistance to protein adsorption and bacterial adhesion; the negatively charged polymer (PNaSS or PNaMAA) grafted membranes showed improved blood compatibility, especially the anticoagulant property. Moreover, the PSBMA/PNaMAA modified membrane showed both antifouling property and anticoagulant property, and exhibited a synergistic effect in inhibiting blood coagulation. The functionalization of membrane surfaces by a combination of ATRP and click chemistry is demonstrated as an effective route to improve the antifouling property and blood compatibility of membranes in blood-contact. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. Bioadhesive control of plasma proteins and blood cells from umbilical cord blood onto the interface grafted with zwitterionic polymer brushes.

    PubMed

    Chang, Yu; Chang, Yung; Higuchi, Akon; Shih, Yu-Ju; Li, Pei-Tsz; Chen, Wen-Yih; Tsai, Eing-Mei; Hsiue, Ging-Ho

    2012-03-06

    In this work, bioadhesive behavior of plasma proteins and blood cells from umbilical cord blood (UCB) onto zwitterionic poly(sulfobetaine methacrylate) (polySBMA) polymer brushes was studied. The surface coverage of polySBMA brushes on a hydrophobic polystyrene (PS) well plate with surface grafting weights ranging from 0.02 mg/cm(2) to 0.69 mg/cm(2) can be effectively controlled using the ozone pretreatment and thermal-induced radical graft-polymerization. The chemical composition, grafting structure, surface hydrophilicity, and hydration capability of prepared polySBMA brushes were determined to illustrate the correlations between grafting properties and blood compatibility of zwitterionic-grafted surfaces in contact with human UCB. The protein adsorption of fibrinogen in single-protein solutions and at complex medium of 100% UCB plasma onto different polySBMA brushes with different grafting coverage was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. The grafting density of the zwitterionic brushes greatly affects the PS surface, thus controlling the adsorption of fibrinogen, the adhesion of platelets, and the preservation of hematopoietic stem and progenitor cells (HSPCs) in UCB. The results showed that PS surfaces grafted with polySBMA brushes possess controllable hydration properties through the binding of water molecules, regulating the bioadhesive and bioinert characteristics of plasma proteins and blood platelets in UCB. Interestingly, it was found that the polySBMA brushes with an optimized grafting weight of approximately 0.1 mg/cm(2) at physiologic temperatures show significant hydrated chain flexibility and balanced hydrophilicity to provide the best preservation capacity for HSPCs stored in 100% UCB solution for 2 weeks. This work suggests that, through controlling grafting structures, the hemocompatible nature of grafted zwitterionic polymer brushes makes them well suited to the molecular design of regulated

  4. Enhancing the specificity of polymerase chain reaction by graphene oxide through surface modification: zwitterionic polymer is superior to other polymers with different charges.

    PubMed

    Zhong, Yong; Huang, Lihong; Zhang, Zhisen; Xiong, Yunjing; Sun, Liping; Weng, Jian

    Graphene oxides (GOs) with different surface characteristics, such as size, reduction degree and charge, are prepared, and their effects on the specificity of polymerase chain reaction (PCR) are investigated. In this study, we demonstrate that GO with a large size and high reduction degree is superior to small and nonreduced GO in enhancing the specificity of PCR. Negatively charged polyacrylic acid (PAA), positively charged polyacrylamide (PAM), neutral polyethylene glycol (PEG) and zwitterionic polymer poly(sulfobetaine) (pSB) are used to modify GO. The PCR specificity-enhancing ability increases in the following order: GO-PAA < GO-PAM < GO-PEG < GO-pSB. Thus, zwitterionic polymer-modified GO is superior to other GO derivatives with different charges in enhancing the specificity of PCR. GO derivatives are also successfully used to enhance the specificity of PCR for the amplification of human mitochondrial DNA using blood genomic DNA as template. Molecular dynamics simulations and molecular docking are performed to elucidate the interaction between the polymers and Pfu DNA polymerase. Our data demonstrate that the size, reduction degree and surface charge of GO affect the specificity of PCR. Based on our results, zwitterionic polymer-modified GO may be used as an efficient additive for enhancing the specificity of PCR.

  5. Zwitterionic peptide anchored to conducting polymer PEDOT for the development of antifouling and ultrasensitive electrochemical DNA sensor.

    PubMed

    Wang, Guixiang; Han, Rui; Su, Xiaoli; Li, Yinan; Xu, Guiyun; Luo, Xiliang

    2017-06-15

    Zwitterionic peptides were anchored to a conducting polymer of citrate doped poly(3,4-ethylenedioxythiophene) (PEDOT) via the nickel cation coordination, and the obtained peptide modified PEDOT, with excellent antifouling ability and good conductivity, was further used for the immobilization of a DNA probe to construct an electrochemical biosensor for the breast cancer marker BRCA1. The DNA biosensor was highly sensitive (with detection limit of 0.03fM) and selective, and it was able to detect BRCA1 in 5% (v/v) human plasma with satisfying accuracy and low fouling. The marriage of antifouling and biocompatible peptides with conducting polymers opened a new avenue to construct electrochemical biosensors capable of assaying targets in complex biological media with high sensitivity and without biofouling. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Hybridized polymer matrix composite

    NASA Technical Reports Server (NTRS)

    Stern, B. A.; Visser, T.

    1981-01-01

    Under certain conditions of combined fire and impact, graphite fibers are released to the atmosphere by graphite fiber composites. The retention of graphite fibers in these situations is investigated. Hybrid combinations of graphite tape and cloth, glass cloth, and resin additives are studied with resin systems. Polyimide resins form the most resistant composites and resins based on simple novolac epoxies the least resistant of those tested. Great improvement in the containment of the fibers is obtained in using graphite/glass hybrids, and nearly complete prevention of individual fiber release is made possible by the use of resin additives.

  7. Hybridized polymer matrix composites

    NASA Technical Reports Server (NTRS)

    House, E. E.; Hoggatt, J. T.; Symonds, W. A.

    1980-01-01

    The extent to which graphite fibers are released from resin matrix composites that are exposed to fire and impact conditions was determined. Laboratory simulations of those conditions that could exist in the event of an aircraft crash and burn situation were evaluated. The effectiveness of various hybridizing concepts in preventing this release of graphite fibers were also evaluated. The baseline (i.e., unhybridized) laminates examined were prepared from commercially available graphite/epoxy, graphite/polyimide, and graphite/phenolic materials. Hybridizing concepts investigated included resin fillers, laminate coatings, resin blending, and mechanical interlocking of the graphite reinforcement. The baseline and hybridized laminates' mechanical properties, before and after isothermal and humidity aging, were also compared. It was found that a small amount of graphite fiber was released from the graphite/epoxy laminates during the burn and impact conditions used in this program. However, the extent to which the fibers were released is not considered a severe enough problem to preclude the use of graphite reinforced composites in civil aircraft structure. It also was found that several hybrid concepts eliminated this fiber release. Isothermal and humidity aging did not appear to alter the fiber release tendencies.

  8. Hybridized polymer matrix composites

    NASA Technical Reports Server (NTRS)

    London, A.

    1981-01-01

    Design approaches and materials are described from which are fabricated pyrostatic graphite/epoxy (Gr/Ep) laminates that show improved retention of graphite particulates when subjected to burning. Sixteen hybridized plus two standard Gr/Ep laminates were designed, fabricated, and tested in an effort to eliminate the release of carbon (graphite) fiber particles from burned/burning, mechanically disturbed samples. The term pyrostatic is defined as meaning mechanically intact in the presence of fire. Graphite particulate retentive laminates were constructed whose constituent materials, cost of fabrication, and physical and mechanical properties were not significantly different from existing Gr/Ep composites. All but one laminate (a Celion graphite/bis-maleimide polyimide) were based on an off-the-shelf Gr/Ep, the AS-1/3501-5A system. Of the 16 candidates studied, four thin (10-ply) and four thick (50-ply) hybridized composites are recommended.

  9. Versatile antifouling polyethersulfone filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive.

    PubMed

    Zhao, Yi-Fan; Zhang, Pei-Bin; Sun, Jian; Liu, Cui-Jing; Yi, Zhuan; Zhu, Li-Ping; Xu, You-Yi

    2015-06-15

    Here we describe the development of versatile antifouling polyethersulfone (PES) filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive. Amphiphilic polyethersulfone-block-poly(2-hydroxyethyl methacrylate) (PES-b-PHEMA) was beforehand designed and used as the blending additive of PES membranes prepared by phase inversion technique. The surface enriched PHEMA blocks on membrane surface acted as an anchor to immobilize the initiating site. Poly(sulfobetaine methacrylate) (PSBMA) were subsequently grafted onto the PES blend membranes by surface-initiated atom transfer radical polymerization (SI-ATRP). The analysis of surface chemistry confirmed the successful grafting of zwitterionic PSBMA brushes on PES membrane surface. The resulted PES-g-PSBMA membranes were capable of separating proteins from protein solution and oil from oil/water emulsion efficiently. Furthermore, the modified membranes showed high hydrophilicity and strongly antifouling properties due to the incorporation of well-defined PSBMA layer. In addition, the PES-g-PSBMA membranes exhibited excellent blood compatibility and durability during the washing process. The developed antifouling PES membranes are versatile and can find their applications in protein filtration, blood purification and oil/water separation, etc. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Surface charge control for zwitterionic polymer brushes: Tailoring surface properties to antifouling applications.

    PubMed

    Guo, Shanshan; Jańczewski, Dominik; Zhu, Xiaoying; Quintana, Robert; He, Tao; Neoh, Koon Gee

    2015-08-15

    Electrostatic interactions play an important role in adhesion phenomena particularly for biomacromolecules and microorganisms. Zero charge valence of zwitterions has been claimed as the key to their antifouling properties. However, due to the differences in the relative strength of their acid and base components, zwitterionic materials may not be charge neutral in aqueous environments. Thus, their charge on surfaces should be further adjusted for a specific pH environment, e.g. physiological pH typical in biomedical applications. Surface zeta potential for thin polymeric films composed of polysulfobetaine methacrylate (pSBMA) brushes is controlled through copolymerizing zwitterionic SBMA and cationic methacryloyloxyethyltrimethyl ammonium chloride (METAC) via surface-initiated atom transfer polymerization. Surface properties including zeta potential, roughness, free energy and thickness are measured and the antifouling performance of these surfaces is assessed. The zeta potential of pSBMA brushes is -40 mV across a broad pH range. By adding 2% METAC, the zeta potential of pSBMA can be tuned to zero at physiological pH while minimally affecting other physicochemical properties including dry brush thickness, surface free energy and surface roughness. Surfaces with zero and negative zeta potential best resist fouling by bovine serum albumin, Escherichia coli and Staphylococcus aureus. Surfaces with zero zeta potential also reduce fouling by lysozyme more effectively than surfaces with negative and positive zeta potential. Copyright © 2015 Elsevier Inc. All rights reserved.

  11. Hybridized polymer matrix composites

    NASA Technical Reports Server (NTRS)

    Henshaw, J.

    1983-01-01

    Methods of improving the fire resistance of graphite epoxy composite laminates were investigated with the objective of reducing the volume of loose graphite fibers disseminated into the airstream as the result of a high intensity aircraft fuel fire. Improvements were sought by modifying the standard graphite epoxy systems without significantly negating their structural effectiveness. The modifications consisted primarily of an addition of a third constituent material such as glass fibers, glass flakes, carbon black in a glassy resin. These additions were designed to encourage coalescense of the graphite fibers and thereby reduce their aerodynamic float characteristics. A total of 38 fire tests were conducted on thin (1.0 mm) and thick (6.0 mm) hybrid panels.

  12. Light-switchable polymer from cationic to zwitterionic form: synthesis, characterization, and interactions with DNA and bacterial cells.

    PubMed

    Sobolčiak, Patrik; Spírek, Mário; Katrlík, Jaroslav; Gemeiner, Peter; Lacík, Igor; Kasák, Peter

    2013-04-25

    A novel cationic polymer poly(N,N-dimethyl-N-[3-(methacroylamino) propyl]-N-[2-[(2-nitrophenyl)methoxy]-2-oxo-ethyl]ammonium chloride) is synthesized by free-radical polymerization of N-[3-(dimethylamino)propyl] methacrylamide and subsequent quaternization with o-nitrobenzyl 2-chloroacetate. The photolabile o-nitrobenzyl carboxymethyl pendant moiety is transformed to the zwitterionic carboxybetaine form upon the irradiation at 365 nm. This feature is used to condense and, upon the light irradiation, to release double-strand DNA tested by gel electrophoresis and surface plasmon resonance experiments as well as to switch the antibacterial activity to non-toxic character demonstrated for Escherichia coli bacterial cells in solution and at the surface using the self-assembled monolayers. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Suppressing Surface Reconstruction of Superhydrophobic PDMS using a Superhydrophilic Zwitterionic Polymer

    PubMed Central

    Keefe, Andrew J.; Brault, Norman D.; Jiang, Shaoyi

    2014-01-01

    Poly(dimethyl siloxane) (PDMS) is extensively used for biomedical applications due to its low cost, ease of fabrication, high durability and flexibility, oxygen permeability, and self-healing properties. PDMS, however, has some significant drawbacks. PDMS endures unacceptably high levels of non-specific protein fouling when used with biological samples due to its superhydrophobic characteristics. Unfortunately, conventional surface modification methods do not work for PDMS due to its low glass transition temperature. This phenomenon has been well-known for years as “hydrophobic regeneration”. For the same reason, it is also very difficult to bring functionalities onto PDMS surfaces. Herein, we demonstrate how a superhydrophilic zwitterionic material, poly(carboxybetaine methacrylate) (pCBMA), can provide a highly stable coating with long term stabilty due to the sharp contrast in hydrophobicity between pCBMA and PDMS. This material is able to suppress nonspecific protein adsorption in complex media and functionalize desired biomolecules needed in applications, such as diagnostics, without sacrificing its nonfouling characteristics. PMID:22512660

  14. Suppressing surface reconstruction of superhydrophobic PDMS using a superhydrophilic zwitterionic polymer.

    PubMed

    Keefe, Andrew J; Brault, Norman D; Jiang, Shaoyi

    2012-05-14

    Poly(dimethyl siloxane) (PDMS) is extensively used for biomedical applications due to its low cost, ease of fabrication, high durability and flexibility, oxygen permeability, and self-healing properties. PDMS, however, has some significant drawbacks. PDMS endures unacceptably high levels of nonspecific protein fouling when used with biological samples due to its superhydrophobic characteristics. Unfortunately, conventional surface modification methods do not work for PDMS due to its low glass transition temperature. This phenomenon has been well-known for years as "hydrophobic regeneration". For the same reason, it is also very difficult to bring functionalities onto PDMS surfaces. Herein, we demonstrate how a superhydrophilic zwitterionic material, poly(carboxybetaine methacrylate) (pCBMA), can provide a highly stable coating with long-term stabilty due to the sharp contrast in hydrophobicity between pCBMA and PDMS. This material is able to suppress nonspecific protein adsorption in complex media and functionalize desired biomolecules needed in applications, such as diagnostics, without sacrificing its nonfouling characteristics.

  15. Electrical conductivity studies on Ammonium bromide incorporated with Zwitterionic polymer blend electrolyte for battery application

    NASA Astrophysics Data System (ADS)

    Parameswaran, V.; Nallamuthu, N.; Devendran, P.; Nagarajan, E. R.; Manikandan, A.

    2017-06-01

    Solid polymer blend electrolytes are widely studied due to their extensive applications particularly in electrochemical devices. Blending polymer makes the thermal stability, higher mechanical strength and inorganic salt provide ionic charge carrier to enhance the conductivity. In these studies, 50% polyvinyl alcohol (PVA), 50% poly (N-vinyl pyrrolidone) (PVP) and 2.5% L-Asparagine mixed with different ratio of the Ammonium bromide (NH4Br), have been synthesized using solution casting technique. The prepared PVA/PVP/L-Asparagine/doped-NH4Br polymer blend electrolyte films have been characterized by various analytical methods such as FT-IR, XRD, impedance spectroscopy, TG-DSC and scanning electron microscopy. FT-IR, XRD and TG/DSC analysis revealed the structural and thermal behavior of the complex formation between PVA/PVP/L-Asparagine/doped-NH4Br. The ionic conductivity and the dielectric properties of PVA/PVP/L-Asparagine/doped-NH4Br polymer blend electrolyte films were examined using impedance analysis. The highest ionic conductivity was found to be 2.34×10-4 S cm-1 for the m.wt. composition of 50%PVA:50%PVP:2.5%L-Asparagine:doped 0.15 g NH4Br at ambient temperature. Solid state proton battery is fabricated and the observed open circuit voltage is 1.1 V and its performance has been studied.

  16. Predictive Model for the Design of Zwitterionic Polymer Brushes: A Statistical Design of Experiments Approach.

    PubMed

    Kumar, Ramya; Lahann, Joerg

    2016-07-06

    The performance of polymer interfaces in biology is governed by a wide spectrum of interfacial properties. With the ultimate goal of identifying design parameters for stem cell culture coatings, we developed a statistical model that describes the dependence of brush properties on surface-initiated polymerization (SIP) parameters. Employing a design of experiments (DOE) approach, we identified operating boundaries within which four gel architecture regimes can be realized, including a new regime of associated brushes in thin films. Our statistical model can accurately predict the brush thickness and the degree of intermolecular association of poly[{2-(methacryloyloxy) ethyl} dimethyl-(3-sulfopropyl) ammonium hydroxide] (PMEDSAH), a previously reported synthetic substrate for feeder-free and xeno-free culture of human embryonic stem cells. DOE-based multifunctional predictions offer a powerful quantitative framework for designing polymer interfaces. For example, model predictions can be used to decrease the critical thickness at which the wettability transition occurs by simply increasing the catalyst quantity from 1 to 3 mol %.

  17. Novel, one-step synthesis of zwitterionic polymer nanoparticles via distillation-precipitation polymerization and its application for dye removal membrane.

    PubMed

    Ibrahim, G P Syed; Isloor, Arun M; Inamuddin; Asiri, Abdullah M; Ismail, Norafiqah; Ismail, Ahmed Fauzi; Ashraf, Ghulam Md

    2017-11-21

    In this work, poly(MBAAm-co-SBMA) zwitterionic polymer nanoparticles were synthesized in one-step via distillation-precipitation polymerization (DPP) and were characterized. [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) as monomer and N, N'-methylene bis(acrylamide) (MBAAm) as cross-linker are used for the synthesis of nanoparticles. As  far as our knowledge, this is the first such report on the synthesis of poly(MBAAm-co-SBMA) nanoparticles via DPP. The newly synthesized nanoparticles were further employed for the surface modification of polysulfone (PSF) hollow fiber membranes for dye removal. The modified hollow fiber membrane exhibited the improved permeability (56 L/ m 2 h bar) and dye removal (>98% of Reactive Black 5 and >80.7% of Reactive orange 16) with the high permeation of salts. Therefore, the as-prepared membrane can have potential application in textile and industrial wastewater treatment.

  18. Characterization of Hybrid CNT Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Grimsley, Brian W.; Cano, Roberto J.; Kinney, Megan C.; Pressley, James; Sauti, Godfrey; Czabaj, Michael W.; Kim, Jae-Woo; Siochi, Emilie J.

    2015-01-01

    Carbon nanotubes (CNTs) have been studied extensively since their discovery and demonstrated at the nanoscale superior mechanical, electrical and thermal properties in comparison to micro and macro scale properties of conventional engineering materials. This combination of properties suggests their potential to enhance multi-functionality of composites in regions of primary structures on aerospace vehicles where lightweight materials with improved thermal and electrical conductivity are desirable. In this study, hybrid multifunctional polymer matrix composites were fabricated by interleaving layers of CNT sheets into Hexcel® IM7/8552 prepreg, a well-characterized toughened epoxy carbon fiber reinforced polymer (CFRP) composite. The resin content of these interleaved CNT sheets, as well as ply stacking location were varied to determine the effects on the electrical, thermal, and mechanical performance of the composites. The direct-current electrical conductivity of the hybrid CNT composites was characterized by in-line and Montgomery four-probe methods. For [0](sub 20) laminates containing a single layer of CNT sheet between each ply of IM7/8552, in-plane electrical conductivity of the hybrid laminate increased significantly, while in-plane thermal conductivity increased only slightly in comparison to the control IM7/8552 laminates. Photo-microscopy and short beam shear (SBS) strength tests were used to characterize the consolidation quality of the fabricated laminates. Hybrid panels fabricated without any pretreatment of the CNT sheets resulted in a SBS strength reduction of 70 percent. Aligning the tubes and pre-infusing the CNT sheets with resin significantly improved the SBS strength of the hybrid composite To determine the cause of this performance reduction, Mode I and Mode II fracture toughness of the CNT sheet to CFRP interface was characterized by double cantilever beam (DCB) and end notch flexure (ENF) testing, respectively. Results are compared to the

  19. Surface grafting of zwitterionic polymers onto dye doped AIE-active luminescent silica nanoparticles through surface-initiated ATRP for biological imaging applications

    NASA Astrophysics Data System (ADS)

    Mao, Liucheng; Liu, Xinhua; Liu, Meiying; Huang, Long; Xu, Dazhuang; Jiang, Ruming; Huang, Qiang; Wen, Yuanqing; Zhang, Xiaoyong; Wei, Yen

    2017-10-01

    Aggregation-induced emission (AIE) dyes have recently been intensively explored for biological imaging applications owing to their outstanding optical feature as compared with conventional organic dyes. The AIE-active luminescent silica nanoparticles (LSNPs) are expected to combine the advantages both of silica nanoparticles and AIE-active dyes. Although the AIE-active LSNPs have been prepared previously, surface modification of these AIE-active LSNPs with functional polymers has not been reported thus far. In this work, we reported a rather facile and general strategy for preparation of polymers functionalized AIE-active LSNPs through the surface-initiated atom transfer radical polymerization (ATRP). The AIE-active LSNPs were fabricated via direct encapsulation of AIE-active dye into silica nanoparticles through a non-covalent modified Stöber method. The ATRP initiator was subsequently immobilized onto these AIE-active LSNPs through amidation reaction between 3-aminopropyl-triethoxy-silane and 2-bromoisobutyryl bromide. Finally, the zwitterionic 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) was selected as model monomer and grafted onto MSNs through ATRP. The characterization results suggested that LSNPs can be successfully modified with poly(MPC) through surface-initiated ATRP. The biological evaluation results demonstrated that the final SNPs-AIE-pMPC composites possess low cytotoxicity, desirable optical properties and great potential for biological imaging. Taken together, we demonstrated that AIE-active LSNPs can be fabricated and surface modified with functional polymers to endow novel functions and better performance for biomedical applications. More importantly, this strategy developed in this work could also be extended for fabrication of many other LSNPs polymer composites owing to the good monomer adoptability of ATRP.

  20. Carbon Redox-Polymer-Gel Hybrid Supercapacitors.

    PubMed

    Vlad, A; Singh, N; Melinte, S; Gohy, J-F; Ajayan, P M

    2016-02-26

    Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances.

  1. Carbon Redox-Polymer-Gel Hybrid Supercapacitors

    PubMed Central

    Vlad, A.; Singh, N.; Melinte, S.; Gohy, J.-F.; Ajayan, P.M.

    2016-01-01

    Energy storage devices that provide high specific power without compromising on specific energy are highly desirable for many electric-powered applications. Here, we demonstrate that polymer organic radical gel materials support fast bulk-redox charge storage, commensurate to surface double layer ion exchange at carbon electrodes. When integrated with a carbon-based electrical double layer capacitor, nearly ideal electrode properties such as high electrical and ionic conductivity, fast bulk redox and surface charge storage as well as excellent cycling stability are attained. Such hybrid carbon redox-polymer-gel electrodes support unprecedented discharge rate of 1,000C with 50% of the nominal capacity delivered in less than 2 seconds. Devices made with such electrodes hold the potential for battery-scale energy storage while attaining supercapacitor-like power performances. PMID:26917470

  2. Ion conducting organic/inorganic hybrid polymers

    NASA Technical Reports Server (NTRS)

    Meador, Maryann B. (Inventor); Kinder, James D. (Inventor)

    2010-01-01

    This invention relates to a series of organic/inorganic hybrid polymers that are easy to fabricate into dimensionally stable films with good ion-conductivity over a wide range of temperatures for use in a variety of applications. The polymers are prepared by the reaction of amines, preferably diamines and mixtures thereof with monoamines with epoxy-functionalized alkoxysilanes. The products of the reaction are polymerized by hydrolysis of the alkoxysilane groups to produce an organic-containing silica network. Suitable functionality introduced into the amine and alkoxysilane groups produce solid polymeric membranes which conduct ions for use in fuel cells, high-performance solid state batteries, chemical sensors, electrochemical capacitors, electro-chromic windows or displays, analog memory devices and the like.

  3. Micro pumping with cardiomyocyte-polymer hybrid.

    PubMed

    Park, Jungyul; Kim, Il Chaek; Baek, Jeongeun; Cha, Misun; Kim, Jinseok; Park, Sukho; Lee, Junghoon; Kim, Byungkyu

    2007-10-01

    This paper presents a hybrid micropump actuated by the up-down motion of a dome shaped cell-polymer membrane composite. The contractile force induced from self-beating cardiomyocytes cultured on the membrane causes shrinkage and relaxation of a microchamber, leading to a flow in a microchannel. Flow direction is controlled by the geometry of diffuser/nozzle in the microchannel. The fabrication process is noninvasive to cells, thus, cardiomyocytes can robustly maintain their activity for a long time. The fluid motion in the microchannel was monitored by tracking 2 microm polystyrene beads. A net flow rate of 0.226 nl min(-1) was obtained in our microscale device. Our device demonstrates a unique performance of a cell-microdevice hybrid lab-on-a-chip that does not require any external power source, preventing electrical or heat shock to analytes.

  4. Methacrylic Zwitterionic, Thermoresponsive, and Hydrophilic (Co)Polymers via Cu(0)-Polymerization: The Importance of Halide Salt Additives.

    PubMed

    Simula, Alexandre; Anastasaki, Athina; Haddleton, David M

    2016-02-01

    The synthesis of hydrophilic, thermoresponsive, and zwitterionic polymethacrylates is reported by Cu(0)-mediated reversible deactivation radical polymerization in water and/or water/alcohol mixtures. The predisproportionation of [Cu(I) (PMDETA)Cl] in water prior to initiator and monomer addition is exploited to yield well-defined polymethacrylates with full monomer conversions in 30 min. The addition of supplementary halide salts (NaCl) enables the synthesis of various molecular weight poly[poly(ethylene glycol) methyl ether methacrylate] (PEGMA475) (DPn = 10-80, Mn ≈ 10,000-40 000 g mol(-1)) with full monomer conversion and narrow molecular weight distributions attained in all cases (Đ ≈ 1.20-1.30). A bifunctional PEG initiator (average Mn ≈ 1000 g mol(-1)) is utilized for the polymerization of a wide range of methacrylates including 2-dimethylaminoethyl methacrylate, 2-morpholinoethyl methacrylate, [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide, and 2-methacryloyloxyethyl phosphorylcholine. Despite the high water content, high end group fidelity is demonstrated by in situ chain extensions and block copolymerizations with PEGMA475 yielding well-defined functional telechelic pentablock copolymers within 2.5 h. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Imaging and cell targeting characteristics of magnetic nanoparticles modified by a functionalizable zwitterionic polymer with adhesive 3,4-dihydroxyphenyl-l-alanine linkages.

    PubMed

    Zhang, Lei; Xue, Hong; Gao, Changlu; Carr, Louisa; Wang, Jinnan; Chu, Baocheng; Jiang, Shaoyi

    2010-09-01

    Multifunctional magnetic nanoparticles (MNPs) modified by a zwitterionic polymer (pCBMA-DOPA(2)) containing one poly(carboxybetaine methacrylate) (pCBMA) chain and two 3,4-dihydroxyphenyl-L-alanine (DOPA) residue groups were developed. Results showed that MNPs modified by pCBMA were not only stable in complex media, but also provided abundant functional groups for ligand immobilization. The pCBMA-DOPA(2) MNPs had a hydrodynamic particle size of about 130 nm, a strong saturation magnetization of 110.2 emu/g Fe and a high transverse relaxivity of 428 mM(-1)s(-1). Long-term stability in phosphate-buffered saline (PBS) and 10% NaCl solution was achieved for over six months. Compared to MNPs coated with dextran, pCBMA-DOPA(2) MNPs presented better stability in 100% human blood serum at 37 degrees C. Macrophage cell uptake studies revealed that the uptake ratio of pCBMA-DOPA(2) MNPs was much lower than that of dextran MNPs. Furthermore, quantitative analysis results showed that after pCBMA-DOPA(2) MNPs were conjugated with a targeting RGD peptide, uptake by human umbilical vein endothelial cell (HUVEC) was notably increased, which was further visualized by magnetic resonance imaging (MRI). Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  6. Biodegradable polymer adhesives, hybrids and nanomaterials

    NASA Astrophysics Data System (ADS)

    Mylonakis, Andreas

    Biodegradable polymeric products and organic-inorganic hybrid materials for a diversity of applications are the two main fields on which this research has been focused. A novel biodegradable adhesive, which mimics marine adhesive proteins, has been synthesized by the covalent incorporation of 3,4-dihydroxybenzoic acid onto the chitosan backbone. The adhesive strength of these materials varies with the molecular weight of the polysaccharide, the amount of diphenolics present and the curing time. Infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR) and ultraviolet-visible spectroscopy (UV) have been used to qualitatively and quantitatively establish the amount of the diphenolic moiety present on the backbone of the biodegradable polymers. The as synthesized polymers combine both the adhesive capability of the diphenolic function and the healing effect of chitosan. The biocompatibility and biodegradability of these modified chitosans offer the promise of utility of these novel materials in dental and medical applications. Organic-inorganic hybrid materials with low volume shrinkage and excellent mechanical properties were synthesized by the covalent incorporation of 2-hydroxyethyl methacrylate and glycidyl methacrylate on pre-hydrolyzed sol-gel silica. These hybrid materials exhibited low volume shrinkage during polymerization and were crack-free during storage for about twelve months. The mechanical properties of these materials are composition dependent. Incorporation of silica effectively increased the compressive yield stress and modulus of the obtained poly(HEMAGMA-silica) hybrid materials. A series of new electroactive hybrid materials have been synthesized by covalent incorporation of polyaniline into polyacrylate-silica hybrids. The formulation involves the radical co-polymerization of glycidyl methacrylate-polyaniline (GMA-PANi) and glycidyl methacrylate2-hydroxyethyl methacrylate-silica (GMA-HEMA-silica) to yield poly

  7. Organic-inorganic hybrid polymer-encapsulated magnetic nanobead catalysts.

    PubMed

    Arai, Takayoshi; Sato, Toru; Kanoh, Hirofumi; Kaneko, Katsumi; Oguma, Koichi; Yanagisawa, Akira

    2008-01-01

    A new strategy for the encapsulation of magnetic nanobeads was developed by using the in situ self-assembly of an organic-inorganic hybrid polymer. The hybrid polymer of {[Cu(bpy)(BF(4))(2)(H(2)O)(2)](bpy)}(n) (bpy=4,4'-bipyridine) was constructed on the surface of amino-functionalized magnetic beads and the resulting hybrid-polymer-encapsulated beads were utilized as catalysts for the oxidation of silyl enolates to provide the corresponding alpha-hydroxy carbonyl compounds in high yield. After the completion of the reaction, the catalyst was readily recovered by magnetic separation and the recovered catalyst could be reused several times. Because the current method did not require complicated procedures for incorporating the catalyst onto the magnetic beads, the preparation and the application of various other types of organic-inorganic hybrid-polymer-coated magnetic beads could be possible.

  8. Silicone-containing aqueous polymer dispersions with hybrid particle structure.

    PubMed

    Kozakiewicz, Janusz; Ofat, Izabela; Trzaskowska, Joanna

    2015-09-01

    In this paper the synthesis, characterization and application of silicone-containing aqueous polymer dispersions (APD) with hybrid particle structure are reviewed based on available literature data. Advantages of synthesis of dispersions with hybrid particle structure over blending of individual dispersions are pointed out. Three main processes leading to silicone-containing hybrid APD are identified and described in detail: (1) emulsion polymerization of organic unsaturated monomers in aqueous dispersions of silicone polymers or copolymers, (2) emulsion copolymerization of unsaturated organic monomers with alkoxysilanes or polysiloxanes with unsaturated functionality and (3) emulsion polymerization of alkoxysilanes (in particular with unsaturated functionality) and/or cyclic siloxanes in organic polymer dispersions. The effect of various factors on the properties of such hybrid APD and films as well as on hybrid particles composition and morphology is presented. It is shown that core-shell morphology where silicones constitute either the core or the shell is predominant in hybrid particles. Main applications of silicone-containing hybrid APD and related hybrid particles are reviewed including (1) coatings which show specific surface properties such as enhanced water repellency or antisoiling or antigraffiti properties due to migration of silicone to the surface, and (2) impact modifiers for thermoplastics and thermosets. Other processes in which silicone-containing particles with hybrid structure can be obtained (miniemulsion polymerization, polymerization in non-aqueous media, hybridization of organic polymer and polysiloxane, emulsion polymerization of silicone monomers in silicone polymer dispersions and physical methods) are also discussed. Prospects for further developments in the area of silicone-containing hybrid APD and related hybrid particles are presented. Copyright © 2015. Published by Elsevier B.V.

  9. Hybrid polymer networks as ultra low `k` dielectric layers

    DOEpatents

    Lewicki, James; Worsley, Marcus A.

    2016-02-16

    According to one embodiment, a polymeric material includes at least one polydimethylsiloxane (PDMS) polymer, and at least one polyhedral oligomericsilsequioxane (POSS) molecule. According to another embodiment, a method includes providing at least one polydimethylsiloxane (PDMS) polymer, providing at least one polyhedral oligomericsilsequioxane (POSS) molecule, and coupling the at least one PDSM polymer to the at least one POSS molecule to form a hybrid polymeric material.

  10. Highly efficient non-biofouling coating of zwitterionic polymers: poly((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide).

    PubMed

    Cho, Woo Kyung; Kong, Bokyung; Choi, Insung S

    2007-05-08

    This work describes the formation of highly efficient non-biofouling polymeric thin films of poly((3-(methacryloylamino)propyl)-dimethyl(3-sulfopropyl)ammonium hydroxide), (poly(MPDSAH)). The poly(MPDSAH) films were generated from the self-assembled monolayers terminating in an initiator of atom transfer radical polymerization (ATRP) by the surface-initiated ATRP of MPDSAH. The poly(MPDSAH) films on a gold surface were characterized by ellipsometry, FT-IR spectroscopy, contact angle goniometery, and X-ray photoelectron spectroscopy. The copper complexes and unpolymerized monomers trapped inside the polymer brushes were completely washed out by soaking the poly(MPDSAH)-coated substrate in water at 40 degrees C for 4 days. The amount of proteins nonspecifically adsorbed onto the poly(MPDSAH) films was evaluated by surface plasmon resonance spectroscopy: the adsorption of proteins was <0.6 ng/cm(2) on the surfaces for all the model proteins. The ability of the poly(MPDSAH) films to resist the nonspecific adsorption of proteins was comparable to that of the best known systems.

  11. Sulfobetaine as a zwitterionic mediator for 3D hydroxyapatite mineralization

    PubMed Central

    Liu, Pingsheng; Song, Jie

    2013-01-01

    Both positively and negatively charged residues play pivotal roles in recruiting precursor ions or ion clusters, and lowering interfacial energy in natural biomineralization process. Synergistic utilization of opposite charges, however, has rarely been implemented in the design of cytocompatible synthetic scaffolds promoting hydroxyapatite (HA)-mineralization and osteointegration. We report the use of cytocompatible zwitterionic sulfobetaine ligands to enable 3-dimensional in vitro mineralization of HA across covalently crosslinked hydrogels. The overall charge-neutral zwitterionic hydrogel effectively recruited oppositely charged precursor ions while overcame excessive swelling exhibited by anionic and cationic hydrogels under physiological conditions, resulting in denser and structurally well-integrated mineralized composites. Further controls over the size, content, and spatial distribution of the mineral domains within the zwitterionic hydrogel are accomplished by facile adjustments of hydrogel crosslinking densities and the supersaturation rate governing heterogeneous mineral nucleation and growth. These findings should inspire many creative uses of zwitterionic polymers and polymer coatings for skeletal tissue repair and regeneration. PMID:23332320

  12. Organic/Inorganic Hybrid Polymer/Clay Nanocomposites

    NASA Technical Reports Server (NTRS)

    Park, Cheol; Connell, John W.; Smith, Joseph G., Jr.

    2003-01-01

    A novel class of polymer/clay nanocomposites has been invented in an attempt to develop transparent, lightweight, durable materials for a variety of aerospace applications. As their name suggests, polymer/ clay nanocomposites comprise organic/ inorganic hybrid polymer matrices containing platelet-shaped clay particles that have sizes of the order of a few nanometers thick and several hundred nanometers long. Partly because of their high aspect ratios and high surface areas, the clay particles, if properly dispersed in the polymer matrix at a loading level of 1 to 5 weight percent, impart unique combinations of physical and chemical properties that make these nanocomposites attractive for making films and coatings for a variety of industrial applications. Relative to the unmodified polymer, the polymer/ clay nanocomposites may exhibit improvements in strength, modulus, and toughness; tear, radiation, and fire resistance; and lower thermal expansion and permeability to gases while retaining a high degree of optical transparency.

  13. Evaluation of tensile strength of hybrid fiber (jute/gongura) reinforced hybrid polymer matrix composites

    NASA Astrophysics Data System (ADS)

    Venkatachalam, G.; Gautham Shankar, A.; Vijay, Kumar V.; Chandan, Byral R.; Prabaharan, G. P.; Raghav, Dasarath

    2015-07-01

    The polymer matrix composites attract many industrial applications due to its light weight, less cost and easy for manufacturing. In this paper, an attempt is made to prepare and study of the tensile strength of hybrid (two natural) fibers reinforced hybrid (Natural + Synthetic) polymer matrix composites. The samples were prepared with hybrid reinforcement consists of two different fibers such as jute and Gongura and hybrid polymer consists of polyester and cashew nut shell resins. The hybrid composites tensile strength is evaluated to study the influence of various fiber parameters on mechanical strength. The parameters considered here are the duration of fiber treatment, the concentration of alkali in fiber treatment and nature of fiber content in the composites.

  14. Design of Hybrid Solid Polymer Electrolytes: Structure and Properties

    NASA Technical Reports Server (NTRS)

    Bronstein, Lyudmila M.; Karlinsey, Robert L.; Ritter, Kyle; Joo, Chan Gyu; Stein, Barry; Zwanziger, Josef W.

    2003-01-01

    This paper reports synthesis, structure, and properties of novel hybrid solid polymer electrolytes (SPE's) consisting of organically modified aluminosilica (OM-ALSi), formed within a poly(ethylene oxide)-in-salt (Li triflate) phase. To alter the structure and properties we fused functionalized silanes containing poly(ethylene oxide) (PEO) tails or CN groups.

  15. Hybrid Course Design: A Different Type of Polymer Blend

    ERIC Educational Resources Information Center

    Pilcher, Spence C.

    2017-01-01

    An upper-division undergraduate polymer chemistry course was developed as a blended/hybrid course. The students met face-to-face once a week for 75 min with all other components being available online. Face-to-face meetings were used for class discussions/problem-based lectures, student presentations, hands-on activities, and examinations. Online…

  16. Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Composites

    NASA Technical Reports Server (NTRS)

    Kang, Jin Ho; Cano, Roberto J.; Ratcliffe, James G.; Luong, Hoa; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strengthand stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Despite several attempts to solve these issues with the addition of carbon nanotubes (CNT) into polymer matrices, and/or by interleaving CNT sheets between conventional carbon fiber (CF) composite layers, there are still interfacial problems that exist between CNTs (or CF) and the resin. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing (double cantilever beam and end-notched flexure test). Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated. Interleaving CNT sheets significantly improved the in-plane (axial and perpendicular direction of CF alignment) thermal conductivity of the hybrid composite laminates by 50 - 400%.

  17. Enzymatic synthesis of lignin-siloxane hybrid functional polymers.

    PubMed

    Prasetyo, Endry Nugroho; Kudanga, Tukayi; Fischer, Roman; Eichinger, Reinhard; Nyanhongo, Gibson S; Guebitz, Georg M

    2012-02-01

    This study combines the properties of siloxanes and lignin polymers to produce hybrid functional polymers that can be used as adhesives, coating materials, and/or multifunctionalized thin-coating films. Lignin-silica hybrid copolymers were synthesized by using a sol-gel process. Laccases from Trametes hirsuta were used to oxidize lignosulphonates to enhance their reactivity towards siloxanes and then were incorporated into siloxane precursors undergoing a sol-gel process. In vitro copolymerization studies using pure lignin monomers with aminosilanes or ethoxytrimethylsilane and analysis by ²⁹Si NMR spectroscopy revealed hybrid products. Except for kraft lignin, an increase in lignin concentration positively affected the tensile strength in all samples. Similarly, the viscosity generally increased in all samples with increasing lignin concentration and also affected the curing time. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Polymer waveguide based hybrid opto-electric integration technology

    NASA Astrophysics Data System (ADS)

    Mao, Jinbin; Deng, Lingling; Jiang, Xiyan; Ren, Rong; Zhai, Yumeng; Wang, Jin

    2014-10-01

    While monolithic integration especially based on InP appears to be quite an expensive solution for optical devices, hybrid integration solutions using cheaper material platforms are considered powerful competitors because of the high freedom of design, yield optimization and relative cost-efficiency. Among them, the polymer planar-lightwave circuit (PLC) technology is regarded attractive as polymer offers the potential of fairly simple and low-cost fabrication, and of low-cost packaging. In our work, polymer PLC was fabricated by using the standard reactive ion etching (RIE) technique, while other active and passive devices can be integrated on the polymer PLC platform. Exemplary polymer waveguide devices was a 13-channel arrayed waveguide grating (AWG) chip, where the central channel cross-talk was below -30dB and the polarization dependent frequency shift was mitigated by inserting a half wave plate. An optical 900 hybrid was also realized with one 2×4 multi-mode interferometer (MMI). The excess insertion losses are below 4dB for the C-band, while the transmission imbalance is below 1.2dB. When such an optical hybrid was integrated vertically with mesa-type photodiodes, the responsivity of the individual PD was around 0.06 A/W, while the 3 dB bandwidth reaches 24 ~ 27 GHz, which is sufficient for 100Gbit/s receivers. Another example of the hybrid integration was to couple the polymer waveguides to fiber by applying fiber grooves, whose typical loss value was 0.2 dB per-facet over a broad spectral range from 1200-1600 nm.

  19. Hybrid protein-synthetic polymer nanoparticles for drug delivery.

    PubMed

    Koseva, Neli S; Rydz, Joanna; Stoyanova, Ekaterina V; Mitova, Violeta A

    2015-01-01

    Among the most common nanoparticulate systems, the polymeric nanocarriers have a number of key benefits, which give a great choice of delivery platforms. Nevertheless, polymeric nanoparticles possess some limitations that include use of toxic solvents in the production process, polymer degradation, drug leakage outside the diseased tissue, and polymer cytotoxicity. The combination of polymers of biological and synthetic origin is an appealing modern strategy for the production of novel nanocarriers with unprecedented properties. Proteins' interface can play an important role in determining bioactivity and toxicity and gives perspective for future development of the polymer-based nanoparticles. The design of hybrid constructs composed of synthetic polymer and biological molecules such as proteins can be considered as a straightforward tool to integrate a broad spectrum of properties and biofunctions into a single device. This review discusses hybrid protein-synthetic polymer nanoparticles with different structures and levels in complexity and functionality, in view of their applications as drug delivery systems. © 2015 Elsevier Inc. All rights reserved.

  20. A zwitterionic macro-crosslinker for durable non-fouling coatings.

    PubMed

    Wang, Wei; Lu, Yang; Xie, Jinbing; Zhu, Hui; Cao, Zhiqiang

    2016-03-28

    A novel zwitterionic macro-crosslinker was developed and applied to fabricate durable non-fouling coatings on a polyurethane substrate. The zwitterionic macro-crosslinker coating exhibited superior durability over the traditional brush polymer coating and was able to retain its non-fouling property even after weeks of shearing in flowing liquid.

  1. Thermal Properties of Hybrid Carbon Nanotube/Carbon Fiber Polymer

    NASA Technical Reports Server (NTRS)

    Kang, Jin Ho; Cano, Roberto J.; Luong, Hoa; Ratcliffe, James G.; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    Carbon fiber reinforced polymer (CFRP) composites possess many advantages for aircraft structures over conventional aluminum alloys: light weight, higher strength- and stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low thermal and electrical conductivities of CFRP composites are deficient in providing structural safety under certain operational conditions such as lightning strikes. One possible solution to these issues is to interleave carbon nanotube (CNT) sheets between conventional carbon fiber (CF) composite layers. However, the thermal and electrical properties of the orthotropic hybrid CNT/CF composites have not been fully understood. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel (Registered Trademark) IM7/8852 prepreg. The CNT sheets were infused with a 5% solution of a compatible epoxy resin prior to composite fabrication. Orthotropic thermal and electrical conductivities of the hybrid polymer composites were evaluated. The interleaved CNT sheets improved the in-plane thermal conductivity of the hybrid composite laminates by about 400% and the electrical conductivity by about 3 orders of magnitude.

  2. Effects of Polymer Conjugation on Hybridization Thermodynamics of Oligonucleic Acids.

    PubMed

    Ghobadi, Ahmadreza F; Jayaraman, Arthi

    2016-09-15

    In this work, we perform coarse-grained (CG) and atomistic simulations to study the effects of polymer conjugation on hybridization/melting thermodynamics of oligonucleic acids (ONAs). We present coarse-grained Langevin molecular dynamics simulations (CG-NVT) to assess the effects of the polymer flexibility, length, and architecture on hybridization/melting of ONAs with different ONA duplex sequences, backbone chemistry, and duplex concentration. In these CG-NVT simulations, we use our recently developed CG model of ONAs in implicit solvent, and treat the conjugated polymer as a CG chain with purely repulsive Weeks-Chandler-Andersen interactions with all other species in the system. We find that 8-100-mer linear polymer conjugation destabilizes 8-mer ONA duplexes with weaker Watson-Crick hydrogen bonding (WC H-bonding) interactions at low duplex concentrations, while the same polymer conjugation has an insignificant impact on 8-mer ONA duplexes with stronger WC H-bonding. To ensure the configurational space is sampled properly in the CG-NVT simulations, we also perform CG well-tempered metadynamics simulations (CG-NVT-MetaD) and analyze the free energy landscape of ONA hybridization for a select few systems. We demonstrate that CG-NVT-MetaD simulation results are consistent with the CG-NVT simulations for the studied systems. To examine the limitations of coarse-graining in capturing ONA-polymer interactions, we perform atomistic parallel tempering metadynamics simulations at well-tempered ensemble (AA-MetaD) for a 4-mer DNA in explicit water with and without conjugation to 8-mer poly(ethylene glycol) (PEG). AA-MetaD simulations also show that, for a short DNA duplex at T = 300 K, a condition where the DNA duplex is unstable, conjugation with PEG further destabilizes DNA duplex. We conclude with a comparison of results from these three different types of simulations and discuss their limitations and strengths.

  3. An investigation of a thermally steerable electroactive polymer/shape memory polymer hybrid actuator

    NASA Astrophysics Data System (ADS)

    Ren, Kailiang; Bortolin, Robert S.; Zhang, Q. M.

    2016-02-01

    This paper investigates the thermal response of a hybrid actuator composed of an electroactive polymer (EAP) and a shape memory polymer (SMP). This study introduces the concept of using the large strain from a phase transition (ferroelectric to paraelectric phase) induced by temperature change in a poly(vinylidene fluoride-trifluoroethylene) film to tune the shape of an SMP film above its glass transition temperature (Tg). Based on the material characterization data, it is revealed that the thickness ratio of the EAP/SMP films plays a critical role in the displacement of the actuator. Further, it is also demonstrated that the displacement of the hybrid actuator can be tailored by varying the temperature, and finite element method simulation results fit well with the measurement data. This specially designed hybrid actuator shows great promise for future morphing aircraft applications.

  4. Polymer-metal hybrid transparent electrodes for flexible electronics

    NASA Astrophysics Data System (ADS)

    Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

    2015-03-01

    Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius <1 mm, a visible-range transmittance>95% and a sheet resistance <10 Ω sq-1. These features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a surface-density on the atomic scale, in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal electrodes for high-end flexible electronic applications, such as polymer solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides.

  5. Polymer-metal hybrid transparent electrodes for flexible electronics

    PubMed Central

    Kang, Hongkyu; Jung, Suhyun; Jeong, Soyeong; Kim, Geunjin; Lee, Kwanghee

    2015-01-01

    Despite nearly two decades of research, the absence of ideal flexible and transparent electrodes has been the largest obstacle in realizing flexible and printable electronics for future technologies. Here we report the fabrication of ‘polymer-metal hybrid electrodes’ with high-performance properties, including a bending radius <1 mm, a visible-range transmittance>95% and a sheet resistance <10 Ω sq−1. These features arise from a surface modification of the plastic substrates using an amine-containing nonconjugated polyelectrolyte, which provides ideal metal-nucleation sites with a surface-density on the atomic scale, in combination with the successive deposition of a facile anti-reflective coating using a conducting polymer. The hybrid electrodes are fully functional as universal electrodes for high-end flexible electronic applications, such as polymer solar cells that exhibit a high power conversion efficiency of 10% and polymer light-emitting diodes that can outperform those based on transparent conducting oxides. PMID:25790133

  6. Conjugated Polymers/DNA Hybrid Materials for Protein Inactivation.

    PubMed

    Zhao, Likun; Zhang, Jiangyan; Xu, Huiming; Geng, Hao; Cheng, Yongqiang

    2016-09-07

    Chromophore-assisted light inactivation (CALI) is a powerful tool for analyzing protein functions due to the high degree of spatial and temporal resolution. In this work, we demonstrate a CALI approach based on conjugated polymers (CPs)/DNA hybrid material for protein inactivation. The target protein is conjugated with single-stranded DNA in advance. Single-stranded DNA can form CPs/DNA hybrid material with cationic CPs via electrostatic and hydrophobic interactions. Through the formation of CPs/DNA hybrid material, the target protein that is conjugated with DNA is brought into close proximity to CPs. Under irradiation, CPs harvest light and generate reactive oxygen species (ROS), resulting in the inactivation of the adjacent target protein. This approach can efficiently inactivate any target protein which is conjugated with DNA and has good specificity and universality, providing a new strategy for studies of protein function and adjustment of protein activity.

  7. Electrochemical DNA hybridization sensors based on conducting polymers.

    PubMed

    Rahman, Md Mahbubur; Li, Xiao-Bo; Lopa, Nasrin Siraj; Ahn, Sang Jung; Lee, Jae-Joon

    2015-02-05

    Conducting polymers (CPs) are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective.

  8. Polymer nano-particle hybrid micelles: Encapsulation of POSS into semi-fluorinated polymer micelles

    NASA Astrophysics Data System (ADS)

    Ratnaweera, Dilru; Perahia, Dvora; Iacono, Scott; Mabry, Joseph; Smith, Dennis

    2012-02-01

    Self-assembly of block copolymers in selective solvents was used to form a nanoparticle (NP)/polymer hybrid micelles. These micelles can be used as a cargo vehicle for other substances such as drug delivery, and as building blocks for polymer-nanocomposites with controlled NP distribution. Association of NPs into specific blocks of the copolymer depends on the compatibility between the NPs and the block as well as their preference to the solvent that micellization takes place. The current work introduces a small angle neutron scattering study of association of Polyhedral Oligomeric Silsesquioxane (POSS) NPs into micelles of a highly segregating random copolymer, Biphenyl Perfluorocyclobutane (BPh-PFCB), in toluene, which is a good solvent for BPh. Incompatibility between the blocks drives copolymer into micelles with PFCB in the core and BPh in swollen corona. Modification of NPs with polymer chains drives POSS cages into the micelle core and prevents the micelle dissociation at higher temperatures.

  9. Hybrid solar cells composed of perovskite and polymer photovoltaic structures

    NASA Astrophysics Data System (ADS)

    Phaometvarithorn, Apatsanan; Chuangchote, Surawut; Kumnorkaew, Pisist; Wootthikanokkhan, Jatuphorn

    2018-06-01

    Organic/inorganic lead halide perovskite solar cells have recently attracted much attention in photovoltaic research, due to the devices show promising ways to achieve high efficiencies. The perovskite devices with high efficiencies, however, are typically fabricated in tandem solar cell which is complicated. In this research work, we introduce a solar cell device with the combination of CH3NH3PbI3-xClx perovskite and bulk heterojunction PCDTBT:PC70BM polymer without any tandem structure. The new integrated perovskite/polymer hybrid structure of ITO/PEDOT:PSS/perovskite/PCDTBT:PC70BM/PC70BM/TiOx/Al provides higher power conversion efficiency (PCE) of devices compared with conventional perovskite cell structure. With the optimized PCDTBT:PC70BM thickness of ∼70 nm, the highest PCE of 11.67% is achieved. Variation of conducting donor polymers in this new structure is also preliminary demonstrated. This study provides an attractively innovative structure and a promising design for further development of the new-generation solar cells.

  10. Electrochemical DNA Hybridization Sensors Based on Conducting Polymers

    PubMed Central

    Rahman, Md. Mahbubur; Li, Xiao-Bo; Lopa, Nasrin Siraj; Ahn, Sang Jung; Lee, Jae-Joon

    2015-01-01

    Conducting polymers (CPs) are a group of polymeric materials that have attracted considerable attention because of their unique electronic, chemical, and biochemical properties. This is reflected in their use in a wide range of potential applications, including light-emitting diodes, anti-static coating, electrochromic materials, solar cells, chemical sensors, biosensors, and drug-release systems. Electrochemical DNA sensors based on CPs can be used in numerous areas related to human health. This review summarizes the recent progress made in the development and use of CP-based electrochemical DNA hybridization sensors. We discuss the distinct properties of CPs with respect to their use in the immobilization of probe DNA on electrode surfaces, and we describe the immobilization techniques used for developing DNA hybridization sensors together with the various transduction methods employed. In the concluding part of this review, we present some of the challenges faced in the use of CP-based DNA hybridization sensors, as well as a future perspective. PMID:25664436

  11. Photoresponsive lipid-polymer hybrid nanoparticles for controlled doxorubicin release

    NASA Astrophysics Data System (ADS)

    Yao, Cuiping; Wu, Ming; Zhang, Cecheng; Lin, Xinyi; Wei, Zuwu; Zheng, Youshi; Zhang, Da; Zhang, Zhenxi; Liu, Xiaolong

    2017-06-01

    Currently, photoresponsive nanomaterials are particularly attractive due to their spatial and temporal controlled drug release abilities. In this work, we report a photoresponsive lipid-polymer hybrid nanoparticle for remote controlled delivery of anticancer drugs. This hybrid nanoparticle comprises three distinct functional components: (i) a poly(D,L-lactide-co-glycolide) (PLGA) core to encapsulate doxorubicin; (ii) a soybean lecithin monolayer at the interface of the core and shell to act as a molecular fence to prevent drug leakage; (iii) a photoresponsive polymeric shell with anti-biofouling properties to enhance nanoparticle stability, which could be detached from the nanoparticle to trigger the drug release via a decrease in the nanoparticle’s stability under light irradiation. In vitro results revealed that this core-shell nanoparticle had excellent light-controlled drug release behavior (76% release with light irradiation versus 10% release without light irradiation). The confocal microscopy and flow cytometry results also further demonstrated the light-controlled drug release behavior inside the cancer cells. Furthermore, a CCK8 assay demonstrated that light irradiation could significantly improve the efficiency of killing cancer cells. Meanwhile, whole-animal fluorescence imaging of a tumor-bearing mouse also confirmed that light irradiation could trigger drug release in vivo. Taken together, our data suggested that a hybrid nanoparticle could be a novel light controlled drug delivery system for cancer therapy.

  12. Sulfobetaine as a zwitterionic mediator for 3D hydroxyapatite mineralization.

    PubMed

    Liu, Pingsheng; Song, Jie

    2013-03-01

    Both positively and negatively charged residues play pivotal roles in recruiting precursor ions or ion clusters, and lowering interfacial energy in natural biomineralization process. Synergistic utilization of opposite charges, however, has rarely been implemented in the design of cytocompatible synthetic scaffolds promoting hydroxyapatite (HA)-mineralization and osteointegration. We report the use of cytocompatible zwitterionic sulfobetaine ligands to enable 3-dimensional in vitro mineralization of HA across covalently crosslinked hydrogels. The overall charge-neutral zwitterionic hydrogel effectively recruited oppositely charged precursor ions while overcame excessive swelling exhibited by anionic and cationic hydrogels under physiological conditions, resulting in denser and structurally well-integrated mineralized composites. Further controls over the size, content, and spatial distribution of the mineral domains within the zwitterionic hydrogel are accomplished by facile adjustments of hydrogel crosslinking densities and the supersaturation rate governing heterogeneous mineral nucleation and growth. These findings should inspire many creative uses of zwitterionic polymers and polymer coatings for skeletal tissue repair and regeneration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Flexural analysis of palm fiber reinforced hybrid polymer matrix composite

    NASA Astrophysics Data System (ADS)

    Venkatachalam, G.; Gautham Shankar, A.; Raghav, Dasarath; Santhosh Kiran, R.; Mahesh, Bhargav; Kumar, Krishna

    2015-07-01

    Uncertainty in availability of fossil fuels in the future and global warming increased the need for more environment friendly materials. In this work, an attempt is made to fabricate a hybrid polymer matrix composite. The blend is a mixture of General Purpose Resin and Cashew Nut Shell Liquid, a natural resin extracted from cashew plant. Palm fiber, which has high strength, is used as reinforcement material. The fiber is treated with alkali (NaOH) solution to increase its strength and adhesiveness. Parametric study of flexure strength is carried out by varying alkali concentration, duration of alkali treatment and fiber volume. Taguchi L9 Orthogonal array is followed in the design of experiments procedure for simplification. With the help of ANOVA technique, regression equations are obtained which gives the level of influence of each parameter on the flexure strength of the composite.

  14. Modular and Orthogonal Synthesis of Hybrid Polymers and Networks

    PubMed Central

    Liu, Shuang; Dicker, Kevin T.; Jia, Xinqiao

    2015-01-01

    Biomaterials scientists strive to develop polymeric materials with distinct chemical make-up, complex molecular architectures, robust mechanical properties and defined biological functions by drawing inspirations from biological systems. Salient features of biological designs include (1) repetitive presentation of basic motifs; and (2) efficient integration of diverse building blocks. Thus, an appealing approach to biomaterials synthesis is to combine synthetic and natural building blocks in a modular fashion employing novel chemical methods. Over the past decade, orthogonal chemistries have become powerful enabling tools for the modular synthesis of advanced biomaterials. These reactions require building blocks with complementary functionalities, occur under mild conditions in the presence of biological molecules and living cells and proceed with high yield and exceptional selectivity. These chemistries have facilitated the construction of complex polymers and networks in a step-growth fashion, allowing facile modulation of materials properties by simple variations of the building blocks. In this review, we first summarize features of several types of orthogonal chemistries. We then discuss recent progress in the synthesis of step growth linear polymers, dendrimers and networks that find application in drug delivery, 3D cell culture and tissue engineering. Overall, orthogonal reactions and modulular synthesis have not only minimized the steps needed for the desired chemical transformations but also maximized the diversity and functionality of the final products. The modular nature of the design, combined with the potential synergistic effect of the hybrid system, will likely result in novel hydrogel matrices with robust structures and defined functions. PMID:25572255

  15. Polymer-lipid hybrid nanoparticles as enhanced indomethacin delivery systems.

    PubMed

    Dalmoro, Annalisa; Bochicchio, Sabrina; Nasibullin, Shamil F; Bertoncin, Paolo; Lamberti, Gaetano; Barba, Anna Angela; Moustafine, Rouslan I

    2018-05-17

    Non-steroidal anti-inflammatory drugs (NSAIDs), i.e. indomethacin used for rheumatoid arthritis and non-rheumatoid inflammatory diseases, are known for their injurious actions on the gastrointestinal (GI) tract. Mucosal damage can be avoided by using nanoscale systems composed by a combination of liposomes and biodegradable natural polymer, i.e. chitosan, for enhancing drug activity. Aim of this study was to prepare chitosan-lipid hybrid delivery systems for indomethacin dosage through a novel continuous method based on microfluidic principles. The drop-wise conventional method was also applied in order to investigate the effect of the two polymeric coverage processes on the nanostructures features and their interactions with indomethacin. Thermal-physical properties, mucoadhesiveness, drug entrapment efficiency, in vitro release behavior in simulated GI fluids and stability in stocking conditions were assayed and compared, respectively, for the uncoated and chitosan-coated nanoliposomes prepared by the two introduced methods. The prepared chitosan-lipid hybrid structures, with nanometric size, have shown high indomethacin loading (about 10%) and drug encapsulation efficiency up to 99%. TEM investigation has highlighted that the developed novel simil-microfluidic method is able to put a polymeric layer, surrounding indomethacin loaded nanoliposomes, thicker and smoother than that achievable by the drop-wise method, improving their storage stability. Finally, double pH tests have confirmed that the chitosan-lipid hybrid nanostructures have a gastro retentive behavior in simulated gastric and intestinal fluids thus can be used as delivery systems for the oral-controlled release of indomethacin. Based on the present results, the simil-microfluidic method, working with large volumes, in a rapid manner, without the use of drastic conditions and with a precise control over the covering process, seems to be the most promising method for the production of suitable

  16. Active metal oxides and polymer hybrids as biomaterials

    NASA Astrophysics Data System (ADS)

    Jarrell, John D.

    show that silver doping improved the photoactivity of oxide coatings, but hindered activity of a specific hybrid. Doped titanium oxide and polymer hybrid coatings have potential for improving soft tissue integration of medical implants and wound healing by modulating cell proliferation, attachment, inflammation and providing controlled delivery of bioactive and antimicrobial compounds and photon induced electro-chemical activity.

  17. Surface zwitterionization: Effective method for preventing oral bacterial biofilm formation on hydroxyapatite surfaces

    NASA Astrophysics Data System (ADS)

    Lee, Myoungjin; Kim, Heejin; Seo, Jiae; Kang, Minji; Kang, Sunah; Jang, Joomyung; Lee, Yan; Seo, Ji-Hun

    2018-01-01

    In this study, we conducted surface zwitterionization of hydroxyapatite (HA) surfaces by immersing them in the zwitterionic polymer solutions to provide anti-bacterial properties to the HA surface. Three different monomers containing various zwitterionic groups, i.e., phosphorylcholine (PC), sulfobetaine (SB), and carboxybetaine (CB), were copolymerized with the methacrylic monomer containing a Ca2+-binding moiety, using the free radical polymerization method. As a control, functionalization of the copolymer containing the Ca2+-binding moiety was synthesized using a hydroxy group. The stable immobilization of the zwitterionic functional groups was confirmed by water contact angle analysis and X-ray photoelectron spectroscopy (XPS) measurement conducted after the sonication process. The zwitterionized HA surface showed significantly decreased protein adsorption, whereas the hydroxyl group-coated HA surface showed limited efficacy. The anti-bacterial adhesion property was confirmed by conducting Streptococcus mutans (S. mutans) adhesion tests for 6 h and 24 h. When furanone C-30, a representative anti-quorum sensing molecule for S. mutans, was used, only a small amount of bacteria adhered after 6 h and the population did not increase after 24 h. In contrast, zwitterionized HA surfaces showed almost no bacterial adhesion after 6 h and the effect was retained for 24 h, resulting in the lowest level of oral bacterial adhesion. These results confirm that surface zwitterionization is a promising method to effectively prevent oral bacterial adhesion on HA-based materials.

  18. Facile synthesis of zwitterionic polymer-coated core-shell magnetic nanoparticles for highly specific capture of N-linked glycopeptides

    NASA Astrophysics Data System (ADS)

    Chen, Yajing; Xiong, Zhichao; Zhang, Lingyi; Zhao, Jiaying; Zhang, Quanqing; Peng, Li; Zhang, Weibing; Ye, Mingliang; Zou, Hanfa

    2015-02-01

    Highly selective and efficient capture of glycosylated proteins and peptides from complex biological samples is of profound significance for the discovery of disease biomarkers in biological systems. Recently, hydrophilic interaction liquid chromatography (HILIC)-based functional materials have been extensively utilized for glycopeptide enrichment. However, the low amount of immobilized hydrophilic groups on the affinity material has limited its specificity, detection sensitivity and binding capacity in the capture of glycopeptides. Herein, a novel affinity material was synthesized to improve the binding capacity and detection sensitivity for glycopeptides by coating a poly(2-(methacryloyloxy)ethyl)-dimethyl-(3-sulfopropyl) ammonium hydroxide (PMSA) shell onto Fe3O4@SiO2 nanoparticles, taking advantage of reflux-precipitation polymerization for the first time (denoted as Fe3O4@SiO2@PMSA). The thick polymer shell endows the nanoparticles with excellent hydrophilic property and several functional groups on the polymer chains. The resulting Fe3O4@SiO2@PMSA demonstrated an outstanding ability for glycopeptide enrichment with high selectivity, extremely high detection sensitivity (0.1 fmol), large binding capacity (100 mg g-1), high enrichment recovery (above 73.6%) and rapid magnetic separation. Furthermore, in the analysis of real complicated biological samples, 905 unique N-glycosylation sites from 458 N-glycosylated proteins were reliably identified in three replicate analyses of a 65 μg protein sample extracted from mouse liver, showing the great potential of Fe3O4@SiO2@PMSA in the detection and identification of low-abundance N-linked glycopeptides in biological samples.Highly selective and efficient capture of glycosylated proteins and peptides from complex biological samples is of profound significance for the discovery of disease biomarkers in biological systems. Recently, hydrophilic interaction liquid chromatography (HILIC)-based functional materials have

  19. Facile synthesis of zwitterionic polymer-coated core-shell magnetic nanoparticles for highly specific capture of N-linked glycopeptides.

    PubMed

    Chen, Yajing; Xiong, Zhichao; Zhang, Lingyi; Zhao, Jiaying; Zhang, Quanqing; Peng, Li; Zhang, Weibing; Ye, Mingliang; Zou, Hanfa

    2015-02-21

    Highly selective and efficient capture of glycosylated proteins and peptides from complex biological samples is of profound significance for the discovery of disease biomarkers in biological systems. Recently, hydrophilic interaction liquid chromatography (HILIC)-based functional materials have been extensively utilized for glycopeptide enrichment. However, the low amount of immobilized hydrophilic groups on the affinity material has limited its specificity, detection sensitivity and binding capacity in the capture of glycopeptides. Herein, a novel affinity material was synthesized to improve the binding capacity and detection sensitivity for glycopeptides by coating a poly(2-(methacryloyloxy)ethyl)-dimethyl-(3-sulfopropyl) ammonium hydroxide (PMSA) shell onto Fe3O4@SiO2 nanoparticles, taking advantage of reflux-precipitation polymerization for the first time (denoted as Fe3O4@SiO2@PMSA). The thick polymer shell endows the nanoparticles with excellent hydrophilic property and several functional groups on the polymer chains. The resulting Fe3O4@SiO2@PMSA demonstrated an outstanding ability for glycopeptide enrichment with high selectivity, extremely high detection sensitivity (0.1 fmol), large binding capacity (100 mg g(-1)), high enrichment recovery (above 73.6%) and rapid magnetic separation. Furthermore, in the analysis of real complicated biological samples, 905 unique N-glycosylation sites from 458 N-glycosylated proteins were reliably identified in three replicate analyses of a 65 μg protein sample extracted from mouse liver, showing the great potential of Fe3O4@SiO2@PMSA in the detection and identification of low-abundance N-linked glycopeptides in biological samples.

  20. Hybrid polymer composite membrane for an electromagnetic (EM) valveless micropump

    NASA Astrophysics Data System (ADS)

    Said, Muzalifah Mohd; Yunas, Jumril; Bais, Badariah; Azlan Hamzah, Azrul; Yeop Majlis, Burhanuddin

    2017-07-01

    In this paper, we report on a hybrid membrane used as an actuator in an electromagnetically driven valveless micropump developed using MEMS processes. The membrane structure consists of the combination of a magnetic polymer composite membrane and an attached bulk permanent magnet which is expected to have a compact structure and a strong magnetic force with maintained membrane flexibility. A soft polymeric material made of polydimethylsiloxane (PDMS) is initially mixed with neodymium magnetic particles (NdFeB) to form a magnetic polymer composite membrane. The membrane is then bonded with the PDMS based microfluidic part, developed using soft lithography process. The developed micropump was tested in terms of the actuator membrane deflection capability and the fluidic flow of the injected fluid sample through the microfluidic channel. The experimental results show that the magnetic composite actuator membrane with an attached bulk permanent magnet is capable of producing a maximum membrane deflection of up to 106 µm. The functionality test of the electromagnetic (EM) actuator for fluid pumping purposes was done by supplying an AC voltage with various amplitudes, signal waves and frequencies. A wide range of sample injection rates from a few µl min-1 to tens of nl min-1 was achieved with a maximum flow rate of 6.6 µl min-1. The injection flow rate of the EM micropump can be controlled by adjusting the voltage amplitude and frequency supplied to the EM coil, to control the membrane deflection in the pump chamber. The designed valveless EM micropump has a very high potential to enhance the drug delivery system capability in biomedical applications.

  1. Metal{Polymer Hybrid Materials For Flexible Transparent Conductors

    NASA Astrophysics Data System (ADS)

    Narayanan, Sudarshan

    The field of organic electronics, till recently a mere research topic, is currently making rapid strides and tremendous progress into entering the mainstream electronics industry with several applications and products such as OLED televisions, curved displays, wearable devices, flexible solar cells, etc. already having been commercialized. A major component in these devices, especially for photovoltaic applications, is a transparent conductor used as one of the electrodes, which in most commercial applications are highly doped wide bandgap semiconducting oxides also called Transparent Conducting Oxides (TCOs). However, TCOs exhibit inherent disadvantages such as limited supply, brittle mechanical properties, expensive processing that present major barriers for the more widespread economic use in applications such as exible transparent conductors, owing to which suitable alternative materials are being sought. In this context we present two approaches in realizing alternative TCs using metal-polymer hybrid materials, with high figures of merit that are easily processable, reasonably inexpensive and mechanically robust as well. In this context, our first approach employs laminated metal-polymer photonic bandgap structures to effectively tune optical and electrical properties by an appropriate design of the material stack, factoring in the effect of the materials involved, the number of layers and layer properties. We have found that in the case of a four-bilayer Au/polystyrene (AujPS) laminate structure, an enhancement in optical transmittance of ˜ 500% in comparison to a monolithic A film of equivalent thickness, can be achieved. The high conductivity (˜ 106 O--1cm--1) of the metallic component, Au in this case, also ensures planar conductivity; metallic inclusions in the dielectric polymer layer can in principle give rise to out-of-plane conductivity as well enabling a fully functional TC. Such materials also have immense potential for several other applications

  2. Conjugated polymers/semiconductor nanocrystals hybrid materials--preparation, electrical transport properties and applications.

    PubMed

    Reiss, Peter; Couderc, Elsa; De Girolamo, Julia; Pron, Adam

    2011-02-01

    This critical review discusses specific preparation and characterization methods applied to hybrid materials consisting of π-conjugated polymers (or oligomers) and semiconductor nanocrystals. These materials are of great importance in the quickly growing field of hybrid organic/inorganic electronics since they can serve as active components of photovoltaic cells, light emitting diodes, photodetectors and other devices. The electronic energy levels of the organic and inorganic components of the hybrid can be tuned individually and thin hybrid films can be processed using low cost solution based techniques. However, the interface between the hybrid components and the morphology of the hybrid directly influences the generation, separation and transport of charge carriers and those parameters are not easy to control. Therefore a large variety of different approaches for assembling the building blocks--conjugated polymers and semiconductor nanocrystals--has been developed. They range from their simple blending through various grafting procedures to methods exploiting specific non-covalent interactions between both components, induced by their tailor-made functionalization. In the first part of this review, we discuss the preparation of the building blocks (nanocrystals and polymers) and the strategies for their assembly into hybrid materials' thin films. In the second part, we focus on the charge carriers' generation and their transport within the hybrids. Finally, we summarize the performances of solar cells using conjugated polymer/semiconductor nanocrystals hybrids and give perspectives for future developments.

  3. Porous-Hybrid Polymers as Platforms for Heterogeneous Photochemical Catalysis.

    PubMed

    Haikal, Rana R; Wang, Xia; Hassan, Youssef S; Parida, Manas R; Murali, Banavoth; Mohammed, Omar F; Pellechia, Perry J; Fontecave, Marc; Alkordi, Mohamed H

    2016-08-10

    A number of permanently porous polymers containing Ru(bpy)n photosensitizer or a cobaloxime complex, as a proton-reduction catalyst, were constructed via one-pot Sonogashira-Hagihara (SH) cross-coupling reactions. This process required minimal workup to access porous platforms with control over the apparent surface area, pore volume, and chemical functionality from suitable molecular building blocks (MBBs) containing the Ru or Co complexes, as rigid and multitopic nodes. The cobaloxime molecular building block, generated through in situ metalation, afforded a microporous solid that demonstrated noticeable catalytic activity toward hydrogen-evolution reaction (HER) with remarkable recyclability. We further demonstrated, in two cases, the ability to affect the excited-state lifetime of the covalently immobilized Ru(bpy)3 complex attained through deliberate utilization of the organic linkers of variable dimensions. Overall, this approach facilitates construction of tunable porous solids, with hybrid composition and pronounced chemical and physical stability, based on the well-known Ru(bpy)nor the cobaloxime complexes.

  4. Exploration of a Doxorubicin-Polymer Conjugate in Lipid-Polymer Hybrid Nanoparticle Drug Delivery

    NASA Astrophysics Data System (ADS)

    Lough, Emily

    Nanoparticle (NP) drug delivery is a major focus in the research community because of its potential to use existing drugs in safer and more effective ways. Chemotherapy encapsulation in NPs shields the drug from the rest of the body while it is within the NP, with less systemic exposure leading to fewer off-target effects of the drug. However, passive loading of drugs into NPs is a suboptimal method, often leading to burst release upon administration. This work explores the impact of incorporating the drug-polymer conjugate doxorubicin-poly (lactic-co-glycolic) acid (Dox-PLGA) into a lipid-polymer hybrid nanoparticle (LPN). The primary difference in using a drug-polymer conjugate for NP drug delivery is the drug's release kinetics. Dox-PLGA LPNs showed a more sustained and prolonged release profile over 28 days compared to LPNs with passively loaded, unconjugated doxorubicin. This sustained release translates to cytotoxicity; when systemic circulation was simulated using dialysis, Dox-PLGA LPNs retained their cytotoxicity at a higher level than the passively loaded LPNs. The in vivo implication of preserving cytotoxic potency through a slower release profile is that the majority of Dox delivered via Dox-PLGA LPNs will be kept within the LPN until it reaches the tumor. This will result in fewer systemic side effects and more effective treatments given the higher drug concentration at the tumor site. An intriguing clinical application of this drug delivery approach lies in using Dox-PLGA LPNs to cross the blood-brain barrier (BBB). The incorporation of Dox-PLGA is hypothesized to have a protective effect on the BBB as its slow release profile will prevent drug from harming the BBB. Using induced pluripotent stem cells differentiated to human brain microvascular endothelial cells that comprise the BBB, the Dox-PLGA LPNs were shown to be less destructive to the BBB than their passively loaded counterparts. Dox-PLGA LPNs showed superior cytotoxicity against plated tumor

  5. Innovative hybrid optics: combining the thermal stability of glass with low manufacturing cost of polymers

    NASA Astrophysics Data System (ADS)

    Doushkina, Valentina

    2010-08-01

    Innovative hybrid glass-polymer optical solutions on a component, module, or system level offer thermal stability of glass with low manufacturing cost of polymers reducing component weight, enhancing the safety and appeal of the products. Narrow choice of polymer materials is compensated by utilizing sophisticated optical surfaces such as refractive, reflective, and diffractive substrates with spherical, aspherical, cylindrical, and freeform prescriptions. Current advancements in polymer technology and injection molding capabilities placed polymer optics in the heart of many high tech devices and applications including Automotive Industry, Defense & Aerospace; Medical/Bio Science; Projection Displays, Sensors, Information Technology, Commercial and Industrial. This paper is about integration of polymer and glass optics for enhanced optical performance with reduced number of components, thermal stability, and low manufacturing cost. The listed advantages are not achievable when polymers or glass optics are used as stand-alone. The author demonstrates that integration of polymer and glass on component or optical system level on one hand offers high resolution and diffraction limited image quality, similar to the glass optics with stable refractive index and stable thermal performance when design is athermalized within the temperature range. On the other hand, the integrated hybrid solution significantly reduces cost, weight, and complexity, just like the polymer optics. The author will describe the design and analyzes process of combining glass and polymer optics for variety of challenging applications such as fast optics with low F/#, wide field of view lenses or systems, free form optics, etc.

  6. Three-Dimensional Microphase Separation and Synergistic Permeability in Stacked Lipid–Polymer Hybrid Membranes

    SciT

    Kang, Minjee; Lee, Byeongdu; Leal, Cecilia

    Here, we present new structures of soft-material thin films that augment the functionality of substrate-mediated delivery systems. A hybrid material composed of phospholipids and block copolymers adopts a multilayered membrane structure supported on a solid surface. The hybrid films comprise intentional intramembrane heterogeneities that register across multilayers. These stacked domains convey unprecedented enhancement and control of permeability of solutes across micrometer-thick films. Using grazing incidence X-ray scattering, phase contrast atomic force microscopy, and confocal microscopy, we observed that in each lamella, lipid and polymers partition unevenly within the membrane plane segregating into lipid- or polymer-rich domains. Interestingly, we found evidencemore » that like-domains align in registry across multilayers, thereby making phase separation three-dimensional. Phase boundaries exist over extended length scales to compensate the height mismatch between lipid and polymer molecules. We show that microphase separation in hybrid films can be exploited to augment the capability of drug-eluting substrates. Lipid–polymer hybrid films loaded with paclitaxel show synergistic permeability of drug compared to single-component counterparts. We present a thorough structural study of stacked lipid–polymer hybrid membranes and propose that the presence of registered domains and domain boundaries impart enhanced drug release functionality. This work offers new perspectives in designing thin films for controlled delivery applications« less

  7. Three-Dimensional Microphase Separation and Synergistic Permeability in Stacked Lipid–Polymer Hybrid Membranes

    DOE PAGES

    Kang, Minjee; Lee, Byeongdu; Leal, Cecilia

    2017-10-20

    Here, we present new structures of soft-material thin films that augment the functionality of substrate-mediated delivery systems. A hybrid material composed of phospholipids and block copolymers adopts a multilayered membrane structure supported on a solid surface. The hybrid films comprise intentional intramembrane heterogeneities that register across multilayers. These stacked domains convey unprecedented enhancement and control of permeability of solutes across micrometer-thick films. Using grazing incidence X-ray scattering, phase contrast atomic force microscopy, and confocal microscopy, we observed that in each lamella, lipid and polymers partition unevenly within the membrane plane segregating into lipid- or polymer-rich domains. Interestingly, we found evidencemore » that like-domains align in registry across multilayers, thereby making phase separation three-dimensional. Phase boundaries exist over extended length scales to compensate the height mismatch between lipid and polymer molecules. We show that microphase separation in hybrid films can be exploited to augment the capability of drug-eluting substrates. Lipid–polymer hybrid films loaded with paclitaxel show synergistic permeability of drug compared to single-component counterparts. We present a thorough structural study of stacked lipid–polymer hybrid membranes and propose that the presence of registered domains and domain boundaries impart enhanced drug release functionality. This work offers new perspectives in designing thin films for controlled delivery applications« less

  8. Polymer planar lightwave circuit based hybrid-integrated coherent receiver for advanced modulation signals

    NASA Astrophysics Data System (ADS)

    Wang, Jin; Han, Yang; Liang, Zhongcheng; Chen, Yongjin

    2012-11-01

    Applying coherent detection technique to advanced modulation formats makes it possible to electronically compensate the signal impairments. A key issue for a successful deployment of coherent detection technique is the availability of cost-efficient and compact integrated receivers, which are composed of an optical 90° hybrid mixer and four photodiodes (PDs). In this work, three different types of optical hybrids are fabricated with polymer planar lightwave circuit (PLC), and hybridly integrated with four vertical backside illuminated III-V PDs. Their performances, such as the insertion loss, the transmission imbalance, the polarization dependence and the phase deviation of 90° hybrid will be discussed.

  9. Polymer and small molecule based hybrid light source

    DOEpatents

    Choong, Vi-En; Choulis, Stelios; Krummacher, Benjamin Claus; Mathai, Mathew; So, Franky

    2010-03-16

    An organic electroluminescent device, includes: a substrate; a hole-injecting electrode (anode) coated over the substrate; a hole injection layer coated over the anode; a hole transporting layer coated over the hole injection layer; a polymer based light emitting layer, coated over the hole transporting layer; a small molecule based light emitting layer, thermally evaporated over the polymer based light emitting layer; and an electron-injecting electrode (cathode) deposited over the electroluminescent polymer layer.

  10. Synthetic Strategies in the Preparation of Polymer/Inorganic Hybrid Nanoparticles

    PubMed Central

    Hood, Matthew A.; Mari, Margherita; Muñoz-Espí, Rafael

    2014-01-01

    This article reviews the recent advances and challenges in the preparation of polymer/inorganic hybrid nanoparticles. We mainly focus on synthetic strategies, basing our classification on whether the inorganic and the polymer components have been formed in situ or ex situ, of the hybrid material. Accordingly, four types of strategies are identified and described, referring to recent examples: (i) ex situ formation of the components and subsequent attachment or integration, either by covalent or noncovalent bonding; (ii) in situ polymerization in the presence of ex situ formed inorganic nanoparticles; (iii) in situ precipitation of the inorganic components on or in polymer structures; and (iv) strategies in which both polymer and inorganic component are simultaneously formed in situ. PMID:28788665

  11. Radiation sterilization of enzyme hybrids with biodegradable polymers

    NASA Astrophysics Data System (ADS)

    Furuta, Masakazu; Oka, Masahito; Hayashi, Toshio

    2002-03-01

    Ionizing radiations, which have already been utilized for the sterilization of medical supplies as well as gas fumigation, should be the final candidate to decontaminate "hybrid" biomaterials containing bio-active materials including enzymes because irradiation induces neither heat nor substances affecting the quality of the materials and our health. In order to check the feasibility of 60Co-gamma rays on these materials, we selected commercial proteases including papain and bromelain hybridized with commercial activated chitosan beads and demonstrated that these enzyme-hybrids suspended in water showed the significant radiation durability of more than twice as much as free enzyme solution at 25-kGy irradiation. Enhanced thermal and storage stability of the enzyme hybrids were not affected by the same dose level of irradiation, either, indicating that commercial irradiation sterilization method is applicable to enzyme hybrids without modification.

  12. Structure of a tethered polymer under flow using molecular dynamics and hybrid molecular-continuum simulations

    NASA Astrophysics Data System (ADS)

    Delgado-Buscalioni, Rafael; Coveney, Peter V.

    2006-03-01

    We analyse the structure of a single polymer tethered to a solid surface undergoing a Couette flow. We study the problem using molecular dynamics (MD) and hybrid MD-continuum simulations, wherein the polymer and the surrounding solvent are treated via standard MD, and the solvent flow farther away from the polymer is solved by continuum fluid dynamics (CFD). The polymer represents a freely jointed chain (FJC) and is modelled by Lennard-Jones (LJ) beads interacting through the FENE potential. The solvent (modelled as a LJ fluid) and a weakly attractive wall are treated at the molecular level. At large shear rates the polymer becomes more elongated than predicted by existing theoretical scaling laws. Also, along the normal-to-wall direction the structure observed for the FJC is, surprisingly, very similar to that predicted for a semiflexible chain. Comparison with previous Brownian dynamics simulations (which exclude both solvent and wall potential) indicates that these effects are due to the polymer-solvent and polymer-wall interactions. The hybrid simulations are in perfect agreement with the MD simulations, showing no trace of finite size effects. Importantly, the extra cost required to couple the MD and CFD domains is negligible.

  13. Hybrid waste filler filled bio-polymer foam composites for sound absorbent materials

    NASA Astrophysics Data System (ADS)

    Rus, Anika Zafiah M.; Azahari, M. Shafiq M.; Kormin, Shaharuddin; Soon, Leong Bong; Zaliran, M. Taufiq; Ahraz Sadrina M. F., L.

    2017-09-01

    Sound absorption materials are one of the major requirements in many industries with regards to the sound insulation developed should be efficient to reduce sound. This is also important to contribute in economically ways of producing sound absorbing materials which is cheaper and user friendly. Thus, in this research, the sound absorbent properties of bio-polymer foam filled with hybrid fillers of wood dust and waste tire rubber has been investigated. Waste cooking oil from crisp industries was converted into bio-monomer, filled with different proportion ratio of fillers and fabricated into bio-polymer foam composite. Two fabrication methods is applied which is the Close Mold Method (CMM) and Open Mold Method (OMM). A total of four bio-polymer foam composite samples were produce for each method used. The percentage of hybrid fillers; mixture of wood dust and waste tire rubber of 2.5 %, 5.0%, 7.5% and 10% weight to weight ration with bio-monomer. The sound absorption of the bio-polymer foam composites samples were tested by using the impedance tube test according to the ASTM E-1050 and Scanning Electron Microscope to determine the morphology and porosity of the samples. The sound absorption coefficient (α) at different frequency range revealed that the polymer foam of 10.0 % hybrid fillers shows highest α of 0.963. The highest hybrid filler loading contributing to smallest pore sizes but highest interconnected pores. This also revealed that when highly porous material is exposed to incident sound waves, the air molecules at the surface of the material and within the pores of the material are forced to vibrate and loses some of their original energy. This is concluded that the suitability of bio-polymer foam filled with hybrid fillers to be used in acoustic application of automotive components such as dashboards, door panels, cushion and etc.

  14. High-speed, Low Voltage, Miniature Electro-optic Modulators Based on Hybrid Photonic-Crystal/Polymer/Sol-Gel Technology

    DTIC Science & Technology

    2012-02-01

    code) 01/02/2012 FINAL 15/11/2008 - 15/11/2011 High-speed, Low Voltage, Miniature Electro - optic Modulators Based on Hybrid Photonic-Crystal/Polymer... optic modulator, silicon photonics, integrated optics, electro - optic polymer, avionics, optical communications, sol-gel, nanotechnology U U U UU 25...2011 Program Manager: Dr. Charles Y-C Lee High-speed, Low Voltage, Miniature Electro - optic Modulators Based on Hybrid Photonic-Crystal/Polymer/Sol

  15. Single-step assembly of polymer-lipid hybrid nanoparticles for mitomycin C delivery

    PubMed Central

    2014-01-01

    Mitomycin C is one of the most effective chemotherapeutic agents for a wide spectrum of cancers, but its clinical use is still hindered by the mitomycin C (MMC) delivery systems. In this study, the MMC-loaded polymer-lipid hybrid nanoparticles (NPs) were prepared by a single-step assembly (ACS Nano 2012, 6:4955 to 4965) of MMC-soybean phosphatidyhlcholine (SPC) complex (Mol. Pharmaceutics 2013, 10:90 to 101) and biodegradable polylactic acid (PLA) polymers for intravenous MMC delivery. The advantage of the MMC-SPC complex on the polymer-lipid hybrid NPs was that MMC-SPC was used as a structural element to offer the integrity of the hybrid NPs, served as a drug preparation to increase the effectiveness and safety and control the release of MMC, and acted as an emulsifier to facilitate and stabilize the formation. Compared to the PLA NPs/MMC, the PLA NPs/MMC-SPC showed a significant accumulation of MMC in the nuclei as the action site of MMC. The PLA NPs/MMC-SPC also exhibited a significantly higher anticancer effect compared to the PLA NPs/MMC or free MMC injection in vitro and in vivo. These results suggested that the MMC-loaded polymer-lipid hybrid NPs might be useful and efficient drug delivery systems for widening the therapeutic window of MMC and bringing the clinical use of MMC one step closer to reality. PMID:25324707

  16. Induced Infiltration of Hole-Transporting Polymer into Photocatalyst for Staunch Polymer-Metal Oxide Hybrid Solar Cells.

    PubMed

    Park, Jong Hwan; Jung, Youngsuk; Yang, Yooseong; Shin, Hyun Suk; Kwon, Soonchul

    2016-10-05

    For efficient solar cells based on organic semiconductors, a good mixture of photoactive materials in the bulk heterojunction on the length scale of several tens of nanometers is an important requirement to prevent exciton recombination. Herein, we demonstrate that nanoporous titanium dioxide inverse opal structures fabricated using a self-assembled monolayer method and with enhanced infiltration of electron-donating polymers is an efficient electron-extracting layer, which enhances the photovoltaic performance. A calcination process generates an inverse opal structure of titanium dioxide (<70 nm of pore diameters) providing three-dimensional (3D) electron transport pathways. Hole-transporting polymers was successfully infiltrated into the pores of the surface-modified titanium dioxide under vacuum conditions at 200 °C. The resulting geometry expands the interfacial area between hole- and electron-transport materials, increasing the thickness of the active layer. The controlled polymer-coating process over titanium dioxide materials enhanced photocurrent of the solar cell device. Density functional theory calculations show improved interfacial adhesion between the self-assembled monolayer-modified surface and polymer molecules, supporting the experimental result of enhanced polymer infiltration into the voids. These results suggest that the 3D inverse opal structure of the surface-modified titanium dioxide can serve as a favorable electron-extracting layer in further enhancing optoelectronic performance based on organic or organic-inorganic hybrid solar cell.

  17. Some fundamental and applicative properties of [polymer/nano-SiC] hybrid nanocomposites

    NASA Astrophysics Data System (ADS)

    Kassiba, A.; Bouclé, J.; Makowska-Janusik, M.; Errien, N.

    2007-08-01

    Hybrid nanocomposites which combine polymer as host matrix and nanocrystals as active elements are promising functional materials for electronics, optics or photonics. In these systems, the physical response is governed by the nanocrystal features (size, surface and defect states), the polymer properties and the polymer-nanocrystal interface. This work reviews some selective nanostructured architectures based on active elements such as silicon carbide (SiC) nanocrystals and polymer host matrices. Beyond an overview of some key properties of the nanocrystals, a main part will be devoted to the electro-optical (EO) properties of SiC based hybrid systems where SiC nanocrystals are embedded in polymer matrices of different chemical nature such as poly-(methylmethacrylate) (PMMA), poly-vinylcarbazole (PVK) or polycarbonate. Using this approach, the organic-inorganic interface effects are emphasised with regard to the dielectric or hole transporting behaviour of PMMA and PVK respectively. These effects are illustrated through different EO responses associated with hybrid composites based on PMMA or PVK.

  18. Ultra-thin silicon/electro-optic polymer hybrid waveguide modulators

    SciT

    Qiu, Feng; Spring, Andrew M.; Sato, Hiromu

    2015-09-21

    Ultra-thin silicon and electro-optic (EO) polymer hybrid waveguide modulators have been designed and fabricated. The waveguide consists of a silicon core with a thickness of 30 nm and a width of 2 μm. The cladding is an EO polymer. Optical mode calculation reveals that 55% of the optical field around the silicon extends into the EO polymer in the TE mode. A Mach-Zehnder interferometer (MZI) modulator was prepared using common coplanar electrodes. The measured half-wave voltage of the MZI with 7 μm spacing and 1.3 cm long electrodes is 4.6 V at 1550 nm. The evaluated EO coefficient is 70 pm/V, which is comparable to that ofmore » the bulk EO polymer film. Using ultra-thin silicon is beneficial in order to reduce the side-wall scattering loss, yielding a propagation loss of 4.0 dB/cm. We also investigated a mode converter which couples light from the hybrid EO waveguide into a strip silicon waveguide. The calculation indicates that the coupling loss between these two devices is small enough to exploit the potential fusion of a hybrid EO polymer modulator together with a silicon micro-photonics device.« less

  19. Monitoring and modulating ion traffic in hybrid lipid/polymer vesicles

    DOE PAGES

    Paxton, Walter F.; McAninch, Patrick T.; Achyuthan, Komandoor E.; ...

    2017-08-01

    Controlling the traffic of molecules and ions across membranes is a critical feature in a number of biologically relevant processes and highly desirable for the development of technologies based on membrane materials. In this study, ion transport behavior of hybrid lipid/polymer membranes was studied in the absence and presence of ion transfer agents. A pH-sensitive fluorophore was used to investigate ion (H +/OH -) permeability across hybrid lipid/polymer membranes as a function of the fraction of amphiphilic block copolymer. It was observed that vesicles with intermediate lipid/polymer ratios tend to be surprisingly more permeable to ion transport than the puremore » lipid or pure polymer vesicles. Hybrid vesicle permeability could be further modulated with valinomycin, nigericin, or gramicidin A, which significantly expedite the dissipation of externally-imposed pH gradients by facilitating the transport of the rate-limiting co-ions (e.g. K +) ions across the membrane. For gramicidin A, ion permeability decreased with increasing polymer mole fraction, and the method of introduction of gramicidin A into the membrane played an important role. Finally, strategies to incorporate biofunctional molecules and facilitate their activity in synthetic systems are highly desirable for developing artificial organelles or other synthetic compartmentalized structures requiring control over molecular traffic across biomimetic membranes.« less

  20. Polymer/Carbon-Based Hybrid Aerogels: Preparation, Properties and Applications

    PubMed Central

    Zuo, Lizeng; Zhang, Youfang; Zhang, Longsheng; Miao, Yue-E; Fan, Wei; Liu, Tianxi

    2015-01-01

    Aerogels are synthetic porous materials derived from sol-gel materials in which the liquid component has been replaced with gas to leave intact solid nanostructures without pore collapse. Recently, aerogels based on natural or synthetic polymers, called polymer or organic aerogels, have been widely explored due to their porous structures and unique properties, such as high specific surface area, low density, low thermal conductivity and dielectric constant. This paper gives a comprehensive review about the most recent progresses in preparation, structures and properties of polymer and their derived carbon-based aerogels, as well as their potential applications in various fields including energy storage, adsorption, thermal insulation and flame retardancy. To facilitate further research and development, the technical challenges are discussed, and several future research directions are also suggested in this review. PMID:28793602

  1. One-pot in situ redox synthesis of hexacyanoferrate/conductive polymer hybrids as lithium-ion battery cathodes.

    PubMed

    Wong, Min Hao; Zhang, Zixuan; Yang, Xianfeng; Chen, Xiaojun; Ying, Jackie Y

    2015-09-14

    An efficient and adaptable method is demonstrated for the synthesis of lithium hexacyanoferrate/conductive polymer hybrids for Li-ion battery cathodes. The hybrids were synthesized via a one-pot method, involving a redox-coupled reaction between pyrrole monomers and the Li3Fe(CN)6 precursor. The hybrids showed much better cyclability relative to reported Prussian Blue (PB) analogs.

  2. Conductivity and properties of polysiloxane-polyether cluster-LiTFSI networks as hybrid polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Boaretto, Nicola; Joost, Christine; Seyfried, Mona; Vezzù, Keti; Di Noto, Vito

    2016-09-01

    This report describes the synthesis and the properties of a series of polymer electrolytes, composed of a hybrid inorganic-organic matrix doped with LiTFSI. The matrix is based on ring-like oligo-siloxane clusters, bearing pendant, partially cross-linked, polyether chains. The dependency of the thermo-mechanic and of the transport properties on several structural parameters, such as polyether chains' length, cross-linkers' concentration, and salt concentration is studied. Altogether, the materials show good thermo-mechanical and electrochemical stabilities, with conductivities reaching, at best, 8·10-5 S cm-1 at 30 °C. In conclusion, the cell performances of one representative sample are shown. The scope of this report is to analyze the correlations between structure and properties in networked and hybrid polymer electrolytes. This could help the design of optimized polymer electrolytes for application in lithium metal batteries.

  3. Transparent organic/inorganic hybrid sol-gel materials based on perfluorinated polymers and silica

    NASA Astrophysics Data System (ADS)

    Wojcik, Anna B.; Klein, Lisa C.

    1996-01-01

    Two types of hybrid gels based on silica and perfluorinated polymers have been prepared. The first type involves a perfluorinated polymer containing acrylate groups. Perfluoropolyether diol diacrylate (PFDA) was functionalized by reacting it with (3-mercapto-propyl) trimethoxysilane by a Michael addition. The resulting silyl derivative (PFDAS) was able to copolymerize with a silica precursor, tetraethylorthosilicate (TEOS), resulting in perfluorinated polymer/silica hybrid gels. For the second type, perfluoroalkylsilane (FAS), vinyltriethoxysilane (VTES), and TEOS were polymerized in one step. In both cases, the gels were transparent, crack-free and water repellent. Since the inorganic and organic components are covalently bonded to each other, these materials can be classified as organic/inorganic copolymers.

  4. Ultra-small lipid-polymer hybrid nanoparticles for tumor-penetrating drug delivery

    NASA Astrophysics Data System (ADS)

    Dehaini, Diana; Fang, Ronnie H.; Luk, Brian T.; Pang, Zhiqing; Hu, Che-Ming J.; Kroll, Ashley V.; Yu, Chun Lai; Gao, Weiwei; Zhang, Liangfang

    2016-07-01

    Lipid-polymer hybrid nanoparticles, consisting of a polymeric core coated by a layer of lipids, are a class of highly scalable, biodegradable nanocarriers that have shown great promise in drug delivery applications. Here, we demonstrate the facile synthesis of ultra-small, sub-25 nm lipid-polymer hybrid nanoparticles using an adapted nanoprecipitation approach and explore their utility for targeted delivery of a model chemotherapeutic. The fabrication process is first optimized to produce a monodisperse population of particles that are stable under physiological conditions. It is shown that these ultra-small hybrid nanoparticles can be functionalized with a targeting ligand on the surface and loaded with drug inside the polymeric matrix. Further, the in vivo fate of the nanoparticles after intravenous injection is characterized by examining the blood circulation and biodistribution. In a final proof-of-concept study, targeted ultra-small hybrid nanoparticles loaded with the cancer drug docetaxel are used to treat a mouse tumor model and demonstrate improved efficacy compared to a clinically available formulation of the drug. The ability to synthesize a significantly smaller version of the established lipid-polymer hybrid platform can ultimately enhance its applicability across a wider range of applications.

  5. Plastic Polymers for Efficient DNA Microarray Hybridization: Application to Microbiological Diagnostics▿

    PubMed Central

    Zhao, Zhengshan; Peytavi, Régis; Diaz-Quijada, Gerardo A.; Picard, Francois J.; Huletsky, Ann; Leblanc, Éric; Frenette, Johanne; Boivin, Guy; Veres, Teodor; Dumoulin, Michel M.; Bergeron, Michel G.

    2008-01-01

    Fabrication of microarray devices using traditional glass slides is not easily adaptable to integration into microfluidic systems. There is thus a need for the development of polymeric materials showing a high hybridization signal-to-background ratio, enabling sensitive detection of microbial pathogens. We have developed such plastic supports suitable for highly sensitive DNA microarray hybridizations. The proof of concept of this microarray technology was done through the detection of four human respiratory viruses that were amplified and labeled with a fluorescent dye via a sensitive reverse transcriptase PCR (RT-PCR) assay. The performance of the microarray hybridization with plastic supports made of PMMA [poly(methylmethacrylate)]-VSUVT or Zeonor 1060R was compared to that with high-quality glass slide microarrays by using both passive and microfluidic hybridization systems. Specific hybridization signal-to-background ratios comparable to that obtained with high-quality commercial glass slides were achieved with both polymeric substrates. Microarray hybridizations demonstrated an analytical sensitivity equivalent to approximately 100 viral genome copies per RT-PCR, which is at least 100-fold higher than the sensitivities of previously reported DNA hybridizations on plastic supports. Testing of these plastic polymers using a microfluidic microarray hybridization platform also showed results that were comparable to those with glass supports. In conclusion, PMMA-VSUVT and Zeonor 1060R are both suitable for highly sensitive microarray hybridizations. PMID:18784318

  6. Self-Assembled CNT-Polymer Hybrids in Single-Walled Carbon Nanotubes Dispersed Aqueous Triblock Copolymer Solutions

    NASA Astrophysics Data System (ADS)

    Vijayaraghavan, D.; Manjunatha, A. S.; Poojitha, C. G.

    2018-04-01

    We have carried out scanning electron microscopy (SEM), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), electrical conductivity, and 1H NMR studies as a function of temperature on single-walled carbon nanotubes (SWCNTs) dispersed aqueous triblock copolymer (P123) solutions. The single-walled carbon nanotubes in this system aggregate to form bundles, and the bundles aggregate to form net-like structures. Depending on the temperature and phases of the polymer, this system exhibits three different self-assembled CNT-polymer hybrids. We find CNT-unimer hybrid at low temperatures, CNT-micelle hybrid at intermediate temperatures wherein the polymer micelles are adsorbed in the pores of the CNT nets, and another type of CNT-micelle hybrid at high temperatures wherein the polymer micelles are adsorbed on the surface of the CNT bundles. Our DSC thermogram showed two peaks related to these structural changes in the CNT-polymer hybrids. Temperature dependence of the 1H NMR chemical shifts of the molecular groups of the polymer and the AC electrical conductivity of the composite also showed discontinuous changes at the temperatures at which the CNT-polymer hybrid's structural changes are seen. Interestingly, for a higher CNT concentration (0.5 wt.%) in the system, the aggregated polymer micelles adsorbed on the CNTs exhibit cone-like and cube-like morphologies at the intermediate and at high temperatures respectively.

  7. Polymer-lipid hybrid systems: merging the benefits of polymeric and lipid-based nanocarriers to improve oral drug delivery.

    PubMed

    Rao, Shasha; Prestidge, Clive A

    2016-01-01

    A number of biobarriers limit efficient oral drug absorption; both polymer-based and lipid-based nanocarriers have demonstrated properties and delivery mechanisms to overcome these biobarriers in preclinical settings. Moreover, in order to address the multifaceted oral drug delivery challenges, polymer-lipid hybrid systems are now being designed to merge the beneficial features of both polymeric and lipid-based nanocarriers. Recent advances in the development of polymer-lipid hybrids with a specific focus on their viability in oral delivery are reviewed. Three classes of polymer-lipid hybrids have been identified, i.e. lipid-core polymer-shell systems, polymer-core lipid-shell systems, and matrix-type polymer-lipid hybrids. We focus on their application to overcome the various biological barriers to oral drug absorption, as exemplified by selected preclinical studies. Numerous studies have demonstrated the superiority of polymer-lipid hybrid systems to their non-hybrid counterparts in providing improved drug encapsulation, modulated drug release, and improved cellular uptake. These features have encouraged their applications in the delivery of chemotherapeutics, proteins, peptides, and vaccines. With further research expected to optimize the manufacturing and scaling up processes and in-depth pre-clinical pharmacological and toxicological assessments, these multifaceted drug delivery systems will have significant clinical impact on the oral delivery of pharmaceuticals and biopharmaceuticals.

  8. Efficient Preparation of Super Antifouling PVDF Ultrafiltration Membrane with One Step Fabricated Zwitterionic Surface.

    PubMed

    Zhao, Xinzhen; He, Chunju

    2015-08-19

    On the basis of the excellent fouling resistance of zwitterionic materials, the super antifouling polyvinylidene fluoride (PVDF) membrane was efficiently prepared though one-step sulfonation of PVDF and polyaniline blend membrane in situ. The self-doped sulfonated polyaniline (SPANI) was generated as a novel zwitterionic polymer to improve the antifouling property of PVDF ultrafiltration membrane used in sewage treatment. Surface attenuated total reflection Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, surface zeta potential, and water contact angle demonstrated the successful fabrication of zwitterionic interface by convenient sulfonation modification. The static adsorption fouling test showed the quantified adsorption mass of bovine serum albumin (BSA) pollutant on the PVDF/SPANI membrane surface decreases to 3(±2) μg/cm(2), and the water flux recovery ratio (FRR) values were no less than 95% for the three model pollutants of BSA, sodium alginate (SA), and humic acid (HA), which were corresponding hydrophobic, hydrophilic, and natural pollutants in sewage, respectively. This Research Article demonstrated the antifouling advantages of zwitterionic SPANI and aimed to provide a simple method for the large scale preparation of zwitterionic antifouling ultrafiltration membranes.

  9. Zwitterionic materials for antifouling membrane surface construction.

    PubMed

    He, Mingrui; Gao, Kang; Zhou, Linjie; Jiao, Zhiwei; Wu, Mengyuan; Cao, Jialin; You, Xinda; Cai, Ziyi; Su, Yanlei; Jiang, Zhongyi

    2016-08-01

    Membrane separation processes are often perplexed by severe and ubiquitous membrane fouling. Zwitterionic materials, keeping electric neutrality with equivalent positive and negative charged groups, are well known for their superior antifouling properties and have been broadly utilized to construct antifouling surfaces for medical devices, biosensors and marine coatings applications. In recent years, zwitterionic materials have been more and more frequently utilized for constructing antifouling membrane surfaces. In this review, the antifouling mechanisms of zwitterionic materials as well as their biomimetic prototypes in cell membranes will be discussed, followed by the survey of common approaches to incorporate zwitterionic materials onto membrane surfaces including surface grafting, surface segregation, biomimetic adhesion, surface coating and so on. The potential applications of these antifouling membranes are also embedded. Finally, we will present a brief perspective on the future development of zwitterionic materials modified antifouling membranes. Membrane fouling is a severe problem hampering the application of membrane separation technology. The properties of membrane surfaces play a critical role in membrane fouling and antifouling behavior/performance. Antifouling membrane surface construction has evolved as a hot research issue for the development of membrane processes. Zwitterionic modification of membrane surfaces has been recognized as an effective strategy to resist membrane fouling. This review summarizes the antifouling mechanisms of zwitterionic materials inspired by cell membranes as well as the popular approaches to incorporate them onto membrane surfaces. It can help form a comprehensive knowledge about the principles and methods of modifying membrane surfaces with zwitterionic materials. Finally, we propose the possible future research directions of zwitterionic materials modified antifouling membranes. Copyright © 2016 Acta Materialia Inc

  10. Conjugated polymer-titania nanoparticle hybrid films: random lasing action and ultrasensitive detection of explosive vapors.

    PubMed

    Deng, Changmin; He, Qingguo; He, Chao; Shi, Liqi; Cheng, Jiangong; Lin, Tong

    2010-04-08

    We have first demonstrated that a random laser action generated by a hybrid film composed of a semiconducting organic polymer (SOP) and TiO(2) nanoparticles can be used to detect 2,4,6-trinitrotoluene (TNT) vapors. The hybrid film was fabricated by spin-casting SOP solution dispersed with nanosized TiO(2) particles on quartz glass. The SOP in the hybrid film functioned as both the gain medium and the sensory transducer. A random lasing action was observed with a certain pump power when the size (diameter of 50 nm) and concentration (8.9 x 10(12)/cm(3)) of TiO(2) nanoparticles were optimized. Measurements of fluorescence quenching behavior of the hybrid film in TNT vapor atmosphere (10 ppb) showed that attenuated lasing in optically pumped hybrid film displayed a sensitivity to vapors of explosives more than 20 times higher than was observed from spontaneous emission. This phenomenon has been explained with the four-level laser model. Since the sensory transducer used in the hybrid polymer/nanoparticles system could be replaced by other functional materials, the concept developed could be extended to more general domains of chemical or environment detection.

  11. Interactions of Polyethylenimines with Zwitterionic and Anionic Lipid Membranes.

    PubMed

    Kwolek, Urszula; Jamróz, Dorota; Janiczek, Małgorzata; Nowakowska, Maria; Wydro, Paweł; Kepczynski, Mariusz

    2016-05-17

    Interactions between polyethylenimines (PEIs) and phospholipid membranes are of fundamental importance for various biophysical applications of these polymers such as gene delivery. Despite investigations into the nature of these interactions, their molecular basis remains poorly understood. In this article, we combined experimental methods and atomistic molecular dynamics (MD) simulations to obtain comprehensive insight into the effect of linear and branched PEIs on zwitterionic and anionic bilayers used as simple models of mammalian cellular membranes. Our results show that PEIs adsorb only partially on the surface of zwitterionic membranes by forming hydrogen bonds to the lipid headgroups, whereas a large part of the polymer chains dangles freely in the aqueous phase. In contrast, PEIs readily adhere to and insert into the anionic membrane. The attraction of the polymer chains to the membrane is due to electrostatic interactions as well as hydrogen bonding between the amine groups of PEI and the phosphate groups of lipids. These interactions were found to induce a substantial reorganization of the bilayer in the polymer vicinity due to the reorientation of lipid molecules. The lipid headgroups were pulled toward the center of the membrane, which can facilitate transmembrane translocations of anionic lipids. Furthermore, the PEI-lipid interactions affect the stability of liposomal dispersions, but we did not see any evidence of disruption of the vesicular structures into small fragments at polymer concentrations typically used in gene therapy. Our results provide a detailed molecular-level description of the lipid organization in the membrane in the presence of polycations that can be useful in understanding their mechanisms of in vitro and in vivo cytotoxicity.

  12. Three-Dimensional (3D) Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling

    PubMed Central

    Fafenrot, Susanna; Grimmelsmann, Nils; Wortmann, Martin

    2017-01-01

    Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid) (PLA) printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength. PMID:29048347

  13. Three-Dimensional (3D) Printing of Polymer-Metal Hybrid Materials by Fused Deposition Modeling.

    PubMed

    Fafenrot, Susanna; Grimmelsmann, Nils; Wortmann, Martin; Ehrmann, Andrea

    2017-10-19

    Fused deposition modeling (FDM) is a three-dimensional (3D) printing technology that is usually performed with polymers that are molten in a printer nozzle and placed line by line on the printing bed or the previous layer, respectively. Nowadays, hybrid materials combining polymers with functional materials are also commercially available. Especially combinations of polymers with metal particles result in printed objects with interesting optical and mechanical properties. The mechanical properties of objects printed with two of these metal-polymer blends were compared to common poly (lactide acid) (PLA) printed objects. Tensile tests and bending tests show that hybrid materials mostly containing bronze have significantly reduced mechanical properties. Tensile strengths of the 3D-printed objects were unexpectedly nearly identical with those of the original filaments, indicating sufficient quality of the printing process. Our investigations show that while FDM printing allows for producing objects with mechanical properties similar to the original materials, metal-polymer blends cannot be used for the rapid manufacturing of objects necessitating mechanical strength.

  14. Cell Nucleus-Targeting Zwitterionic Carbon Dots.

    PubMed

    Jung, Yun Kyung; Shin, Eeseul; Kim, Byeong-Su

    2015-12-22

    An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation.

  15. Cell Nucleus-Targeting Zwitterionic Carbon Dots

    PubMed Central

    Jung, Yun Kyung; Shin, Eeseul; Kim, Byeong-Su

    2015-01-01

    An innovative nucleus-targeting zwitterionic carbon dot (CD) vehicle has been developed for anticancer drug delivery and optical monitoring. The zwitterionic functional groups of the CDs introduced by a simple one-step synthesis using β-alanine as a passivating and zwitterionic ligand allow cytoplasmic uptake and subsequent nuclear translocation of the CDs. Moreover, multicolor fluorescence improves the accuracy of the CDs as an optical code. The CD-based drug delivery system constructed by non-covalent grafting of doxorubicin, exhibits superior antitumor efficacy owing to enhanced nuclear delivery in vitro and tumor accumulation in vivo, resulting in highly effective tumor growth inhibition. Since the zwitterionic CDs are highly biocompatible and effectively translocated into the nucleus, it provides a compelling solution to a multifunctional nanoparticle for substantially enhanced nuclear uptake of drugs and optical monitoring of translocation. PMID:26689549

  16. The hybrid photonic planar integrated receiver with a polymer optical waveguide

    NASA Astrophysics Data System (ADS)

    Busek, Karel; Jerábek, Vitezslav; Armas Arciniega, Julio; Prajzler, Václav

    2008-11-01

    This article describes design of the photonic receiver composed of the system polymer planar waveguides, InGaAs p-i-n photodiode and integrated HBT amplifier on a low loss composite substrate. The photonic receiver was the main part of the hybrid integrated microwave optoelectronic transceiver TRx (transciever TRx) for the optical networks PON (passive optical networks) with FTTH (fiber-to-the-home) topology. In this article are presented the research results of threedimensional field between output facet of a optical waveguide and p-i-n photodiode. In terms of our research, there was optimized the optical coupling among the facet waveguide and pi-n photodiode and the electrical coupling among p-i-n photodiode and input of HBT amplifier. The hybrid planar lightwave circuit (PLC) of the transceiver TRx will be composed from a two parts - polymer optical waveguide including VHGT filter section and a optoelectronic microwave section.

  17. Zirconium oxocluster/polymer hybrid nanoparticles prepared by photoactivated miniemulsion copolymerization

    NASA Astrophysics Data System (ADS)

    Benedetti, Cesare; Flouda, Paraskevi; Antonello, Alice; Rosenauer, Christine; Pérez-Pla, Francisco F.; Landfester, Katharina; Gross, Silvia; Muñoz-Espí, Rafael

    2017-09-01

    The photoactivated free radical miniemulsion copolymerization of methyl methacrylate (MMA) and the zirconium oxocluster Zr4O2(methacrylate)12 is used as an effective and fast preparation method for polymer/inorganic hybrid nanoparticles. The oxoclusters, covalently anchored to the polymer network, act as metal-organic cross-linkers, thus improving the thermomechanical properties of the resulting hybrid nanoparticles. Benzoin carbonyl organic compounds were used as photoinitiators. The obtained materials are compared in terms of cross-linking, effectiveness of cluster incorporation, and size distribution with the analogous nanoparticles produced by using conventional thermally induced free radical miniemulsion copolymerization. The kinetics of the polymerization process in the absence and in the presence of the oxocluster is also investigated.

  18. Factors affecting drug encapsulation and stability of lipid-polymer hybrid nanoparticles.

    PubMed

    Cheow, Wean Sin; Hadinoto, Kunn

    2011-07-01

    Lipid-polymer hybrid nanoparticles are polymeric nanoparticles enveloped by lipid layers that combine the highly biocompatible nature of lipids with the structural integrity afforded by polymeric nanoparticles. Recognizing them as attractive drug delivery vehicles, antibiotics are encapsulated in the present work into hybrid nanoparticles intended for lung biofilm infection therapy. Modified emulsification-solvent-evaporation methods using lipid as surfactant are employed to prepare the hybrid nanoparticles. Biodegradable poly (lactic-co-glycolic acid) and phosphatidylcholine are used as the polymer and lipid models, respectively. Three fluoroquinolone antibiotics (i.e. levofloxacin, ciprofloxacin, and ofloxacin), which vary in their ionicity, lipophilicity, and aqueous solubility, are used. The hybrid nanoparticles are examined in terms of their drug encapsulation efficiency, drug loading, stability, and in vitro drug release profile. Compared to polymeric nanoparticles prepared using non-lipid surfactants, hybrid nanoparticles in general are larger and exhibit higher drug loading, except for the ciprofloxacin-encapsulated nanoparticles. Hybrid nanoparticles, however, are unstable in salt solutions, but the stability can be conferred by adding TPGS into the formulation. Drug-lipid ionic interactions and drug lipophilicity play important roles in the hybrid nanoparticle preparation. First, interactions between oppositely charged lipid and antibiotic (i.e. ciprofloxacin) during preparation cause failed nanoparticle formation. Charge reversal of the lipid facilitated by adding counterionic surfactants (e.g. stearylamine) must be performed before drug encapsulation can take place. Second, drug loading and the release profile are strongly influenced by drug lipophilicity, where more lipophilic drug (i.e. levofloxacin) exhibit a higher drug loading and a sustained release profile attributed to the interaction with the lipid coat. Copyright © 2011 Elsevier B.V. All

  19. Polymer-Attached Functional Inorganic-Organic Hybrid Nano-Composite Aerogels

    DTIC Science & Technology

    2003-01-01

    drugs. The chemistry to synthesize polyamino- siloxane based aerogel composite was discussed. In addition, two approaches to synthesize PHEMA aerogel... Composite Aerogels DISTRIBUTION: Approved for public release, distribution unlimited This paper is part of the following report: TITLE: Materials...Proc. Vol. 740 © 2003 Materials Research Society 112.24 Polymer-Attached Functional Inorganic-Organic Hybrid Nano- composite Aerogels Xipeng Liu, Mingzhe

  20. Thermal response of novel shape memory polymer-shape memory alloy hybrids

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Takashima, Kazuto; Mukai, Toshiharu

    2014-03-01

    Shape memory polymers (SMP) and shape memory alloys (SMA) have both been proven important smart materials in their own fields. Shape memory polymers can be formed into complex three-dimensional structures and can undergo shape programming and large strain recovery. These are especially important for deployable structures including those for space applications and micro-structures such as stents. Shape memory alloys on the other hand are readily exploitable in a range of applications where simple, silent, light-weight and low-cost repeatable actuation is required. These include servos, valves and mobile robotic artificial muscles. Despite their differences, one important commonality between SMPs and SMAs is that they are both typically activated by thermal energy. Given this common characteristic it is important to consider how these two will behave when in close environmental proximity, and hence exposed to the same thermal stimulus, and when they are incorporated into a hybrid SMA-SMP structure. In this paper we propose and examine the operation of SMA-SMP hybrids. The relationship between the two temperatures Tg, the glass transition temperature of the polymer, and Ta, the nominal austenite to martensite transition temperature of the alloy is considered. We examine how the choice of these two temperatures affects the thermal response of the hybrid. Electrical stimulation of the SMA is also considered as a method not only of actuating the SMA but also of inducing heating in the surrounding polymer, with consequent effects on actuator behaviour. Likewise by varying the rate and degree of thermal stimulation of the SMA significantly different actuation and structural stiffness can be achieved. Novel SMP-SMA hybrid actuators and structures have many ready applications in deployable structures, robotics and tuneable engineering systems.

  1. Thermo-optic characteristics of hybrid polymer/silica microstructured optical fiber: An analytical approach

    NASA Astrophysics Data System (ADS)

    Sharma, Dinesh Kumar; Sharma, Anurag; Tripathi, Saurabh Mani

    2018-04-01

    Microstructured optical fibers (MOFs) allow a variety of advanced materials to be infiltrated in their air-voids for obtaining the increased fiber functionality, and offering a new versatile platform for developing the compact sensors devices. We aim to investigate the thermal characteristics of high-index core triangular hybrid polymer/silica MOFs with circular air-voids infused with polymer by using the analytical field model [1]. We demonstrate that infiltration of air-voids with polymer, e.g., polydimethylsiloxane (PDMS) can facilitate to tune the fundamental modal properties of MOF such as effective index of the mode, near and the far-field profiles, effective mode area and the numerical aperture over the temperature ranging from 0 °C to 100 °C, for different values of relative air-void ratios. The evolution of the mode shape for a given temperature has been investigated in transition from near-field to far-field regime. We have studied the thermal dependence of splice losses between hybrid MOF and the standard step-index single-mode optical fiber in combination with Fresnel losses. For enhancing the evanescent field interactions, we have evaluated fraction of power associated with fundamental mode of hybrid MOF. We have compared the accuracy of our results with those based on full-vector finite-difference (FD) method, as available in the literature.

  2. Properties of Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Matrix Composites

    NASA Technical Reports Server (NTRS)

    Cano, Roberto J.; Kang, Jin Ho; Grimsley, Brian W.; Ratcliffe, James G.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strength- and stiffness-to-weight ratios, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Carbon nanotubes (CNT) offer the potential to enhance the multi-functionality of composites with improved thermal and electrical conductivity. In this study, hybrid CNT/carbon fiber (CF) polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing. Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated.

  3. Effect of reduced graphene oxide-carbon nanotubes hybrid nanofillers in mechanical properties of polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Sa, Kadambinee; Mahakul, Prakash C.; Subramanyam, B. V. R. S.; Raiguru, Jagatpati; Das, Sonali; Alam, Injamul; Mahanandia, Pitamber

    2018-03-01

    Graphene and carbon nanotubes (CNTs) have tremendous interest as reinforcing fillers due to their excellent physical properties. However, their reinforcing effect in polymer matrix is limited due to agglomeration of graphene and CNTs within the polymer matrix. Mechanical properties by the admixture of reduced graphene oxide (rGO) and CNTs in Poly (methyl methacrylate) (PMMA) prepared by solution mixing method has been investigated. The prepared samples are characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscopy. The hybrid composite shows improvement in the mechanical properties compared to rGO/PMMA and MWCNTs/PMMA composites due to better interaction between rGO-MWCNTs and polymer matrix.

  4. Electrochemical sensor for catechol and dopamine based on a catalytic molecularly imprinted polymer-conducting polymer hybrid recognition element.

    PubMed

    Lakshmi, Dhana; Bossi, Alessandra; Whitcombe, Michael J; Chianella, Iva; Fowler, Steven A; Subrahmanyam, Sreenath; Piletska, Elena V; Piletsky, Sergey A

    2009-05-01

    One of the difficulties with using molecularly imprinted polymers (MIPs) and other electrically insulating materials as the recognition element in electrochemical sensors is the lack of a direct path for the conduction of electrons from the active sites to the electrode. We have sought to address this problem through the preparation and characterization of novel hybrid materials combining a catalytic MIP, capable of oxidizing the template, catechol, with an electrically conducting polymer. In this way a network of "molecular wires" assists in the conduction of electrons from the active sites within the MIP to the electrode surface. This was made possible by the design of a new monomer that combines orthogonal polymerizable functionality; comprising an aniline group and a methacrylamide. Conducting films were prepared on the surface of electrodes (Au on glass) by electropolymerization of the aniline moiety. A layer of MIP was photochemically grafted over the polyaniline, via N,N'-diethyldithiocarbamic acid benzyl ester (iniferter) activation of the methacrylamide groups. Detection of catechol by the hybrid-MIP sensor was found to be specific, and catechol oxidation was detected by cyclic voltammetry at the optimized operating conditions: potential range -0.6 V to +0.8 V (vs Ag/AgCl), scan rate 50 mV/s, PBS pH 7.4. The calibration curve for catechol was found to be linear to 144 microM, with a limit of detection of 228 nM. Catechol and dopamine were detected by the sensor, whereas analogues and potentially interfering compounds, including phenol, resorcinol, hydroquinone, serotonin, and ascorbic acid, had minimal effect (< or = 3%) on the detection of either analyte. Non-imprinted hybrid electrodes and bare gold electrodes failed to give any response to catechol at concentrations below 0.5 mM. Finally, the catalytic properties of the sensor were characterized by chronoamperometry and were found to be consistent with Michaelis-Menten kinetics.

  5. Hybrid device based on GaN nanoneedles and MEH-PPV/PEDOT:PSS polymer

    SciT

    Shin, Min Jeong; Gwon, Dong-Oh; Lee, Chan-Mi

    2015-08-15

    Highlights: • A hybrid device was demonstrated by using MEH-PPV, PEDOT:PSS, and GaN nanoneedles. • I–V curve of the hybrid device showed its rectification behaviour, similar to a diode. • EL peak originated by the different potential barriers at MEH-PPV and GaN interface. - Abstract: A hybrid device that combines the properties of organic and inorganic semiconductors was fabricated and studied. It incorporated poly[2-methoxy-5-(2-ethylhexyloxy)- 1,4-phenylenevinylene] (MEH-PPV) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as organic polymers and GaN nanoneedles as an inorganic semiconductor. Layers of the two polymers were spin coated on to the GaN nanoneedles. The one peak in the electroluminescence spectrum originatedmore » from the MEH-PPV layer owing to the different potential barriers of electrons and holes at its interface with the GaN nanoneedles. However, the photoluminescence spectrum showed peaks due to both GaN nanoneedles and MEH-PPV. Such hybrid structures, suitably developed, might be able to improve the efficiency of optoelectronic devices.« less

  6. Compliant glass–polymer hybrid single ion-conducting electrolytes for lithium batteries

    SciT

    Villaluenga, Irune; Wujcik, Kevin H.; Tong, Wei

    2015-12-22

    Despite high ionic conductivities, current inorganic solid electrolytes cannot be used in lithium batteries because of a lack of compliance and adhesion to active particles in battery electrodes as they are discharged and charged. Here, we have successfully developed a compliant, nonflammable, hybrid single ion-conducting electrolyte comprising inorganic sulfide glass particles covalently bonded to a perfluoropolyether polymer. The hybrid with 23 wt% perfluoropolyether exhibits low shear modulus relative to neat glass electrolytes, ionic conductivity of 10 -4 S/cm at room temperature, a cation transference number close to unity, and an electrochemical stability window up to 5 V relative to Limore » +/Li. X-ray absorption spectroscopy indicates that the hybrid electrolyte limits lithium polysulfide dissolution and is, thus, ideally suited for Li-S cells. Our work opens a previously unidentified route for developing compliant solid electrolytes that will address the challenges of lithium batteries.« less

  7. Compliant glass–polymer hybrid single ion-conducting electrolytes for lithium batteries

    PubMed Central

    Villaluenga, Irune; Wujcik, Kevin H.; Tong, Wei; Devaux, Didier; Wong, Dominica H. C.; DeSimone, Joseph M.; Balsara, Nitash P.

    2016-01-01

    Despite high ionic conductivities, current inorganic solid electrolytes cannot be used in lithium batteries because of a lack of compliance and adhesion to active particles in battery electrodes as they are discharged and charged. We have successfully developed a compliant, nonflammable, hybrid single ion-conducting electrolyte comprising inorganic sulfide glass particles covalently bonded to a perfluoropolyether polymer. The hybrid with 23 wt% perfluoropolyether exhibits low shear modulus relative to neat glass electrolytes, ionic conductivity of 10−4 S/cm at room temperature, a cation transference number close to unity, and an electrochemical stability window up to 5 V relative to Li+/Li. X-ray absorption spectroscopy indicates that the hybrid electrolyte limits lithium polysulfide dissolution and is, thus, ideally suited for Li-S cells. Our work opens a previously unidentified route for developing compliant solid electrolytes that will address the challenges of lithium batteries. PMID:26699512

  8. Reversible conversion of dominant polarity in ambipolar polymer/graphene oxide hybrids

    DOE PAGES

    Zhou, Ye; Han, Su -Ting; Sonar, Prashant; ...

    2015-03-24

    The possibility to selectively modulate the charge carrier transport in semiconducting materials is extremely challenging for the development of high performance and low-power consuming logic circuits. Systematical control over the polarity (electrons and holes) in transistor based on solution processed layer by layer polymer/graphene oxide hybrid system has been demonstrated. The conversion degree of the polarity is well controlled and reversible by trapping the opposite carriers. Basically, an electron device is switched to be a hole only device or vice versa. Finally, a hybrid layer ambipolar inverter is demonstrated in which almost no leakage of opposite carrier is found. Wemore » conclude that this hybrid material has wide range of applications in planar p-n junctions and logic circuits for high-throughput manufacturing of printed electronic circuits.« less

  9. Bioinspired Smart Actuator Based on Graphene Oxide-Polymer Hybrid Hydrogels.

    PubMed

    Wang, Tao; Huang, Jiahe; Yang, Yiqing; Zhang, Enzhong; Sun, Weixiang; Tong, Zhen

    2015-10-28

    Rapid response and strong mechanical properties are desired for smart materials used in soft actuators. A bioinspired hybrid hydrogel actuator was designed and prepared by series combination of three trunks of tough polymer-clay hydrogels to accomplish the comprehensive actuation of "extension-grasp-retraction" like a fishing rod. The hydrogels with thermo-creep and thermo-shrinking features were successively irradiated by near-infrared (NIR) to execute extension and retraction, respectively. The GO in the hydrogels absorbed the NIR energy and transformed it into thermo-energy rapidly and effectively. The hydrogel with adhesion or magnetic force was adopted as the "hook" of the hybrid hydrogel actuator for grasping object. The hook of the hybrid hydrogel actuator was replaceable according to applications, even with functional materials other than hydrogels. This study provides an innovative concept to explore new soft actuators through combining response hydrogels and programming the same stimulus.

  10. Reversible Conversion of Dominant Polarity in Ambipolar Polymer/Graphene Oxide Hybrids

    PubMed Central

    Zhou, Ye; Han, Su-Ting; Sonar, Prashant; Ma, Xinlei; Chen, Jihua; Zheng, Zijian; Roy, V. A. L.

    2015-01-01

    The possibility to selectively modulate the charge carrier transport in semiconducting materials is extremely challenging for the development of high performance and low-power consuming logic circuits. Systematical control over the polarity (electrons and holes) in transistor based on solution processed layer by layer polymer/graphene oxide hybrid system has been demonstrated. The conversion degree of the polarity is well controlled and reversible by trapping the opposite carriers. Basically, an electron device is switched to be a hole only device or vice versa. Finally, a hybrid layer ambipolar inverter is demonstrated in which almost no leakage of opposite carrier is found. This hybrid material has wide range of applications in planar p-n junctions and logic circuits for high-throughput manufacturing of printed electronic circuits. PMID:25801827

  11. Targeted delivery of 10-hydroxycamptothecin to human breast cancers by cyclic RGD-modified lipid-polymer hybrid nanoparticles.

    PubMed

    Yang, Zhe; Luo, Xingen; Zhang, Xiaofang; Liu, Jie; Jiang, Qing

    2013-04-01

    Lipid-polymer hybrid nanoparticles (NPs) combining the positive attributes of both liposomes and polymeric NPs are increasingly being considered as promising candidates to carry therapeutic agents safely and efficiently into targeted sites. Herein, a modified emulsification technique was developed and optimized for the targeting lipid-polymer hybrid NPs fabrication; the surface properties and stability of the hybrid NPs were systematically investigated, which confirmed that the hybrid NPs consisted of a poly (lactide-co-glycolide) core with ∼90% surface coverage of the lipid monolayer and a ∼4.4 nm hydrated polyethylene glycol (PEG) shell. Optimization results showed that the lipid:polymer mass ratio and the lipid-PEG:lipid molar ratio could affect the size, lipid association efficiency and stability of hybrid NPs. Furthermore, a model chemotherapy drug, 10-hydroxycamptothecin, was encapsulated into hybrid NPs with a higher drug loading compared to PLGA NPs. Surface modification of the lipid layer and the PEG conjugated targeting ligand did not affect their drug release kinetics. Finally, the cytotoxicity and cellular uptake studies indicated that the lipid coverage and the c(RGDyk) conjugation of the hybrid NPs gained a significantly enhanced ability of cell killing and endocytosis. Our results suggested that lipid-polymer hybrid NPs prepared by the modified emulsion technique have great potential to be utilized as an engineered drug delivery system with precise control ability of surface targeting modification.

  12. Photovoltaic Performance of Inverted Polymer Solar Cells Using Hybrid Carbon Quantum Dots and Absorption Polymer Materials

    NASA Astrophysics Data System (ADS)

    Lim, Hwain; Lee, Kyu Seung; Liu, Yang; Kim, Hak Yong; Son, Dong Ick

    2018-05-01

    We report the synthesis and characterization of the carbon quantum dots (C-dots) easily obtained from citric acid and ethanediamine, and also investigated structural, optical and electrical properties. The C-dots have extraordinary optical and electrical features such as absorption of ultraviolet range and effective interface for charge separation and transport in active layer, which make them attractive materials for applications in photovoltaic devices (PV). The C-dots play important roles in charge extraction in the PV structures, they can be synthesized by a simple method and used to insert in active layer of polymer solar cells. In this study, we demonstrate that improve charge transport properties of inverted polymer solar cells (iPSCs) with C-dots and structural, optical and electrical properties of C-dots. As a result, iPSCs with C-dots showed enhancement of more than 30% compared with that of the contrast device in power conversion efficiency.

  13. Zwitterion-functionalized polymer microspheres as a sorbent for solid phase extraction of trace levels of V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II) prior to their determination by ICP-MS.

    PubMed

    Jia, Xiaoyu; Gong, Dirong; Zhao, Junyi; Ren, Hongyun; Wang, Jiani; Zhang, Xian

    2018-03-19

    This paper describes the preparation of zwitterion-functionalized polymer microspheres (ZPMs) and their application to simultaneous enrichment of V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II) from environmental water samples. The ZPMs were prepared by emulsion copolymerization of ethyl methacrylate, 2-diethylaminoethyl methacrylate and triethylene glycol dimethyl acrylate followed by modification with 1,3-propanesultone. The components were analyzed by elemental analyses as well as Fourier transform infrared spectroscopy, and the structures were characterized by scanning electron microscopy and transmission electron microscopy. The ZPMs were packed into a mini-column for on-line solid-phase extraction (SPE) of the above metal ions. Following extraction with 40 mM NH 4 NO 3 and 0.5 M HNO 3 solution, the ions were quantified by ICP-MS. Under the optimized conditions, the enrichment factors (from a 40 mL sample) are up to 60 for the ions V(V), As(III), Sb(III) and Hg(II), and 55 for Cr(III) and Sn(IV). The detection limits are 1.2, 3.4, 1.0, 3.7, 2.1 and 1.6 ng L -1 for V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II), respectively, and the relative standard deviations (RSDs) are below 5.2%. The feasibility and accuracy of the method were validated by successfully analyzing six certified reference materials as well as lake, well and river waters. Graphical abstract Zwitterion-functionalized polymer microspheres (ZPMs) were prepared and packed into a mini-column for on-line solid-phase extraction (SPE) via pump 1. Then V(V), Cr(III), As(III), Sn(IV), Sb(III) and Hg(II) ions in environmental waters were eluted and submitted to ICP-MS via pump 2.

  14. Transparent and High Refractive Index Thermoplastic Polymer Glasses Using Evaporative Ligand Exchange of Hybrid Particle Fillers.

    PubMed

    Wang, Zongyu; Lu, Zhao; Mahoney, Clare; Yan, Jiajun; Ferebee, Rachel; Luo, Danli; Matyjaszewski, Krzysztof; Bockstaller, Michael R

    2017-03-01

    Development of high refractive index glasses on the basis of commodity polymer thermoplastics presents an important requisite to further advancement of technologies ranging from energy efficient lighting to cost efficient photonics. This contribution presents a novel particle dispersion strategy that enables uniform dispersion of zinc oxide (ZnO) particles in a poly(methyl methacrylate) (PMMA) matrix to facilitate hybrid glasses with inorganic content exceeding 25% by weight, optical transparency in excess of 0.8/mm, and a refractive index greater than 1.64 in the visible wavelength range. The method is based on the application of evaporative ligand exchange to synthesize poly(styrene-r-acrylonitrile) (PSAN)-tethered zinc oxide (ZnO) particle fillers. Favorable filler-matrix interactions are shown to enable the synthesis of isomorphous blends with high molecular PMMA that exhibit improved thermomechanical stability compared to that of the pristine PMMA matrix. The concurrent realization of high refractive index and optical transparency in polymer glasses by modification of a thermoplastic commodity polymer could present a viable alternative to expensive specialty polymers in applications where high costs or demands for thermomechanical stability and/or UV resistance prohibit the application of specialty polymer solutions.

  15. Synthesis of nanostructured bio-related materials by hybridization of synthetic polymers with polysaccharides or saccharide residues.

    PubMed

    Kaneko, Yoshiro; Kadokawa, Jun-Ichi

    2006-01-01

    In the first part of this review, we describe the synthesis of nanostructured hybrid materials composed of polysaccharides and synthetic polymers. Amylose-synthetic polymer inclusion complexes were synthesized by amylose-forming polymerization using phosphorylase enzyme in the presence of synthetic polymers such as polyethers and polyesters. Alginate-polymethacrylate hybrid materials were prepared by free-radical polymerization of cationic methacrylate in the presence of sodium alginate. These methods allow the simultaneous control of the nanostructure with polymerization, giving well-defined hybrid materials. In the second part of this review, we describe the synthesis of novel glycopolymers with rigid structures. Polyaniline-based glycopolymers were synthesized by means of oxidative polymerization of N-glycosylaniline. Polysiloxane-based glycopolymers were prepared by means of introduction of sugar-lactone to the rodlike polysiloxane. These glycopolymers had regular higher-ordered structures due to their rigid polymer backbones, resulting in control of the three-dimensional array of sugar-residues.

  16. Peptides, polypeptides and peptide-polymer hybrids as nucleic acid carriers.

    PubMed

    Ahmed, Marya

    2017-10-24

    Cell penetrating peptides (CPPs), and protein transduction domains (PTDs) of viruses and other natural proteins serve as a template for the development of efficient peptide based gene delivery vectors. PTDs are sequences of acidic or basic amphipathic amino acids, with superior membrane trespassing efficacies. Gene delivery vectors derived from these natural, cationic and cationic amphipathic peptides, however, offer little flexibility in tailoring the physicochemical properties of single chain peptide based systems. Owing to significant advances in the field of peptide chemistry, synthetic mimics of natural peptides are often prepared and have been evaluated for their gene expression, as a function of amino acid functionalities, architecture and net cationic content of peptide chains. Moreover, chimeric single polypeptide chains are prepared by a combination of multiple small natural or synthetic peptides, which imparts distinct physiological properties to peptide based gene delivery therapeutics. In order to obtain multivalency and improve the gene delivery efficacies of low molecular weight cationic peptides, bioactive peptides are often incorporated into a polymeric architecture to obtain novel 'polymer-peptide hybrids' with improved gene delivery efficacies. Peptide modified polymers prepared by physical or chemical modifications exhibit enhanced endosomal escape, stimuli responsive degradation and targeting efficacies, as a function of physicochemical and biological activities of peptides attached onto a polymeric scaffold. The focus of this review is to provide comprehensive and step-wise progress in major natural and synthetic peptides, chimeric polypeptides, and peptide-polymer hybrids for nucleic acid delivery applications.

  17. Free flow cell electrophoresis using zwitterionic buffer

    NASA Technical Reports Server (NTRS)

    Rodkey, R. Scott

    1990-01-01

    Studies of a zwitterionic buffer formulated for cell electrophoresis were done using the McDonnell-Douglas Continuous Flow Electrophoresis System. Standard buffers were analyzed for their stability in the electrical field and the results showed that both buffers tested were inherently unstable. Further, titration studies showed that the standards buffers buffered poorly at the pH employed for electrophoresis. The zwitterionic buffer buffered well at its nominal pH and was shown to be stable in the electrical field. Comparative studies of the buffer with standard cell separation buffers using formalin fixed rabbit and goose red blood cells showed that the zwitterionic buffer gave better resolution of the fixed cells. Studies with viable hybridoma cells showed that buffer Q supported cell viability equal to Hank's Balanced Salt Solution and that hybridoma cells in different stages of the growth cycle demonstrated reproducible differences in electrophoretic mobility.

  18. RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

    SciT

    Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan

    2012-07-30

    Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host matrix. A unique emulsion-based RIR-MAPLE approach has been developed that reduces substrate exposure to solvents and provides controlled and repeatable organic thin film deposition. In order to establish emulsion-based RIR-MAPLE as a preferred deposition technique for conjugated polymer or hybrid nanocomposite optoelectronic devices, studies have been conducted to demonstrate the value added by the approach in comparison to traditional solution-based deposition techniques, and this workmore » will be reviewed. The control of hybrid nanocomposite thin film deposition, and the photoconductivity in such materials deposited using emulsion-based RIR-MAPLE, will also be reviewed. The overall result of these studies is the demonstration of emulsion-based RIR-MAPLE as a viable option for the fabrication of conjugated polymer and hybrid nanocomposite optoelectronic devices that could yield improved device performance.« less

  19. Influence of cationic lipid concentration on properties of lipid-polymer hybrid nanospheres for gene delivery.

    PubMed

    Bose, Rajendran J C; Arai, Yoshie; Ahn, Jong Chan; Park, Hansoo; Lee, Soo-Hong

    2015-01-01

    Nanoparticles have been widely used for nonviral gene delivery. Recently, cationic hybrid nanoparticles consisting of two different materials were suggested as a promising delivery vehicle. In this study, nanospheres with a poly(D,L-lactic-co-glycolic acid) (PLGA) core and cationic lipid shell were prepared, and the effect of cationic lipid concentrations on the properties of lipid polymer hybrid nanocarriers investigated. Lipid-polymer hybrid nanospheres (LPHNSs) were fabricated by the emulsion-solvent evaporation method using different concentrations of cationic lipids and characterized for size, surface charge, stability, plasmid DNA-binding capacity, cytotoxicity, and transfection efficiency. All LPHNSs had narrow size distribution with positive surface charges (ζ-potential 52-60 mV), and showed excellent plasmid DNA-binding capacity. In vitro cytotoxicity measurements with HEK293T, HeLa, HaCaT, and HepG2 cells also showed that LPHNSs exhibited less cytotoxicity than conventional transfection agents, such as Lipofectamine and polyethyleneimine-PLGA. As cationic lipid concentrations increased, the particle size of LPHNSs decreased while their ζ-potential increased. In addition, the in vitro transfection efficiency of LPHNSs increased as lipid concentration increased.

  20. Studies on Effective Elastic Properties of CNT/Nano-Clay Reinforced Polymer Hybrid Composite

    NASA Astrophysics Data System (ADS)

    Thakur, Arvind Kumar; Kumar, Puneet; Srinivas, J.

    2016-02-01

    This paper presents a computational approach to predict elastic propertiesof hybrid nanocomposite material prepared by adding nano-clayplatelets to conventional CNT-reinforced epoxy system. In comparison to polymers alone/single-fiber reinforced polymers, if an additional fiber is added to the composite structure, it was found a drastic improvement in resultant properties. In this regard, effective elastic moduli of a hybrid nano composite are determined by using finite element (FE) model with square representative volume element (RVE). Continuum mechanics based homogenization of the nano-filler reinforced composite is considered for evaluating the volumetric average of the stresses and the strains under different periodic boundary conditions.A three phase Halpin-Tsai approach is selected to obtain the analytical result based on micromechanical modeling. The effect of the volume fractions of CNTs and nano-clay platelets on the mechanical behavior is studied. Two different RVEs of nano-clay platelets were used to investigate the influence of nano-filler geometry on composite properties. The combination of high aspect ratio of CNTs and larger surface area of clay platelets contribute to the stiffening effect of the hybrid samples. Results of analysis are validated with Halpin-Tsai empirical formulae.

  1. Influence of cationic lipid concentration on properties of lipid–polymer hybrid nanospheres for gene delivery

    PubMed Central

    Bose, Rajendran JC; Arai, Yoshie; Ahn, Jong Chan; Park, Hansoo; Lee, Soo-Hong

    2015-01-01

    Nanoparticles have been widely used for nonviral gene delivery. Recently, cationic hybrid nanoparticles consisting of two different materials were suggested as a promising delivery vehicle. In this study, nanospheres with a poly(d,l-lactic-co-glycolic acid) (PLGA) core and cationic lipid shell were prepared, and the effect of cationic lipid concentrations on the properties of lipid polymer hybrid nanocarriers investigated. Lipid–polymer hybrid nanospheres (LPHNSs) were fabricated by the emulsion-solvent evaporation method using different concentrations of cationic lipids and characterized for size, surface charge, stability, plasmid DNA-binding capacity, cytotoxicity, and transfection efficiency. All LPHNSs had narrow size distribution with positive surface charges (ζ-potential 52–60 mV), and showed excellent plasmid DNA-binding capacity. In vitro cytotoxicity measurements with HEK293T, HeLa, HaCaT, and HepG2 cells also showed that LPHNSs exhibited less cytotoxicity than conventional transfection agents, such as Lipofectamine and polyethyleneimine–PLGA. As cationic lipid concentrations increased, the particle size of LPHNSs decreased while their ζ-potential increased. In addition, the in vitro transfection efficiency of LPHNSs increased as lipid concentration increased. PMID:26379434

  2. Phospholipid—polymer amphiphile hybrid assemblies and their interaction with macrophages

    PubMed Central

    Panneerselvam, Karthiga; Lynge, Martin E.; Riber, Camilla Frich; Mena-Hernando, Sofia; Smith, Anton A. A.; Goldie, Kenneth N.; Zelikin, Alexander N.; Städler, Brigitte

    2015-01-01

    Recently, the combination of lipids and block copolymers has become an alternative to liposomes and polymersomes as nano-sized drug carriers. We synthesize novel block copolymers consisting of poly(cholesteryl acrylate) as the hydrophobic core and poly(N-isopropylacrylamide) (PNIPAAm) as the hydrophilic extensions. Their successful phospholipid-assisted assembly into vesicles is demonstrated using the evaporation-hydration method. The preserved thermo-responsive property of the lipid-polymer hybrids is shown by a temperature dependent adsorption behaviour of the vesicles to poly(l lysine) coated surfaces. As expected, the vesicle adsorption is found to be higher at elevated temperatures. The cellular uptake efficiency of hybrids is assessed using macrophages with applied shear stress. The amount of adhering macrophages is affected by the time and level of applied shear stress. Further, it is found that shorter PNIPAAm extensions lead to higher uptake of the assemblies by the macrophages with applied shear stress. No inherent cytotoxicity is observed at the tested conditions. Taken together, this first example of responsive lipid-polymer hybrids, and their positive biological evaluation makes them promising nano-sized drug carrier candidates. PMID:26339330

  3. Zwitterionic modification of polyurethane membranes for enhancing the anti-fouling property.

    PubMed

    Liu, Peiming; Huang, Tao; Liu, Pingsheng; Shi, Shufeng; Chen, Qiang; Li, Li; Shen, Jian

    2016-10-15

    Polyurethane (PU) is a biopolymer that has been commonly used for biomedical applications. However, the biofouling phenomenon on the hydrophobic PU surface is one of the crucial issues that embarrassing its applications. Here, we report a facile & efficient approach to improve the anti-biofouling ability of the PU substrates. Active residues were firstly generated on the PU surface by using the low temperature air-plasma treatment, promoting the immobilization of the atom transfer radical polymerization (ATRP) initiators on the surface. Then, three types of zwitterionic polymer brushes, as well as PEG brushes, have been fabricated on the PU substrates through surface-initiated ATRP (SI-ATRP). Robust surface characterizations that capable of revealing the surface chemistry (including X-ray photoelectron spectroscopy (XPS) and wettability tests), and antifouling evaluations of the PU substrates (protein adsorption, platelet adhesion, and cell adhesion measurements) were performed. Results showed that three types of zwitterionic brushes have been successful grafted on the PU surface, respectively. And the three types of zwitterionic brushes, in general, significantly inhibited the protein adsorption, the platelet adhesion, and the cell adhesion on the PU surface, endowing a significantly improved anti-fouling ability to the PU substrates. Furthermore, we found that this facial zwitterionic surface modification did not compromise the mechanical property of the PU substrates. This strategy could be easily exploited to PU-based biomaterials to improve their performance in many applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Interactions of a hydrophobically modified polycation with zwitterionic lipid membranes.

    PubMed

    Kepczynski, Mariusz; Jamróz, Dorota; Wytrwal, Magdalena; Bednar, Jan; Rzad, Ewa; Nowakowska, Maria

    2012-01-10

    The interactions between synthetic polycations and phospholipid bilayers play an important role in some biophysical applications such as gene delivery or antibacterial usage. Despite extensive investigation into the nature of these interactions, their physical and molecular bases remain poorly understood. In this Article, we present the results of our studies on the impact of a hydrophobically modified strong polycation on the properties of a zwitterionic bilayer used as a model of the mammalian cellular membrane. The study was carried out using a set of complementary experimental methods and molecular dynamic (MD) simulations. A new polycation, poly(allyl-N,N-dimethyl-N-hexylammonium chloride) (polymer 3), was synthesized, and its interactions with liposomes composed of 2-oleoyl-1-palmitoyl-sn-glycero-3-phosphocholine (POPC) were examined using dynamic light scattering (DLS), zeta potential measurements, and cryo-transmission electron microscopy (cryo-TEM). Our results have shown that polymer 3 can efficiently associate with and insert into the POPC membrane. However, it does not change its lamellar structure, as was demonstrated by cryo-TEM. The influence of polymer 3 on the membrane functionality was studied by leakage experiments applying a fluorescence dye (calcein) encapsulated in the phospholipid vesicles. The MD simulations of model systems reveal that polymer 3 promotes formation of hydrophilic pores in the membrane, thus increasing considerably its permeability.

  5. Functional Hybrid Biomaterials based on Peptide-Polymer Conjugates for Nanomedicine

    NASA Astrophysics Data System (ADS)

    Shu, Jessica Yo

    The focus of this dissertation is the design, synthesis and characterization of hybrid functional biomaterials based on peptide-polymer conjugates for nanomedicine. Generating synthetic materials with properties comparable to or superior than those found in nature has been a "holy grail" for the materials community. Man-made materials are still rather simplistic when compared to the chemical and structural complexity of a cell. Peptide-polymer conjugates have the potential to combine the advantages of the biological and synthetic worlds---that is they can combine the precise chemical structure and diverse functionality of biomolecules with the stability and processibility of synthetic polymers. As a new family of soft matter, they may lead to materials with novel properties that have yet to be realized with either of the components alone. In order for peptide-polymer conjugates to reach their full potential as useful materials, the structure and function of the peptide should be maintained upon polymer conjugation. The success in achieving desirable, functional assemblies relies on fundamentally understanding the interactions between each building block and delicately balancing and manipulating these interactions to achieve targeted assemblies without interfering with designed structures and functionalities. Such fundamental studies of peptide-polymer interactions were investigated as the nature of the polymer (hydrophilic vs. hydrophobic) and the site of its conjugation (end-conjugation vs. side-conjugation) were varied. The fundamental knowledge gained was then applied to the design of amphiphiles that self-assemble to form stable functional micelles. The micelles exhibited exceptional monodispersity and long-term stability, which is atypical of self-assembled systems. Thus such micelles based on amphiphilic peptide-polymer conjugates may meet many current demands in nanomedicine, in particular for drug delivery of hydrophobic anti-cancer therapeutics. Lastly

  6. Electrochromic conductive polymer fuses for hybrid organic/inorganic semiconductor memories

    NASA Astrophysics Data System (ADS)

    Möller, Sven; Forrest, Stephen R.; Perlov, Craig; Jackson, Warren; Taussig, Carl

    2003-12-01

    We demonstrate a nonvolatile, write-once-read-many-times (WORM) memory device employing a hybrid organic/inorganic semiconductor architecture consisting of thin film p-i-n silicon diode on a stainless steel substrate integrated in series with a conductive polymer fuse. The nonlinearity of the silicon diodes enables a passive matrix memory architecture, while the conductive polyethylenedioxythiophene:polystyrene sulfonic acid polymer serves as a reliable switch with fuse-like behavior for data storage. The polymer can be switched at ˜2 μs, resulting in a permanent decrease of conductivity of the memory pixel by up to a factor of 103. The switching mechanism is primarily due to a current and thermally dependent redox reaction in the polymer, limited by the double injection of both holes and electrons. The switched device performance does not degrade after many thousand read cycles in ambient at room temperature. Our results suggest that low cost, organic/inorganic WORM memories are feasible for light weight, high density, robust, and fast archival storage applications.

  7. Hybrid Silver Mesh Electrode for ITO-Free Flexible Polymer Solar Cells with Good Mechanical Stability.

    PubMed

    Kim, Wanjung; Kim, Soyeon; Kang, Iljoong; Jung, Myung Sun; Kim, Sung June; Kim, Jung Kyu; Cho, Sung Min; Kim, Jung-Hyun; Park, Jong Hyeok

    2016-05-10

    Herein, we report a tailored Ag mesh electrode coated with poly(3,4-ethylenedioxythiophene) (PEDOT) polymer on a flexible polyethylene terephthalate (PET) substrate. The introduction of this highly conductive polymer solves the existing problems of Ag mesh-type transparent conductive electrodes, such as high pitch, roughness, current inhomogeneity, and adhesion problems between the Ag mesh grid and PEDOT polymer or PET substrate, to result in excellent electron spreading from the discrete Ag mesh onto the entire surface without sacrificing sheet conductivity and optical transparency. Based on this hybrid anode, we demonstrate highly efficient flexible polymer solar cells (PSCs) with a high fill factor of 67.11 %, which results in a power conversion efficiency (PCE) of 6.9 % based on a poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b'] dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl) carbonyl]thieno[3,4-b]thiophenediyl}):[6,6]-phenyl-C71 -butyric acid methyl ester bulk heterojunction device. Furthermore, the PSC device with the Ag mesh electrode also exhibits a good mechanical bending stability, as indicated by a 70 % retention of the initial PCE after 500 bending cycles compared with the PSC device with a PET/indium tin oxide electrode, which retained 0 % of the initial PCE after 300 bending cycles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A Hybrid Tandem Solar Cell Combining a Dye-Sensitized and a Polymer Solar Cell.

    PubMed

    Shao, Zhipeng; Chen, Shuanghong; Zhang, Xuhui; Zhu, Liangzheng; Ye, Jiajiu; Dai, Songyuan

    2016-06-01

    A hybrid tandem solar cell was assambled by connecting a dye sensitized solar cell and a polymer solar cell in series. A N719 sensitized TiO2 was used as photocathode in dye-sensitized subcell, and a MEH-PPV/PCBM composite was used as active layer in the polymer subcell. The polymer subcell fabricated on the counter electrode of the dye sensitized solar cell. A solution processed TiO(x) layer was used as electron collection layer of the polymer sub cell and the charge recombination layer. The effects of the TiO(x) interlayer and the spectral overlap between the two sub cells have been studied and optimized. The results shows that a proper thickness of the TiO(x) layer is needed for tandem solar cells. Thick TiO(x) will enhance the series resistance, but too thin TiO(x), layer will damage the hole blocking effect and its hydrophilic. The resulting optimized tandem solar cells exhibited a power conversion efficiency of 1.28% with a V(oc) of 0.95 V under simulated 100 mW cm(-2) AM 1.5 illumination.

  9. High renewable content sandwich structures based on flax-basalt hybrids and biobased epoxy polymers

    NASA Astrophysics Data System (ADS)

    Colomina, S.; Boronat, T.; Fenollar, O.; Sánchez-Nacher, L.; Balart, R.

    2014-05-01

    In the last years, a growing interest in the development of high environmental efficiency materials has been detected and this situation is more accentuated in the field of polymers and polymer composites. In this work, green composite sandwich structures with high renewable content have been developed with core cork materials. The base resin for composites was a biobased epoxy resin derived from epoxidized vegetable oils. Hybrid basalt-flax fabrics have been used as reinforcements for composites and the influence of the stacking sequence has been evaluated in order to optimize the appropriate laminate structure for the sandwich bases. Core cork materials with different thickness have been used to evaluate performance of sandwich structures thus leading to high renewable content composite sandwich structures. Results show that position of basalt fabrics plays a key role in flexural fracture of sandwich structures due to differences in stiffness between flax and basalt fibers.

  10. Charge Separation and Recombination at Polymer-Fullerene Heterojunctions: Delocalization and Hybridization Effects.

    PubMed

    D'Avino, Gabriele; Muccioli, Luca; Olivier, Yoann; Beljonne, David

    2016-02-04

    We address charge separation and recombination in polymer/fullerene solar cells with a multiscale modeling built from accurate atomistic inputs and accounting for disorder, interface electrostatics and genuine quantum effects on equal footings. Our results show that bound localized charge transfer states at the interface coexist with a large majority of thermally accessible delocalized space-separated states that can be also reached by direct photoexcitation, thanks to their strong hybridization with singlet polymer excitons. These findings reconcile the recent experimental reports of ultrafast exciton separation ("hot" process) with the evidence that high quantum yields do not require excess electronic or vibrational energy ("cold" process), and show that delocalization, by shifting the density of charge transfer states toward larger effective electron-hole radii, may reduce energy losses through charge recombination.

  11. Hybrid capacitor with activated carbon electrode, Ni(OH) 2 electrode and polymer hydrogel electrolyte

    NASA Astrophysics Data System (ADS)

    Nohara, Shinji; Asahina, Toshihide; Wada, Hajime; Furukawa, Naoji; Inoue, Hiroshi; Sugoh, Nozomu; Iwasaki, Hideharu; Iwakura, Chiaki

    A new hybrid capacitor (HC) cell was assembled using an activated carbon (AC) negative electrode, an Ni(OH) 2 positive electrode and a polymer hydrogel electrolyte prepared from crosslinked potassium poly(acrylate) (PAAK) and KOH aqueous solution. The HC cell was characterized compared with an electric double layer capacitor (EDLC) using two AC electrodes and the polymer hydrogel electrolyte. It was found that the HC cell successfully worked in the larger voltage range and exhibited ca. 2.4 times higher capacitance than the EDLC cell. High-rate dischargeability of the HC cell was also superior to that of the EDLC cell. These improved characteristics strongly suggest that the HC cell can be a promising system of capacitors with high energy and power densities.

  12. Luminescence from Zinc Oxide Nanostructures and Polymers and their Hybrid Devices

    PubMed Central

    Willander, Magnus; Nur, Omer; Sadaf, Jamil Rana; Qadir, Muhammad Israr; Zaman, Saima; Zainelabdin, Ahmed; Bano, Nargis; Hussain, Ijaz

    2010-01-01

    Zinc oxide (ZnO) is a strong luminescent material, as are several polymers. These two materials have distinct drawbacks and advantages, and they can be combined to form nanostructures with many important applications, e.g., large-area white lighting. This paper discusses the origin of visible emission centers in ZnO nanorods grown with different approaches. White light emitting diodes (LEDs) were fabricated by combining n-ZnO nanorods and hollow nanotubes with different p-type materials to form heterojunctions. The p-type component of the hybrids includes p-SiC, p-GaN, and polymers. We conclude by analyzing the electroluminescence of the different light emitting diodes we fabricated. The observed optical, electrical, and electro-optical characteristics of these LEDs are discussed with an emphasis on the deep level centers that cause the emission.

  13. Lipid-polymer hybrid nanoparticle-mediated therapeutics delivery: advances and challenges.

    PubMed

    Bose, Rajendran J C; Ravikumar, Rramaswamy; Karuppagounder, Vengadeshprabu; Bennet, Devasier; Rangasamy, Sabarinathan; Thandavarayan, Rajarajan A

    2017-08-01

    With rapid advances in nanomedicine, lipid-polymer hybrid nanoparticles (LPHNPs) have emerged as promising nanocarriers for several biomedical applications, including therapeutics delivery and biomedical imaging. Significant research has been dedicated to biomimetic or targeting functionalization, as well as controlled and image-guided drug-release capabilities. Despite this research, the clinical translation of LPHNP-mediated therapeutics delivery has progressed incrementally. In this review, we discuss the recent advances in and challenges to the development and application of LPHNPs, present examples to demonstrate the advantages of LPHNPs in therapeutics delivery and imaging applications, and discuss the translational obstacles to LPHNP technology. Copyright © 2017. Published by Elsevier Ltd.

  14. Probing photocurrent generation mechanisms in hybrid IR-senstive quantum dot/conjugated polymer solar cells

    NASA Astrophysics Data System (ADS)

    Strein, Elisabeth

    The work in this dissertation aims to improve the ability of hybrid polymer/quantum dot solar cells to harvest and utilize sunlight by contributing mechanistic insights into photocurrent generation. The mechanisms of charge transfer and energy transfer are explored spectroscopically in chapter three and both are found to contribute to photocurrent. Chapter four looks at excitation energy in excess of the bandgap and finds a rise in polaron yield which correlates with excess photon energy. Chapter two discusses details of the experimental techniques used to access the data discussed in the chapters that follow.

  15. A hybrid electro-optic polymer and TiO2 double-slot waveguide modulator

    PubMed Central

    Qiu, Feng; Spring, Andrew M.; Maeda, Daisuke; Ozawa, Masa-aki; Odoi, Keisuke; Otomo, Akira; Aoki, Isao; Yokoyama, Shiyoshi

    2015-01-01

    An electro-optic (EO) modulator using a TiO2 slot hybrid waveguide has been designed and fabricated. Optical mode calculations revealed that the mode was primarily confined within the slots when using a double-slot configuration, thus achieving a high EO activity experimentally. The TiO2 slots also acted as an important barrier to induce an enhanced DC field during the poling of the EO polymer and the driving of the EO modulator. The hybrid phase modulator exhibited a driving voltage (Vπ) of 1.6 V at 1550 nm, which can be further reduced to 0.8 V in a 1 cm-long push-pull Mach–Zehnder interferometer (MZI) structure. The modulator demonstrated a low propagation loss of 5 dB/cm and a relatively high end-fire coupling efficiency. PMID:25708425

  16. Infiltration and Selective Interactions at the Interface in Polymer-Oxide Hybrid Solar Cells

    NASA Astrophysics Data System (ADS)

    Ferragut, R.; Aghion, S.; Moia, F.; Binda, M.; Canesi, E. V.; Lanzani, G.; Petrozza, A.

    2013-06-01

    Positron annihilation spectroscopy was used to characterize polymer-based hybrid solar cells formed by poly(3-hexylthiophene) (P3HT) finely infiltrated in a porous TiO2 skeleton. A step-change improvement in the device performance is enabled by engineering the hybrid interface by the insertion of a proper molecular interlayer namely 4-mercaptopyridine (4-MP). In order to obtain depth-resolved data, positrons were implanted in the sample using a variable-energy positron beam. The characteristics of the partially filled nanoporous structures were evaluated in terms of the depth profile of the positronium yield and the S-parameter. A quantitative evaluation of the pore filling in the deep region is given from the analysis of Coincidence Doppler Broadening taken at fixed implantation energy. We note a remarkable difference in terms of the positronium yield when the 4-MP interlayer is introduced, which means a better covering of P3HT on the porous surface.

  17. Development of zwitterionic chromophores for electro-optic applications

    NASA Astrophysics Data System (ADS)

    Xiong, Ying

    In order to unlock the full potential of the zwitterionic NLO chromophores for electro-optic (EO) applications, a new series of PeQDM chromophores with large first hyperpolarizabilities (beta0 ˜ 600 x 10-30 esu) have been designed and synthesized. A large EO coefficient (r33) of 110 pm/V at 1550 nm has been realized with a 5 wt% (corresponding to 3.8 wt% core content) chromophore doped polymer. The EO study of guest-host polymers reveals that dipolar dye aggregation in a less polar medium is responsible for a low chromophore loading and low EO activity. Modification of NLO chromophore by attaching large dendrons can effectively increase the chromophore loading in a host and improve the poling efficiency. Crosslinkable NLO polymers have also been prepared to improve the temporal stability of the poled noncentrosymmetric order. The following are some important highlights from this thesis work. (1) A series of thermally stable zwitterionic chromophores (PeQDM) with large first hyperpolarizabilities (beta up to -1797 x 10-30 esu) are synthesized in good yields (˜ 50%). The charge-separated ground state is evident by a negative solvatochromism. X-ray crystallographic data further confirms the zwitterionic nature and demonstrates a face-to-face anti-parallel H-aggregation of two monomers due to strong electrostatic interactions between the dipoles. (2) PeQDM chromophores are also NIR fluorescent (lambdaPL ˜ 840-870 nm in solution) and labile to acid, making them potential candidates for NIR pH sensor applications. (3) The hydroxyl-containing PeQDM chromophores are modified with ES-dendron, which exhibit good solubility in solvents and polymers. Self-forming films can be prepared by direct casting or spin-coating of two dendrons modified chromophores (ES-PeQDM-2 and ES-PeQDM-3), in which the chromophore core contents reach 14.9 and 16.9 wt%, respectively. Compared to ES-PeQDM-2 with two dendrons only at the donor part (r33 = 0 pm/V), ES-PeQDM-3 with the bulky ES

  18. Roles of interfacial modifiers in hybrid solar cells: inorganic/polymer bilayer vs inorganic/polymer:fullerene bulk heterojunction.

    PubMed

    Eom, Seung Hun; Baek, Myung-Jin; Park, Hanok; Yan, Liang; Liu, Shubin; You, Wei; Lee, Soo-Hyoung

    2014-01-22

    Hybrid solar cells (HSCs) incorporating both organic and inorganic materials typically have significant interfacial issues which can significantly limit the device efficiency by allowing charge recombination, macroscopic phase separation, and nonideal contact. All these issues can be mitigated by applying carefully designed interfacial modifiers (IMs). In an attempt to further understand the function of these IMs, we investigated two IMs in two different HSCs structures: an inverted bilayer HSC of ZnO:poly(3-hexylthiophene) (P3HT) and an inverted bulk heterojunction (BHJ) solar cell of ZnO/P3HT:[6,6]-phenyl C61-butyric acid methyl ester (PCBM). In the former device configuration, ZnO serves as the n-type semiconductor, while in the latter device configuration, it functions as an electron transport layer (ETL)/hole blocking layer (HBL). In the ZnO:P3HT bilayer device, after the interfacial modification, a power conversion efficiency (PCE) of 0.42% with improved Voc and FF and a significantly increased Jsc was obtained. In the ZnO/P3HT:PCBM based BHJ device, including IMs also improved the PCE to 4.69% with an increase in Voc and FF. Our work clearly demonstrates that IMs help to reduce both the charge recombination and leakage current by minimizing the number of defect sites and traps and to increase the compatibility of hydrophilic ZnO with the organic layers. Furthermore, the major role of IMs depends on the function of ZnO in different device configurations, either as n-type semiconductor in bilayer devices or as ETL/HBL in BHJ devices. We conclude by offering insights for designing ideal IMs in future efforts, in order to achieve high-efficiency in both ZnO:polymer bilayer structure and ZnO/polymer:PCBM BHJ devices.

  19. Electron-transporting small molecule/ o-xylene hybrid additives to boost the performance of simplified inverted polymer solar cells

    NASA Astrophysics Data System (ADS)

    Qin, Dashan; Cao, Huan; Zhang, Jidong

    2017-05-01

    Electron-transporting small molecule bathophenanthroline (Bphen) together with o-xylene has been used as hybrid additives to improve the performance of simplified inverted polymer solar cells employing ITO alone as cathode and photoactive layer based on polymer [[2,6'-4,8-di(5-ethylhexylthienyl)benzo[1,2-b;3,3-b] dithiophene] [3-fluoro-2[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  20. Ordered mesoporous polymer-silica hybrid nanoparticles as vehicles for the intracellular controlled release of macromolecules.

    PubMed

    Kim, Tae-Wan; Slowing, Igor I; Chung, Po-Wen; Lin, Victor Shang-Yi

    2011-01-25

    A two-dimensional hexagonal ordered mesoporous polymer-silica hybrid nanoparticle (PSN) material was synthesized by polymerization of acrylate monomers on the surface of SBA-15 mesoporous silica nanoparticles. The structure of the PSN material was analyzed using a series of different techniques, including transmission electron microscopy, powder X-ray diffraction, and N(2) sorption analysis. These structurally ordered mesoporous polymer-silica hybrid nanoparticles were used for the controlled release of membrane-impermeable macromolecules inside eukaryotic cells. The cellular uptake efficiency and biocompatibility of PSN with human cervical cancer cells (HeLa) were investigated. Our results show that the inhibitory concentration (IC(50)) of PSN is very high (>100 μg/mL per million cells), while the median effective concentration for the uptake (EC(50)) of PSN is low (EC(50) = 4.4 μg/mL), indicating that PSNs are fairly biocompatible and easily up-taken in vitro. A membrane-impermeable macromolecule, 40 kDa FITC-Dextran, was loaded into the mesopores of PSNs at low pH. We demonstrated that the PSN material could indeed serve as a transmembrane carrier for the controlled release of FITC-Dextran at the pH level inside live HeLa cells. We believe that further developments of this PSN material will lead to a new generation of nanodevices for intracellular controlled delivery applications.

  1. Nanowire-Intensified Metal-Enhanced Fluorescence in Hybrid Polymer-Plasmonic Electrospun Filaments.

    PubMed

    Camposeo, Andrea; Jurga, Radoslaw; Moffa, Maria; Portone, Alberto; Cardarelli, Francesco; Della Sala, Fabio; Ciracì, Cristian; Pisignano, Dario

    2018-05-01

    Hybrid polymer-plasmonic nanostructures might combine high enhancement of localized fields from metal nanoparticles with light confinement and long-range transport in subwavelength dielectric structures. Here, the complex behavior of fluorophores coupling to Au nanoparticles within polymer nanowires, which features localized metal-enhanced fluorescence (MEF) with unique characteristics compared to conventional structures, is reported. The intensification effect when the particle is placed in the organic filaments is remarkably higher with respect to thin films of comparable thickness, thus highlighting a specific, nanowire-related enhancement of MEF effects. A dependence on the confinement volume in the dielectric nanowire is also indicated, with MEF significantly increasing upon reduction of the wire diameter. These findings are rationalized by finite element simulations, predicting a position-dependent enhancement of the quantum yield of fluorophores embedded in the fibers. Calculation of the ensemble-averaged fluorescence enhancement unveils the possibility of strongly enhancing the overall emission intensity for structures with size twice the diameter of the embedded metal particles. These new, hybrid fluorescent systems with localized enhanced emission, and the general nanowire-enhanced MEF effects associated to them, are highly relevant for developing nanoscale light-emitting devices with high efficiency and intercoupled through nanofiber networks, highly sensitive optical sensors, and novel laser architectures. © 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA Weinheim.

  2. Calculation of photonic bandgap for 2D hexagonal and square structure base on hybrid polymer material

    NASA Astrophysics Data System (ADS)

    Hidayat, S.; Riveli, N.

    2018-05-01

    We have calculated 2D photonic crystal band gap using plane-wave expansion method. The studied model of structures is hexagonal lattice and square lattice of rod cylinder in air. We have simulated the dispersion relation of it structure using hybrid polymer as rod material. The parameter structures are nrod = 1.5, nhole = 1, and rrod = 0.25a, where a is lattice constant. We found the distributed feedback occurs at the edge of upper band or frequency at 0.66 (a/λ). In our experimental work, we have successfully fabricated the 2D photonic crystal from hybrid polymer incorporated with organic dye laser. The lasing characteristics ware investigated using strip-line excitation light of SHG Nd-YAG laser (λ=532 nm). The lasing wavelengths for hexagonal structure are observed at 606 nm and 621 nm for photonic crystal period of 400 nm and 410 nm, respectively. λ=532 nm). Whereas the square structure, the lasing wavelengths are observed at (588 nm ± 2) and (606 nm ± 2 nm) for grating period of 391 nm and 405 nm.

  3. Design and construction of a VHGT-attached WDM-type triplex transceiver module using polymer PLC hybrid integration technology

    NASA Astrophysics Data System (ADS)

    Jerábek, Vitezslav; Hüttel, Ivan; Prajzler, Václav; Busek, K.; Seliger, P.

    2008-11-01

    We report about design and construction of the bidirectional transceiver TRx module for subscriber part of the passive optical network PON for a fiber to the home FTTH topology. The TRx module consists of a epoxy novolak resin polymer planar lightwave circuit (PLC) hybrid integration technology with volume holographic grating triplex filter VHGT, surface-illuminated photodetectors and spot-size converted Fabry-Pérot laser diode in SMD package. The hybrid PLC has composed from a two parts-polymer optical waveguide including VHGT filter section and a optoelectronic microwave section. The both parts are placed on the composite substrate.

  4. Exploring the segregating and mineralization-inducing capacities of cationic hydrophilic polymers for preparation of robust, multifunctional mesoporous hybrid microcapsules.

    PubMed

    Shi, Jiafu; Zhang, Wenyan; Wang, Xiaoli; Jiang, Zhongyi; Zhang, Shaohua; Zhang, Xiaoman; Zhang, Chunhong; Song, Xiaokai; Ai, Qinghong

    2013-06-12

    A facile approach to preparing mesoporous hybrid microcapsules is developed by exploring the segregating and mineralization-inducing capacities of cationic hydrophilic polymer. The preparation process contains four steps: segregation of cationic hydrophilic polymer during template formation, cross-linking of the segregated polymer, biomimetic mineralization within cross-linked polymer network, and removal of template to simultaneously generate capsule lumen and mesopores on the capsule wall. Poly(allylamine hydrochloride) (PAH) is chosen as the model polymer, its hydrophilicity renders the segregating capacity and spontaneous enrichment in the near-surface region of CaCO3 microspheres; its biopolyamine-mimic structure renders the mineralization-inducing capacity to produce titania from the water-soluble titanium(IV) precursor. Meanwhile, CaCO3 microspheres serve the dual templating functions in the formation of hollow lumen and mesoporous wall. The thickness of capsule wall can be controlled by changing the polymer segregating and cross-linking conditions, while the pore size on the capsule wall can be tuned by changing the template synthesizing conditions. The robust hybrid microcapsules exhibit desirable efficiency in enzymatic catalysis, wastewater treatment and drug delivery. This approach may open facile, generic, and efficient pathway to designing and preparing a variety of hybrid microcapsules with high and tunable permeability, good stability and multiple functionalities for a broad range of applications.

  5. Improved antifouling performance of ultrafiltration membrane via preparing novel zwitterionic polyimide

    NASA Astrophysics Data System (ADS)

    Huang, Haitao; Yu, Jiayu; Guo, Hanxiang; Shen, Yibo; Yang, Fan; Wang, Han; Liu, Rong; Liu, Yang

    2018-01-01

    On the basis of the outstanding fouling resistance of zwitterionic polymers, an antifouling ultrafiltration membrane was fabricated through phase inversion induced by immersion precipitation method, directly using the novel zwitterionic polyimide (Z-PI), which was synthesized via a two-step procedure including polycondensation and quaternary amination reaction, as membrane material. The chemical structure and composition of the obtained polymer were confirmed by using FTIR, 1H NMR and XPS analysis, and its thermal stability was thoroughly characterized by TGA measurement, respectively. The introduction of zwitterionic groups into polyimide could effectively increase membrane pore size, porosity and wettability, and convert the membrane surface from hydrophobic to highly hydrophilic. As a result, Z-PI membrane displayed significantly improved water permeability compared with that of the reference polyimide (R-PI) membrane without having an obvious compromise in protein rejection. According to the static adsorption and dynamic cycle ultrafiltration experiments of bovine serum albumin (BSA) solution, Z-PI membrane exhibited better fouling resistant ability, especially irreversible fouling resistant ability, suggesting superior antifouling property and long-term performance stability. Moreover, Z-PI membrane had a water flux recovery ratio of 93.7% after three cycle of BSA solution filtration, whereas only about 68.5% was obtained for the control R-PI membrane. These findings demonstrated the advantages of Z-PI membrane material and aimed to provide a facile and scalable method for the large-scale preparation of low fouling ultrafiltration membranes for potential applications.

  6. Application of hybrid organic/inorganic polymers as coatings on metallic substrates

    NASA Astrophysics Data System (ADS)

    Augustinho, T. R.; Motz, G.; Ihlow, S.; Machado, R. A. F.

    2016-09-01

    Acrylic polymers, particularly poly (methyl methacrylate) (PMMA), have certain specific properties, such as good film formation, transparency, and good mechanical properties, which have been widely used in paints, coatings and adhesives. However, the limited chemical and physical stability of these pure polymers limits their applications when exposed to hostile conditions, as in ship hulls, for example. A suitable way to enhance PMMA properties is the addition of silicon polymers with very good protective characteristics. In this study, a PMMA and HTT 1800 (commercial silazane) copolymer were applied on metallic substrate and compared to pure PMMA and HTT 1800. All the materials were applied as coatings. They were applied on stainless steel via dip-coating to investigate the coating properties. Thermal cycling was employed to analyze coating durability at high temperatures (50 °C to 600 °C). Optical microscopy (OM) and scanning electron microscopy (SEM) were used to characterize the coated surfaces, and the adhesion of pure PMMA, pure HTT 1800 and PMMA/HTT 1800 coatings on metallic substrate was investigated by Cross-Cut-Test (ASTM D 3359). The sessile drop method was used to determine the contact angle. PMMA coatings presented complete degradation from 250 °C, while hybrid coatings of PMMA and HTT 1800 have good protection until 400 °C. The adherence of the coating on metallic substrate showed improvement in all synthesized materials when compared to pure PMMA, obtaining the best adherence possible. The contact angle test showed that the hydrophobicity of the hybrid coatings is higher than that of the pure coatings.

  7. Optical studies of photoactive states in mixed organic-inorganic hybrid perovskites stabilized in polymers

    NASA Astrophysics Data System (ADS)

    Kardynal, Beata; Xi, Lifei; Salim, Teddy; Borghardt, Sven; Stoica, Toma; Lam, Yeng Ming

    2015-03-01

    Mixed organic-inorganic hybrid perovskites MAX-PbY2(X,Y =I, Br,Cl) have been demonstrated as very attractive materials for absorbers of solar cells and active layers of light emitting diodes and optically driven lasers. The bandgap of the perovskites can be tuned by mixing halogen atoms in different ratios. In this presentation we study mixed MAX-PbY2(X,Y =I, Br, Cl) particles synthesized directly in protective polymer matrices as light emitters. Both, time integrated and time resolved photoluminescence have been used to study the materials. So synthesized MAX-PbX2 are very stable when measured at room temperature and in air with radiative recombination of photogenerated carriers as the main decay path. In contrast, MAX-PbY2 with mixed halogen atoms display luminescence from sub-bandgap states which saturate at higher excitation levels. The density of these states depends on the used polymer matrix and increases upon illumination. We further compare the MAX-PbY2 synthesized in polymers and as films and show that these states are inherent to the material rather than its microstructure. This works has been supported by EU NWs4LIGHT grant.

  8. Color tunable hybrid light-emitting diodes based on perovskite quantum dot/conjugated polymer

    NASA Astrophysics Data System (ADS)

    Germino, José C.; Yassitepe, Emre; Freitas, Jilian N.; Santiago, Glauco M.; Bonato, Luiz Gustavo; de Morais, Andréia; Atvars, Teresa D. Z.; Nogueira, Ana F.

    2017-08-01

    Inorganic organic metal halide perovskite materials have been investigated for several technological applications, such as photovoltaic cells, lasers, photodetectors and light emitting diodes (LEDs), either in the bulk form or as colloidal nanoparticles. Recently, all inorganic Cesium Lead Halide (CsPbX3, X=Cl,Br, I) perovskite quantum dots (PQDs) were reported with high photoluminescence quantum yield with narrow emission lines in the visible wavelengths. Here, green-emitting perovskite quantum dots (PQDs) prepared by a synthetic method based on a mixture of oleylamine and oleic acid as surfactants were applied in the electroluminescent layer of hybrid LEDs in combination with two different conjugated polymers: polyvinylcarbazole (PVK) or poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO). The performance of the diodes and the emission color tuning upon dispersion of different concentrations of the PQDs in the polymer matrix is discussed. The presented approach aims at the combination of the optical properties of the PQDs and their interaction with wide bandgap conjugated polymers, associated with the solution processing ability of these materials.

  9. Lipid-polymer hybrid nanoparticles as a new generation therapeutic delivery platform: a review.

    PubMed

    Hadinoto, Kunn; Sundaresan, Ajitha; Cheow, Wean Sin

    2013-11-01

    Lipid-polymer hybrid nanoparticles (LPNs) are core-shell nanoparticle structures comprising polymer cores and lipid/lipid-PEG shells, which exhibit complementary characteristics of both polymeric nanoparticles and liposomes, particularly in terms of their physical stability and biocompatibility. Significantly, the LPNs have recently been demonstrated to exhibit superior in vivo cellular delivery efficacy compared to that obtained from polymeric nanoparticles and liposomes. Since their inception, the LPNs have advanced significantly in terms of their preparation strategy and scope of applications. Their preparation strategy has undergone a shift from the conceptually simple two-step method, involving preformed polymeric nanoparticles and lipid vesicles, to the more principally complex, yet easier to perform, one-step method, relying on simultaneous self-assembly of the lipid and polymer, which has resulted in better products and higher production throughput. The scope of LPNs' applications has also been extended beyond single drug delivery for anticancer therapy, to include combinatorial and active targeted drug deliveries, and deliveries of genetic materials, vaccines, and diagnostic imaging agents. This review details the current state of development for the LPNs preparation and applications from which we identify future research works needed to bring the LPNs closer to its clinical realization. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Modeling and simulation of surfactant-polymer flooding using a new hybrid method

    NASA Astrophysics Data System (ADS)

    Daripa, Prabir; Dutta, Sourav

    2017-04-01

    Chemical enhanced oil recovery by surfactant-polymer (SP) flooding has been studied in two space dimensions. A new global pressure for incompressible, immiscible, multicomponent two-phase porous media flow has been derived in the context of SP flooding. This has been used to formulate a system of flow equations that incorporates the effect of capillary pressure and also the effect of polymer and surfactant on viscosity, interfacial tension and relative permeabilities of the two phases. The coupled system of equations for pressure, water saturation, polymer concentration and surfactant concentration has been solved using a new hybrid method in which the elliptic global pressure equation is solved using a discontinuous finite element method and the transport equations for water saturation and concentrations of the components are solved by a Modified Method Of Characteristics (MMOC) in the multicomponent setting. Numerical simulations have been performed to validate the method, both qualitatively and quantitatively, and to evaluate the relative performance of the various flooding schemes for several different heterogeneous reservoirs.

  11. How morphology influences relaxivity - comparative study of superparamagnetic iron oxide-polymer hybrid nanostructures.

    PubMed

    Ebert, Sandro; Bannwarth, Markus B; Musyanovych, Anna; Landfester, Katharina; Münnemann, Kerstin

    2015-01-01

    Superparamagnetic iron oxides (SPIOs) are widely used in MRI as T2 contrast agents, and interest is still growing. Here, the T2 relaxivity of three different SPIO-polymer hybrid morphologies, i.e. homogeneously distributed iron oxide within a polymer matrix, Janus-like nanoparticles and polymer nanocapsules containing iron oxides, is studied. Making use of calculations based on theory for agglomerated systems, the obtained T2 values could be predicted for all different morphologies, except for nanocapsules. Nanocapsules, in contrast to full spheres, allow for water exchange between encapsulated water and bulk water, and thus have two contributions to relaxivity. One originates from the capsules acting as a weakly magnetized cluster and the other stems from the individual SPIOs inside the capsule. Therefore, the relaxivities were also computed using an empirical equation found in the literature, which considers water exchange, resulting in a better T2 forecast for the nanocapsules. The presented study is the first example of a comparison between measured and calculated relaxivities of nanocapsules. Copyright © 2015 John Wiley & Sons, Ltd.

  12. Generic delivery of payload of nanoparticles intracellularly via hybrid polymer capsules for bioimaging applications.

    PubMed

    Sami, Haider; Maparu, Auhin K; Kumar, Ashok; Sivakumar, Sri

    2012-01-01

    Towards the goal of development of a generic nanomaterial delivery system and delivery of the 'as prepared' nanoparticles without 'further surface modification' in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb(3+) was observed after internalization of LaF(3):Tb(3+)(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification.

  13. Generic Delivery of Payload of Nanoparticles Intracellularly via Hybrid Polymer Capsules for Bioimaging Applications

    PubMed Central

    Sami, Haider; Maparu, Auhin K.; Kumar, Ashok; Sivakumar, Sri

    2012-01-01

    Towards the goal of development of a generic nanomaterial delivery system and delivery of the ‘as prepared’ nanoparticles without ‘further surface modification’ in a generic way, we have fabricated a hybrid polymer capsule as a delivery vehicle in which nanoparticles are loaded within their cavity. To this end, a generic approach to prepare nanomaterials-loaded polyelectrolyte multilayered (PEM) capsules has been reported, where polystyrene sulfonate (PSS)/polyallylamine hydrochloride (PAH) polymer capsules were employed as nano/microreactors to synthesize variety of nanomaterials (metal nanoparticles; lanthanide doped inorganic nanoparticles; gadolinium based nanoparticles, cadmium based nanoparticles; different shapes of nanoparticles; co-loading of two types of nanoparticles) in their hollow cavity. These nanoparticles-loaded capsules were employed to demonstrate generic delivery of payload of nanoparticles intracellularly (HeLa cells), without the need of individual nanoparticle surface modification. Validation of intracellular internalization of nanoparticles-loaded capsules by HeLa cells was ascertained by confocal laser scanning microscopy. The green emission from Tb3+ was observed after internalization of LaF3:Tb3+(5%) nanoparticles-loaded capsules by HeLa cells, which suggests that nanoparticles in hybrid capsules retain their functionality within the cells. In vitro cytotoxicity studies of these nanoparticles-loaded capsules showed less/no cytotoxicity in comparison to blank capsules or untreated cells, thus offering a way of evading direct contact of nanoparticles with cells because of the presence of biocompatible polymeric shell of capsules. The proposed hybrid delivery system can be potentially developed to avoid a series of biological barriers and deliver multiple cargoes (both simultaneous and individual delivery) without the need of individual cargo design/modification. PMID:22649489

  14. Magnetic field activated lipid-polymer hybrid nanoparticles for stimuli-responsive drug release.

    PubMed

    Kong, Seong Deok; Sartor, Marta; Hu, Che-Ming Jack; Zhang, Weizhou; Zhang, Liangfang; Jin, Sungho

    2013-03-01

    Stimuli-responsive nanoparticles (SRNPs) offer the potential of enhancing the therapeutic efficacy and minimizing the side-effects of chemotherapeutics by controllably releasing the encapsulated drug at the target site. Currently controlled drug release through external activation remains a major challenge during the delivery of therapeutic agents. Here we report a lipid-polymer hybrid nanoparticle system containing magnetic beads for stimuli-responsive drug release using a remote radio frequency (RF) magnetic field. These hybrid nanoparticles show long-term stability in terms of particle size and polydispersity index in phosphate-buffered saline (PBS). Controllable loading of camptothecin (CPT) and Fe(3)O(4) in the hybrid nanoparticles was demonstrated. RF-controlled drug release from these nanoparticles was observed. In addition, cellular uptake of the SRNPs into MT2 mouse breast cancer cells was examined. Using CPT as a model anticancer drug the nanoparticles showed a significant reduction in MT2 mouse breast cancer cell growth in vitro in the presence of a remote RF field. The ease of preparation, stability, and controllable drug release are the strengths of the platform and provide the opportunity to improve cancer chemotherapy. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Multiplexed instrument-free meningitis diagnosis on a polymer/paper hybrid microfluidic biochip.

    PubMed

    Dou, Maowei; Sanjay, Sharma T; Dominguez, Delfina C; Liu, Peng; Xu, Feng; Li, XiuJun

    2017-01-15

    Neisseria meningitidis (N. meningitidis), Streptococcus pneumoniae (S. pneumoniae), and Haemophilus influenzae type b (Hib) are three most common pathogens accounting for most bacterial meningitis, a serious global infectious disease with high fatality, especially in developing nations. Because the treatment and antibiotics differ among each type, the identification of the exact bacteria causing the disease is vital. Herein, we report a polymer/paper hybrid microfluidic biochip integrated with loop-mediated isothermal amplification (LAMP) for multiplexed instrument-free diagnosis of these three major types of bacterial meningitis, with high sensitivity and specificity. Results can be visually observed by the naked eye or imaged by a smartphone camera under a portable UV light source. Without using any specialized laboratory instrument, the limits of detection of a few DNA copies per LAMP zone for N. meningitidis, S. pneumoniae and Hib were achieved within 1h. In addition, these three types of microorganisms spiked in artificial cerebrospinal fluid (ACSF) were directly detected simultaneously, avoiding cumbersome sample preparation procedures in conventional methods. Compared with the paper-free non-hybrid microfluidic biochip over a period of three months, the hybrid microfluidic biochip was found to have a much longer shelf life. Hence, this rapid, instrument-free and highly sensitive microfluidic approach has great potential for point-of-care (POC) diagnosis of multiple infectious diseases simultaneously, especially in resource-limited settings. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A Flexible and Thin Graphene/Silver Nanowires/Polymer Hybrid Transparent Electrode for Optoelectronic Devices.

    PubMed

    Dong, Hua; Wu, Zhaoxin; Jiang, Yaqiu; Liu, Weihua; Li, Xin; Jiao, Bo; Abbas, Waseem; Hou, Xun

    2016-11-16

    A typical thin and fully flexible hybrid electrode was developed by integrating the encapsulation of silver nanowires (AgNWs) network between a monolayer graphene and polymer film as a sandwich structure. Compared with the reported flexible electrodes based on PET or PEN substrate, this unique electrode exhibits the superior optoelectronic characteristics (sheet resistance of 8.06 Ω/□ at 88.3% light transmittance). Meanwhile, the specific up-to-bottom fabrication process could achieve the superflat surface (RMS = 2.58 nm), superthin thickness (∼8 μm thickness), high mechanical robustness, and lightweight. In addition, the strong corrosion resistance and stability for the hybrid electrode were proved. With these advantages, we employ this electrode to fabricate the simple flexible organic light-emitting device (OLED) and perovskite solar cell device (PSC), which exhibit the considerable performance (best PCE of OLED = 2.11 cd/A 2 ; best PCE of PSC = 10.419%). All the characteristics of the unique hybrid electrode demonstrate its potential as a high-performance transparent electrode candidate for flexible optoelectronics.

  17. Hole Transfer from Low Band Gap Quantum Dots to Conjugated Polymers in Organic/Inorganic Hybrid Photovoltaics.

    PubMed

    Colbert, Adam E; Janke, Eric M; Hsieh, Stephen T; Subramaniyan, Selvam; Schlenker, Cody W; Jenekhe, Samson A; Ginger, David S

    2013-01-17

    We use photoinduced absorption (PIA) spectroscopy to investigate pathways for photocurrent generation in hybrid organic/inorganic quantum dot bulk heterojunction solar cells. We study blends of the conjugated polymer poly(2,3-bis(2-(hexyldecyl)quinoxaline-5,8-diyl-alt-N-(2-hexyldecyl)dithieno[3,2-b:2',3'-d]pyrrole) (PDTPQx-HD) with PbS quantum dots and find that positively charged polarons are formed on the conjugated polymer following selective photoexcitation of the PbS quantum dots. This result provides a direct spectroscopic fingerprint demonstrating that photoinduced hole transfer occurs from the photoexcited quantum dots to the host polymer. We compute the relative yields of long-lived holes following photoexcitation of both the polymer and quantum dot phases and estimate that more long-lived polarons are produced per photon absorbed by the polymer phase than by the quantum dot phase.

  18. Formation mechanism of monodispersed spherical core-shell ceria/polymer hybrid nanoparticles

    SciT

    Izu, Noriya, E-mail: n-izu@aist.go.jp; Uchida, Toshio; Matsubara, Ichiro

    2011-08-15

    Graphical abstract: The formation mechanism for core-shell nanoparticles is considered to be as follows: nucleation and particle growth occur simultaneously (left square); very slow particle growth occurs (middle square). Highlights: {yields} The size of the resultant nanoparticles was strongly and complicatedly dependent on the set temperature used during reflux heating and the PVP molecular weight. {yields} The size of the nanoparticles increased by a 2-step process as the reflux heating time increased. {yields} The IR spectral changes with increasing reflux time indicated the increase in the number of cross-linked polymers in the shell. -- Abstract: Very unique core-shell ceria (ceriummore » oxide)/polymer hybrid nanoparticles that have monodispersed spherical structures and are easily dispersed in water or alcohol without the need for a dispersant were reported recently. The formation mechanism of the unique nanoparticles, however, was not clear. In order to clarify the formation mechanism, these nanoparticles were prepared using a polyol method (reflux heating) under varied conditions of temperature, time, and concentration and molecular weight of added polymer (poly(vinylpyrrolidone)). The size of the resultant nanoparticles was strongly and complicatedly dependent on the set temperature used during reflux heating and the poly(vinylpyrrolidone) molecular weight. Furthermore, the size of the nanoparticles increased by a 2-step process as the reflux heating time increased. The IR spectral changes with increasing reflux time indicated the increase in the number of cross-linked polymers in the shell. From these results, the formation mechanism was discussed and proposed.« less

  19. Time-Domain Ab Initio Analysis of Excitation Dynamics in a Quantum Dot/Polymer Hybrid: Atomistic Description Rationalizes Experiment.

    PubMed

    Long, Run; Prezhdo, Oleg V

    2015-07-08

    Hybrid organic/inorganic polymer/quantum dot (QD) solar cells are an attractive alternative to the traditional cells. The original, simple models postulate that one-dimensional polymers have continuous energy levels, while zero-dimensional QDs exhibit atom-like electronic structure. A realistic, atomistic viewpoint provides an alternative description. Electronic states in polymers are molecule-like: finite in size and discrete in energy. QDs are composed of many atoms and have high, bulk-like densities of states. We employ ab initio time-domain simulation to model the experimentally observed ultrafast photoinduced dynamics in a QD/polymer hybrid and show that an atomistic description is essential for understanding the time-resolved experimental data. Both electron and hole transfers across the interface exhibit subpicosecond time scales. The interfacial processes are fast due to strong electronic donor-acceptor, as evidenced by the densities of the photoexcited states which are delocalized between the donor and the acceptor. The nonadiabatic charge-phonon coupling is also strong, especially in the polymer, resulting in rapid energy losses. The electron transfer from the polymer is notably faster than the hole transfer from the QD, due to a significantly higher density of acceptor states. The stronger molecule-like electronic and charge-phonon coupling in the polymer rationalizes why the electron-hole recombination inside the polymer is several orders of magnitude faster than in the QD. As a result, experiments exhibit multiple transfer times for the long-lived hole inside the QD, ranging from subpicoseconds to nanoseconds. In contrast, transfer of the short-lived electron inside the polymer does not occur beyond the first picosecond. The energy lost by the hole on its transit into the polymer is accommodated by polymer's high-frequency vibrations. The energy lost by the electron injected into the QD is accommodated primarily by much lower-frequency collective and

  20. Increasing the operation temperature of polymer electrolyte membranes for fuel cells: From nanocomposites to hybrids

    NASA Astrophysics Data System (ADS)

    Licoccia, Silvia; Traversa, Enrico

    Among the possible systems investigated for energy production with low environmental impact, polymeric electrolyte membrane fuel cells (PEMFCs) are very promising as electrochemical power sources for application in portable technology and electric vehicles. For practical applications, operating FCs at temperatures above 100 °C is desired, both for hydrogen and methanol fuelled cells. When hydrogen is used as fuel, an increase of the cell temperature produces enhanced CO tolerance, faster reaction kinetics, easier water management and reduced heat exchanger requirement. The use of methanol instead of hydrogen as a fuel for vehicles has several practical benefits such as easy transport and storage, but the slow oxidation kinetics of methanol needs operating direct methanol fuel cells (DMFCs) at intermediate temperatures. For this reason, new membranes are required. Our strategy to achieve the goal of operating at temperatures above 120 °C is to develop organic/inorganic hybrid membranes. The first approach was the use of nanocomposite class I hybrids where nanocrystalline ceramic oxides were added to Nafion. Nanocomposite membranes showed enhanced characteristics, hence allowing their operation up to 130 °C when the cell was fuelled with hydrogen and up to 145 °C in DMFCs, reaching power densities of 350 mW cm -2. The second approach was to prepare Class II hybrids via the formation of covalent bonds between totally aromatic polymers and inorganic clusters. The properties of such covalent hybrids can be modulated by modifying the ratio between organic and inorganic groups and the nature of the chemical components allowing to reach high and stable conductivity values up to 6.4 × 10 -2 S cm -1 at 120 °C.

  1. Evaluation of hybrid polymers for high-precision manufacturing of 3D optical interconnects by two-photon absorption lithography

    NASA Astrophysics Data System (ADS)

    Schleunitz, A.; Klein, J. J.; Krupp, A.; Stender, B.; Houbertz, R.; Gruetzner, G.

    2017-02-01

    The fabrication of optical interconnects has been widely investigated for the generation of optical circuit boards. Twophoton absorption (TPA) lithography (or high-precision 3D printing) as an innovative production method for direct manufacture of individual 3D photonic structures gains more and more attention when optical polymers are employed. In this regard, we have evaluated novel ORMOCER-based hybrid polymers tailored for the manufacture of optical waveguides by means of high-precision 3D printing. In order to facilitate future industrial implementation, the processability was evaluated and the optical performance of embedded waveguides was assessed. The results illustrate that hybrid polymers are not only viable consumables for industrial manufacture of polymeric micro-optics using generic processes such as UV molding. They also are potential candidates to fabricate optical waveguide systems down to the chip level where TPA-based emerging manufacturing techniques are engaged. Hence, it is shown that hybrid polymers continue to meet the increasing expectations of dynamically growing markets of micro-optics and optical interconnects due to the flexibility of the employed polymer material concept.

  2. Crystal structure of zwitterionic bisimidazolium sulfonates

    NASA Astrophysics Data System (ADS)

    Kohmoto, Shigeo; Okuyama, Shinpei; Yokota, Nobuyuki; Takahashi, Masahiro; Kishikawa, Keiki; Masu, Hyuma; Azumaya, Isao

    2012-05-01

    Crystal structures of three zwitterionic bisimidazolium salts 1-3 in which imidazolium sulfonate moieties were connected with aromatic linkers, p-xylylene, 4,4'-dimethylenebiphenyl, and phenylene, respectively, were examined. The latter two were obtained as hydrates. An S-shaped molecular structure in which the sulfonate moiety was placed on the imidazolium ring was observed for 1. A helical array of hydrated water molecules was obtained for 2 while a linear array of hydrated water molecules was observed for 3.

  3. Self-Assembled Core-Shell-Type Lipid-Polymer Hybrid Nanoparticles: Intracellular Trafficking and Relevance for Oral Absorption.

    PubMed

    Li, Qiuxia; Xia, Dengning; Tao, Jinsong; Shen, Aijun; He, Yuan; Gan, Yong; Wang, Chi

    2017-10-01

    Lipid-polymer hybrid nanoparticles (NPs) are advantageous for drug delivery. However, their intracellular trafficking mechanism and relevance for oral drug absorption are poorly understood. In this study, self-assembled core-shell lipid-polymer hybrid NPs made of poly(lactic-co-glycolic acid) (PLGA) and various lipids were developed to study their differing intracellular trafficking in intestinal epithelial cells and their relevance for oral absorption of a model drug saquinavir (SQV). Our results demonstrated that the endocytosis and exocytosis of hybrid NPs could be changed by varying the kind of lipid. A glyceride mixture (hybrid NPs-1) decreased endocytosis but increased exocytosis in Caco-2 cells, whereas the phospholipid (E200) (hybrid NPs-2) decreased endocytosis but exocytosis was unaffected as compared with PLGA nanoparticles. The transport of hybrid NPs-1 in cells involved various pathways, including caveolae/lipid raft-dependent endocytosis, and clathrin-mediated endocytosis and macropinocytosis, which was different from the other groups of NPs that involved only caveolae/lipid raft-dependent endocytosis. Compared with that of the reference formulation (nanoemulsion), the oral absorption of SQV-loaded hybrid NPs in rats was poor, probably due to the limited drug release and transcytosis of NPs across the intestinal epithelium. In conclusion, the intracellular processing of hybrid NPs in intestinal epithelia can be altered by adding lipids to the NP. However, it appears unfavorable to use PLGA-based NPs to improve oral absorption of SQV compared with nanoemulsion. Our findings will be essential in the development of polymer-based NPs for the oral delivery of drugs with the purpose of improving their oral absorption. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  4. Polymer/silica hybrid waveguide temperature sensor based on asymmetric Mach-Zehnder interferometer

    NASA Astrophysics Data System (ADS)

    Niu, Donghai; Wang, Xibin; Sun, Shiqi; Jiang, Minghui; Xu, Qiang; Wang, Fei; Wu, Yuanda; Zhang, Daming

    2018-04-01

    A highly sensitive waveguide temperature sensor based on asymmetric Mach-Zehnder interferometer was designed and experimentally demonstrated. The interferometer is based on the polymer/silica hybrid waveguide structure, and Norland Optical Adhesive 73 (NOA 73) was employed as the waveguide core to enhance the temperature sensitivity. The influence of the different length differences between the two interferometer arms on the sensitivity of the sensor was systemically studied. It is shown that the maximum temperature sensitivity of -431 pm °C-1 can be obtained in the range of 25 °C-75 °C, while the length difference is 92 μm. Moreover, the temperature sensitivity contributions from different core materials were also investigated experimentally. It is shown that the waveguide material and microstructure of the device have significant influences on the sensitivity of the waveguide temperature sensor.

  5. Mass production and size control of lipid-polymer hybrid nanoparticles through controlled microvortices

    PubMed Central

    Kim, YongTae; Chung, Bomy Lee; Ma, Mingming; Mulder, Willem J. M.; Fayad, Zahi A.; Farokhzad, Omid C.; Langer, Robert

    2012-01-01

    Lipid-polymer hybrid (LPH) nanoparticles can deliver a wide range of therapeutic compounds in a controlled manner. LPH nanoparticle syntheses using microfluidics improve the mixing process, but are restricted by a low throughput. In this study we present a pattern-tunable microvortex platform that allows mass production and size control of LPH nanoparticles with superior reproducibility and homogeneity. We demonstrate that by varying flow rates (i.e. Reynolds number (30∼150)) we can control the nanoparticle size (30∼170nm) with high productivity (∼3g/hour) and low polydispersity (∼0.1). Our approach may contribute to efficient development and optimization of a wide range of multicomponent nanoparticles for medical imaging and drug delivery. PMID:22716029

  6. Self-assembled lipid--polymer hybrid nanoparticles: a robust drug delivery platform.

    PubMed

    Zhang, Liangfang; Chan, Juliana M; Gu, Frank X; Rhee, June-Wha; Wang, Andrew Z; Radovic-Moreno, Aleksandar F; Alexis, Frank; Langer, Robert; Farokhzad, Omid C

    2008-08-01

    We report the engineering of a novel lipid-polymer hybrid nanoparticle (NP) as a robust drug delivery platform, with high drug encapsulation yield, tunable and sustained drug release profile, excellent serum stability, and potential for differential targeting of cells or tissues. The NP comprises three distinct functional components: (i) a hydrophobic polymeric core where poorly water-soluble drugs can be encapsulated; (ii) a hydrophilic polymeric shell with antibiofouling properties to enhance NP stability and systemic circulation half-life; and (iii) a lipid monolayer at the interface of the core and the shell that acts as a molecular fence to promote drug retention inside the polymeric core, thereby enhancing drug encapsulation efficiency, increasing drug loading yield, and controlling drug release. The NP is prepared by self-assembly through a single-step nanoprecipitation method in a reproducible and predictable manner, making it potentially suitable for scale-up.

  7. Self-Assembled Lipid-Polymer Hybrid Nanoparticles: A Robust Drug Delivery Platform

    PubMed Central

    Zhang, Liangfang; Chan, Juliana M; Gu, Frank X; Rhee, June-Wha; Wang, Andrew Z; Radovic-Moreno, Aleksandar F; Alexis, Frank; Langer, Robert; Farokhzad, Omid C

    2014-01-01

    We report the engineering of a novel lipid-polymer hybrid nanoparticle (NP) as a robust drug delivery platform, with high drug encapsulation yield, tunable and sustained drug release profile, excellent serum stability, and potential for differential targeting of cells or tissues. The NP is comprised of three distinct functional components: i) a hydrophobic polymeric core where poorly water-soluble drugs can be encapsulated; ii) a hydrophilic polymeric shell with anti-biofouling properties to enhance NP stability and systemic circulation half-life; and iii) a lipid monolayer at the interface of the core and the shell that acts as a molecular fence to promote drug retention inside the polymeric core, thereby enhancing drug encapsulation efficiency, increasing drug loading yield, and controlling drug release. The NP is prepared by self-assembly through a single-step nanoprecipitation method in a reproducible and predictable manner, making it potentially suitable for scale-up PMID:19206374

  8. Nanoporous metal organic frameworks as hybrid polymer-metal composites for drug delivery and biomedical applications.

    PubMed

    Beg, Sarwar; Rahman, Mahfoozur; Jain, Atul; Saini, Sumant; Midoux, Patrick; Pichon, Chantal; Ahmad, Farhan Jalees; Akhter, Sohail

    2017-04-01

    Metal organic frameworks (MOFs), porous hybrid polymer-metal composites at the nanoscale, are recent innovations in the field of chemistry; they are novel polymeric materials with diverse biomedical applications. MOFs are nanoporous materials, consisting of metal ions linked together by organic bridging ligands. The unique physical and chemical characteristics of MOFs have attracted wider attention from the scientific community, exploring their utility in the field of material science, biology, nanotechnology and drug delivery. The practical feasibility of MOFs is possible owing to their abilities for biodegradability, excellent porosity, high loading capacity, ease of surface modification, among others. In this regard, this review provides an account of various types of MOFs, their physiochemical characteristics and use in diverse disciplines of biomedical sciences - with special emphasis on drug delivery and theranostics. Moreover, this review also highlights the stability and toxicity issues of MOFs, along with their market potential for biomedical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Control of Electron Flow Direction in Photoexcited Cycloplatinated Complex Containing Conjugated Polymer-Single Walled Carbon Nanotube Hybrids.

    PubMed

    Xiong, Wenjuan; Du, Lili; Lo, Kin Cheung; Shi, Haiting; Takaya, Tomohisa; Iwata, Koichi; Chan, Wai Kin; Phillips, David Lee

    2018-06-25

    Conjugated polymers incorporated with cycloplatinated complexes (P1-Pt and P2-Pt) were used as dispersants for single walled carbon nanotubes (SWCNTs). Significant changes in the UV-vis absorption spectra were observed after the formation of the polymer/SWCNT hybrids. Molecular dynamics (MD) simulations revealed the presence of a strong interaction between the cycloplatinated complex moieties and the SWCNT surface. The photoinduced electron transfer processes in these hybrids were strongly dependent on the type of the comonomer unit. Upon photoexcitation, the excited P1-Pt donates electrons to the SWCNT, while P2-Pt accepts electrons from the photoexcited SWCNT. These observations were supported by results from Raman and femtosecond time-resolved transient absorption spectroscopy experiments. The strong electronic interaction between the Pt complexes and the SWCNT gives rise to a new hybrid system that has a controllable photo-induced electron transfer flow, which are important in regulating the charge transport processes SWCNT-based optoelectronic devices.

  10. Natural-Synthetic Hybrid Polymers Developed via Electrospinning: The Effect of PET in Chitosan/Starch System

    PubMed Central

    Espíndola-González, Adolfo; Martínez-Hernández, Ana Laura; Fernández-Escobar, Francisco; Castaño, Victor Manuel; Brostow, Witold; Datashvili, Tea; Velasco-Santos, Carlos

    2011-01-01

    Chitosan is an amino polysaccharide found in nature, which is biodegradable, nontoxic and biocompatible. It has versatile features and can be used in a variety of applications including films, packaging, and also in medical surgery. Recently a possibility to diversify chitosan properties has emerged by combining it with synthetic materials to produce novel natural-synthetic hybrid polymers. We have studied structural and thermophysical properties of chitosan + starch + poly(ethylene terephthalate) (Ch + S + PET) fibers developed via electrospinning. Properties of these hybrids polymers are compared with extant chitosan containing hybrids synthesized by electrospinning. Molecular interactions and orientation in the fibers are analyzed by infrared and Raman spectroscopies respectively, morphology by scanning electron microscopy and thermophysical properties by thermogravimetric analysis and differential scanning calorimetry. Addition of PET to Ch + S systems results in improved thermal stability at elevated temperatures. PMID:21673930

  11. Zwitterionic Nanocages Overcome the Efficacy Loss of Biologic Drugs.

    PubMed

    Li, Bowen; Yuan, Zhefan; Zhang, Peng; Sinclair, Andrew; Jain, Priyesh; Wu, Kan; Tsao, Caroline; Xie, Jingyi; Hung, Hsiang-Chieh; Lin, Xiaojie; Bai, Tao; Jiang, Shaoyi

    2018-04-01

    For biotherapeutics that require multiple administrations to fully cure diseases, the induction of undesirable immune response is one common cause for the failure of their treatment. Covalent binding of hydrophilic polymers to proteins is commonly employed to mitigate potential immune responses. However, while this technique is proved to partially reduce the antibodies (Abs) reactive to proteins, it may induce Abs toward their associated polymers and thus result in the loss of efficacy. Zwitterionic poly(carboxybetaine) (PCB) is recently shown to improve the immunologic properties of proteins without inducing any antipolymer Abs against itself. However, it is unclear if the improved immunologic profiles can translate to better clinical outcomes since improved immunogenicity cannot directly reflect amelioration in efficacy. Here, a PCB nanocage (PCB NC) is developed, which can physically encase proteins while keeping their structure intact. PCB NC encapsulation of uricase, a highly immunogenic enzyme, is demonstrated to eradicate all the immune responses. To bridge the gap between immunogenicity and efficacy studies, the therapeutic performance of PCB NC uricase is evaluated and compared with its PEGylated counterpart in a clinical-mimicking gouty rat model to determine any loss of efficacy evoked after five administrations. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Single-step assembly of cationic lipid-polymer hybrid nanoparticles for systemic delivery of siRNA.

    PubMed

    Yang, Xian-Zhu; Dou, Shuang; Wang, Yu-Cai; Long, Hong-Yan; Xiong, Meng-Hua; Mao, Cheng-Qiong; Yao, Yan-Dan; Wang, Jun

    2012-06-26

    The clinical success of therapeutics of small interfering RNA (siRNA) is still hindered by its delivery systems. Cationic polymer or lipid-based vehicles as the major delivery systems of siRNA cannot sufficiently satisfy siRNA therapeutic applications. It is hypothesized that cationic lipid-polymer hybrid nanoparticles may take advantage of both polymeric and lipid-based nanoparticles for siRNA delivery, while diminishing the shortcomings of both. In this study, cationic lipid-polymer hybrid nanoparticles were prepared by a single-step nanoprecipitation of a cationic lipid (N,N-bis(2-hydroxyethyl)-N-methyl-N-(2-cholesteryloxycarbonyl aminoethyl) ammonium bromide, BHEM-Chol) and amphiphilic polymers for systemic delivery of siRNA. The formed hybrid nanoparticles comprised a hydrophobic polylactide core, a hydrophilic poly(ethylene glycol) shell, and a cationic lipid monolayer at the interface of the core and the shell. Such hybrid nanoparticles exhibited excellent stability in serum and showed significantly improved biocompatibility compared to that of pure BHEM-Chol particles. The hybrid nanoparticles were capable of delivering siRNA into BT474 cells and facilitated the escape of loaded siRNA from the endosome into the cytoplasm. The hybrid nanoparticles carrying polo-like kinase 1 (Plk1)-specific siRNA (siPlk1) remarkably and specifically downregulated expression of the oncogene Plk1 and induced cancer cell apoptosis both in vitro and in vivo and significantly suppressed tumor growth following systemic administration. We demonstrate that this system is stable, nontoxic, highly efficient, and easy to scale up, bringing the clinical application of siRNA therapy one important step closer to reality.

  13. Hybrid solid polymer electrolyte from diapers as separator for electrochemical double layer capacitor (EDLC)

    NASA Astrophysics Data System (ADS)

    Hashim, Mohd Azman; Yatim, Nadhrah Md.; Mahmud, Nor Azura Che; Sazali, Nur Ezniera Shafieza; Hamdan, Ellisah; Yahya, Mohd Adib; Ngah, Che Wan Zanariah Che Wan; Suhaimi, Syahida

    2018-06-01

    EDLC was fabricated using hybrid solid polymer electrolyte from PVA-diapers and an activated carbon powder as electrode by using solution casting method. For comparison, four types of EDLC cells were constructed and tested. It was found that an EDLC with a PVA-diapers (60:40) polymer electrolyte exhibited much higher capacitance and longer cycle-life. The electrocapacitive properties of the supercapacitor (P50HD50, P60HD40, P70HD30 and P80HD20) were done using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and galvanostatic charge discharge (GCD). Results from these analysis showed that P60HD40 cell had recorded excellent rate capability and highest Csp value of 179 F g-1 (EIS), 50 F g-1 (CV), 328 F g-1 (GCD) respectively. Futher, results from ESR (GCD) analysis showed that P60HD40 composition of PVA/H3PO4 liquid electroyte gave a lower value of 88.05 Ω in the supercapacitor cell compared with another cells.

  14. Preparation and characterization of functional material based on hybrid polymer composites

    NASA Astrophysics Data System (ADS)

    Agusu, La; Amiruddin; Taswito, Chen Chen; Herdianto; Zamrun, Muh.

    2016-08-01

    The microstructures and properties of hybrid polymer composites based on polyaniline (PANi)/γ-Fe2O3 nanoparticles/TiO2/carbon have been investigated for multifunctional applications such as heavy metal removal and initial study for radar absorbing material application. γ-Fe2O3 nanoparticles with spherical shape were synthetized by a coprecipitation method from iron sand. By activating the polyethylene glycol (PEG-400) coated carbon of coconut shell, the homogenous shape and size of carbon was achieved. Then, γ- Fe2O3, TiO2, and carbon were mixed with PANi by an in situ polymerization method at low temperature 0-5 oC. Characterization process involved XRD, SEM, FTIR, VSM, and DC conductivity measurements. For radar absorber application, the functionalized polymer composites showed good electrical conductivity 0.45 S/cm to absorb the incoming electromagnetic energy. An efficient and effective reduction of Pb2+ ion from the water has been achieved by using this material.

  15. Ultrahigh Elastic Strain Energy Storage in Metal-Oxide-Infiltrated Patterned Hybrid Polymer Nanocomposites

    SciT

    Dusoe, Keith J.; Ye, Xinyi; Kisslinger, Kim

    Modulus of resilience, the measure of a material’s capacity to store and release elastic strain energy, is critical for realizing advanced mechanical actuation technologies in micro/nanoelectromechanical systems. In general, engineering the modulus of resilience is difficult because it requires asymmetrically increasing yield strength and Young’s modulus against their mutual scaling behavior. This task becomes further challenging if it needs to be carried out at the nanometer scale. Here, we demonstrate organic–inorganic hybrid composite nanopillars with one of the highest modulus of resilience per density by utilizing vapor-phase aluminum oxide infiltration in lithographically patterned negative photoresist SU-8. In situ nanomechanical measurementsmore » reveal a metal-like high yield strength (~500 MPa) with an unusually low, foam-like Young’s modulus (~7 GPa), a unique pairing that yields ultrahigh modulus of resilience, reaching up to ~24 MJ/m 3 as well as exceptional modulus of resilience per density of ~13.4 kJ/kg, surpassing those of most engineering materials. The hybrid polymer nanocomposite features lightweight, ultrahigh tunable modulus of resilience and versatile nanoscale lithographic patternability with potential for application as nanomechanical components which require ultrahigh mechanical resilience and strength.« less

  16. Self-diagnosis of structures strengthened with hybrid carbon-fiber-reinforced polymer sheets

    NASA Astrophysics Data System (ADS)

    Wu, Z. S.; Yang, C. Q.; Harada, T.; Ye, L. P.

    2005-06-01

    The correlation of mechanical and electrical properties of concrete beams strengthened with hybrid carbon-fiber-reinforced polymer (HCFRP) sheets is studied in this paper. Two types of concrete beams, with and without reinforcing bars, are strengthened with externally bonded HCFRP sheets, which have a self-structural health monitoring function due to the electrical conduction and piezoresistivity of carbon fibers. Parameters investigated include the volume fractions and types of carbon fibers. According to the investigation, it is found that the hybridization of uniaxial HCFRP sheets with several different types of carbon fibers is a viable method for enhancing the mechanical properties and obtaining a built-in damage detection function for concrete structures. The changes in electrical resistance during low strain ranges before the rupture of carbon fibers are generally smaller than 1%. Nevertheless, after the gradual ruptures of carbon fibers, the electrical resistance increases remarkably with the strain in a step-wise manner. For the specimens without reinforcing bars, the electrical behaviors are not stable, especially during the low strain ranges. However, the electrical behaviors of the specimens with reinforcing bars are relatively stable, and the whole range of self-sensing function of the HCFRP-strengthened RC structures has realized the conceptual design of the HCFRP sensing models and is confirmed by the experimental investigations. The relationships between the strain/load and the change in electrical resistance show the potential self-monitoring capacity of HCFRP reinforcements used for strengthening concrete structures.

  17. Ultrahigh Elastic Strain Energy Storage in Metal-Oxide-Infiltrated Patterned Hybrid Polymer Nanocomposites

    DOE PAGES

    Dusoe, Keith J.; Ye, Xinyi; Kisslinger, Kim; ...

    2017-10-19

    Modulus of resilience, the measure of a material’s capacity to store and release elastic strain energy, is critical for realizing advanced mechanical actuation technologies in micro/nanoelectromechanical systems. In general, engineering the modulus of resilience is difficult because it requires asymmetrically increasing yield strength and Young’s modulus against their mutual scaling behavior. This task becomes further challenging if it needs to be carried out at the nanometer scale. Here, we demonstrate organic–inorganic hybrid composite nanopillars with one of the highest modulus of resilience per density by utilizing vapor-phase aluminum oxide infiltration in lithographically patterned negative photoresist SU-8. In situ nanomechanical measurementsmore » reveal a metal-like high yield strength (~500 MPa) with an unusually low, foam-like Young’s modulus (~7 GPa), a unique pairing that yields ultrahigh modulus of resilience, reaching up to ~24 MJ/m 3 as well as exceptional modulus of resilience per density of ~13.4 kJ/kg, surpassing those of most engineering materials. The hybrid polymer nanocomposite features lightweight, ultrahigh tunable modulus of resilience and versatile nanoscale lithographic patternability with potential for application as nanomechanical components which require ultrahigh mechanical resilience and strength.« less

  18. Polymer-entanglement-driven coassembly of hybrid superparamagnetic nanoparticles: Tunable structures and flexible functionalization.

    PubMed

    Zhan, Xiaohui; Yi, Qiangying; Cai, Shuang; Zhou, Xiaoxi; Ma, Shaohua; Lan, Fang; Gu, Zhongwei; Wu, Yao

    2017-12-15

    In this study, we report a facile and versatile strategy for preparing a type of pH-responsive superparamagnetic hybrid coassemblies featuring a series of controls over the morphology and multi-functionalization simultaneously and efficiently. Via the entanglement interactions, the combine of fixed PEG-b-P4VP modified Fe 3 O 4 NPs (D-Fe 3 O 4 @mPEG-b-P4VP) and different well-designed free PEG-b-P4VP, which are analogous to two amphiphiles, contributes these hybrid superstructures with multiple, well-defined morphologies and targeted fluorescent properties. In contrast to other studies, our work overcame several defects (e.g., interior NPs' randomness, cumbersome assembly parameter adjustment and functionalization) of the conventional assembly of modified inorganic NPs and demonstrated that this coassembly strategy can be used as a versatile tool for the controllable assembly of other NPs or polymers. Finally, taking the coassembly C1 as a desirable drug delivery carrier, good biocompatibility and pH-triggered drug release were successfully verified. The current study indicated that these magnetic coassemblies are promising as multifunctional and multipurpose carriers in biological, medical, catalytic, and coating applications. Copyright © 2017. Published by Elsevier Inc.

  19. Farnesylthiosalicylic acid-loaded lipid-polyethylene glycol-polymer hybrid nanoparticles for treatment of glioblastoma.

    PubMed

    Kaffashi, Abbas; Lüle, Sevda; Bozdağ Pehlivan, Sibel; Sarısözen, Can; Vural, İmran; Koşucu, Hüsnü; Demir, Taner; Buğdaycı, Kadir Emre; Söylemezoğlu, Figen; Karlı Oğuz, Kader; Mut, Melike

    2017-08-01

    We aimed to develop lipid-polyethylene glycol (PEG)-polymer hybrid nanoparticles, which have high affinity to tumour tissue with active ingredient, a new generation antineoplastic drug, farnesylthiosalicylic acid (FTA) for treatment of glioblastoma. Farnesylthiosalicylic acid-loaded poly(lactic-co-glycolic acid)-1,2 distearoyl-glycerol-3-phospho-ethanolamine-N [methoxy (PEG)-2000] ammonium salt (PLGA-DSPE-PEG) with or without 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) hybrid nanoparticles has been prepared and evaluated for in-vitro characterization. Cytotoxicity of FTA-loaded nanoparticles along with its efficacy on rat glioma-2 (RG2) cells was also evaluated both in vitro (in comparison with non-malignant cell line, L929) and in vivo. Scanning electron microscopy studies showed that all formulations prepared had smooth surface and spherical in shape. FTA and FTA-loaded nanoparticles have cytotoxic activity against RG2 glioma cell lines in cell culture studies, which further increases with addition of DOTAP. Magnetic resonance imaging and histopathologic evaluation on RG2 tumour cells in rat glioma model (49 female Wistar rats, 250-300 g) comparing intravenous and intratumoral injections of the drug have been performed and FTA-loaded nanoparticles reduced tumour size significantly in in-vivo studies, with higher efficiency of intratumoral administration than intravenous route. Farnesylthiosalicylic acid-loaded PLGA-DSPE-PEG-DOTAP hybrid nanoparticles are proven to be effective against glioblastoma in both in-vitro and in-vivo experiments. © 2017 Royal Pharmaceutical Society.

  20. Polysulfone and polyacrylate-based zwitterionic coatings for the prevention and easy removal of marine biofouling

    DOE PAGES

    Hibbs, Michael R.; Hernandez-Sanchez, Bernadette A.; Daniels, Justin; ...

    2015-09-07

    A series of polysulfone and polyacrylate-based zwitterionic coatings were prepared on epoxy-primed aluminum substrata and characterized for their antifouling (AF) and fouling-release (FR) properties towards marine bacteria, microalgae and barnacles. The zwitterionic polymer coatings provided minimal resistance against bacterial biofilm retention and microalgal cell attachment, but facilitated good removal of attached microbial biomass by exposure to water-jet apparatus generated hydrodynamic shearing forces. Increasing the ion content of the coatings improved the AF properties, but required a stronger adhesive bond to the epoxy-primed aluminum substratum to prevent coating swelling and dissolution. Grafted poly(sulfobetaine) (gpSBMA), the most promising zwitterionic coating identified frommore » microfouling evaluations, enabled the removal of four out of five barnacles reattached to its surface without incurring damage to their baseplates. As a result, this significant result indicated that gpSBMA relied predominately on its surface chemistry for its FR properties since it was very thin (~1–2 µm) relative to commercial coating standards (>200 µm).« less

  1. Polymer-lipid-PEG hybrid nanoparticles as photosensitizer carrier for photodynamic therapy.

    PubMed

    Pramual, Sasivimon; Lirdprapamongkol, Kriengsak; Svasti, Jisnuson; Bergkvist, Magnus; Jouan-Hureaux, Valérie; Arnoux, Philippe; Frochot, Céline; Barberi-Heyob, Muriel; Niamsiri, Nuttawee

    2017-08-01

    Polymer-lipid-PEG hybrid nanoparticles were investigated as carriers for the photosensitizer (PS), 5,10,15,20-Tetrakis(4-hydroxy-phenyl)-21H,23H-porphine (pTHPP) for use in photodynamic therapy (PDT). A self-assembled nanoprecipitation technique was used for preparing two types of core polymers poly(d,l-lactide-co-glycolide) (PLGA) and poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) with lipid-PEG as stabilizer. The resulting nanoparticles had an average particle size of 88.5±3.4nm for PLGA and 215.0±6.3nm for PHBV. Both nanoparticles exhibited a core-shell structure under TEM with high zeta potential and loading efficiency. X-ray powder diffraction analysis showed that the encapsulated pTHPP molecules in polymeric nanoparticles no longer had peaks of free pTHPP in the crystalline state. The pTHPP molecules encapsulated inside the polymeric core demonstrated improved photophysical properties in terms of singlet oxygen generation and cellular uptake rate in a FTC-133 human thyroid carcinoma cell line, compared to non-encapsulated pTHPP. The pTHPP-loaded polymer-lipid-PEG nanoparticles showed better in vitro phototoxicity compared to free pTHPP, in both time- and concentration-dependent manners. Overall, this study provides detailed analysis of the photophysical properties of pTHPP molecules when entrapped within either PLGA or PHBV nanoparticle cores, and demonstrates the effectiveness of these systems for delivery of photosensitizers. The two polymeric systems may have different potential benefits, when used with cancer cells. For instance, the pTHPP-loaded PLGA system requires only a short time to show a PDT effect and may be suitable for topical PDT, while the delayed photo-induced cytotoxic effect of the pTHPP-loaded PHBV system may be more suitable for cancer solid tumors. Hence, both pTHPP-encapsulated polymer-lipid-PEG nanoparticles can be considered promising delivery systems for PDT cancer treatment. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Rifampicin Lipid-Polymer hybrid nanoparticles (LIPOMER) for enhanced Peyer's patch uptake.

    PubMed

    Bachhav, Sagar S; Dighe, Vikas D; Kotak, Darsheen; Devarajan, Padma V

    2017-10-30

    The oral uptake of intact nanocarriers through Peyer's patches is an important uptake pathway. We report Rifampicin Lipid-Polymer hybrid nanoparticles (RIF-LIPOMER) using glyceryl monostearate as lipid and the mucoadhesive polymer, Gantrez, with the objective of balancing hydrophobicity and mucoadhesion for enhanced Peyer's patch uptake. RIF-LIPOMER was optimized for size, hydrophobicity, and mucoadhesion using Box-Behnken. Designed RIF-LIPOMER (RIF-LIPO-120) exhibited average particle size in the range 300-400nm with drug loading >12%. DSC and XRD confirmed complete amorphization. Contact angle and mucoadhesion force revealed that RIF-LIPO-120 exhibited greater hydrophobicity and lower mucoadhesion compared to Gantrez nanoparticles (RIF-GzNP). Comparative uptake of fluorescent labelled RIF-LIPO-120 and RIF-GzNP, through Peyer's patch following intraduodenal administration in rats, revealed the high accumulation of RIF-GzNP at the villi border, and high Peyer's patch uptake of RIF-LIPO-120. Furthermore, lower accumulation of RIF-LIPO-120 in the liver, compared to RIF-GzNP, suggested bypass of the portal circulation and lymphatic uptake through Peyer's patches. Significantly higher lung: plasma concentration ratio exhibited by RIF-LIPO-120 compared to RIF-GzNP confirmed the same (p<0.05). Our study demonstrated that optimization of hydrophobicity and mucoadhesion of nanoparticles could favor Peyer's patch uptake, which in turn could enable enhanced drug accumulation in the lungs with advantage in the therapy of pulmonary afflictions. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Graphene-polymer hybrid nanostructure-based bioenergy storage device for real-time control of biological motor activity.

    PubMed

    Byun, Kyung-Eun; Choi, Dong Shin; Kim, Eunji; Seo, David H; Yang, Heejun; Seo, Sunae; Hong, Seunghun

    2011-11-22

    We report a graphene-polymer hybrid nanostructure-based bioenergy storage device to turn on and off biomotor activity in real-time. In this strategy, graphene was functionalized with amine groups and utilized as a transparent electrode supporting the motility of biomotors. Conducting polymer patterns doped with adenosine triphosphate (ATP) were fabricated on the graphene and utilized for the fast release of ATP by electrical stimuli through the graphene. The controlled release of biomotor fuel, ATP, allowed us to control the actin filament transportation propelled by the biomotor in real-time. This strategy should enable the integrated nanodevices for the real-time control of biological motors, which can be a significant stepping stone toward hybrid nanomechanical systems based on motor proteins. © 2011 American Chemical Society

  4. Metal-conductive polymer hybrid nanostructures: preparation and electrical properties of palladium-polyimidazole nanowires

    NASA Astrophysics Data System (ADS)

    Al-Hinai, Mariam; Hassanien, Reda; Watson, Scott M. D.; Wright, Nicholas G.; Houlton, Andrew; Horrocks, Benjamin R.

    2016-03-01

    A simple, convenient method for the formation of hybrid metal/conductive polymer nanostructures is described. Polyimidazole (PIm) has been templated on λ-DNA via oxidative polymerisation of imidazole using FeCl3 to produce conductive PIm/DNA nanowires. The PIm/DNA nanowires were decorated with Pd (Pd/PIm/DNA) by electroless reduction of {{{{PdCl}}}4}2- with NaBH4 in the presence of PIm/DNA; the choice of imidazole was motivated by the potential Pd(II) binding site at the pyridinic N atom. The formation of PIm/DNA and the presence of metallic Pd on Pd/PIm/DNA nanowires were verified by FTIR, UV-vis and XPS spectroscopy techniques. AFM studies show that the nanowires have diameters in the range 5-45 nm with a slightly greater mean diameter (17.1 ± 0.75 nm) for the Pd-decorated nanowires than the PIm/DNA nanowires (14.5 ± 0.89 nm). After incubation for 24 h in the polymerisation solution, the PIm/DNA nanowires show a smooth, uniform morphology, which is retained after decoration with Pd. Using a combination of scanned conductance microscopy, conductive AFM and two-terminal measurements we show that both types of nanowire are conductive and that it is possible to discriminate different possible mechanisms of transport. The conductivity of the Pd/PIm/DNA nanowires, (0.1-1.4 S cm-1), is comparable to the PIm/DNA nanowires (0.37 ± 0.029 S cm-1). In addition, the conductance of Pd/PIm/DNA nanowires exhibits Arrhenius behaviour (E a = 0.43 ± 0.02 eV) as a function of temperature in contrast to simple Pd/DNA nanowires. These results indicate that although the Pd crystallites on Pd/PIm/DNA nanowires decorate the PIm polymer, the major current pathway is through the polymer rather than the Pd.

  5. Facile modification of electrospun fibrous structures with antifouling zwitterionic hydrogels.

    PubMed

    Xu, Tong; Yang, Jing; Zhang, Jiamin; Zhu, Yingnan; Li, Qingsi; Pan, Chao; Zhang, Lei

    2017-12-28

    Electrospinning technology can easily produce different shaped fibrous structures, making them highly valuable to various biomedical applications. However, surface contamination of biomolecules, cells, or blood has emerged as a significant challenge to the success of electrospun devices, especially artificial blood vessels, catheters and wound dressings etc. Many efforts have been made to resist the surface non-specific biomolecules or cells adsorption, but most of them require complex pre-treatment processes, hard-to-remove metal catalysts or rigorous reaction conditions. In addition, the stability of antifouling coatings, especially in complex conditions, is still a major concern. In this work, inspired by the interpenetrating polymer network and reinforced concrete structure, an efficient and facile strategy for modifying hydrophobic electrospun meshes and tubes with antifouling zwitterionic hydrogels has been introduced. The resulting products could efficiently resist the adhesion of proteins, cells, or even fresh whole blood. Meanwhile, they could maintain the shapes and mechanical strength of the original electrospun structures. Furthermore, the hydrogel structures could retain stable in a physiological condition for at least 3 months. This paper provided a general antifouling and hydrophilicity surface modification strategy for various fibrous structures, and could be of great value for many biomedical applications where antifouling properties are critical.

  6. Electrochemical energy storage devices comprising self-compensating polymers

    SciT

    Johnson, Paul; Bautista-Martinez, Jose Antonio; Friesen, Cody

    The disclosed technology relates generally to devices comprising conductive polymers and more particularly to electrochemical devices comprising self-compensating conductive polymers. In one aspect, electrochemical energy storage device comprises a negative electrode comprising an active material including a redox-active polymer. The device additionally comprises a positive electrode comprising an active material including a redox-active polymer. The device further comprises an electrolyte material interposed between the negative electrode and positive electrode and configured to conduct mobile counterions therethrough between the negative electrode and positive electrode. At least one of the negative electrode redox-active polymer and the positive electrode redox-active polymer comprises amore » zwitterionic polymer unit configured to reversibly switch between a zwitterionic state in which the zwitterionic polymer unit has first and second charge centers having opposite charge states that compensate each other, and a non-zwitterionic state in which the zwitterionic polymer unit has one of the first and second charge centers whose charge state is compensated by mobile counterions.« less

  7. Dry powder inhaler formulation of lipid-polymer hybrid nanoparticles via electrostatically-driven nanoparticle assembly onto microscale carrier particles.

    PubMed

    Yang, Yue; Cheow, Wean Sin; Hadinoto, Kunn

    2012-09-15

    Lipid-polymer hybrid nanoparticles have emerged as promising nanoscale carriers of therapeutics as they combine the attractive characteristics of liposomes and polymers. Herein we develop dry powder inhaler (DPI) formulation of hybrid nanoparticles composed of poly(lactic-co-glycolic acid) and soybean lecithin as the polymer and lipid constituents, respectively. The hybrid nanoparticles are transformed into inhalable microscale nanocomposite structures by a novel technique based on electrostatically-driven adsorption of nanoparticles onto polysaccharide carrier particles, which eliminates the drawbacks of conventional techniques based on controlled drying (e.g. nanoparticle-specific formulation, low yield). First, we engineer polysaccharide carrier particles made up of chitosan cross-linked with tripolyphosphate and dextran sulphate to exhibit the desired aerosolization characteristics and physical robustness. Second, we investigate the effects of nanoparticle to carrier mass ratio and salt inclusion on the adsorption efficiency, in terms of the nanoparticle loading and yield, from which the optimal formulation is determined. Desorption of the nanoparticles from the carrier particles in phosphate buffer saline is also examined. Lastly, we characterize aerosolization efficiency of the nanocomposite product in vitro, where the emitted dose and respirable fraction are found to be comparable to the values of conventional DPI formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. A comparative study of the mechanical performance of Glass and Glass/Carbon hybrid polymer composites at different temperature environments

    NASA Astrophysics Data System (ADS)

    Shukla, M. J.; Kumar, D. S.; Mahato, K. K.; Rathore, D. K.; Prusty, R. K.; Ray, B. C.

    2015-02-01

    Glass Fiber Reinforced Polymer (GFRP) composites have been widely accepted as high strength, low weight structural material as compared to their metallic counterparts. Some specific advanced high performance applications such as aerospace components still require superior specific strength and specific modulus. Carbon Fiber Reinforced Polymer (CFRP) composites exhibit superior specific strength and modulus but have a lower failure strain and high cost. Hence, the combination of both glass and carbon fiber in polymer composite may yield optimized mechanical properties. Further the in-service environment has a significant role on the mechanical performance of this class of materials. Present study aims to investigate the mechanical property of GFRP and Glass/Carbon (G/C hybrid) composites at room temperature, in-situ and ex-situ temperature conditions. In-situ testing at +70°C and +100°C results in significant loss in inter-laminar shear strength (ILSS) for both the composites as compared to room temperature. The ILSS was nearly equal for both the composite systems tested in-situ at +100°C and effect of fiber hybridisation was completely diminished there. At low temperature ex-situ conditioning significant reduction in ILSS was observed for both the systems. Further at -60°C G/C hybrid exhibited 32.4 % higher ILSS than GFRP. Hence this makes G/C hybrid a better choice of material in low temperature environmental applications.

  9. Development of ductile hybrid fiber reinforced polymer (D-H-FRP) reinforcement for concrete structures

    NASA Astrophysics Data System (ADS)

    Somboonsong, Win

    The corrosion of steel rebars has been the major cause of the reinforced concrete deterioration in transportation structures and port facilities. Currently, the Federal Highway Administration (FHWA) spends annually $31 billion for maintaining and repairing highways and highway bridges. The study reported herein represents the work done in developing a new type of reinforcement called Ductile Hybrid Fiber Reinforced Polymer or D-H-FRP using non-corrosive fiber materials. Unlike the previous FRP reinforcements that fail in a brittle manner, the D-H-FRP bars exhibit the stress-strain curves that are suitable for concrete reinforcement. The D-H-FRP stress-strain curves are linearly elastic with a definite yield point followed by plastic deformation and strain hardening resembling that of mild steel. In addition, the D-H-FRP reinforcement has integrated ribs required for concrete bond. The desirable mechanical properties of D-H-FRP reinforcement are obtained from the integrated design based on the material hybrid and geometric hybrid concepts. Using these concepts, the properties can be tailored to meet the specific design requirements. An analytical model was developed to predict the D-H-FRP stress-strain curves with different combination of fiber materials and geometric configuration. This model was used to optimize the design of D-H-FRP bars. An in-line braiding-pultrusion manufacturing process was developed at Drexel University to produce high quality D-H-FRP reinforcement in diameters that can be used in concrete structures. A series of experiments were carried out to test D-H-FRP reinforcement as well as their individual components in monotonic and cyclic tensile tests. Using the results from the tensile tests and fracture analysis, the stress-strain behavior of the D-H-FRP reinforcement was fully characterized and explained. Two series of concrete beams reinforced with D-H-FRP bars were studied. The D-H-FRP beam test results were then compared with companion

  10. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    PubMed Central

    Le, Minh-Tai; Huang, Shyh-Chour

    2015-01-01

    In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs) by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg), as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs. PMID:28793521

  11. MRI-guided targeting delivery of doxorubicin with reduction-responsive lipid-polymer hybrid nanoparticles.

    PubMed

    Wu, Bo; Lu, Shu-Ting; Deng, Kai; Yu, Hui; Cui, Can; Zhang, Yang; Wu, Ming; Zhuo, Ren-Xi; Xu, Hai-Bo; Huang, Shi-Wen

    2017-01-01

    In recent years, there has been increasing interest in developing a multifunctional nanoscale platform for cancer monitoring and chemotherapy. However, there is still a big challenge for current clinic contrast agents to improve their poor tumor selectivity and response. Herein, we report a new kind of Gd complex and folate-coated redox-sensitive lipid-polymer hybrid nanoparticle (Gd-FLPNP) for tumor-targeted magnetic resonance imaging and therapy. Gd-FLPNPs can simultaneously accomplish diagnostic imaging, and specific targeting and controlled release of doxorubicin (DOX). They exhibit good monodispersity, excellent size stability, and a well-defined core-shell structure. Paramagnetic nanoparticles based on gadolinium-diethylenetriaminepentaacetic acid-bis-cetylamine have paramagnetic properties with an approximately two-fold enhancement in the longitudinal relaxivity compared to clinical used Magnevist. For targeted and reduction-sensitive drug delivery, Gd-FLPNPs released DOX faster and enhanced cell uptake in vitro, and exhibited better antitumor effect both in vitro and in vivo.

  12. Folate-containing reduction-sensitive lipid-polymer hybrid nanoparticles for targeted delivery of doxorubicin.

    PubMed

    Wu, Bo; Yu, Ping; Cui, Can; Wu, Ming; Zhang, Yang; Liu, Lei; Wang, Cai-Xia; Zhuo, Ren-Xi; Huang, Shi-Wen

    2015-04-01

    The development and evaluation of folate-targeted and reduction-triggered biodegradable nanoparticles are introduced to the research on targeted delivery of doxorubicin (DOX). This type of folate-targeted lipid-polymer hybrid nanoparticles (FLPNPs) is comprised of a poly(D,L-lactide-co-glycolide) (PLGA) core, a soybean lecithin monolayer, a monomethoxy-poly(ethylene glycol)-S-S-hexadecyl (mPEG-S-S-C16) reduction-sensitive shell, and a folic acid-targeted ligand. FLPNPs exhibited high size stability but fast disassembly in a simulated cancer cell reductive environment. The experiments on the release process in vitro revealed that as a reduction-sensitive drug delivery system, FLPNPs released DOX faster in the presence of 10 mM dithiothreitol (DTT). Results from flow cytometry, confocal image and in vitro cytotoxicity assays revealed that FLPNPs further enhanced cell uptake and generated higher cytotoxicity against human epidermoid carcinoma in the oral cavity than non-targeted redox-sensitive and targeted redox-insensitive controls. Furthermore, in vivo animal experiments demonstrated that systemic administration of DOX-loaded FLPNPs remarkably reduced tumor growth. Experiments on biodistribution of DOX-loaded FLPNPs showed that an increasing amount of DOX accumulated in the tumor. Therefore, FLPNPs formulations have proved to be a stable, controllable and targeted anticancer drug delivery system.

  13. Mechanistic profiling of the siRNA delivery dynamics of lipid-polymer hybrid nanoparticles.

    PubMed

    Colombo, Stefano; Cun, Dongmei; Remaut, Katrien; Bunker, Matt; Zhang, Jianxin; Martin-Bertelsen, Birte; Yaghmur, Anan; Braeckmans, Kevin; Nielsen, Hanne M; Foged, Camilla

    2015-03-10

    Understanding the delivery dynamics of nucleic acid nanocarriers is fundamental to improve their design for therapeutic applications. We investigated the carrier structure-function relationship of lipid-polymer hybrid nanoparticles (LPNs) consisting of poly(DL-lactic-co-glycolic acid) (PLGA) nanocarriers modified with the cationic lipid dioleoyltrimethyl-ammoniumpropane (DOTAP). A library of siRNA-loaded LPNs was prepared by systematically varying the nitrogen-to-phosphate (N/P) ratio. Atomic force microscopy (AFM) and cryo-transmission electron microscopy (cryo-TEM) combined with small angle X-ray scattering (SAXS) and confocal laser scanning microscopy (CLSM) studies suggested that the siRNA-loaded LPNs are characterized by a core-shell structure consisting of a PLGA matrix core coated with lamellar DOTAP structures with siRNA localized both in the core and in the shell. Release studies in buffer and serum-containing medium combined with in vitro gene silencing and quantification of intracellular siRNA suggested that this self-assembling core-shell structure influences the siRNA release kinetics and the delivery dynamics. A main delivery mechanism appears to be mediated via the release of transfection-competent siRNA-DOTAP lipoplexes from the LPNs. Based on these results, we suggest a model for the nanostructural characteristics of the LPNs, in which the siRNA is organized in lamellar superficial assemblies and/or as complexes entrapped in the polymeric matrix. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. PEG-detachable lipid-polymer hybrid nanoparticle for delivery of chemotherapy drugs to cancer cells.

    PubMed

    Du, Jiang-bo; Song, Yan-feng; Ye, Wei-liang; Cheng, Ying; Cui, Han; Liu, Dao-zhou; Liu, Miao; Zhang, Bang-le; Zhou, Si-yuan

    2014-08-01

    The experiment aimed to increase the drug-delivery efficiency of poly-lactic-co-glycolic acid (PLGA) nanoparticles. Lipid-polymer hybrid nanoparticles (LPNs-1) were prepared using PLGA as a hydrophobic core and FA-PEG-hyd-DSPE as an amphiphilic shell. Uniform and spherical nanoparticles with an average size of 185 nm were obtained using the emulsification solvent evaporation method. The results indicated that LPNs-1 showed higher drug loading compared with naked PLGA nanoparticles (NNPs). Drug release from LPNs-1 was faster in an acidic environment than in a neutral environment. LPNs-1 showed higher cytotoxicity on KB cells, A549 cells, MDA-MB-231 cells, and MDA-MB-231/ADR cells compared with free doxorubicin (DOX) and NNPs. The results also showed that, compared with free DOX and NNPs, LPNs-1 delivered more DOX to the nuclear of KB cells and MDA-MB-231/ADR cells. LPNs-1 induced apoptosis in KB cells and MDA-MB-231/ADR cells in a dose-dependent manner. The above data indicated that DOX-loaded LPNs-1 could kill not only normal tumor cells but also drug-resistant tumor cells. These results indicated that modification of PLGA nanoparticles with FA-PEG-hyd-DSPE could considerably increase the drug-delivery efficiency and LPNs-1 had potential in the delivery of chemotherapeutic agents in the treatment of cancer.

  15. General overview of lipid-polymer hybrid nanoparticles, dendrimers, micelles, liposomes, spongosomes and cubosomes.

    PubMed

    Wakaskar, Rajesh R

    2018-04-01

    In recent years, the wider use of nanotechnology has attracted greater attention from scientists in multi-disciplinary fields. Nanotechnological research has come a long way in the past decade, with major advances being made, both in terms of diagnostic and therapeutic potential of nanoparticles. Areas covered: Some of the prominently discussed nanoparticles in this day and age are polymeric micelles, liposomes, lipid-polymer hybrid nanoparticles, dendrimers, spongosomes and cubosomes. This review attempts to focus on the conventional advantages and exemplary features that these particles possess, thus making them some of the most ideal vehicles for drug delivery. Expert opinion: Particulate systems, which have been extensively studied in this article, have been employed to enhance the pharmacokinetic and pharmacodynamic characteristics of various hydrophobic and hydrophilic drug moieties, thus attempting to prolong the blood circulation times and increase their efficacy over unmodified drug molecules. These modification techniques have enabled these drug molecules to be delivered to the pharmacological sites of action at an optimised controlled rate, thus trying to minimise the potential for any toxicity resulting from the non-specific distribution of drug to various organs.

  16. Refractive Index Tuning of Hybrid Materials for Highly Transmissive Luminescent Lanthanide Particle-Polymer Composites.

    PubMed

    Kim, Paul; Li, Cheng; Riman, Richard E; Watkins, James

    2018-03-14

    High-refractive-index ZrO 2 nanoparticles were used to tailor the refractive index of a polymer matrix to match that of luminescent lanthanide-ion-doped (La 0.92 Yb 0.075 Er 0.005 F 3 ) light-emitting particles, thereby reducing scattering losses to yield highly transparent emissive composites. Photopolymerization of blends of an amine-modified poly(ether acrylate) oligomer and tailored quantities of ZrO 2 nanoparticles yielded optically transparent composites with tailored refractive indices between 1.49 and 1.69. By matching the refractive index of the matrix to that of La 0.92 Yb 0.075 Er 0.005 F 3 , composites with high transmittance (>85%) and low haze from the visible to infrared regions, bright 1530 nm optical emissions were achieved at solids loadings of La 0.92 Yb 0.075 Er 0.005 F 3 , ranging from 5 to 30 vol %. These optical results suggest that a hybrid matrix approach is a versatile strategy for the fabrication of functional luminescent optical composites of high transparency.

  17. Inhibition of hemangioma growth using polymer-lipid hybrid nanoparticles for delivery of rapamycin.

    PubMed

    Li, Haitao; Teng, Yunfei; Sun, Jin; Liu, Jianyong

    2017-11-01

    Although infantile hemangiomas is benign, its rapid growth may induce serious complications. However, only one drug Hemangeol™ has been approved by US Food and Drug Administration (FDA) to treat infantile hemangiomas. Thus it is necessary to develop novel alternative drugs to treat infantile hemangiomas. Rapamycin is a well-know potent antiangiogenic agent, whereas the daily oral administration of rapamycin exerts undesired metabolic effects due to its inhibition of mechanistic target of rapamycin (mTOR) which is critical in cell metabolism. We hereby developed rapamycin-loaded polymer-lipid hybrid nanoparticles (Rapamycin-PLNPs) as a local controlled release system to realize local and sustained release of rapamycin, aiming to reduce the side effects and frequency of administration of rapamycin. Rapamycin-PLNPs are of a small size (129.1nm), desired drug encapsulation efficiency (63.7%), and sustained drug release for 5 days. Rapamycin-PLNPs were shown to be able to effectively bind to hemangioma endothelia cells (HemECs), induce significant proliferation inhibition and reduce expression of angiogenesis factors in HemECs. The therapeutic effect of Rapamycin-PLNPs against infantile hemangioma in vivo was superior to rapamycin, as reflected by reduced hemangioma volume, weight and microvessel density. Taken together, Rapamycin-PLNPs represent a very promising local approach in the treatment of infantile hemangiomas. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  18. Efficient and Tunable Three-Dimensional Functionalization of Fully Zwitterionic Antifouling Surface Coatings.

    PubMed

    Lange, Stefanie C; van Andel, Esther; Smulders, Maarten M J; Zuilhof, Han

    2016-10-11

    To enhance the sensitivity and selectivity of surface-based (bio)sensors, it is of crucial importance to diminish background signals that arise from the nonspecific binding of biomolecules, so-called biofouling. Zwitterionic polymer brushes have been shown to be excellent antifouling materials. However, for sensing purposes, antifouling does not suffice but needs to be combined with the possibility to efficiently modify the brush with recognition units. So far this has been achieved only at the expense of either antifouling properties or binding capacity. Herein we present a conceptually new approach by integrating both characteristics into a single tailor-made monomer: a novel sulfobetaine-based zwitterionic monomer equipped with a clickable azide moiety. Copolymerization of this monomer with a well-established standard sulfobetaine monomer results in highly antifouling surface coatings with a large yet tunable number of clickable groups present throughout the entire brush. Subsequent functionalization of the azido brushes via widely used strain-promoted alkyne azide click reactions yields fully zwitterionic 3D-functionalized coatings with a recognition unit of choice that can be tailored for any specific application. Here we show a proof of principle with biotin-functionalized brushes on Si 3 N 4 that combine excellent antifouling properties with specific avidin binding from a protein mixture. The signal-to-noise ratio is significantly improved over that of traditional chain-end modification of sulfobetaine polymer brushes, even if the azide content is lowered to 1%. This therefore offers a viable approach to the development of biosensors with greatly enhanced performance on any surface.

  19. Polymers.

    ERIC Educational Resources Information Center

    Tucker, David C.

    1986-01-01

    Presents an open-ended experiment which has students exploring polymer chemistry and reverse osmosis. This activity involves construction of a polymer membrane, use of it in a simple osmosis experiment, and application of its principles in solving a science-technology-society problem. (ML)

  20. Organic-inorganic hybrid polymer electrolytes based on polyether diamine, alkoxysilane, and trichlorotriazine: Synthesis, characterization, and electrochemical applications

    NASA Astrophysics Data System (ADS)

    Saikia, Diganta; Wu, Cheng-Gang; Fang, Jason; Tsai, Li-Duan; Kao, Hsien-Ming

    2014-12-01

    A new type of highly conductive organic-inorganic hybrid polymer electrolytes has been synthesized by the reaction of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol) bis(2-aminopropyl ether), 2,4,6-trichloro-1,3,5-triazine and alkoxysilane precursor 3-(glycidyloxypropyl)trimethoxysilane, followed by doping of LiClO4. The 13C and 29Si solid-sate NMR results confirm the successful synthesis of the organic-inorganic hybrid structure. The solid hybrid electrolyte thus obtained exhibits a maximum ionic conductivity of 1.6 × 10-4 S cm-1 at 30 °C, which is the highest among the organic-inorganic hybrid electrolytes. The hybrid electrolytes are electrochemically stable up to 4.2 V. The prototype electrochromic device with such a solid hybrid electrolyte demonstrates a good coloration efficiency value of 183 cm2 C-1 with a cycle life over 200 cycles. For the lithium-ion battery test, the salt free solid hybrid membrane is swelled with a LiPF6-containing electrolyte solution to reach an acceptable ionic conductivity value of 6.5 × 10-3 S cm-1 at 30 °C. The battery cell carries an initial discharge capacity of 100 mAh g-1 at 0.2C-rate and a coulombic efficiency of about 95% up to 30 cycles without the sign of cell failure. The present organic-inorganic hybrid electrolytes hold promise for applications in electrochromic devices and lithium ion batteries.

  1. Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

    NASA Astrophysics Data System (ADS)

    Gupta, Sanju; Price, Carson

    2015-10-01

    Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL) assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO)1, (PPy/ErGO)1, (PAni/GO)1 and (PPy/GO)1. The rationale design is to create thin films that possess interconnected graphene nanosheets (GNS) with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, Cs, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent Cs of ≥350 F g-1 as compared with constituents (˜70 F g-1) at discharge current density of 0.3 A g-1 that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM) technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting) and conducting polymers (semiconducting) backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to determine electrochemical (re)activity of surface ion adsorption sites

  2. Scanning electrochemical microscopy of graphene/polymer hybrid thin films as supercapacitors: Physical-chemical interfacial processes

    SciT

    Gupta, Sanju, E-mail: sanju.gupta@wku.edu; Price, Carson

    2015-10-15

    Hybrid electrode comprising an electric double-layer capacitor of graphene nanosheets and a pseudocapacitor of the electrically conducting polymers namely, polyaniline; PAni and polypyrrole; PPy are constructed that exhibited synergistic effect with excellent electrochemical performance as thin film supercapacitors for alternative energy. The hybrid supercapacitors were prepared by layer-by-layer (LbL) assembly based on controlled electrochemical polymerization followed by reduction of graphene oxide electrochemically producing ErGO, for establishing intimate electronic contact through nanoscale architecture and chemical stability, producing a single bilayer of (PAni/ErGO){sub 1}, (PPy/ErGO){sub 1}, (PAni/GO){sub 1} and (PPy/GO){sub 1}. The rationale design is to create thin films that possess interconnectedmore » graphene nanosheets (GNS) with polymer nanostructures forming well-defined tailored interfaces allowing sufficient surface adsorption and faster ion transport due to short diffusion distances. We investigated their electrochemical properties and performance in terms of gravimetric specific capacitance, C{sub s}, from cyclic voltammograms. The LbL-assembled bilayer films exhibited an excellent C{sub s} of ≥350 F g{sup −1} as compared with constituents (∼70 F g{sup −1}) at discharge current density of 0.3 A g{sup −1} that outperformed many other hybrid supercapacitors. To gain deeper insights into the physical-chemical interfacial processes occurring at the electrode/electrolyte interface that govern their operation, we have used scanning electrochemical microscopy (SECM) technique in feedback and probe approach modes. We present our findings from viewpoint of reinforcing the role played by heterogeneous electrode surface composed of nanoscale graphene sheets (conducting) and conducting polymers (semiconducting) backbone with ordered polymer chains via higher/lower probe current distribution maps. Also targeted is SECM imaging that allowed to

  3. Hybrid Nanoscale Architecture of Wound Dressing with Super Hydrophilic, Antimicrobial, and Ultralow Fouling Attributes.

    PubMed

    Depan, D; Misra, R D K

    2015-02-01

    Currently available wound dressings to heal thermal and chronic wounds are unable to respond to the challenges of resistance to bacterial infection, protein adsorption, and increased levels of wound exudates. To this end, we have conceived the fabrication of a new and ideal wound dressing with a number of key attributes. They include effective antimicrobial activity in a controlled manner, ultralow fouling property that provides resistance to protein adsorption and bacterial adhesion, maintain a moist but not saturated environment to promote healing, and is non-adherent and effective in the presence of heavy wound exudate. The novel approach to reduce infection and bacterial colonization involves incorporation of a unique silver-clay nanohybrid architecture in zwitterionic polymer, poly(sulfobetaine). The innovative concept of silver-clay hybrid structure enables us to obtain high, sustained, and diffusion-controlled antimicrobial activity of silver eluting polymer. The sustained and diffusion-controlled high antimicrobial efficiency is obtained through a process involving in situ precipitation of silver nanoparticles with large surface area on the surface of clay platelets. Furthermore, the use of recently developed zwitterionic polymer, poly(sulfobetaine) [poly(SB)] for wound dressing, provides antifouling property, which resists protein adsorption.

  4. Synthesis of mesoporous nano-hydroxyapatite by using zwitterions surfactant

    EPA Science Inventory

    Mesoporous nano-hydroxyapatite (mn-HAP) was successfully synthesized via a novel micelle-templating method using lauryl dimethylaminoacetic acid as zwitterionic surfactant. The systematic use of such a surfactant in combination with microwave energy inputenables the precise contr...

  5. Pulmonary delivery of antitubercular drugs using spray-dried lipid-polymer hybrid nanoparticles.

    PubMed

    Bhardwaj, Ankur; Mehta, Shuchi; Yadav, Shailendra; Singh, Sudheer K; Grobler, Anne; Goyal, Amit Kumar; Mehta, Abhinav

    2016-09-01

    The present study aimed to develop lipid-polymer hybrid nanoparticles (LPNs) for the combined pulmonary delivery of isoniazid (INH) and ciprofloxacin hydrochloride (CIP HCl). Drug-loaded LPNs were prepared by the double-emulsification solvent evaporation method using the three-factor three-level Box-Behnken design. The optimized formulation had a size of 111.81 ± 1.2 nm, PDI of 0.189 ± 1.4, and PDE of 63.64 ± 2.12% for INH-loaded LPN, and a size of 172.23 ± 2.31 nm, PDI of 0.169 ± 1.23, and PDE of 68.49 ± 2.54% for CIP HCl-loaded LPN. Drug release was found to be sustained and controlled at lower pH and followed the Peppas model. The in vitro uptake study in alveolar macrophage (AM) showed that uptake of the drugs was increased significantly if administered in the form of LPN. The stability study proved the applications of adding PLGA in LPN as the polymeric core, which leads to a much more stable product as compared to other novel drug delivery systems. Spray drying was done to produce an inhalable, dry, powdered form of drug-loaded LPN. The spray-dried (SD) powder was equally capable of producing nano-aggregates having morphology, density, flowability and reconstitutibility in the range ideal for inhaled drug delivery. The nano aggregates produced by spray drying manifested their aerosolization efficiency in terms of the higher emitted dose and fine particle fraction with lower mass median aerodynamic diameter. The in vivo study using pharmacokinetic and pharmacodynamic approaches revealed that maximum internalization efficiency was achieved by delivering LPN in SD powdered forms by pulmonary route.

  6. Unveiling the hybrid interface in polymer nanocomposites enclosing silsesquioxanes with tunable molecular structure: Spectroscopic, thermal and mechanical properties.

    PubMed

    D'Arienzo, Massimiliano; Diré, Sandra; Redaelli, Matteo; Borovin, Evgeny; Callone, Emanuela; Di Credico, Barbara; Morazzoni, Franca; Pegoretti, Alessandro; Scotti, Roberto

    2018-02-15

    Organic-inorganic nanobuilding blocks (NBBs) based on silsesquioxanes (SSQs) have potential applications as nanofillers, thermal stabilizers, and rheological modifiers, which can improve thermomechanical properties of polymer hosts. The possibility to tune both siloxane structure and pendant groups can promote compatibilization and peculiar interactions with a plethora of polymers. However, the control on SSQs molecular architecture and functionalities is usually delicate and requires careful synthetic details. Moreover, investigating the influence of NBBs loading and structure on the hybrid interface and, in turn, on the polymer chains mobility and mechanical properties, may be challenging, especially for low-loaded materials. Herein, we describe the preparation and characterization of polybutadiene (PB) nanocomposites using as innovative fillers thiol-functionalized SSQs nanobuilding blocks (SH-NBBs), with both tailorable functionality and structure. Swelling experiments and, more clearly, solid-state NMR, enlightened a remarkable effect of SH-NBBs on the molecular structure and mobility of the polymeric chains, envisaging the occurrence of chemical interactions at the hybrid interface. Finally, thermal and DMTA analyses revealed that nanocomposites, even containing very low filler loadings (i.e. 1, 3 wt%), exhibited enhanced thermomechanical properties, which seem to be connected not only to the loading, but also to the peculiar cage or ladder-like architecture of SH-NBBs. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Construction of multifunctional MoSe2 hybrid towards the simultaneous improvements in fire safety and mechanical property of polymer.

    PubMed

    Wang, Junling; Ma, Chao; Mu, Xiaowei; Cai, Wei; Liu, Longxiang; Zhou, Xia; Hu, Weizhao; Hu, Yuan

    2018-06-15

    Organic modification of MoSe 2 sheets is firstly achieved by Atherton-Todd reaction, aiming at the acquisition of multifunctional MoSe 2 hybrid. Simultaneous enhancements in fire safety and mechanical property of thermalplastic polyurethane (TPU) are obtained with the presence of this hybrid. Strong interfacial interactions between the functionalized MoSe 2 sheets and TPU can be obtained, making more efficient load transfer from the weak polymer chains to the robust sheets. Besides, more coherent barrier network may be formed in polymer matrix, restraining the diffusion of decomposed fragments and reducing the supply for combustion fuel. Consequently, the decreases in heat release are observed for polymer composites. Notably, the releases of toxic gases, such as HCN and CO, are also suppressed by this barrier network, resulting in the reductions in fire toxicity. This work may open a new door for the functionalization of MoSe 2 sheets and evoke significant developments in its promising applications. Copyright © 2018. Published by Elsevier B.V.

  8. Polymer-silica hybrids for separation of CO2 and catalysis of organic reactions

    NASA Astrophysics Data System (ADS)

    Silva Mojica, Ernesto

    spectroscopic investigation of the interactions of CO 2 with amine molecules under simulated CO2 capture conditions. Industrial CO2 capture processes involve fluidization and require degradation-resistant sorbents in the form of pellets. Agglomeration of silica-based CO2 capture sorbents involved the formulation of a polymer binder solution and the design of a scalable pelletization process. The characterization of these pellets revealed the formation of a CO 2-permeable polymer-silica network, which is resistant to attrition, and exhibits similar CO2 capture and degradation performance as the non-pelletized sorbents. The performance of these sorbents and pellets was tested in lab-scale and bench-scale adsorption units, using in-house fabricated fixed-bed and fluidized-bed reactors. A compartmental modeling technique was used to simulate the CO2 adsorption process and to elucidate the kinetic and thermodynamic parameters that impact the commercial viability of emerging CO2 capture technologies. The fundamental concepts and experimental techniques developed for the preparation of CO2 capture sorbents served as a basis for fabricating amine-functionalized polymer-silica hybrids for applications in catalysis of organic reactions. (i) Basic catalysts for carbon-carbon addition reactions were prepared by immobilization of amine molecules on silica supports. The activity of these catalysts and the mechanisms of base-catalyzed organic condensation reactions were investigated by an in-situ FTIR micro-scale reactor. (ii) Particle-loaded PVA composite membranes were selected for immobilization of glucose oxidase (GOx). GOx was immobilized by adsorption at pH values between 3.5 and 7.1. The results showed that adsorption was primarily achieved via hydrophobic interactions, and that PVA membranes loaded with amine-functionalized particles could help retain the activity of immobilized GOx by providing a proper hydrophilic/hydrophobic balance to the immobilized enzymes micro-environment.

  9. Zwitterionic Group VIII transition metal initiators supported by olefin ligands

    DOEpatents

    Bazan, Guillermo C [Goleta, CA; Chen, Yaofeng [Shanghai, CN

    2011-10-25

    A zwitterionic Group VIII transition metal complex containing the simple and relatively small 3-(arylimino)-but-1-en-2-olato ligand that catalyzes the formation of polypropylene and high molecular weight polyethylene. A novel feature of this catalyst is that the active species is stabilized by a chelated olefin adduct. The present invention also provides methods of polymerizing olefin monomers using zwitterionic catalysts, particularly polypropylene and high molecular weight polyethylene.

  10. Zwitteration: Coating Surfaces with Zwitterionic Functionality to Reduce Nonspecific Adsorption

    PubMed Central

    2015-01-01

    Coating surfaces with thin or thick films of zwitterionic material is an effective way to reduce or eliminate nonspecific adsorption to the solid/liquid interface. This review tracks the various approaches to zwitteration, such as monolayer assemblies and polymeric brush coatings, on micro- to macroscopic surfaces. A critical summary of the mechanisms responsible for antifouling shows how zwitterions are ideally suited to this task. PMID:24754399

  11. Preparation of a collagen/polymer hybrid gel designed for tissue membranes. Part I: controlling the polymer-collagen cross-linking process using an ethanol/water co-solvent.

    PubMed

    Nam, Kwangwoo; Kimura, Tsuyoshi; Funamoto, Seiichi; Kishida, Akio

    2010-02-01

    The drawback with collagen/2-methacryloyloxyethyl phosphorylcholine (MPC) polymer hybrid gels (collagen/phospholipid polymer hybrid gels) prepared in alkaline morpholinoethane sulfonic acid (MES) aqueous solution is that the cross-linking rate between the polymer and the collagen is low. To solve this problem, ethanol has been adopted as the reaction solvent, to prevent 1-ethyl-3-(3-dimethylaminopropyl)-1-carbodiimide hydrochloride (EDC) hydrolysis. Alterations in the ethanol mole concentration changed the cross-linking rate between the MPC polymer and the collagen gel. Prevention of EDC hydrolysis is clearly observed; protonation of carboxyl groups implies that the ratio of ethanol to water should be controlled. The polymer shows signs of penetration into the collagen gel layer, thus forming a totally homogeneous phase gel. This affects the mechanical strength of the collagen gel, making the gel much stiffer and brittle with an increase in the swelling ratio, as compared with that prepared in MES buffer. However, it is possible to obtain a collagen/phospholipid polymer hybrid gel with a high polymer portion and the cross-linking rate can be successfully controlled.

  12. Multidentate zwitterionic chitosan oligosaccharide modified gold nanoparticles: stability, biocompatibility and cell interactions

    NASA Astrophysics Data System (ADS)

    Liu, Xiangsheng; Huang, Haoyuan; Liu, Gongyan; Zhou, Wenbo; Chen, Yangjun; Jin, Qiao; Ji, Jian

    2013-04-01

    Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt conditions, wide pH range and serum or plasma containing media. The AuNPs also show strong resistance to competition from dithiothreitol (as high as 1.5 M). Moreover, the modified AuNPs demonstrate low cytotoxicity investigated by both MTT and LDH assays, and good hemocompatibility evaluated by hemolysis of human red blood cells. In addition, the intracellular fate of AuNPs was investigated by ICP-MS and TEM. It showed that the AuNPs are uptaken by cells in a concentration dependent manner, and they can escape from endosomes/lysosomes to cytosol and tend to accumulate around the nucleus after 24 h incubation but few of them are excreted out of the cells. Gold nanorods are also stabilized by this ligand, which demonstrates robust dispersion stability and excellent hemocompatibility. This kind of multidentate zwitterionic chitosan derivative could be widely used for stabilizing other inorganic nanoparticles, which will greatly improve their performance in a variety of bio-related applications.Surface engineering of nanoparticles plays an essential role in their colloidal stability, biocompatibility and interaction with biosystems. In this study, a novel multidentate zwitterionic biopolymer derivative is obtained from conjugating dithiolane lipoic acid and zwitterionic acryloyloxyethyl phosphorylcholine to the chitosan oligosaccharide backbone. Gold nanoparticles (AuNPs) modified by this polymer exhibit remarkable colloidal stabilities under extreme conditions including high salt

  13. An insight into the mechanism of charge-transfer of hybrid polymer:ternary/quaternary chalcopyrite colloidal nanocrystals.

    PubMed

    Chawla, Parul; Singh, Son; Sharma, Shailesh Narain

    2014-01-01

    In this work, we have demonstrated the structural and optoelectronic properties of the surface of ternary/quaternary (CISe/CIGSe/CZTSe) chalcopyrite nanocrystallites passivated by tri-n-octylphosphine-oxide (TOPO) and tri-n-octylphosphine (TOP) and compared their charge transfer characteristics in the respective polymer: chalcopyrite nanocomposites by dispersing them in poly(3-hexylthiophene) polymer. It has been found that CZTSe nanocrystallites due to their high crystallinity and well-ordered 3-dimensional network in its pristine form exhibit a higher steric- and photo-stability, resistance against coagulation and homogeneity compared to the CISe and CIGSe counterparts. Moreover, CZTSe nanocrystallites display efficient photoluminescence quenching as evident from the high value of the Stern-Volmer quenching constant (K SV) and eventually higher charge transfer efficiency in their respective polymer P3HT:CZTSe composites. We modelled the dependency of the charge transfer from the donor and the charge separation mechanism across the donor-acceptor interface from the extent of crystallinity of the chalcopyrite semiconductors (CISe/CIGSe/CZTSe). Quaternary CZTSe chalcopyrites with their high crystallinity and controlled morphology in conjunction with regioregular P3HT polymer is an attractive candidate for hybrid solar cells applications.

  14. Luminescence properties and molecular mechanics calculation of bis-β-diketonate Eu3+ complex/polymer hybrid fibers

    NASA Astrophysics Data System (ADS)

    Bai, Jinyuan; Gu, Huiquan; Hou, Yanjun; Wang, Shuhong

    2018-05-01

    Two series of bis-β-diketonate Eu3+ complex/polymer hybrid fibers, namely, Eu2(BTP)3(H2O)4/PMMA (Eu/PMMA) and Eu2(BTP)3(H2O)4/PVP (Eu/PVP) have been prepared by electrospinning technology (BTP = 1,3-bis(4,4,4-trifluoro-1,3-dioxobutyl)phenyl, PVP = poly (vinyl pyrrolidone) and PMMA = poly (methyl methacrylate)). The effect of complex Eu2(BTP)3(H2O)4 on the luminescence, thermal stability and morphology of composite fibers were studied by characterization techniques. The Judd-Ofelt theory was applied to this study for explaining the effect of the distribution of Eu2(BTP)3(H2O)4 and the mutual effect of the Eu2(BTP)3(H2O)4 coordination compound and neighboring chain segments of PMMA and PVP polymer matrix.

  15. Organic-Inorganic Hybrid Polymers as Adsorbents for Removal of Heavy Metal Ions from Solutions: A Review

    PubMed Central

    Samiey, Babak; Cheng, Chil-Hung; Wu, Jiangning

    2014-01-01

    Over the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores), assembling of nanobuilding blocks (e.g., layered or core-shell compounds) and as interpenetrating networks and hierarchically structures. Lastly, the adsorption characteristics of heavy metals of these materials, including different kinds of functional groups, selectivity of them for heavy metals, effect of pH and synthesis conditions on adsorption capacity, are studied. PMID:28788483

  16. Variation in emulsion stabilization behavior of hybrid silicone polymers with change in molecular structure: Phase diagram study.

    PubMed

    Mehta, Somil C; Somasundaran, P; Kulkarni, Ravi

    2009-05-15

    Silicone oils are widely used in cosmetics and personal care applications to improve softness and condition skin and hair. Being insoluble in water and most hydrocarbons, a common mode of delivering them is in the form of emulsions. Currently most applications use polyoxyethylene (non-ionic) modified siloxanes as emulsifiers to stabilize silicone oil emulsions. However, ionically grafted silicone polymers have not received much attention. Ionic silicones have significantly different properties than the non-ionic counterpart. Thus considerable potential exists to formulate emulsions of silicones with different water/silicone oil ratios for novel applications. In order to understand the mechanisms underlying the effects of hydrophilic modifications on the ability of hybrid silicone polymers to stabilize various emulsions, this article focuses on the phase diagram studies for silicone emulsions. The emulsifying ability of functional silicones was seen to depend on a number of factors including hydrophilicity of the polymer, nature of the functional groups, the extent of modification, and the method of emulsification. It was observed that the region of stable emulsion in a phase diagram expanded with increase in shear rate. At a given shear rate, the region of stable emulsion and the nature of emulsion (water-in-oil or oil-in-water) was observed to depend on hydrophilic-hydrophobic balance of the hybrid silicone emulsifier. At a fixed amount of modification, the non-ionically modified silicone stabilized an oil-in-water emulsion, whereas the ionic silicones stabilized inverse water-in-oil emulsions. This was attributed to the greater hydrophilicity of the polyoxyethylene modified silicones than the ionic counterparts. In general, it is postulated that with progressive increase in hydrophilicity of hybrid silicone emulsifiers, their tendency to stabilize water-in-oil emulsion decreases with corresponding increase in oil-in-water emulsion. Further, this behavior is

  17. Methacrylated monosaccharides as the modifiers for carbochain polymers: Synthesis, mechanical/thermal properties and biodegradability of hybrids

    NASA Astrophysics Data System (ADS)

    Yakushev, P.; Bershtein, V.; Bukowska-Śluz, I.; Sobiesiak, M.; Gawdzik, B.

    2016-05-01

    Methacrylated derivatives of glucose (MGLU) and galactose (MGAL) were synthesized by the procedure described by Vogel, and their copolymers with methyl methacrylate (MMA) and MMA/N-vinyl pyrrolidone (MMA/NVP) (1:1) mixture were obtained with the aim to modify some properties of carbochain polymers, in particular to generate their biodegradability. These hybrids of synthetic and natural products, with 10, 20 or 30 wt. % modifiers, were characterized by DMA and TGA methods and in the biodegradation tests. Increasing Tg values by 20-30°C was registered in all cases whereas thermal stability was improved only for PMMA due to modification. On the contrary, only for hybrids based on hygroscopic MMA/NVP copolymer the essential biodegradability could be generated.

  18. Organometallic exposure dependence on organic–inorganic hybrid material formation in polyethylene terephthalate and polyamide 6 polymer fibers

    SciT

    Akyildiz, Halil I.; Jur, Jesse S., E-mail: jsjur@ncsu.edu

    2015-03-15

    The effect of exposure conditions and surface area on hybrid material formation during sequential vapor infiltrations of trimethylaluminum (TMA) into polyamide 6 (PA6) and polyethylene terephthalate (PET) fibers is investigated. Mass gain of the fabric samples after infiltration was examined to elucidate the reaction extent with increasing number of sequential TMA single exposures, defined as the times for a TMA dose and a hold period. An interdependent relationship between dosing time and holding time on the hybrid material formation is observed for TMA exposure PET, exhibited as a linear trend between the mass gain and total exposure (dose time ×more » hold time × number of sequential exposures). Deviation from this linear relationship is only observed under very long dose or hold times. In comparison, amount of hybrid material formed during sequential exposures to PA6 fibers is found to be highly dependent on amount of TMA dosed. Increasing the surface area of the fiber by altering its cross-sectional dimension is shown to have little on the reaction behavior but does allow for improved diffusion of the TMA into the fiber. This work allows for the projection of exposure parameters necessary for future high-throughput hybrid modifications to polymer materials.« less

  19. Multi-component lanthanide hybrids based on zeolite A/L and zeolite A/L-polymers for tunable luminescence.

    PubMed

    Chen, Lei; Yan, Bing

    2015-02-01

    Some multi-component hybrids based on zeolite L/A are prepared. Firstly, zeolite A/L is loaded with lanthanide complexes (Eu-DBM or Tb-AA (acetylacetone = AA, dibenzoylmethane = DBM)) into its channels. Secondly, 3-methacryloyloxypropyltrimethoxysilane (γ-MPS) is used to covalently graft onto the surface of functionalized zeolite A/L (Si-[ZA/L⊃Eu-DBM(Tb-AA)]). Thirdly, lanthanide ions (Eu(3+)/Tb(3+)) are coordinated to the functionalized zeolite A/L and ligands (phen(1,10-phenanthroline) or bipy (2,2'-bipyridyl)) are introduced by a ship-in-bottle method. The inside-outside double modifications of ZA/L with lanthanide complexes afford the final hybrids and these are characterized by means of XRD, FT-IR, UV-vis DRS, SEM and luminescence spectroscopy, some of which display white or near-white light emission. Furthermore, selected above-mentioned hybrids are incorporated into PEMA/PMMA (poly ethyl methylacryate/poly methyl methacrylate) hosts to prepare luminescent polymer films. These results provide abundant data that these hybrid materials can be expected to have potential application in various practical fields.

  20. Polymer composites and porous materials prepared by thermally induced phase separation and polymer-metal hybrid methods

    NASA Astrophysics Data System (ADS)

    Yoon, Joonsung

    The primary objective of this research is to investigate the morphological and mechanical properties of composite materials and porous materials prepared by thermally induced phase separation. High melting crystallizable diluents were mixed with polymers so that the phase separation would be induced by the solidification of the diluents upon cooling. Theoretical phase diagrams were calculated using Flory-Huggins solution thermodynamics which show good agreement with the experimental results. Porous materials were prepared by the extraction of the crystallized diluents after cooling the mixtures (hexamethylbenzene/polyethylene and pyrene/polyethylene). Anisotropic structures show strong dependence on the identity of the diluents and the composition of the mixtures. Anisotropic crystal growth of the diluents was studied in terms of thermodynamics and kinetics using DSC, optical microscopy and SEM. Microstructures of the porous materials were explained in terms of supercooling and dendritic solidification. Dual functionality of the crystallizable diluents for composite materials was evaluated using isotactic polypropylene (iPP) and compatible diluents that crystallize upon cooling. The selected diluents form homogeneous mixtures with iPP at high temperature and lower the viscosity (improved processability), which undergo phase separation upon cooling to form solid particles that function as a toughening agent at room temperature. Tensile properties and morphology of the composites showed that organic crystalline particles have the similar effect as rigid particles to increase toughness; de-wetting between the particle and iPP matrix occurs at the early stage of deformation, followed by unhindered plastic flow that consumes significant amount of fracture energy. The effect of the diluents, however, strongly depends on the identity of the diluents that interact with the iPP during solidification step, which was demonstrated by comparing tetrabromobisphenol-A and

  1. Modelling zwitterions in solution: 3-fluoro-γ-aminobutyric acid (3F-GABA).

    PubMed

    Cao, Jie; Bjornsson, Ragnar; Bühl, Michael; Thiel, Walter; van Mourik, Tanja

    2012-01-02

    The conformations and relative stabilities of folded and extended 3-fluoro-γ-aminobutyric acid (3F-GABA) conformers were studied using explicit solvation models. Geometry optimisations in the gas phase with one or two explicit water molecules favour folded and neutral structures containing intramolecular NH···O-C hydrogen bonds. With three or five explicit water molecules zwitterionic minima are obtained, with folded structures being preferred over extended conformers. The stability of folded versus extended zwitterionic conformers increases on going from a PCM continuum solvation model to the microsolvated complexes, though extended structures become less disfavoured with the inclusion of more water molecules. Full explicit solvation was studied with a hybrid quantum-mechanical/molecular-mechanical (QM/MM) scheme and molecular dynamics simulations, including more than 6000 TIP3P water molecules. According to free energies obtained from thermodynamic integration at the PM3/MM level and corrected for B3LYP/MM total energies, the fully extended conformer is more stable than folded ones by about -4.5 kJ mol(-1). B3LYP-computed (3)J(F,H) NMR spin-spin coupling constants, averaged over PM3/MM-MD trajectories, agree best with experiment for this fully extended form, in accordance with the original NMR analysis. The seeming discrepancy between static PCM calculations and experiment noted previously is now resolved. That the inexpensive semiempirical PM3 method performs so well for this archetypical zwitterion is encouraging for further QM/MM studies of biomolecular systems. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Redox polymer and probe DNA tethered to gold electrodes for enzyme-amplified amperometric detection of DNA hybridization.

    PubMed

    Kavanagh, Paul; Leech, Dónal

    2006-04-15

    The detection of nucleic acids based upon recognition surfaces formed by co-immobilization of a redox polymer mediator and DNA probe sequences on gold electrodes is described. The recognition surface consists of a redox polymer, [Os(2,2'-bipyridine)2(polyvinylimidazole)(10)Cl](+/2+), and a model single DNA strand cross-linked and tethered to a gold electrode via an anchoring self-assembled monolayer (SAM) of cysteamine. Hybridization between the immobilized probe DNA of the recognition surface and a biotin-conjugated target DNA sequence (designed from the ssrA gene of Listeria monocytogenes), followed by addition of an enzyme (glucose oxidase)-avidin conjugate, results in electrical contact between the enzyme and the mediating redox polymer. In the presence of glucose, the current generated due to the catalytic oxidation of glucose to gluconolactone is measured, and a response is obtained that is binding-dependent. The tethering of the probe DNA and redox polymer to the SAM improves the stability of the surface to assay conditions of rigorous washing and high salt concentration (1 M). These conditions eliminate nonspecific interaction of both the target DNA and the enzyme-avidin conjugate with the recognition surfaces. The sensor response increases linearly with increasing concentration of target DNA in the range of 1 x 10(-9) to 2 x 10(-6) M. The detection limit is approximately 1.4 fmol, (corresponding to 0.2 nM of target DNA). Regeneration of the recognition surface is possible by treatment with 0.25 M NaOH solution. After rehybridization of the regenerated surface with the target DNA sequence, >95% of the current is recovered, indicating that the redox polymer and probe DNA are strongly bound to the surface. These results demonstrate the utility of the proposed approach.

  3. Applying thermosettable zwitterionic copolymers as general fouling-resistant and thermal-tolerant biomaterial interfaces.

    PubMed

    Chou, Ying-Nien; Chang, Yung; Wen, Ten-Chin

    2015-05-20

    We introduced a thermosettable zwitterionic copolymer to design a high temperature tolerance biomaterial as a general antifouling polymer interface. The original synthetic fouling-resistant copolymer, poly(vinylpyrrolidone)-co-poly(sulfobetaine methacrylate) (poly(VP-co-SBMA)), is both thermal-tolerant and fouling-resistant, and the antifouling stability of copolymer coated interfaces can be effectively controlled by regulating the VP/SBMA composition ratio. We studied poly(VP-co-SBMA) copolymer gels and networks with a focus on their general resistance to protein, cell, and bacterial bioadhesion, as influenced by the thermosetting process. Interestingly, we found that the shape of the poly(VP-co-SBMA) copolymer material can be set at a high annealing temperature of 200 °C while maintaining good antifouling properties. However, while the zwitterionic PSBMA polymer gels were bioinert as expected, control of the fouling resistance of the PSBMA polymer networks was lost in the high temperature annealing process. A poly(VP-co-SBMA) copolymer network composed of PSBMA segments at 32 mol % showed reduced fibrinogen adsorption, tissue cell adhesion, and bacterial attachment, but a relatively higher PSBMA content of 61 mol % was required to optimize resistance to platelet adhesion and erythrocyte attachment to confer hemocompatibility to human blood. We suggest that poly(VP-co-SBMA) copolymers capable of retaining stable fouling resistance after high temperature shaping have a potential application as thermosettable materials in a bioinert interface for medical devices, such as the thermosettable coating on a stainless steel blood-compatible metal stent investigated in this study.

  4. Novel hybrid structure silica/CdTe/molecularly imprinted polymer: synthesis, specific recognition, and quantitative fluorescence detection of bovine hemoglobin.

    PubMed

    Li, Dong-Yan; He, Xi-Wen; Chen, Yang; Li, Wen-You; Zhang, Yu-Kui

    2013-12-11

    This work presented a novel strategy for the synthesis of the hybrid structure silica/CdTe/molecularly imprinted polymer (Si-NP/CdTe/MIP) to recognize and detect the template bovine hemoglobin (BHb). First, amino-functionalized silica nanoparticles (Si-NP) and carboxyl-terminated CdTe quantum dots (QDs) were assembled into composite nanoparticles (Si-NP/CdTe) using the EDC (1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride) chemistry. Next, Si-NP/CdTe/MIP was synthesized by anchoring molecularly imprinted polymer (MIP) layer on the surface of Si-NP/CdTe through the sol-gel technique and surface imprinting technique. The hybrid structure possessed the selectivity of molecular imprinting technique and the sensitivity of CdTe QDs as well as well-defined morphology. The binding experiment and fluorescence method demonstrated its special recognition performance toward the template BHb. Under the optimized conditions, the fluorescence intensity of the Si-NP/CdTe/MIP decreased linearly with the increase of BHb in the concentration range 0.02-2.1 μM, and the detection limit was 9.4 nM. Moreover, the reusability and reproducibility and the successful applications in practical samples indicated the synthesis of Si-NP/CdTe/MIP provided an alternative solution for special recognition and determination of protein from real samples.

  5. Polymer Hydrogel/Polybutadiene/Iron Oxide Nanoparticle Hybrid Actuators for the Characterization of NiTi Implants

    PubMed Central

    Jeličić, Aleksandra; Friedrich, Alwin; Jeremić, Katarina; Siekmeyer, Gerd; Taubert, Andreas

    2009-01-01

    One of the main issues with the use of nickel titanium alloy (NiTi) implants in cardiovascular implants (stents) is that these devices must be of very high quality in order to avoid subsequent operations due to failing stents. For small stents with diameters below ca. 2 mm, however, stent characterization is not straightforward. One of the main problems is that there are virtually no methods to characterize the interior of the NiTi tubes used for fabrication of these tiny stents. The current paper reports on a robust hybrid actuator for the characterization of NiTi tubes prior to stent fabrication. The method is based on a polymer/hydrogel/magnetic nanoparticle hybrid material and allows for the determination of the inner diameter at virtually all places in the raw NiTi tubes. Knowledge of the inner structure of the raw NiTi tubes is crucial to avoid regions that are not hollow or regions that are likely to fail due to defects inside the raw tube. The actuator enables close contact of a magnetic polymer film with the inner NiTi tube surface. The magnetic signal can be detected from outside and be used for a direct mapping of the tube interior. As a result, it is possible to detect critical regions prior to expensive and slow stent fabrication processes.

  6. AN EXACT METHOD FOR RELATING ZWITTERIONIC MICROSCOPIC TO MACROSCOPIC ACIDITY CONSTANTS

    EPA Science Inventory

    Zwitterions are aqueous solvated molecules simultaneously possessing one negatively and one positively charged site. Although electroneutral, the environmental interaction of zwitterions with other ionic species is likely to differ significantly from the behavior of comparable e...

  7. Hemocompatible control of sulfobetaine-grafted polypropylene fibrous membranes in human whole blood via plasma-induced surface zwitterionization.

    PubMed

    Chen, Sheng-Han; Chang, Yung; Lee, Kueir-Rarn; Wei, Ta-Chin; Higuchi, Akon; Ho, Feng-Ming; Tsou, Chia-Chun; Ho, Hsin-Tsung; Lai, Juin-Yih

    2012-12-21

    In this work, the hemocompatibility of zwitterionic polypropylene (PP) fibrous membranes with varying grafting coverage of poly(sulfobetaine methacrylate) (PSBMA) via plasma-induced surface polymerization was studied. Charge neutrality of PSBMA-grafted layers on PP membrane surfaces was controlled by the low-pressure and atmospheric plasma treatment in this study. The effects of grafting composition, surface hydrophilicity, and hydration capability on blood compatibility of the membranes were determined. Protein adsorption onto the different PSBMA-grafted PP membranes from human fibrinogen solutions was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Blood platelet adhesion and plasma clotting time measurements from a recalcified platelet-rich plasma solution were used to determine if platelet activation depends on the charge bias of the grafted PSBMA layer. The charge bias of PSBMA layer deviated from the electrical balance of positively and negatively charged moieties can be well-controlled via atmospheric plasma-induced interfacial zwitterionization and was further tested with human whole blood. The optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and keeps its original blood-inert property of antifouling, anticoagulant, and antithrmbogenic activities when it comes into contact with human blood. This work suggests that the hemocompatible nature of grafted PSBMA polymers by controlling grafting quality via atmospheric plasma treatment gives a great potential in the surface zwitterionization of hydrophobic membranes for use in human whole blood.

  8. Efficient Organic/Inorganic Hybrid Solar Cell Integrating Polymer Nanowires and Inorganic Nanotetrapods.

    PubMed

    Xu, Weizhe; Tan, Furui; Liu, Xiansheng; Zhang, Weifeng; Qu, Shengchun; Wang, Zhijie; Wang, Zhanguo

    2017-12-01

    Constructing a highly efficient bulk-heterojunction is of critical importance to the hybrid organic/inorganic solar cells. Here in this work, we introduce a novel hybrid architecture containing P3HT nanowire and CdSe nanotetrapod as bicontinuous charge channels for holes and electrons, respectively. Compared to the traditionally applied P3HT molecules, the well crystallized P3HT nanowires qualify an enhanced light absorption at the long wavelength as well as strengthened charge carrier transport in the hybrid active layer. Accordingly, based on efficient dissociation of photogenerated excitons, the interpercolation of these two nano-building blocks allows a photovoltaic conversion efficiency of 1.7% in the hybrid solar cell, up to 42% enhancement compared to the reference solar cell with traditional P3HT molecules as electron donor. Our work provides a promising hybrid structure for efficient organic/inorganic bulk-heterojunction solar cells.

  9. From the Solution Processing of Hydrophilic Molecules to Polymer-Phthalocyanine Hybrid Materials for Ammonia Sensing in High Humidity Atmospheres

    PubMed Central

    Gaudillat, Pierre; Jurin, Florian; Lakard, Boris; Buron, Cédric; Suisse, Jean-Moïse; Bouvet, Marcel

    2014-01-01

    We have prepared different hybrid polymer-phthalocyanine materials by solution processing, starting from two sulfonated phthalocyanines, s-CoPc and CuTsPc, and polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly(acrylic acid-co-acrylamide) (PAA-AM), poly(diallyldimethylammonium chloride) (PDDA) and polyaniline (PANI) as polymers. We also studied the response to ammonia (NH3) of resistors prepared from these sensing materials. The solvent casted films, prepared from s-CoPc and PVP, PEG and PAA-AM, were highly insulating and very sensitive to the relative humidity (RH) variation. The incorporation of s-CoPc in PDDA by means of layer-by-layer (LBL) technique allowed to stabilize the film, but was too insulating to be interesting. We also prepared PANI-CuTsPc hybrid films by LBL technique. It allowed a regular deposition as evidenced by the linear increase of the absorbance at 688 nm as a function of the number of bilayers. The sensitivity to ammonia (NH3) of PANi-CuTsPc resistors was very high compared to that of individual materials, giving up to 80% of current decrease when exposed to 30 ppm NH3. Contrarily to what happens with neutral polymers, in PANI, CuTsPc was stabilized by strong electrostatic interactions, leading to a stable response to NH3, whatever the relative humidity in the range 10%–70%. Thus, the synergy of PANI with ionic macrocycles used as counteranions combined with their simple aqueous solution processing opens the way to the development of new gas sensors capable of operating in real world conditions. PMID:25061841

  10. From the solution processing of hydrophilic molecules to polymer-phthalocyanine hybrid materials for ammonia sensing in high humidity atmospheres.

    PubMed

    Gaudillat, Pierre; Jurin, Florian; Lakard, Boris; Buron, Cédric; Suisse, Jean-Moïse; Bouvet, Marcel

    2014-07-24

    We have prepared different hybrid polymer-phthalocyanine materials by solution processing, starting from two sulfonated phthalocyanines, s-CoPc and CuTsPc, and polyvinylpyrrolidone (PVP), polyethylene glycol (PEG), poly(acrylic acid-co-acrylamide) (PAA-AM), poly(diallyldimethylammonium chloride) (PDDA) and polyaniline (PANI) as polymers. We also studied the response to ammonia (NH3) of resistors prepared from these sensing materials. The solvent casted films, prepared from s-CoPc and PVP, PEG and PAA-AM, were highly insulating and very sensitive to the relative humidity (RH) variation. The incorporation of s-CoPc in PDDA by means of layer-by-layer (LBL) technique allowed to stabilize the film, but was too insulating to be interesting. We also prepared PANI-CuTsPc hybrid films by LBL technique. It allowed a regular deposition as evidenced by the linear increase of the absorbance at 688 nm as a function of the number of bilayers. The sensitivity to ammonia (NH3) of PANi-CuTsPc resistors was very high compared to that of individual materials, giving up to 80% of current decrease when exposed to 30 ppm NH3. Contrarily to what happens with neutral polymers, in PANI, CuTsPc was stabilized by strong electrostatic interactions, leading to a stable response to NH3, whatever the relative humidity in the range 10%-70%. Thus, the synergy of PANI with ionic macrocycles used as counteranions combined with their simple aqueous solution processing opens the way to the development of new gas sensors capable of operating in real world conditions.

  11. Structure of water at zwitterionic copolymer film-liquid water interfaces as examined by the sum frequency generation method.

    PubMed

    Kondo, Takuya; Nomura, Kouji; Gemmei-Ide, Makoto; Kitano, Hiromi; Noguchi, Hidenori; Uosaki, Kohei; Saruwatari, Yoshiyuki

    2014-01-01

    A copolymer film composed of zwitterionic carboxymethylbetaine (CMB) and n-butyl methacrylate (BMA), Poly(CMB-r-BMA), was cast on a flat plane of an octadecyltrichlorosilane (ODS)-modified fused quartz prism with a semi-cylindrical shape. CH stretching of the polymer film and O-H stretching of water at the surface of the film were examined using the sum frequency generation (SFG) technique. The C-H stretching band of the cast film, indicating a gauche defect of the film, was affected by the contact medium including dry nitrogen, water vapor-saturated nitrogen and liquid water. In contrast, the C-H stretching of an octadecyl group introduced onto the quartz prism for stable attachment of the cast film was not significantly changed by the contact medium. The O-H stretching band indicated that water molecules at the surface of the Poly(CMB-r-BMA) film in contact with liquid water were not greatly oriented in comparison with those at the surfaces of a bare prism, an ODS SAM-modified prism, and a prism covered with a PolyBMA film or a copolymer film of BMA and methacrylic acid or 2-(dimethylamino)ethyl methacrylate. A similar small perturbation of the structure of water was previously observed in the vicinity of water-soluble zwitterionic polymers and zwitterionic copolymer films using Raman and attenuated total reflection infrared spectroscopies, respectively. A distinct effect of charge neutralization to diminish the perturbation of the structure of interfacial water around polymer materials was suggested. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Ruthenium based metallopolymer grafted reduced graphene oxide as a new hybrid solar light harvester in polymer solar cells

    PubMed Central

    Vinoth, R.; Babu, S. Ganesh; Bharti, Vishal; Gupta, V.; Navaneethan, M.; Bhat, S. Venkataprasad; Muthamizhchelvan, C.; Ramamurthy, Praveen C.; Sharma, Chhavi; Aswal, Dinesh K.; Hayakawa, Yasuhiro; Neppolian, B.

    2017-01-01

    A new class of pyridyl benzimdazole based Ru complex decorated polyaniline assembly (PANI-Ru) was covalently grafted onto reduced graphene oxide sheets (rGO) via covalent functionalization approach. The covalent attachment of PANI-Ru with rGO was confirmed from XPS analysis and Raman spectroscopy. The chemical bonding between PANI-Ru and rGO induced the electron transfer from Ru complex to rGO via backbone of the conjugated PANI chain. The resultant hybrid metallopolymer assembly was successfully demonstrated as an electron donor in bulk heterojunction polymer solar cells (PSCs). A PSC device fabricated with rGO/PANI-Ru showed an utmost ~6 fold and 2 fold enhancement in open circuit potential (Voc) and short circuit current density (Jsc) with respect to the standard device made with PANI-Ru (i.e., without rGO) under the illumination of AM 1.5 G. The excellent electronic properties of rGO significantly improved the electron injection from PANI-Ru to PCBM and in turn the overall performance of the PSC device was enhanced. The ultrafast excited state charge separation and electron transfer role of rGO sheet in hybrid metallopolymer was confirmed from ultrafast spectroscopy measurements. This covalent modification of rGO with metallopolymer assembly may open a new strategy for the development of new hybrid nanomaterials for light harvesting applications. PMID:28225039

  13. Preparation and unique electrical behaviors of monodispersed hybrid nanorattles of metal nanocores with hairy electroactive polymer shells.

    PubMed

    Cai, Tao; Zhang, Bin; Chen, Yu; Wang, Cheng; Zhu, Chun Xiang; Neoh, Koon-Gee; Kang, En-Tang

    2014-03-03

    A versatile template-assisted strategy for the preparation of monodispersed rattle-type hybrid nanospheres, encapsulating a movable Au nanocore in the hollow cavity of a hairy electroactive polymer shell (Au@air@PTEMA-g-P3HT hybrid nanorattles; PTEMA: poly(2-(thiophen-3-yl)ethyl methacrylate; P3HT: poly(3-hexylthiophene), was reported. The Au@silica core-shell nanoparticles, prepared by the modified Stöber sol-gel process on Au nanoparticle seeds, were used as templates for the synthesis of Au@silica@PTEMA core-double shell nanospheres. Subsequent oxidative graft polymerization of 3-hexylthiophene from the exterior surface of the Au@silica@PTEMA core-double shell nanospheres allowed the tailoring of surface functionality with electroactive P3HT brushes (Au@silica@PTEMA-g-P3HT nanospheres). The Au@air@ PTEMA-g-P3HT hybrid nanorattles were obtained after etching of the silica interlayer by HF. The as-prepared nanorattles were dispersed into an electrically insulating polystyrene matrix and for the first time used to fabricate nonvolatile memory devices. As a result, unique electrical behaviors, including insulator behavior, write-once-read-many-times and rewritable memory effects, and conductor behavior as well, were observed in the Al/Au@air@PTEMA-g-P3HT+PS/ITO (ITO: indium-tin oxide) sandwich thin-film devices. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Modulation of surgical fibrosis by microbial zwitterionic polysaccharides

    NASA Astrophysics Data System (ADS)

    Ruiz-Perez, Begonia; Chung, Doo R.; Sharpe, Arlene H.; Yagita, Hideo; Kalka-Moll, Wiltrud M.; Sayegh, Mohamed H.; Kasper, Dennis L.; Tzianabos, Arthur O.

    2005-11-01

    Bacterial carbohydrates have long been considered T cell-independent antigens that primarily induce humoral immune responses. Recently, it has been demonstrated that bacterial capsules that possess a zwitterionic charge motif can activate CD4+ T cells after processing and presentation by antigen-presenting cells. Here we show that these zwitterionic polysaccharides can prevent T helper 1-mediated fibrosis by signaling for the release of IL-10 from CD4+ T cells in vivo. IL-10 production by these T cells and their ability to prevent fibrosis is controlled by the inducible costimulator (ICOS)-ICOS ligand pathway. These data demonstrate that the interaction of the zwitterionic polysaccharides with T cells results in modulation of surgical fibrosis in vivo and suggest a previously undescribed approach to "harnessing" T cell function to prevent inflammatory tissue disorders in humans. IL-10 | microbial polysaccharides | inducible costimulator

  15. New zwitterionic monoterpene indole alkaloids from Uncaria rhynchophylla.

    PubMed

    Guo, Qiang; Yang, Hongshuai; Liu, Xinyu; Si, Xiali; Liang, Hong; Tu, Pengfei; Zhang, Qingying

    2018-01-31

    Four new zwitterionic monoterpene indole alkaloids, rhynchophyllioniums A-D (1-4), together with eight known alkaloids (5-12), were isolated from the hook-bearing stems of Uncaria rhynchophylla. Their structures were elucidated by extensive spectroscopic data analysis of MS, 1D and 2D NMR, and ECD, and the zwitterionic forms and absolute configurations of 1 and 2 were unambiguously confirmed by single crystal X-ray diffraction analysis. All the isolates, including the monoterpene indole alkaloids with free C-22 carboxyl group and those with C-22 carboxyl methyl ester, were proved to be naturally coexisting in the herb by LC-MS analysis. This is the first report of monoterpene indole alkaloids that exist in the form of zwitterion. Additionally, the cytotoxic activities of all isolates against A549, HepG2, and MCF-7 cell lines are reported. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Universal Coatings Based on Zwitterionic-Dopamine Copolymer Microgels.

    PubMed

    Vatankhah-Varnosfaderani, Mohammad; Hu, Xiaobo; Li, Qiaoxi; Adelnia, Hossein; Ina, Maria; Sheiko, Sergei S

    2018-06-05

    Multifunctional coatings that adhere to chemically distinct substrates are vital in many industries, including automotive, aerospace, shipbuilding, construction, petrochemical, biomedical, and pharmaceutical. We design well-defined, nearly monodisperse microgels that integrate hydrophobic dopamine methacrylamide monomers and hydrophilic zwitterionic monomers. The dopamine functionalities operate as both intraparticle cross-linkers and interfacial binders, respectively providing mechanical strength of the coatings and their strong adhesion to different substrates. In tandem, the zwitterionic moieties enable surface hydration to empower antifouling and antifogging properties. Drop-casting of microgel suspensions in ambient as well as humid environments facilitates rapid film formation and tunable roughness through regulation of cross-linking density and deposition conditions.

  17. Poly(zwitterionic)protein conjugates offer increased stability without sacrificing binding affinity or bioactivity

    NASA Astrophysics Data System (ADS)

    Keefe, Andrew J.; Jiang, Shaoyi

    2012-01-01

    Treatment with therapeutic proteins is an attractive approach to targeting a number of challenging diseases. Unfortunately, the native proteins themselves are often unstable in physiological conditions, reducing bioavailability and therefore increasing the dose that is required. Conjugation with poly(ethylene glycol) (PEG) is often used to increase stability, but this has a detrimental effect on bioactivity. Here, we introduce conjugation with zwitterionic polymers such as poly(carboxybetaine). We show that poly(carboxybetaine) conjugation improves stability in a manner similar to PEGylation, but that the new conjugates retain or even improve the binding affinity as a result of enhanced protein-substrate hydrophobic interactions. This chemistry opens a new avenue for the development of protein therapeutics by avoiding the need to compromise between stability and affinity.

  18. Covalent-supramolecular hybrid polymers as muscle-inspired anisotropic actuators.

    PubMed

    Chin, Stacey M; Synatschke, Christopher V; Liu, Shuangping; Nap, Rikkert J; Sather, Nicholas A; Wang, Qifeng; Álvarez, Zaida; Edelbrock, Alexandra N; Fyrner, Timmy; Palmer, Liam C; Szleifer, Igal; Olvera de la Cruz, Monica; Stupp, Samuel I

    2018-06-19

    Skeletal muscle provides inspiration on how to achieve reversible, macroscopic, anisotropic motion in soft materials. Here we report on the bottom-up design of macroscopic tubes that exhibit anisotropic actuation driven by a thermal stimulus. The tube is built from a hydrogel in which extremely long supramolecular nanofibers are aligned using weak shear forces, followed by radial growth of thermoresponsive polymers from their surfaces. The hierarchically ordered tube exhibits reversible anisotropic actuation with changes in temperature, with much greater contraction perpendicular to the direction of nanofiber alignment. We identify two critical factors for the anisotropic actuation, macroscopic alignment of the supramolecular scaffold and its covalent bonding to polymer chains. Using finite element analysis and molecular calculations, we conclude polymer chain confinement and mechanical reinforcement by rigid supramolecular nanofibers are responsible for the anisotropic actuation. The work reported suggests strategies to create soft active matter with molecularly encoded capacity to perform complex tasks.

  19. A Combined Experimental and Numerical Approach to the Laser Joining of Hybrid Polymer - Metal Parts

    NASA Astrophysics Data System (ADS)

    Rodríguez-Vidal, E.; Lambarri, J.; Soriano, C.; Sanz, C.; Verhaeghe, G.

    A two-step method for the joining of opaque polymer to metal is presented. Firstly, the metal is structured locally on a micro-scale level, to ensure adhesion with the polymeric counterpart. In a second step, the opposite side of the micro-structured metal is irradiated by means of a laser source. The heat thereby created is conducted by the metal and results in the melting of the polymer at the interface. The polymer thereby adheres to the metal and flows into the previously engraved structures, creating an additional mechanical interlock between the two materials. The welding parameters are fine-tuned with the assistance of a finite element model, to ensure the required interface temperature. The method is illustrated using a dual phase steel joined to a fiber-reinforced polyamide. The effect of different microstructures, in particular geometry and cavity aspect ratio, on the joint's tensile-shear mechanical performance is discussed.

  20. New Avenue for Limiting Degradation in NanoLi4Ti5O12 for Ultrafast-Charge Lithium-Ion Batteries: Hybrid Polymer-Inorganic Particles.

    PubMed

    Daigle, Jean-Christophe; Asakawa, Yuichiro; Beaupré, Mélanie; Vieillette, René; Laul, Dharminder; Trudeau, Michel; Zaghib, Karim

    2017-12-13

    Lithium titanium oxide (Li 4 Ti 5 O 12 )-based cells are a very promising battery technology for ultrafast-charge-discharge and long-cycle-life batteries. However, the surface reactivity of lithium titanium oxide in the presence of organic electrolytes continues to be a problem that may cause expansion of pouch cells. In this study, we report on the development of a simple and economical grafting method for forming hybrid polymer-Li 4 Ti 15 O 12 nanoparticles, which can be successfully applied in lithium-ion batteries. This method utilizes a low-cost and scalable hydrophobic polymer that is applicable in industrial processes. The hybrid materials demonstrated exceptional capability for preventing the degradation of cells in accelerated aging and operating over 150 cycles at 1C and 45 °C.

  1. Near-infrared sensitive photorefractive device using polymer dispersed liquid crystal and BSO:Ru hybrid structure.

    PubMed

    Liu, Ren Chung; Marinova, Vera; Lin, Shiuan Huei; Chen, Ming-Syuan; Lin, Yi-Hsin; Hsu, Ken Yuh

    2014-06-01

    A near-infrared sensitive hybrid device, based on a Ru-doped BSO photorefractive substrate and polymer dispersed liquid crystal (PDLC) layer, is reported. It is found that the photoexcited charge carriers generated in the BSO:Ru substrate create an optically induced space charge field, sufficient to penetrate into the PDLC layer and to re-orient the LC molecules inside the droplets. Beam-coupling measurements at the Bragg regime are performed showing prospective amplification values and high spatial resolution. The proposed structure does not require indium tin oxide (ITO) contacts and alignment layers. Such a device allows all the processes to be controlled by light, thus opening further potential for real-time image processing at the near-infrared range.

  2. Photonics of a conjugated organometallic Pt-Ir polymer and its model compounds exhibiting hybrid CT excited states.

    PubMed

    Soliman, Ahmed M; Fortin, Daniel; Zysman-Colman, Eli; Harvey, Pierre D

    2012-04-13

    Trans- dichlorobis(tri-n-butylphosphine)platinum(II) reacts with bis(2- phenylpyridinato)-(5,5'-diethynyl-2,2'-bipyridine)iridium(III) hexafluorophosphate to form the luminescent conjugated polymer poly[trans-[(5,5'-ethynyl-2,2'-bipyridine)bis(2- phenylpyridinato)-iridium(III)]bis(tri-n-butylphosphine)platinum(II)] hexafluorophosphate ([Pt]-[Ir])n. Gel permeation chromatography indicates a degree of polymerization of 9 inferring the presence of an oligomer. Comparison of the absorption and emission band positions and their temperature dependence, emission quantum yields, and lifetimes with those for models containing only the [Pt] or the [Ir] units indicates hybrid excited states including features from both chromophores. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Hierarchically structured transparent hybrid membranes by in situ growth of mesostructured organosilica in host polymer

    NASA Astrophysics Data System (ADS)

    Vallé, Karine; Belleville, Philippe; Pereira, Franck; Sanchez, Clément

    2006-02-01

    The elaborate performances characterizing natural materials result from functional hierarchical constructions at scales ranging from nanometres to millimetres, each construction allowing the material to fit the physical or chemical demands occurring at these different levels. Hierarchically structured materials start to demonstrate a high input in numerous promising applied domains such as sensors, catalysis, optics, fuel cells, smart biologic and cosmetic vectors. In particular, hierarchical hybrid materials permit the accommodation of a maximum of elementary functions in a small volume, thereby optimizing complementary possibilities and properties between inorganic and organic components. The reported strategies combine sol-gel chemistry, self-assembly routes using templates that tune the material's architecture and texture with the use of larger inorganic, organic or biological templates such as latex, organogelator-derived fibres, nanolithographic techniques or controlled phase separation. We propose an approach to forming transparent hierarchical hybrid functionalized membranes using in situ generation of mesostructured hybrid phases inside a non-porogenic hydrophobic polymeric host matrix. We demonstrate that the control of the multiple affinities existing between organic and inorganic components allows us to design the length-scale partitioning of hybrid nanomaterials with tuned functionalities and desirable size organization from ångström to centimetre. After functionalization of the mesoporous hybrid silica component, the resulting membranes have good ionic conductivity offering interesting perspectives for the design of solid electrolytes, fuel cells and other ion-transport microdevices.

  4. Microfluidic based high throughput synthesis of lipid-polymer hybrid nanoparticles with tunable diameters

    PubMed Central

    Feng, Qiang; Zhang, Lu; Liu, Chao; Li, Xuanyu; Hu, Guoqing; Sun, Jiashu; Jiang, Xingyu

    2015-01-01

    Core-shell hybrid nanoparticles (NPs) for drug delivery have attracted numerous attentions due to their enhanced therapeutic efficacy and good biocompatibility. In this work, we fabricate a two-stage microfluidic chip to implement a high-throughput, one-step, and size-tunable synthesis of mono-disperse lipid-poly (lactic-co-glycolic acid) NPs. The size of hybrid NPs is tunable by varying the flow rates inside the two-stage microfluidic chip. To elucidate the mechanism of size-controllable generation of hybrid NPs, we observe the flow field in the microchannel with confocal microscope and perform the simulation by a numerical model. Both the experimental and numerical results indicate an enhanced mixing effect at high flow rate, thus resulting in the assembly of small and mono-disperse hybrid NPs. In vitro experiments show that the large hybrid NPs are more likely to be aggregated in serum and exhibit a lower cellular uptake efficacy than the small ones. This microfluidic chip shows great promise as a robust platform for optimization of nano drug delivery system. PMID:26180574

  5. Preparation of psoralen polymer-lipid hybrid nanoparticles and their reversal of multidrug resistance in MCF-7/ADR cells.

    PubMed

    Huang, Qingqing; Cai, Tiange; Li, Qianwen; Huang, Yinghong; Liu, Qian; Wang, Bingyue; Xia, Xi; Wang, Qi; Whitney, John C C; Cole, Susan P C; Cai, Yu

    2018-11-01

    Multidrug resistance (MDR) is the leading cause of failure for breast cancer in the clinic. Thus far, polymer-lipid hybrid nanoparticles (PLN) loaded chemotherapeutic agents has been used to overcome MDR in breast cancer. In this study, we prepared psoralen polymer-lipid hybrid nanoparticles (PSO-PLN) to reverse drug resistant MCF-7/ADR cells in vitro and in vivo. PSO-PLN was prepared by the emulsification evaporation-low temperature solidification method. The formulation, water solubility and bioavailability, particle size, zeta potential and entrapment efficiency, and in vitro release experiments were optimized in order to improve the activity of PSO to reverse MDR. Optimal formulation: soybean phospholipids 50 mg, poly(lactic-co-glycolic) acid (PLGA) 15 mg, PSO 3 mg, and Tween-80 1%. The PSO-PLN possessed a round appearance, uniform size, exhibited no adhesion. The average particle size was 93.59 ± 2.87 nm, the dispersion co-efficient was 0.249 ± 0.06, the zeta potential was 25.47 ± 2.84 mV. In vitro analyses revealed that PSO resistance index was 3.2, and PSO-PLN resistance index was 5.6, indicating that PSO-PLN versus MCF-7/ADR reversal effect was significant. Moreover, PSO-PLN is somewhat targeted to the liver, and has an antitumor effect in the xenograft model of drug-resistant MCF-7/ADR cells. In conclusion, PSO-PLN not only reverses MDR but also improves therapeutic efficiency by enhancing sustained release of PSO.

  6. Arginine-Glycine-Aspartic Acid-Modified Lipid-Polymer Hybrid Nanoparticles for Docetaxel Delivery in Glioblastoma Multiforme.

    PubMed

    Shi, Kairong; Zhou, Jin; Zhang, Qianyu; Gao, Huile; Liu, Yayuan; Zong, Taili; He, Qin

    2015-03-01

    Hybrid nanoparticles consisting of lipids and the biodegradable polymer, poly (D,L-lactide-co-glycolide) (PLGA), were developed for the targeted delivery of the anticancer drug, docetaxel. Transmission electron microscopic observations confirmed the presence of a lipid coating over the polymeric core. Using coumarin-6 as a fluorescent probe, the uptake efficacy of RGD conjugated lipid coated nanoparticles (RGD-L-P) by C6 cells was increased significantly, compared with that of lipid-polymer hybrid nanoparticles (L-P; 2.5-fold higher) or PLGA-nanoparticles (PLGA-P; 1.76-fold higher). The superior tumor spheroid penetration of RGD-L-P indicated that RGD-L-P could target effectively and specifically to C6 cells overexpressing integrin α(v)β3. The anti-proliferative activity of docetaxel-loaded RGD-L-P against C6 cells was increased 2.69- and 4.13-fold compared with L-P and PLGA-P, respectively. Regarding biodistribution, the strongest brain-localized fluorescence signals were detected in glioblastoma multiforme (GBM)-bearing rats treated with 1,10-Dioctadecyl-3,3,30,30-tetramethylindotricarb-ocyanine iodide (DiR)-loaded RGD-L-P, compared to rats treated with DiR-loaded L-P or PLGA-P. The median survival time of GBM-bearing rats treated with docetaxel-loaded RGD-L-P was 57 days, a fold increase of 1.43, 1.78, 3.35, and 3.56 compared with animals given L-P (P < 0.05), PLGA-P (P < 0.05), Taxotere (P < 0.01) and saline (P < 0.01), respectively. Collectively, these results support RGD-L-P as a promising drug delivery system for the specific targeting and the treatment of GBM.

  7. Gas barrier properties of bio-inspired Laponite-LC polymer hybrid films.

    PubMed

    Tritschler, Ulrich; Zlotnikov, Igor; Fratzl, Peter; Schlaad, Helmut; Grüner, Simon; Cölfen, Helmut

    2016-05-26

    Bio-inspired Laponite (clay)-liquid crystal (LC) polymer composite materials with high clay fractions (>80%) and a high level of orientation of the clay platelets, i.e. with structural features similar to the ones found in natural nacre, have been shown to exhibit a promising behavior in the context of reduced oxygen transmission. Key characteristics of these bio-inspired composite materials are their high inorganic content, high level of exfoliation and orientation of the clay platelets, and the use of a LC polymer forming the organic matrix in between the Laponite particles. Each single feature may be beneficial to increase the materials gas barrier property rendering this composite a promising system with advantageous barrier capacities. In this detailed study, Laponite/LC polymer composite coatings with different clay loadings were investigated regarding their oxygen transmission rate. The obtained gas barrier performance was linked to the quality, respective Laponite content and the underlying composite micro- and nanostructure of the coatings. Most efficient oxygen barrier properties were observed for composite coatings with 83% Laponite loading that exhibit a structure similar to sheet-like nacre. Further on, advantageous mechanical properties of these Laponite/LC polymer composites reported previously give rise to a multifunctional composite system.

  8. Hole transfer from CdSe nanoparticles to TQ1 polymer in hybrid solar cell device

    NASA Astrophysics Data System (ADS)

    Sohail, Muhammad; Shah, Zawar Hussain; Saeed, Shomaila; Bibi, Nasreen; Shahbaz, Sadia; Ahmed, Safeer; Shabbir, Saima; Siddiq, Muhammad; Iqbal, Azhar

    2018-05-01

    In view of realizing the economic viability, we fabricate a solar cell device containing low band gap and easily processable polymer 5-yl-8-(thiophene-2,5-diyl)-2,3-bis(3-(octyloxy)phenyl) quinoxaline (TQ1) and CdSe nanoparticles (NPs) and investigate its charge transport properties. When the TQ1 is combined with the CdSe NPs a strong photoluminescence quenching and shortening of photoluminescence lifetime of the TQ1 is observed indicating exciton transfer from TQ1 to the CdSe NPs. The time-resolved photoluminescence further reveals that the exciton transfer from the polymer to CdSe NPs is very efficient (68%) and it occurs in <1 ns. The exciton transfer from TQ1 to the NPs and electron-hole pair separation followed by hole transfer from the NPs to the TQ1 at the interface indeed increases the lifetime of the charge carriers. This in turn increases the efficiency of the solar cell as compared to polymer only device. These observations suggest the importance of other II-VI semiconductor NPs to achieve higher efficiency for photovoltaic devices containing TQ1 polymer.

  9. Nonlinear mechanics of hybrid polymer networks that mimic the complex mechanical environment of cells

    NASA Astrophysics Data System (ADS)

    Jaspers, Maarten; Vaessen, Sarah L.; van Schayik, Pim; Voerman, Dion; Rowan, Alan E.; Kouwer, Paul H. J.

    2017-05-01

    The mechanical properties of cells and the extracellular environment they reside in are governed by a complex interplay of biopolymers. These biopolymers, which possess a wide range of stiffnesses, self-assemble into fibrous composite networks such as the cytoskeleton and extracellular matrix. They interact with each other both physically and chemically to create a highly responsive and adaptive mechanical environment that stiffens when stressed or strained. Here we show that hybrid networks of a synthetic mimic of biological networks and either stiff, flexible and semi-flexible components, even very low concentrations of these added components, strongly affect the network stiffness and/or its strain-responsive character. The stiffness (persistence length) of the second network, its concentration and the interaction between the components are all parameters that can be used to tune the mechanics of the hybrids. The equivalence of these hybrids with biological composites is striking.

  10. An antibacterial coating based on a polymer/sol-gel hybrid matrix loaded with silver nanoparticles

    NASA Astrophysics Data System (ADS)

    Rivero, Pedro José; Urrutia, Aitor; Goicoechea, Javier; Zamarreño, Carlos Ruiz; Arregui, Francisco Javier; Matías, Ignacio Raúl

    2011-12-01

    In this work a novel antibacterial surface composed of an organic-inorganic hybrid matrix of tetraorthosilicate and a polyelectrolyte is presented. A precursor solution of tetraethoxysilane (TEOS) and poly(acrylic acid sodium salt) (PAA) was prepared and subsequently thin films were fabricated by the dip-coating technique using glass slides as substrates. This hybrid matrix coating is further loaded with silver nanoparticles using an in situ synthesis route. The morphology and composition of the coatings have been studied using UV-VIS spectroscopy and atomic force microscopy (AFM). Energy dispersive X-ray (EDX) was also used to confirm the presence of the resulting silver nanoparticles within the thin films. Finally the coatings have been tested in bacterial cultures of genus Lactobacillus plantarum to observe their antibacterial properties. It has been experimentally demonstrated that these silver loaded organic-inorganic hybrid films have a very good antimicrobial behavior against this type of bacteria.

  11. A three-dimensional transient mixed hybrid finite element model for superabsorbent polymers with strain-dependent permeability.

    PubMed

    Yu, Cong; Malakpoor, Kamyar; Huyghe, Jacques M

    2018-05-16

    A hydrogel is a cross-linked polymer network with water as solvent. Industrially widely used superabsorbent polymers (SAP) are partially neutralized sodium polyacrylate hydrogels. The extremely large degree of swelling is one of the most distinctive characteristics of such hydrogels, as the volume increase can be about 30 times its original volume when exposed to physiological solution. The large deformation resulting from the swelling demands careful numerical treatment. In this work, we present a biphasic continuum-level swelling model using the mixed hybrid finite element method (MHFEM) in three dimensions. The hydraulic permeability is highly dependent on the swelling ratio, resulting in values that are orders of magnitude apart from each other. The property of the local mass conservation of MHFEM contributes to a more accurate calculation of the deformation as the permeability across the swelling gel in a transient state is highly non-uniform. We show that the proposed model is able to simulate the free swelling of a random-shaped gel and the squeezing of fluid out of a swollen gel. Finally, we make use of the proposed numerical model to study the onset of surface instability in transient swelling.

  12. Development and optimization of methotrexate-loaded lipid-polymer hybrid nanoparticles for controlled drug delivery applications.

    PubMed

    Tahir, Nayab; Madni, Asadullah; Balasubramanian, Vimalkumar; Rehman, Mubashar; Correia, Alexandra; Kashif, Prince Muhammad; Mäkilä, Ermei; Salonen, Jarno; Santos, Hélder A

    2017-11-25

    Lipid-polymer hybrid nanoparticles (LPHNPs) are emerging platforms for drug delivery applications. In the present study, methotrexate loaded LPHNPs consisted of PLGA and Lipoid S100 were fabricated by employing a single-step modified nanoprecipitation method combined with self-assembly. A three factor, three level Box Behnken design using Design-Expert ® software was employed to access the influence of three independent variables on the particle size, drug entrapment and percent drug release. The optimized formulation was selected through numeric optimization approach. The results were supported with the ANOVA analysis, regression equations and response surface plots. Transmission electron microscope images indicated the nanosized and spherical shape of the LPHNPs with fair size distribution. The nanoparticles ranged from 176 to 308nm, which increased with increased polymer concentration. The increase in polymer and lipid concentration also increased the drug entrapment efficiency. The in vitro drug release was in range 70.34-91.95% and the release mechanism follow the Higuchi model (R 2 =0.9888) and Fickian diffusion (n<0.5). The in vitro cytotoxicity assay and confocal microscopy of the optimized formulation demonstrate the good safety and better internalization of the LPHNPs. The cell antiproliferation showed the spatial and controlled action of the nanoformulation as compared to the plain drug solution. The results suggest that LPHNPs can be a promising delivery system envisioned to safe, stable and potentially controlled delivery of methotrexate to the cancer cells to achieve better therapeutic outcomes. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Prevention of bacterial adhesion to zwitterionic biocompatible mesoporous glasses.

    PubMed

    Sánchez-Salcedo, Sandra; García, Ana; Vallet-Regí, María

    2017-07-15

    Novel materials, based on Mesoporous Bioactive Glasses (MBGs) in the ternary system SiO 2 -CaO-P 2 O 5 , decorated with (3-aminopropyl)triethoxysilane (APTES) and subsequently with amino acid Lysine (Lys), by post-grafting method on the external surface of the glasses (named MBG-NH 2 and MBG-Lys), are reported. The surface functionalization with organic groups did not damage the mesoporous network and their structural and textural properties were also preserved despite the high solubility of MBG matrices. The incorporation of Lys confers a zwitterionic nature to these MBG materials due to the presence of adjacent amine and carboxylic groups in the external surface. At physiologic pH, this coexistence of basic amine and carboxilic acid groups from anchored Lys provided zero surface charge named zwitterionic effect. This behaviour could give rise to potential applications of antibacterial adhesion. Therefore, in order to assess the influence of zwitterionic nature in in vitro bacterial adhesion, studies were carried out with Staphylococcus aureus. It was demonstrated that the efficient interaction of these zwitterionic pairs onto the MBG surfaces reduced bacterial adhesion up to 99.9% compared to bare MBGs. In order to test the suitability of zwitterionic MBGs materials as bone grafts, their cytocompatibility was investigated in vitro with MC3T3-E1 preosteoblasts. These findings suggested that the proposed surface functionalization strategy provided MBG materials with notable antibacterial adhesion properties, hence making these materials promising candidates for local bone infection therapy. The present research work is focused in finding a preventive treatment of bone infection based on Mesoporous Bioactive Glasses (MBGs) with antibacterial adhesion properties obtained by zwitterionic surface modification. MBGs exhibit unique nanostructural, textural and bioactive characteristics. The novelty and originality of this manuscript is based on the design and

  14. Nanotribology of charged polymer brushes

    NASA Astrophysics Data System (ADS)

    Klein, Jacob

    Polymers at surfaces, whose modern understanding may be traced back to early work by Sam Edwards1, have become a paradigm for modification of surface properties, both as steric stabilizers and as remarkable boundary lubricants2. Charged polymer brushes are of particular interest, with both technological implications and especially biological relevance where most macromolecules are charged. In the context of biolubrication, relevant in areas from dry eye syndrome to osteoarthritis, charged polymer surface phases and their complexes with other macromolecules may play a central role. The hydration lubrication paradigm, where tenaciously-held yet fluid hydration shells surrounding ions or zwitterions serve as highly-efficient friction-reducing elements, has been invoked to understand the excellent lubrication provided both by ionized3 and by zwitterionic4 brushes. In this talk we describe recent advances in our understanding of the nanotribology of such charged brush systems. We consider interactions between charged end-grafted polymers, and how one may disentangle the steric from the electrostatic surface forces5. We examine the limits of lubrication by ionized brushes, both synthetic and of biological origins, and how highly-hydrated zwitterionic chains may provide extremely effective boundary lubrication6. Finally we describe how the lubrication of articular cartilage in the major joints, a tribosystem presenting some of the greatest challenges and opportunities, may be understood in terms of a supramolecular synergy between charged surface-attached polymers and zwitterionic groups7. Work supported by European Research Council (HydrationLube), Israel Science Foundation (ISF), Petroleum Research Fund of the American Chemical Society, ISF-NSF China Joint Program.

  15. Application of nonlinear rheology to assess the effect of secondary nanofiller on network structure of hybrid polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Kamkar, Milad; Aliabadian, Ehsan; Shayesteh Zeraati, Ali; Sundararaj, Uttandaraman

    2018-02-01

    Carbon nanotube (CNT)/polymer nanocomposites exhibit excellent electrical properties by forming a percolated network. Adding a secondary filler can significantly affect the CNTs' network, resulting in changing the electrical properties. In this work, we investigated the effect of adding manganese dioxide nanowires (MnO2NWs) as a secondary nanofiller on the CNTs' network structure inside a poly(vinylidene fluoride) (PVDF) matrix. Incorporating MnO2NWs to PVDF/CNT samples produced a better state of dispersion of CNTs, as corroborated by light microscopy and transmission electron microscopy. The steady shear and oscillatory shear flows were employed to obtain a better insight into the nanofiller structure and viscoelastic behavior of the nanocomposites. The transient response under steady shear flow revealed that the stress overshoot of hybrid nanocomposites (two-fillers), PVDF/CNT/MnO2NWs, increased dramatically in comparison to binary nanocomposites (single-filler), PVDF/CNT and PVDF/MnO2NWs. This can be attributed to microstructural changes. Large amplitude oscillatory shear characterization was also performed to further investigate the effect of the secondary nanofiller on the nonlinear viscoelastic behavior of the samples. The nonlinear rheological observations were explained using quantitative nonlinear parameters [strain-stiffening ratio (S) and shear-thickening ratio (T)] and Lissajous-Bowditch plots. Results indicated that a more rigid nanofiller network was formed for the hybrid nanocomposites due to the better dispersion state of CNTs and this led to a more nonlinear viscoelastic behavior.

  16. Hybrid nanocomposites of 2D black phosphorus nanosheets encapsulated in PMMA polymer material: new platforms for advanced device fabrication

    NASA Astrophysics Data System (ADS)

    Telesio, Francesca; Passaglia, Elisa; Cicogna, Francesca; Costantino, Federica; Serrano-Ruiz, Manuel; Peruzzini, Maurizio; Heun, Stefan

    2018-07-01

    Hybrid materials, containing a 2D filler embedded in a polymeric matrix, are an interesting platform for several applications, because of the variety of properties that the filler can impart to the polymer matrix when dispersed at the nanoscale. Moreover, novel properties could arise from the interaction between the two. Mostly the bulk properties of these materials have been studied so far, especially focusing on how the filler changes the polymeric matrix properties. Here we propose a complete change of perspective by using the hybrid nanocomposite material as a platform suitable to engineer the properties of the filler and to exploit its potential in the fabrication of devices. As a proof of concept of the versatility and the potential of the new method, we applied this approach to prepare black phosphorus (bP) nanocomposites through its dispersion in poly (methyl methacrylate). bP is a very interesting 2D material, whose application have so far been limited by its high reactivity to oxygen and water. In this respect, we show that electronic-grade bP flakes, already embedded in a protecting matrix since their exfoliation from the bulk material, are endowed with significantly increased stability and can be further processed into devices without degrading their properties.

  17. Hybrid Nanocomposites of 2D Black Phosphorous Nanosheets Encapsulated in PMMA Polymer Material: New Platforms for Advanced Device Fabrication.

    PubMed

    Telesio, Francesca; Passaglia, Elisa; Cicogna, Francesca; Costantino, Federica; Serrano-Ruiz, Manuel; Peruzzini, Maurizio; Heun, Stefan

    2018-04-12

    Hybrid materials, containing a 2D filler embedded in a polymeric matrix, are an interesting platform for several applications, because of the variety of properties that the filler can impart to the polymer matrix when dispersed at the nanoscale. Moreover, novel properties could arise from the interaction between the two. Mostly the bulk properties of these materials have been studied so far, especially focusing on how the filler changes the polymeric matrix properties. Here we propose a complete change of perspective by using the hybrid nanocomposite material as a platform suitable to engineer the properties of the filler and to exploit its potential in the fabrication of devices. As a proof of concept of the versatility and potentiality of the new method, we applied this approach to prepare black phosphorus nanocomposites through its dispersion in poly (methyl methacrylate). Black phosphorus is a very interesting 2D material, whose application have so far been limited by its very high reactivity to oxygen and water. In this respect, we show that electronic-grade black phosphorus flakes, already embedded in a protecting matrix since their exfoliation from the bulk material, are endowed with significant increased stability, and can be further processed into devices without degrading their properties. Creative Commons Attribution license.

  18. Fabrication and Characterization of Hybrid Organic-Inorganic Electron Extraction Layers for Polymer Solar Cells toward Improved Processing Robustness and Air Stability.

    PubMed

    Fredj, Donia; Pourcin, Florent; Alkarsifi, Riva; Kilinc, Volkan; Liu, Xianjie; Ben Dkhil, Sadok; Boudjada, Nassira Chniba; Fahlman, Mats; Videlot-Ackermann, Christine; Margeat, Olivier; Ackermann, Jörg; Boujelbene, Mohamed

    2018-05-23

    Organic-inorganic hybrid materials composed of bismuth and diaminopyridine are studied as novel materials for electron extraction layers in polymer solar cells using regular device structures. The hybrid materials are solution processed on top of two different low band gap polymers (PTB7 or PTB7-Th) as donor materials mixed with fullerene PC 70 BM as the acceptor. The intercalation of the hybrid layer between the photoactive layer and the aluminum cathode leads to solar cells with a power conversion efficiency of 7.8% because of significant improvements in all photovoltaic parameters, that is, short-circuit current density, fill factor, and open-circuit voltage, similar to the reference devices using ZnO as the interfacial layer. However when using thick layers of such hybrid materials for electron extraction, only small losses in photocurrent density are observed in contrast to the reference material ZnO of pronounced losses because of optical spacer effects. Importantly, these hybrid electron extraction layers also strongly improve the device stability in air compared with solar cells processed with ZnO interlayers. Both results underline the high potential of this new class of hybrid materials as electron extraction materials toward robust processing of air stable organic solar cells.

  19. Hybrid metal grid-polymer-carbon nanotube electrodes for high luminance organic light emitting diodes

    NASA Astrophysics Data System (ADS)

    Sam, F. Laurent M.; Dabera, G. Dinesha M. R.; Lai, Khue T.; Mills, Christopher A.; Rozanski, Lynn J.; Silva, S. Ravi P.

    2014-08-01

    Organic light emitting diodes (OLEDs) incorporating grid transparent conducting electrodes (TCEs) with wide grid line spacing suffer from an inability to transfer charge carriers across the gaps in the grids to promote light emission in these areas. High luminance OLEDs fabricated using a hybrid TCE composed of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS PH1000) or regioregular poly(3-hexylthiophene)-wrapped semiconducting single-walled carbon nanotubes (rrP3HT-SWCNT) in combination with a nanometre thin gold grid are reported here. OLEDs fabricated using the hybrid gold grid/PH1000 TCE have a luminance of 18 000 cd m-2 at 9 V; the same as the reference indium tin oxide (ITO) OLED. The gold grid/rrP3HT-SWCNT OLEDs have a lower luminance of 8260 cd m-2 at 9 V, which is likely due to a rougher rrP3HT-SWCNT surface. These results demonstrate that the hybrid gold grid/PH1000 TCE is a promising replacement for ITO in future plastic electronics applications including OLEDs and organic photovoltaics. For applications where surface roughness is not critical, e.g. electrochromic devices or discharge of static electricity, the gold grid/rrP3HT-SWCNT hybrid TCE can be employed.

  20. Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

    PubMed Central

    Bassanini, Ivan; Hult, Karl

    2015-01-01

    Summary Dicarboxylic acids and their derivatives (esters and anhydrides) have been used as acylating agents in lipase-catalyzed reactions in organic solvents. The synthetic outcomes have been dimeric or hybrid derivatives of bioactive natural compounds as well as functionalized polyesters. PMID:26664578

  1. Bismaleimide/Preceramic Polymer Blends for Hybrid Material Transition Regions. Part 2. Incorporating Compatibilizers

    DTIC Science & Technology

    2014-01-01

    afford- ing only 80% yield.10 Synthesis of compatibilizer based on homopolymer containing tetramethyldisilylethyl and bis(n- propyl )bisphenol A units... synthesis , and characteriza- tion of polymeric compatibilizers utilized in the formation of the hybrid material; also described are the processing and the...from Gelest, Inc (Gelest Inc., Morrisville, Pennsylvania, USA) and were used without further purification. Synthesis of polymeric compatibilizers for

  2. Synthesis and Characterization of Elastin-Mimetic Hybrid Polymers with Multiblock, Alternating Molecular Architecture and Elastomeric Properties

    PubMed Central

    Grieshaber, Sarah E.; Farran, Alexandra J. E.; Lin-Gibson, Sheng; Kiick, Kristi L.; Jia, Xinqiao

    2009-01-01

    We are interested in developing elastin–mimetic hybrid polymers (EMHPs) that capture the multiblock molecular architecture of tropoelastin as well as the remarkable elasticity of mature elastin. In this study, multiblock EMHPs containing flexible synthetic segments based on poly(ethylene glycol) (PEG) alternating with alanine-rich, lysine-containing peptides were synthesized by step-growth polymerization using α,ω-azido-PEG and alkyne-terminated AKA3KA (K = lysine, A = alanine) peptide, employing orthogonal click chemistry. The resulting EMHPs contain an estimated three to five repeats of PEG and AKA3KA and have an average molecular weight of 34 kDa. While the peptide alone exhibited α-helical structures at high pH, the fractional helicity for EMHPs was reduced. Covalent cross-linking of EMHPs with hexamethylene diisocyanate (HMDI) through the lysine residue in the peptide domain afforded an elastomeric hydrogel (xEMHP) with a compressive modulus of 0.12 MPa when hydrated. The mechanical properties of xEMHP are comparable to a commercial polyurethane elastomer (Tecoflex SG80A) under the same conditions. In vitro toxicity studies showed that while the soluble EMHPs inhibited the growth of primary porcine vocal fold fibroblasts (PVFFs) at concentrations ≥0.2 mg/mL, the cross-linked hybrid elastomers did not leach out any toxic reagents and allowed PVFFs to grow and proliferate normally. The hybrid and modular approach provides a new strategy for developing elastomeric scaffolds for tissue engineering. PMID:19763157

  3. Universal Surface-initiated Polymerization of Antifouling Zwitterionic Brushes Using A Mussel-Mimetic Peptide Initiator

    PubMed Central

    Kuang, Jinghao; Messersmith, Phillip B.

    2012-01-01

    We report a universal method for the surface-initated polymerization (SIP) of a antifouling polymer brush on various classes of surfaces, including noble metals, metal oxides and inert polymers. Inspired by the versatility of mussel adhesive proteins, we synthesized a novel bifunctional tripeptide bromide (BrYKY) which combines an atom transfer radical polymerization (ATRP) initiating alkyl bromide with l-3,4-dihydroxyphenylalanine (DOPA) and lysine. Simple dip-coating of substrates with variable wetting properties and compositions, including Teflon®, in a BrYKY solution at pH 8.5 led to formation of a thin film of cross-linked BrYKY. Subsequently, we showed that the BrYKY layer initiated the ATRP of a zwitterionic monomer, sulfobetaine methacrylate (SBMA) on all substrates, resulting in high density antifouling pSBMA brushes. Both BrYKY deposition and pSBMA grafting were unambiguously confirmed by ellipsometry, X-ray photoelectron spectroscopy and goniometry. All substrates that were coated with BrYKY/pSBMA dramatically reduced bacterial adhesion for 24 h and also resisted mammalian cell adhesion for at least 4 months, demonstrating the long-term stability of the BrYKY anchoring and antifouling properties of pSBMA. The use of BrYKY as a primer and polymerization initiator has the potential to be widely employed in surface grafted polymer brush modifications for biomedical and other applications. PMID:22506651

  4. Full-color tuning in binary polymer:perovskite nanocrystals organic-inorganic hybrid blends

    NASA Astrophysics Data System (ADS)

    Perulli, A.; Balena, A.; Fernandez, M.; Nedelcu, G.; Cretí, A.; Kovalenko, M. V.; Lomascolo, M.; Anni, M.

    2018-04-01

    The excellent optical and electronic properties of metal halide perovskites recently proposed these materials as interesting active materials for optoelectronic applications. In particular, the high color purity of perovskite colloidal nanocrystals (NCs) had recently motivated their exploration as active materials for light emitting diodes with tunable emission across the visible range. In this work, we investigated the emission properties of binary blends of conjugated polymers and perovskite NCs. We demonstrate that the emission color of the blends is determined by the superposition of the component photoluminescence spectra, allowing color tuning by acting on the blend relative composition. The use of two different polymers, two different perovskite NCs, and different blend compositions is exploited to tune the blend color in the blue-green, yellow-red, and blue-red ranges, including white light generation.

  5. From neutral to zwitterionic poly(α-amino acid) nonfouling surfaces: Effects of helical conformation and anchoring orientation.

    PubMed

    Zhang, Chong; Yuan, Jingsong; Lu, Jianhua; Hou, Yingqin; Xiong, Wei; Lu, Hua

    2018-02-03

    The development of high-performance nonfouling polymer surfaces for implantable medical devices and therapeutic nanomaterials is of great importance. Elaborating the relationship of polymer structural characteristics and the resulted surface properties can offer useful guidance toward ideal biointerfaces. In this work, we investigate the effects of the helical conformation and anchoring orientation of poly(α-amino acid)s (PαAAs) to produce advanced nonfouling surfaces. By using the neutral poly(γ-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)esteryl glutamates) (P(EG 3 Glu)s) as a model system, the adsorption kinetics are monitored by ex-situ variable angle spectroscopic ellipsometry and in-situ quartz crystal microbalance with dissipation. It is found that the polymers adopting a rigid rod-like α-helical conformation can self-assemble more rapidly to produce denser adlayers, and generate significantly improved nonfouling surfaces compared to those flexible polymer analogues including the widely used antifouling polymer PEG. Moreover, the surface properties can be further enhanced by using the antiparallel orientated helical P(EG 3 Glu)s. Most importantly, the insights gained from the P(EG 3 Glu) model system are successfully applied to the generation of ultra-low-fouling surfaces using zwitterionic PαAAs brushes, underscoring the generality of the approach. Particularly, the surface based on the antiparallel aligned zwitterionic helical PαAAs exhibits ∼98-99% reduction of human serum adsorption relative to the bare gold, and gives almost no adhesion of mouse platelet. Taken together, this work depicts an extremely simple yet highly effective approach to manipulate surface properties for numerous applications in biomaterial interfaces, diagnostics, and biosensors. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Self-assembled hybrid polymer-TiO2 nanotube array heterojunction solar cells.

    PubMed

    Shankar, Karthik; Mor, Gopal K; Prakasam, Haripriya E; Varghese, Oomman K; Grimes, Craig A

    2007-11-20

    Films comprised of 4 microm long titanium dioxide nanotube arrays were fabricated by anodizing Ti foils in an ethylene glycol based electrolyte. A carboxylated polythiophene derivative was self-assembled onto the TiO2 nanotube arrays by immersing them in a solution of the polymer. The binding sites of the carboxylate moiety along the polymer chain provide multiple anchoring sites to the substrate, making for a stable rugged film. Backside illuminated liquid junction solar cells based on TiO2 nanotube films sensitized by the self-assembled polymeric layer showed a short-circuit current density of 5.5 mA cm-2, a 0.7 V open circuit potential, and a 0.55 fill factor yielding power conversion efficiencies of 2.1% under AM 1.5 sun. A backside illuminated single heterojunction solid state solar cell using the same self-assembled polymer was demonstrated and yielded a photocurrent density as high as 2.0 mA cm-2. When a double heterojunction was formed by infiltrating a blend of poly(3-hexylthiophene) (P3HT) and C60-methanofullerene into the self-assembled polymer coated nanotube arrays, a photocurrent as high as 6.5 mA cm-2 was obtained under AM 1.5 sun with a corresponding efficiency of 1%. The photocurrent action spectra showed a maximum incident photon-to-electron conversion efficiency (IPCE) of 53% for the liquid junction cells and 25% for the single heterojunction solid state solar cells.

  7. Towards 4th generation biomaterials: a covalent hybrid polymer-ormoglass architecture

    NASA Astrophysics Data System (ADS)

    Sachot, N.; Mateos-Timoneda, M. A.; Planell, J. A.; Velders, A. H.; Lewandowska, M.; Engel, E.; Castaño, O.

    2015-09-01

    Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed on its surface mimicking the structure of the ECM of bone. Here, polylactic acid electrospun fibers have been successfully and reproducibly coated with a bioactive organically modified glass (ormoglass, Si-Ca-P2 system) covalently. In comparison with the pure polymeric mats, the fibers obtained showed improved hydrophilicity and mechanical properties, bioactive ion release, exhibited a nanoroughness and enabled good cell adhesion and spreading after just one day of culture (rMSCs and rEPCs). The fibers were coated with different ormoglass compositions to tailor their surface properties (roughness, stiffness, and morphology) by modifying the experimental parameters. Knowing that cells modulate their behavior according to the exposed physical and chemical signals, the development of this instructive material is a valuable advance in the design of functional regenerative biomaterials.Hybrid materials are being extensively investigated with the aim of mimicking the ECM microenvironment to develop effective solutions for bone tissue engineering. However, the common drawbacks of a hybrid material are the lack of interactions between the scaffold's constituents and the masking of its bioactive phase. Conventional hybrids often degrade in a non-homogeneous manner and the biological response is far from optimal. We have developed a novel material with strong interactions between constituents. The bioactive phase is directly exposed

  8. Ion-Specific Modulation of Interfacial Interaction Potentials between Solid Substrates and Cell-Sized Particles Mediated via Zwitterionic, Super-Hydrophilic Poly(sulfobetaine) Brushes.

    PubMed

    Higaki, Yuji; Fröhlich, Benjamin; Yamamoto, Akihisa; Murakami, Ryo; Kaneko, Makoto; Takahara, Atsushi; Tanaka, Motomu

    2017-02-16

    Zwitterionic polymer brushes draw increasing attention not only because of their superhydrophilic, self-cleaning capability but also due to their excellent antifouling capacity. We investigated the ion-specific modulation of the interfacial interaction potential via densely packed, uniform poly(sulfobetaine) brushes. The vertical Brownian motion of a cell-sized latex particle was monitored by microinterferometry, yielding the effective interfacial interaction potentials V(Δh) and the autocorrelation function of height fluctuation. The potential curvature V″(Δh) exhibited a monotonic increase according to the increase in monovalent salt concentrations, implying the sharpening of the potential confinement. An opposite tendency was observed in CaCl 2 solutions, suggesting that the ion specific modulation cannot be explained by the classical Hofmeister series. When the particle fluctuation was monitored in the presence of free sulfobetaine molecules, the increase in [sulfobetaine] resulted in a distinct increase in hydrodynamic friction. This was never observed in all the other salt solutions, suggesting the interference of zwitterionic pairing of sulfobetaine side chains by the intercalation of sulfobetaine molecules into the brush layer. Furthermore, poly(sulfobetaine) brushes exhibited a very low V″(Δh) and hydrodynamic friction to human erythrocytes, which seems to explain the excellent blood repellency of zwitterionic polymer materials.

  9. Optical modulation from an electro-optic polymer based hybrid Fabry-Perot etalon using transparent conducting oxides

    NASA Astrophysics Data System (ADS)

    Gan, Haiyong; Zhang, Hongxi; DeRose, Christopher T.; Norwood, Robert A.; Fallahi, Mahmoud; Luo, Jingdong; Jen, Alex K.-Y.; Liu, Boyang; Ho, Seng-Tiong; Peyghambarian, Nasser

    2007-02-01

    Fabry-Perot etalons using electro-optic (EO) organic materials can be used for devices such as tunable filters and spatial light modulators (SLM's) for wavelength division multiplexing (WDM) communication systems 1-5 and ultrafast imaging systems. For these applications the SLM's need to have: (i) low insertion loss, (ii) high speed operation, and (iii) large modulation depth with low drive voltage. Recently, there have been three developments which together can enhance the SLM performance to a higher level. First, low loss distributed Bragg reflector (DBR) mirrors are now used in SLM's to replace thin metal mirrors, resulting in reduced transmission loss, high reflectivity (>99%) and high finesse. Second, EO polymer materials have shown excellent properties for wide bandwidth optical modulation for information technology due to their fabrication flexibility, compatibility with high speed operation, and large EO coefficients at telecommunication wavelengths. For instance, the EO polymer AJL8/APC (AJL8: nonlinear optical chromophore, and APC: amorphous polycarbonate has recently been incorporated into waveguide modulators and achieved good performance for optical modulation. Finally, very low loss transparent conducting oxide (TCO) electrodes have drawn increasing attention for applications in optoelectronic devices. Here we will address how the low loss indium oxide (In IIO 3) electrodes with an absorption coefficient ~1000/cm and conductivity ~204 S/cm can help improve the modulation performance of EO polymer Fabry-Pérot étalons using the advanced electro-optic (EO) polymer material (AJL8/APC). A hybrid etalon structure with one highly conductive indium tin oxide (ITO) electrode outside the etalon cavity and one low-absorption In IIO 3 electrode inside etalon cavity has been demonstrated. High finesse (~234), improved effective applied voltage ratio (~0.25), and low insertion loss (~4 dB) have been obtained. A 10 dB isolation ratio and ~10% modulation depth at

  10. Effect of Surface Hydration on Antifouling Properties of Mixed Charged Polymers.

    PubMed

    Leng, Chuan; Huang, Hao; Zhang, Kexin; Hung, Hsiang-Chieh; Xu, Yao; Li, Yaoxin; Jiang, Shaoyi; Chen, Zhan

    2018-05-07

    Interfacial water structure on a polymer surface in water (or surface hydration) is related to the antifouling activity of the polymer. Zwitterionic polymer materials exhibit excellent antifouling activity due to their strong surface hydration. It was proposed to replace zwitterionic polymers using mixed charged polymers because it is much easier to prepare mixed charged polymer samples with much lower costs. In this study, using sum frequency generation (SFG) vibrational spectroscopy, we investigated interfacial water structures on mixed charged polymer surfaces in water, and how such structures change while exposing to salt solutions and protein solutions. The 1:1 mixed charged polymer exhibits excellent antifouling property while other mixed charged polymers with different ratios of the positive/negative charges do not. It was found that on the 1:1 mixed charged polymer surface, SFG water signal is dominated by the contribution of the strongly hydrogen bonded water molecules, indicating strong hydration of the polymer surface. The responses of the 1:1 mixed charged polymer surface to salt solutions are similar to those of zwitterionic polymers. Interestingly, exposure to high concentrations of salt solutions leads to stronger hydration of the 1:1 mixed charged polymer surface after replacing the salt solution with water. Protein molecules do not substantially perturb the interfacial water structure on the 1:1 mixed charged polymer surface and do not adsorb to the surface, showing that this mixed charged polymer is an excellent antifouling material.

  11. Photothermally Activated Pyroelectric Polymer Films for Harvesting of Solar Heat with a Hybrid Energy Cell Structure.

    PubMed

    Park, Teahoon; Na, Jongbeom; Kim, Byeonggwan; Kim, Younghoon; Shin, Haijin; Kim, Eunkyoung

    2015-12-22

    Photothermal effects in poly(3,4-ethylenedioxythiophene)s (PEDOTs) were explored for pyroelectric conversion. A poled ferroelectric film was coated on both sides with PEDOT via solution casting polymerization of EDOT, to give highly conductive and effective photothermal thin films of PEDOT. The PEDOT films not only provided heat source upon light exposure but worked as electrodes for the output energy from the pyroelectric layer in an energy harvester hybridized with a thermoelectric layer. Compared to a bare thermoelectric system under NIR irradiation, the photothermal-pyro-thermoelectric device showed more than 6 times higher thermoelectric output with the additional pyroelectric output. The photothermally driven pyroelectric harvesting film provided a very fast electric output with a high voltage output (Vout) of 15 V. The pyroelectric effect was significant due to the transparent and high photothermal PEDOT film, which could also work as an electrode. A hybrid energy harvester was assembled to enhance photoconversion efficiency (PCE) of a solar cell with a thermoelectric device operated by the photothermally generated heat. The PCE was increased more than 20% under sunlight irradiation (AM 1.5G) utilizing the transmitted light through the photovoltaic cell as a heat source that was converted into pyroelectric and thermoelectric output simultaneously from the high photothermal PEDOT electrodes. Overall, this work provides a dynamic and static hybrid energy cell to harvest solar energy in full spectral range and thermal energy, to allow solar powered switching of an electrochromic display.

  12. High-efficiency hybrid solar cells based on polymer/PbSx Se1-x nanocrystals benefiting from vertical phase segregation.

    PubMed

    Liu, Zeke; Sun, Yaxiang; Yuan, Jianyu; Wei, Huaixin; Huang, Xiaodong; Han, Lu; Wang, Weiwei; Wang, Haiqiao; Ma, Wanli

    2013-10-25

    Solution-processed hybrid solar cells employing a low band-gap polymer and PbSx Se1-x alloy nanocrystals, achieving a record high PCE of 5.50% and an optimal FF of 67% are presented. The remarkable device efficiency can be attributed to the high-performance active materials, the optimal polymer/NCs ratio and, more importantly, the vertical donor/(donor:acceptor)/acceptor structure which benefits charge dissociation and transport. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Engineering of a novel adjuvant based on lipid-polymer hybrid nanoparticles: A quality-by-design approach.

    PubMed

    Rose, Fabrice; Wern, Jeanette Erbo; Ingvarsson, Pall Thor; van de Weert, Marco; Andersen, Peter; Follmann, Frank; Foged, Camilla

    2015-07-28

    properties of DDA/TDB are maintained in the PLGA hybrid matrix. This study demonstrates the complexity of formulation design for the engineering of a hybrid lipid-polymer nanoparticle adjuvant. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. High Temperature Resistant Organic/Inorganic Hybrid Polymers: An Architectural Study

    DTIC Science & Technology

    2007-04-18

    period. List the papers, including journal references: Iyer, P.; Beck , J. B.; Rowan, S.J., Weder C. Synthesis and Optical Properties of Metallo...publication and to a new grant being submitted in response to the ARO BAA W911NF-06-R-0005 "Basic Research Program in Chemical, Biological, Radiological...2002, 35, 3315. (e) Ishaque, M.; Agarwal, S.; Greiner, A. E-Polymers 2002, Art. No. 31. (15) Beck , B.J.; Kokil, A.; Ray, D.; Rowan, S.J.; Weder, C

  15. Development of PLA hybrid yarns for biobased self-reinforced polymer composites

    NASA Astrophysics Data System (ADS)

    Köhler, T.; Gries, T.; Seide, G.

    2017-10-01

    Lightweight materials are a necessity in various industries. Lightweight design is in the key interest of the mobility sector, e.g. the automotive and aerospace industry. This trend applies also for the consumer industries, e.g. sporting goods. In addition, the worldwide demand for replacing fossil-based materials has led to a significant growth of bioplastics. Due to their low mechanical performance and durability, their use is still limited. Therefore, it is necessary to develop biobased, sustainable polymeric materials with high stiffness, high impact and high durability without impairing recyclability at a similar price level of non-biobased solutions. Biobased self-reinforced polymer composites offer these unique properties.

  16. Hybrid Materials Based on the Embedding of Organically Modified Transition Metal Oxoclusters or Polyoxometalates into Polymers for Functional Applications: A Review

    PubMed Central

    Carraro, Mauro; Gross, Silvia

    2014-01-01

    The covalent incorporation of inorganic building blocks into a polymer matrix to obtain stable and robust materials is a widely used concept in the field of organic-inorganic hybrid materials, and encompasses the use of different inorganic systems including (but not limited to) nanoparticles, mono- and polynuclear metal complexes and clusters, polyhedral oligomeric silsesquioxanes (POSS), polyoxometalates (POM), layered inorganic systems, inorganic fibers, and whiskers. In this paper, we will review the use of two particular kinds of structurally well-defined inorganic building blocks, namely transition metals oxoclusters (TMO) and polyoxometalates (POM), to obtain hybrid materials with enhanced functional (e.g., optical, dielectric, magnetic, catalytic) properties. PMID:28788659

  17. Polysulfide-Blocking Microporous Polymer Membrane Tailored for Hybrid Li-Sulfur Flow Batteries.

    PubMed

    Li, Changyi; Ward, Ashleigh L; Doris, Sean E; Pascal, Tod A; Prendergast, David; Helms, Brett A

    2015-09-09

    Redox flow batteries (RFBs) present unique opportunities for multi-hour electrochemical energy storage (EES) at low cost. Too often, the barrier for implementing them in large-scale EES is the unfettered migration of redox active species across the membrane, which shortens battery life and reduces Coulombic efficiency. To advance RFBs for reliable EES, a new paradigm for controlling membrane transport selectivity is needed. We show here that size- and ion-selective transport can be achieved using membranes fabricated from polymers of intrinsic microporosity (PIMs). As a proof-of-concept demonstration, a first-generation PIM membrane dramatically reduced polysulfide crossover (and shuttling at the anode) in lithium-sulfur batteries, even when sulfur cathodes were prepared as flowable energy-dense fluids. The design of our membrane platform was informed by molecular dynamics simulations of the solvated structures of lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) vs lithiated polysulfides (Li2Sx, where x = 8, 6, and 4) in glyme-based electrolytes of different oligomer length. These simulations suggested polymer films with pore dimensions less than 1.2-1.7 nm might incur the desired ion-selectivity. Indeed, the polysulfide blocking ability of the PIM-1 membrane (∼0.8 nm pores) was improved 500-fold over mesoporous Celgard separators (∼17 nm pores). As a result, significantly improved battery performance was demonstrated, even in the absence of LiNO3 anode-protecting additives.

  18. Hybrid Titanium/Biodegradable Polymer Implants with an Hierarchical Pore Structure as a Means to Control Selective Cell Movement

    PubMed Central

    Vrana, Nihal Engin; Dupret, Agnès; Coraux, Christelle; Vautier, Dominique; Debry, Christian; Lavalle, Philippe

    2011-01-01

    In order to improve implant success rate, it is important to enhance their responsiveness to the prevailing conditions following implantation. Uncontrolled movement of inflammatory cells and fibroblasts is one of these in vivo problems and the porosity properties of the implant have a strong effect on these. Here, we describe a hybrid system composed of a macroporous titanium structure filled with a microporous biodegradable polymer. This polymer matrix has a distinct porosity gradient to accommodate different cell types (fibroblasts and epithelial cells). The main clinical application of this system will be the prevention of restenosis due to excessive fibroblast migration and proliferation in the case of tracheal implants. Methodology/Principal Findings A microbead-based titanium template was filled with a porous Poly (L-lactic acid) (PLLA) body by freeze-extraction method. A distinct porosity difference was obtained between the inner and outer surfaces of the implant as characterized by image analysis and Mercury porosimetry (9.8±2.2 µm vs. 36.7±11.4 µm, p≤0.05). On top, a thin PLLA film was added to optimize the growth of epithelial cells, which was confirmed by using human respiratory epithelial cells. To check the control of fibroblast movement, PKH26 labeled fibroblasts were seeded onto Titanium and Titanium/PLLA implants. The cell movement was quantified by confocal microscopy: in one week cells moved deeper in Ti samples compared to Ti/PLLA. Conclusions In vitro experiments showed that this new implant is effective for guiding different kind of cells it will contact upon implantation. Overall, this system would enable spatial and temporal control over cell migration by a gradient ranging from macroporosity to nanoporosity within a tracheal implant. Moreover, mechanical properties will be dependent mainly on the titanium frame. This will make it possible to create a polymeric environment which is suitable for cells without the need to meet mechanical

  19. Hybrid titanium/biodegradable polymer implants with an hierarchical pore structure as a means to control selective cell movement.

    PubMed

    Vrana, Nihal Engin; Dupret, Agnès; Coraux, Christelle; Vautier, Dominique; Debry, Christian; Lavalle, Philippe

    2011-01-01

    In order to improve implant success rate, it is important to enhance their responsiveness to the prevailing conditions following implantation. Uncontrolled movement of inflammatory cells and fibroblasts is one of these in vivo problems and the porosity properties of the implant have a strong effect on these. Here, we describe a hybrid system composed of a macroporous titanium structure filled with a microporous biodegradable polymer. This polymer matrix has a distinct porosity gradient to accommodate different cell types (fibroblasts and epithelial cells). The main clinical application of this system will be the prevention of restenosis due to excessive fibroblast migration and proliferation in the case of tracheal implants. A microbead-based titanium template was filled with a porous Poly (L-lactic acid) (PLLA) body by freeze-extraction method. A distinct porosity difference was obtained between the inner and outer surfaces of the implant as characterized by image analysis and Mercury porosimetry (9.8±2.2 µm vs. 36.7±11.4 µm, p≤0.05). On top, a thin PLLA film was added to optimize the growth of epithelial cells, which was confirmed by using human respiratory epithelial cells. To check the control of fibroblast movement, PKH26 labeled fibroblasts were seeded onto Titanium and Titanium/PLLA implants. The cell movement was quantified by confocal microscopy: in one week cells moved deeper in Ti samples compared to Ti/PLLA. In vitro experiments showed that this new implant is effective for guiding different kind of cells it will contact upon implantation. Overall, this system would enable spatial and temporal control over cell migration by a gradient ranging from macroporosity to nanoporosity within a tracheal implant. Moreover, mechanical properties will be dependent mainly on the titanium frame. This will make it possible to create a polymeric environment which is suitable for cells without the need to meet mechanical requirements with the polymeric structure.

  20. Hybrid calcium carbonate/polymer microparticles containing silver nanoparticles as antibacterial agents

    NASA Astrophysics Data System (ADS)

    Długosz, Maciej; Bulwan, Maria; Kania, Gabriela; Nowakowska, Maria; Zapotoczny, Szczepan

    2012-12-01

    We report here on synthesis and characterization of novel hybrid material consisting of silver nanoparticles (nAgs) embedded in calcium carbonate microparticles (μ-CaCO3) serving as carriers for sustained release. nAgs are commonly used as antimicrobial agents in many commercial products (textiles, cosmetics, and drugs). Although they are considered to be safe, their interactions with human organisms are still not fully understood; therefore it is important to apply them with caution and limit their presence in the environment. The synthesis of the new material was based on the co-precipitation of CaCO3 and nAg in the presence of poly(sodium 4-styrenesulfonate). Such designed system enables sustained release of nAg to the environment. This hybrid colloidal material (nAg/μ-CaCO3) was characterized by microscopic and spectroscopic methods. The release of nAg from μ-CaCO3 microparticles was followed in water at various pH values. Microbiological tests confirmed the effectiveness of these microparticles as an antibacterial agent. Importantly, the material can be stored as a dry powder and subsequently re-suspended in water without the risk of losing its antimicrobial activity. nAg/μ-CaCO3 was applied here to insure bacteriostatic properties of down feathers that may significantly prolong their lifetime in typical applications. Such microparticles may be also used as, e.g., components of coatings and paints protecting various surfaces against microorganism colonization.

  1. A paper/polymer hybrid microfluidic microplate for rapid quantitative detection of multiple disease biomarkers

    NASA Astrophysics Data System (ADS)

    Sanjay, Sharma T.; Dou, Maowei; Sun, Jianjun; Li, Xiujun

    2016-07-01

    Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings.

  2. A paper/polymer hybrid microfluidic microplate for rapid quantitative detection of multiple disease biomarkers.

    PubMed

    Sanjay, Sharma T; Dou, Maowei; Sun, Jianjun; Li, XiuJun

    2016-07-26

    Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings.

  3. A paper/polymer hybrid microfluidic microplate for rapid quantitative detection of multiple disease biomarkers

    PubMed Central

    Sanjay, Sharma T.; Dou, Maowei; Sun, Jianjun; Li, XiuJun

    2016-01-01

    Enzyme linked immunosorbent assay (ELISA) is one of the most widely used laboratory disease diagnosis methods. However, performing ELISA in low-resource settings is limited by long incubation time, large volumes of precious reagents, and well-equipped laboratories. Herein, we developed a simple, miniaturized paper/PMMA (poly(methyl methacrylate)) hybrid microfluidic microplate for low-cost, high throughput, and point-of-care (POC) infectious disease diagnosis. The novel use of porous paper in flow-through microwells facilitates rapid antibody/antigen immobilization and efficient washing, avoiding complicated surface modifications. The top reagent delivery channels can simply transfer reagents to multiple microwells thus avoiding repeated manual pipetting and costly robots. Results of colorimetric ELISA can be observed within an hour by the naked eye. Quantitative analysis was achieved by calculating the brightness of images scanned by an office scanner. Immunoglobulin G (IgG) and Hepatitis B surface Antigen (HBsAg) were quantitatively analyzed with good reliability in human serum samples. Without using any specialized equipment, the limits of detection of 1.6 ng/mL for IgG and 1.3 ng/mL for HBsAg were achieved, which were comparable to commercial ELISA kits using specialized equipment. We envisage that this simple POC hybrid microplate can have broad applications in various bioassays, especially in resource-limited settings. PMID:27456979

  4. Discovery and in vivo evaluation of novel RGD-modified lipid-polymer hybrid nanoparticles for targeted drug delivery.

    PubMed

    Zhao, Yinbo; Lin, Dayong; Wu, Fengbo; Guo, Li; He, Gu; Ouyang, Liang; Song, Xiangrong; Huang, Wei; Li, Xiang

    2014-09-29

    In the current study, the lipid-shell and polymer-core hybrid nanoparticles (lpNPs) modified by Arg-Gly-Asp(RGD) peptide, loaded with curcumin (Cur), were developed by emulsification-solvent volatilization method. The RGD-modified hybrid nanoparticles (RGD-lpNPs) could overcome the poor water solubility of Cur to meet the requirement of intravenous administration and tumor active targeting. The obtained optimal RGD-lpNPs, composed of PLGA (poly(lactic-co-glycolic acid))-mPEG (methoxyl poly(ethylene- glycol)), RGD-polyethylene glycol (PEG)-cholesterol (Chol) copolymers and lipids, had good entrapment efficiency, submicron size and negatively neutral surface charge. The core-shell structure of RGD-lpNPs was verified by TEM. Cytotoxicity analysis demonstrated that the RGD-lpNPs encapsulated Cur retained potent anti-tumor effects. Flow cytometry analysis revealed the cellular uptake of Cur encapsulated in the RGD-lpNPs was increased for human umbilical vein endothelial cells (HUVEC). Furthermore, Cur loaded RGD-lpNPs were more effective in inhibiting tumor growth in a subcutaneous B16 melanoma tumor model. The results of immunofluorescent and immunohistochemical studies by Cur loaded RGD-lpNPs therapies indicated that more apoptotic cells, fewer microvessels, and fewer proliferation-positive cells were observed. In conclusion, RGD-lpNPs encapsulating Cur were developed with enhanced anti-tumor activity in melanoma, and Cur loaded RGD-lpNPs represent an excellent tumor targeted formulation of Cur which might be an attractive candidate for cancer therapy.

  5. Crystal engineering of a zwitterionic drug to neutral cocrystals: a general solution for floxacins.

    PubMed

    Gunnam, Anilkumar; Suresh, Kuthuru; Ganduri, Ramesh; Nangia, Ashwini

    2016-10-18

    The transformation of zwitterionic Sparfloxacin (SPX) to the neutral form is achieved by cocrystallization. Neutral forms of drugs are important for higher membrane permeability, while zwitterions are more soluble in water. The twin advantages of higher solubility/dissolution rate and good stability of neutral SPX are achieved in a molecular cocrystal compared to its zwitterionic SPX hydrate. The amine-phenol supramolecular synthon drives cocrystal formation, with the paraben ester acting as a "proton migrator" for the ionic to neutral transformation.

  6. Preparation of hybrid molecularly imprinted polymer with double-templates for rapid simultaneous purification of theophylline and chlorogenic acid in green tea.

    PubMed

    Tang, Weiyang; Li, Guizhen; Row, Kyung Ho; Zhu, Tao

    2016-05-15

    A novel double-templates technique was adopted for solid-phase extraction packing agent, and the obtained hybrid molecularly imprinted polymers with double-templates (theophylline and chlorogenic acid) were characterized by fourier transform infrared and field emission scanning electron microscope. The molecular recognition ability and binding capability for theophylline and chlorogenic acid of polymers was evaluated by static absorption and dynamic adsorption curves. A rapid and accurate approach was established for simultaneous purification of theophylline and chlorogenic acid in green tea by coupling hybrid molecularly imprinted solid-phase extraction with high performance liquid chromatography. With optimization of SPE procedure, a reliable analytical method was developed for highly recognition towards theophylline and chlorogenic acid in green tea with satisfactory extraction recoveries (theophylline: 96.7% and chlorogenic acid: 95.8%). The limit of detection and limit of quantity of the method were 0.01 μg/mL and 0.03 μg/mL for theophylline, 0.05 μg/mL and 0.17 μg/mL for chlorogenic acid, respectively. The recoveries of proposed method at three spiked levels analysis were 98.7-100.8% and 98.3-100.2%, respectively, with the relative standard deviation less than 1.9%. Hybrid molecularly imprinted polymers with double-templates showed good performance for two kinds of targets, and the proposed approach with high affinity of hybrid molecularly imprinted polymers might offer a novel method for the purification of complex samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Broadband Energy Harvester Using Non-linear Polymer Spring and Electromagnetic/Triboelectric Hybrid Mechanism

    PubMed Central

    Gupta, Rahul Kumar; Shi, Qiongfeng; Dhakar, Lokesh; Wang, Tao; Heng, Chun Huat; Lee, Chengkuo

    2017-01-01

    Over the years, several approaches have been devised to widen the operating bandwidth, but most of them can only be triggered at high accelerations. In this work, we investigate a broadband energy harvester based on combination of non-linear stiffening effect and multimodal energy harvesting to obtain high bandwidth over wide range of accelerations (0.1 g–2.0 g). In order to achieve broadband behavior, a polymer based spring exhibiting multimodal energy harvesting is used. Besides, non-linear stiffening effect is introduced by using mechanical stoppers. At low accelerations (<0.5 g), the nearby mode frequencies of polymer spring contribute to broadening characteristics, while proof mass engages with mechanical stoppers to introduce broadening by non-linear stiffening at higher accelerations. The electromagnetic mechanism is employed in this design to enhance its output at low accelerations when triboelectric output is negligible. Our device displays bandwidth of 40 Hz even at low acceleration of 0.1 g and it is increased up to 68 Hz at 2 g. When non-linear stiffening is used along with multimodal energy-harvesting, the obtained bandwidth increases from 23 Hz to 68 Hz with percentage increment of 295% at 1.8 g. Further, we have demonstrated the triboelectric output measured as acceleration sensing signals in terms of voltage and current sensitivity of 4.7 Vg−1 and 19.7 nAg−1, respectively. PMID:28120924

  8. Broadband Energy Harvester Using Non-linear Polymer Spring and Electromagnetic/Triboelectric Hybrid Mechanism

    NASA Astrophysics Data System (ADS)

    Gupta, Rahul Kumar; Shi, Qiongfeng; Dhakar, Lokesh; Wang, Tao; Heng, Chun Huat; Lee, Chengkuo

    2017-01-01

    Over the years, several approaches have been devised to widen the operating bandwidth, but most of them can only be triggered at high accelerations. In this work, we investigate a broadband energy harvester based on combination of non-linear stiffening effect and multimodal energy harvesting to obtain high bandwidth over wide range of accelerations (0.1 g-2.0 g). In order to achieve broadband behavior, a polymer based spring exhibiting multimodal energy harvesting is used. Besides, non-linear stiffening effect is introduced by using mechanical stoppers. At low accelerations (<0.5 g), the nearby mode frequencies of polymer spring contribute to broadening characteristics, while proof mass engages with mechanical stoppers to introduce broadening by non-linear stiffening at higher accelerations. The electromagnetic mechanism is employed in this design to enhance its output at low accelerations when triboelectric output is negligible. Our device displays bandwidth of 40 Hz even at low acceleration of 0.1 g and it is increased up to 68 Hz at 2 g. When non-linear stiffening is used along with multimodal energy-harvesting, the obtained bandwidth increases from 23 Hz to 68 Hz with percentage increment of 295% at 1.8 g. Further, we have demonstrated the triboelectric output measured as acceleration sensing signals in terms of voltage and current sensitivity of 4.7 Vg-1 and 19.7 nAg-1, respectively.

  9. Micromechanics of Amorphous Metal/Polymer Hybrid Structures with 3D Cellular Architectures: Size Effects, Buckling Behavior, and Energy Absorption Capability.

    PubMed

    Mieszala, Maxime; Hasegawa, Madoka; Guillonneau, Gaylord; Bauer, Jens; Raghavan, Rejin; Frantz, Cédric; Kraft, Oliver; Mischler, Stefano; Michler, Johann; Philippe, Laetitia

    2017-02-01

    By designing advantageous cellular geometries and combining the material size effects at the nanometer scale, lightweight hybrid microarchitectured materials with tailored structural properties are achieved. Prior studies reported the mechanical properties of high strength cellular ceramic composites, obtained by atomic layer deposition. However, few studies have examined the properties of similar structures with metal coatings. To determine the mechanical performance of polymer cellular structures reinforced with a metal coating, 3D laser lithography and electroless deposition of an amorphous layer of nickel-boron (NiB) is used for the first time to produce metal/polymer hybrid structures. In this work, the mechanical response of microarchitectured structures is investigated with an emphasis on the effects of the architecture and the amorphous NiB thickness on their deformation mechanisms and energy absorption capability. Microcompression experiments show an enhancement of the mechanical properties with the NiB thickness, suggesting that the deformation mechanism and the buckling behavior are controlled by the brittle-to-ductile transition in the NiB layer. In addition, the energy absorption properties demonstrate the possibility of tuning the energy absorption efficiency with adequate designs. These findings suggest that microarchitectured metal/polymer hybrid structures are effective in producing materials with unique property combinations. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Long-Term Stability of Photovoltaic Hybrid Perovskites achieved by Graphene Passivation via a Water- and Polymer-Free Graphene Transfer Method

    NASA Astrophysics Data System (ADS)

    Tseng, W.-S.; Jao, M.-H.; Hsu, C.-C.; Wu, C.-I.; Yeh, N.-C.

    Organic-inorganic hybrid perovskites such as CH3NH3PbX3 (X = I, Br) have been intensively studied in recent years because of their rapidly improving photovoltaic power conversion efficiency. However, severe instability of these materials in ambient environment has been a primary challenge for practical applications. To address this issue, we employ high-quality PECVD-grown graphene to passivate the hybrid perovskites. In contrast to existing processes for transferring graphene from the growth substrates to other surfaces that involve either polymer or water, which are incompatible with photovoltaic applications of these water-sensitive hybrid perovskites, we report here a new water- and polymer-free graphene transferring method. Studies of the Raman, x-ray and ultraviolet photoemission spectroscopy (XPS and UPS) demonstrated excellent quality of monolayer PECVD-grown graphene samples after their transfer onto different substrates with the water- and polymer-free processing method. In particular, graphene was successfully transferred onto the surface of CH3NH3PbI3 thin films with sample quality intact. Moreover, XPS and UPS studies indicated that even after 3 months, the fully graphene-covered perovskite films remained spectroscopically invariant, which was in sharp contrast to the drastic changes, after merely one week, in both the XPS and UPS of a control CH3NH3PbI3 sample without graphene protection. Beckman Inst. in Caltech. Dragon Gate Program in Taiwan.

  11. In-situ preparation of poly(ethylene oxide)/Li3PS4 hybrid polymer electrolyte with good nanofiller distribution for rechargeable solid-state lithium batteries

    NASA Astrophysics Data System (ADS)

    Chen, Shaojie; Wang, Junye; Zhang, Zhihua; Wu, Linbin; Yao, Lili; Wei, Zhenyao; Deng, Yonghong; Xie, Dongjiu; Yao, Xiayin; Xu, Xiaoxiong

    2018-05-01

    Nano-sized fillers in a polymer matrix with good distribution can play a positive role in improving polymer electrolytes in the aspects of ionic conductivity, mechanical property and electrochemical performance of Li-ion cells. Herein, polyethylene oxide (PEO)/Li3PS4 hybrid polymer electrolyte is prepared via a new in-situ approach. The ionic conductivities of the novel hybrid electrolytes with variable proportions are measured, and the optimal electrolyte of PEO-2%vol Li3PS4 presents a considerable ionic conductivity of 8.01 × 10-4 S cm-1 at 60 °C and an electrochemical window up to 5.1 V. The tests of DSC and EDXS reveal that the Li3PS4 nanoparticles with better distribution, as active fillers scattering in the PEO, exhibit a positive effect on the transference of lithium ion and electrochemical interfacial stabilities. Finally, the assembled solid-state LiFePO4/Li battery presents a decent cycling performance (80.9% retention rate after 325 cycles at 60 °C) and excellent rate capacities with 153, 143, 139 and 127 mAh g-1 at the discharging rate of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C. It is fully proved that it is an advanced strategy to preparing the new organic/inorganic hybrid electrolytes for lithium-ion batteries applications.

  12. A zwitterionic gel electrolyte for efficient solid-state supercapacitors

    PubMed Central

    Peng, Xu; Liu, Huili; Yin, Qin; Wu, Junchi; Chen, Pengzuo; Zhang, Guangzhao; Liu, Guangming; Wu, Changzheng; Xie, Yi

    2016-01-01

    Gel electrolytes have attracted increasing attention for solid-state supercapacitors. An ideal gel electrolyte usually requires a combination of advantages of high ion migration rate, reasonable mechanical strength and robust water retention ability at the solid state for ensuring excellent work durability. Here we report a zwitterionic gel electrolyte that successfully brings the synergic advantages of robust water retention ability and ion migration channels, manifesting in superior electrochemical performance. When applying the zwitterionic gel electrolyte, our graphene-based solid-state supercapacitor reaches a volume capacitance of 300.8 F cm−3 at 0.8 A cm−3 with a rate capacity of only 14.9% capacitance loss as the current density increases from 0.8 to 20 A cm−3, representing the best value among the previously reported graphene-based solid-state supercapacitors, to the best of our knowledge. We anticipate that zwitterionic gel electrolyte may be developed as a gel electrolyte in solid-state supercapacitors. PMID:27225484

  13. Hybrid polymer/ZnO solar cells sensitized by PbS quantum dots

    PubMed Central

    2012-01-01

    Poly[2-methoxy-5-(2-ethylhexyloxy-p-phenylenevinylene)]/ZnO nanorod hybrid solar cells consisting of PbS quantum dots [QDs] prepared by a chemical bath deposition method were fabricated. An optimum coating of the QDs on the ZnO nanorods could strongly improve the performance of the solar cells. A maximum power conversion efficiency of 0.42% was achieved for the PbS QDs' sensitive solar cell coated by 4 cycles, which was increased almost five times compared with the solar cell without using PbS QDs. The improved efficiency is attributed to the cascade structure formed by the PbS QD coating, which results in enhanced open-circuit voltage and exciton dissociation efficiency. PMID:22313746

  14. Linking 1D Transition-Metal Coordination Polymers and Different Inorganic Boron Oxides To Construct a Series of 3D Inorganic-Organic Hybrid Borates.

    PubMed

    Zhi, Shao-Chen; Wang, Yue-Lin; Sun, Li; Cheng, Jian-Wen; Yang, Guo-Yu

    2018-02-05

    Three inorganic-organic hybrid borates, M(1,4-dab)[B 5 O 7 (OH) 3 ] [M = Zn (1), Cd (2), 1,4-dab = 1,4-diaminobutane)] and Co(1,3-dap)[B 4 O 7 ] (3, 1,3-dap = 1,3-diaminopropane), which integrated characteristics of 1D coordination polymers and 1D/3D inorganic boron oxides have been obtained under solvothermal conditions. Compounds 1 and 2 are isostructural and crystallize in a centrosymmetric space group P2 1 /c; the 3D achiral structures of 1 and 2 consist of the nonhelical Zn/Cd-1,4-dap coordination polymers and 1D B-O chains. Compound 3 crystallizes in a chiral space group P4 3 2 1 2; the helical Co-1,3-dap coordination polymer chains are entrained within a 3D B-O network and finally form the chiral framework. Compounds 1-3 represent good examples of using coordination polymers to construct mixed-motif inorganic-organic hybrid borates. Compounds 1 and 2 display blue luminescence when excited with UV light.

  15. Dual-Ligand Modified Polymer-Lipid Hybrid Nanoparticles for Docetaxel Targeting Delivery to Her2/neu Overexpressed Human Breast Cancer Cells.

    PubMed

    Yang, Zhe; Tang, Wenxin; Luo, Xingen; Zhang, Xiaofang; Zhang, Chao; Li, Hao; Gao, Di; Luo, Huiyan; Jiang, Qing; Liu, Jie

    2015-08-01

    In this study, a dual-ligand polymer-lipid hybrid nanoparticle drug delivery vehicle comprised of an anti-HER2/neu peptide (AHNP) mimic with a modified HIV-1 Tat (mTAT) was established for the targeted treatment of Her2/neu-overexpressing cells. The resultant dual-ligand hybrid nanoparticles (NPs) consisted of a poly(lactide-co-glycolide) core, a near 90% surface coverage of the lipid monolayer, and a 5.7 nm hydrated polyethylene glycol shell. Ligand density optimization study revealed that cellular uptake efficiency of the hybrid NPs could be manipulated by controlling the surface-ligand densities. Furthermore, the cell uptake kinetics and mechanism studies showed that the dual-ligand modifications of hybrid NPs altered the cellular uptake pathway from caveolae-mediated endocytosis (CvME) to the multiple endocytic pathways, which would significantly enhance the NP internalization. Upon the systemic investigation of the cellular uptake behavior of dual-ligand hybrid NPs, docetaxel (DTX), a hydrophobic anticancer drug, was successfully encapsulated into dual-ligand hybrid NPs with high drug loading for Her2/neu-overexpressing SK-BR-3 breast cancer cell treatment. The DTX-loaded dual-ligand hybrid NPs showed a decreased burst release and a more gradual sustained drug release property. Because of the synergistic effect of dual-ligand modification, DTX-loaded dual-ligand hybrid NPs exerted substantially better therapeutic potency against SK-BR-3 cancer cells than other NP formulations and free DTX drugs. These results demonstrate that the dual-ligand hybrid NPs could be a promising vehicle for targeted drug delivery to treat breast cancer.

  16. Spin coating and plasma process for 2.5D and hybrid 3D micro-resonators on multilayer polymers

    NASA Astrophysics Data System (ADS)

    Bêche, B.; Gaviot, E.; Godet, C.; Zebda, A.; Potel, A.; Barbe, J.; Camberlein, L.; Vié, V.; Panizza, P.; Loas, G.; Hamel, C.; Zyss, J.; Huby, N.

    2009-05-01

    We have designed and realized three integrated photonic families of micro-resonators (MR) on multilayer organic materials. Such so-called 2.5D-MR and 3D-MR structures show off radius values ranging from 40 to 200μm. Both first and second families are especially designed on organic multilayer materials and shaped as ring- and disk-MR organics structures arranged upon (and coupled with) a pair of SU8-organic waveguides. The third family is related to hybrid 3D-MR structures composed of spherical glass-MR coupled to organic waveguides by a Langmuir-Blodgett lipid film about three nanometers in thickness. At first, polymer spin coating, surface plasma treatment and selective UV-lithography processes have been developed to realize 2.5D photonic micro-resonators. Secondly, we have designed and characterized photonic-quadripoles made of 3D-glass-MR arranged upon a pair of SU8 waveguides. Such structures are defined by a 4-ports or 4-waveguides coupled by the spherical glass-MR. We have achieved an evanescent photonic coupling between the 3D-MR and the 4-ports structure. Spectral resonances have been measured for 4-whispering gallery-modes (WGM) into such 3D-structures respectively characterized by a 0.97 nm free spectral range (FSR) and a high quality Q-factor up to 4.104.

  17. Waterborne Colloidal Polymer/Silica Hybrid Dispersions and Their Assembly into Mesoporous Poly(melamine-formaldehyde) Xerogels.

    PubMed

    Schwarz, Dana; Weber, Jens

    2015-08-04

    The acid-catalyzed polycondensation of oligo(melamine-formaldehyde) in aqueous phase and in the presence of silica nanoparticles leads to a stable dispersion of coexisting silica and polymer nanoparticles. The dispersion can be processed into mesoporous xerogels (SBET ≈ 200 m(2) g(-1)), whose porosity can be enhanced by etching of silica up to specific surface areas of >400 m(2) g(-1). The formation mechanism and the characteristics of the hybrid dispersion are crucial to the materials derived from it and analyzed in detail using a variety of experimental techniques (electron and force microscopy, light and X-ray scattering, ultracentrifugation, and spectroscopy). The transformation of the dispersion into xerogels by electrostatic destabilization is described. Furthermore, the obtained materials are characterized with regard to their porosity and morphology using microscopy and porosimetry. The impact of selected synthesis parameters on the obtained properties is discussed, and it was found (most interestingly) that stable porosity was only observed if silica nanoparticles were present within the dispersion.

  18. Total Life Cycle-Based Materials Selection for Polymer Metal Hybrid Body-in-White Automotive Components

    NASA Astrophysics Data System (ADS)

    Grujicic, M.; Sellappan, V.; He, T.; Seyr, Norbert; Obieglo, Andreas; Erdmann, Marc; Holzleitner, Jochen

    2009-03-01

    Over the last dozen of years, polymer metal hybrid (PMH) technologies have established themselves as viable alternatives for use in light-weight automotive body-in-white bolt-on as well as load-bearing (structural) components. Within the PMH technologies, sheet-metal stamped/formed and thermoplastic injection molding subcomponents are integrated into a singular component/module. Due to attending synergetic effects, the performance of the PMH component typically exceeds that attainable by an alternative single-material technologies. In the present work, a total life cycle (TLC) approach to the selection of metallic and thermoplastic materials (as well as the selection of structural adhesives, where appropriate) is considered. The TLC material selection approach considers the consequences and ramifications of material selection at each major stage of the vehicle manufacturing process chain (press shop, injection molding shop, body shop, paint shop, and assembly), as well as relation to the vehicle performance, durability and the end-of-the-life-of-the-vehicle considerations. The approach is next applied to the case of injection overmolding technology to identify the optimal grade of short glass-fiber reinforced nylon when used in a prototypical PMH load-bearing automotive body-in-white component.

  19. Enzyme-assisted growth of nacreous CaCO3/polymer hybrid nanolaminates via the formation of mineral bridges

    NASA Astrophysics Data System (ADS)

    Yeom, Bongjun; Char, Kookheon

    2016-06-01

    Laminated nanostructures in nacre have been adopted as models in the fabrication of strong, tough synthetic nanocomposites. However, the utilization of CaCO3 biominerals in these composites is limited by the complexity of the synthesis method for nanosized biominerals. In this study, we use the enzymatic reaction of urease to generate a nanoscale CaCO3 thin film to prepare CaCO3/polymer hybrid nanolaminates. Additional layers of CaCO3 thin film are consecutively grown over the base CaCO3 layer with the intercalation of organic layers. The morphology and crystallinity of the added CaCO3 layers depend strongly on the thickness of the organic layer coated on the underlying CaCO3 layer. When the organic layer is less than 20 nm thick, the amorphous CaCO3 layer is spontaneously transformed into crystalline calcite layer during the growth process. We also observe crystalline continuity between adjacent CaCO3 layers through interconnecting mineral bridges. The formation of these mineral bridges is crucial to the epitaxial growth of CaCO3 layers, similar to the formation of natural nacre.

  20. C,N-bipyrazole receptor grafted onto a porous silica surface as a novel adsorbent based polymer hybrid.

    PubMed

    Radi, Smaail; Attayibat, Ahmed; El-Massaoudi, Mohamed; Bacquet, Maryse; Jodeh, Shehdeh; Warad, Ismail; Al-Showiman, Salim S; Mabkhot, Yahia N

    2015-10-01

    A simple heterogeneous synthesis of pure adsorbent based polymer hybrid made by condensing a functionalized C,N-bipyrazole with a 3-glycidoxypropyl-trimethoxysilane silylant agent, previously anchored on a silica surface was developed. The formed material (SG2P) was characterized through elemental analysis, FT-IR spectroscopy, (13)C NMR of solid state, scanning electron microscope (SEM), and was studied and evaluated by determination of the surface area using the BET equation, the adsorption and desorption capability using the isotherm of nitrogen and B.J.H. pore sizes. The new material exhibits good thermal stability determined by thermogravimetry curves and good chemical stability was examined in various acidic and buffer solutions (pH 1-7). The binding and adsorption abilities of SG2P were investigated for Hg(2+), Cd(2+), Pb(2+), Zn(2+), K(+), Na(+) and Li(+) cations and compared to the results of classical liquid-liquid extraction with the unbound C,N-bipyrazole compound. The grafting at the surface of silica does not affect complexing properties of the ligand and the SG2P exhibits a high selectivity toward Hg(2+) ion with no complexation being observed towards zinc and alkali metals. The extracted and the complexing cation percentages were determined by atomic absorption measurements. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. White-emissive tandem-type hybrid organic/polymer diodes with (0.33, 0.33) chromaticity coordinates.

    PubMed

    Guo, Tzung-Fang; Wen, Ten-Chin; Huang, Yi-Shun; Lin, Ming-Wei; Tsou, Chuan-Cheng; Chung, Chia-Tin

    2009-11-09

    This study reports fabrication of white-emissive, tandem-type, hybrid organic/polymer light-emitting diodes (O/PLED). The tandem devices are made by stacking a blue-emissive OLED on a yellow-emissive phenyl-substituted poly(para-phenylene vinylene) copolymer-based PLED and applying an organic oxide/Al/molybdenum oxide (MoO(3)) complex structure as a connecting structure or charge-generation layer (CGL). The organic oxide/Al/MoO(3) CGL functions as an effective junction interface for the transport and injection of opposite charge carriers through the stacked configuration. The electroluminescence (EL) spectra of the tandem-type devices can be tuned by varying the intensity of the emission in each emissive component to yield the visible-range spectra from 400 to 750 nm, with Commission Internationale de l'Eclairage chromaticity coordinates of (0.33, 0.33) and a high color rendering capacity as used for illumination. The EL spectra also exhibit good color stability under various bias conditions. The tandem-type device of emission with chromaticity coordinates, (0.30, 0.31), has maximum brightness and luminous efficiency over 25,000 cd/m(2) and approximately 4.2 cd/A, respectively.

  2. Hybrid composite membranes of chitosan/sulfonated polyaniline/silica as polymer electrolyte membrane for fuel cells.

    PubMed

    Vijayakumar, Vijayalekshmi; Khastgir, Dipak

    2018-01-01

    A series of novel ionic cross-linked chitosan (CS) based hybrid nanocomposites were prepared by using polyaniline/nano silica (PAni/SiO 2 ) as inorganic filler and sulfuric acid as an ionic cross-linking agent. The CS-PAni/SiO 2 nanocomposites show enhanced mechanical properties and improved oxidative stabilities. These nanocomposites can be effectively used as environmental friendly proton exchange membranes. Incorporation of PAni/SiO 2 into CS matrix enhances water uptake and facilitates the phase separation which enables the formation of hydrophilic domains and improves the proton transport. Moreover, the doped polyaniline also provides some additional pathways for proton conduction. The membrane containing 3wt% loading of PAni/SiO 2 in chitosan (CS-PAni/SiO 2 -3) exhibits high proton conductivity at 80°C (8.39×10 -3 Scm -1 ) in fully hydrated state due to its excellent water retention properties. Moreover, methanol permeability of the ionic cross-linked CS-PAni/SiO 2 nanocomposite membranes significantly reduces with the addition of PAni/SiO 2 nano particles. The CS-PAni/SiO 2 -3 composite membrane displays the best overall performance as a polymer electrolyte membrane. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of Bending Stiffness of the Electroactive Polymer Element on the Performance of a Hybrid Actuator System (HYBAS)

    NASA Technical Reports Server (NTRS)

    Xu, Tian-Bing; Su, Ji; Jiang, Xiaoning; Rehrig, Paul W.; Zhang, Shujun; Shrout, Thomas R.; Zhang, Qiming

    2006-01-01

    An electroactive polymer (EAP)-ceramic hybrid actuation system (HYBAS) was developed recently at NASA Langley Research Center. This paper focuses on the effect of the bending stiffness of the EAP component on the performance of a HYBAS, in which the actuation of the EAP element can match the theoretical prediction at various length/thickness ratios for a constant elastic modulus of the EAP component. The effects on the bending stiffness of the elastic modulus and length/thickness ratio of the EAP component were studied. A critical bending stiffness to keep the actuation of the EAP element suitable for a rigid beam theory-based modeling was found for electron irradiated P(VDF-TrFE) copolymer. For example, the agreement of experimental data and theoretical modeling for a HYBAS with the length/thickness ratio of EAP element at 375 times is demonstrated. However, the beam based theoretical modeling becomes invalid (i.e., the profile of the HYBAS movement does not follow the prediction of theoretical modeling) when the bending stiffness is lower than a critical value.

  4. Strategic modulation of the photonic properties of conjugated organometallic Pt-Ir polymers exhibiting hybrid CT-excited states.

    PubMed

    Soliman, Ahmed M; Zysman-Colman, Eli; Harvey, Pierre D

    2015-04-01

    Polymer 6, ([trans-Pt(PBu3 )2 (C≡C)2 ]-[Ir(dFMeppy)2 (N^N)](PF6 ))n , (([Pt]-[Ir](PF6 ))n ; N^N = 5,5'-disubstituted-2,2'-bipyridyl; dFMeppy = 2-(2,4-difluoro-phenyl)-5-methylpyridine) is prepared along with model compounds. These complexes are investigated by absorption and emission spectroscopy and their photophysical and electrochemical properties are measured and compared with their corresponding non fluorinated complexes. Density functional theory (DFT) and time-dependent DFT computations corroborate the nature of the excited state as being a hybrid between the metal-to-ligand charge transfer ((1,3) MLCT) for the trans-Pt(PBu3 )2 (C≡CAr)2 unit, [Pt] and the metal-to-ligand/ligand-to-ligand' charge transfer ((1,3) ML'CT/LL'CT) for [Ir] with L = dFMeppy. Overall, the fluorination of the phenylpyridine group expectedly does not change the nature of the excited state but desirably induces a small blue shift of the absorption and emission bands along a slight decrease in emission quantum yields and lifetimes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Receptor-mediated membrane adhesion of lipid-polymer hybrid (LPH) nanoparticles studied by dissipative particle dynamics simulations

    NASA Astrophysics Data System (ADS)

    Li, Zhenlong; Gorfe, Alemayehu A.

    2014-12-01

    Lipid-polymer hybrid (LPH) nanoparticles represent a novel class of targeted drug delivery platforms that combine the advantages of liposomes and biodegradable polymeric nanoparticles. However, the molecular details of the interaction between LPHs and their target cell membranes remain poorly understood. We have investigated the receptor-mediated membrane adhesion process of a ligand-tethered LPH nanoparticle using extensive dissipative particle dynamics (DPD) simulations. We found that the spontaneous adhesion process follows a first-order kinetics characterized by two distinct stages: a rapid nanoparticle-membrane engagement, followed by a slow growth in the number of ligand-receptor pairs coupled with structural re-organization of both the nanoparticle and the membrane. The number of ligand-receptor pairs increases with the dynamic segregation of ligands and receptors toward the adhesion zone causing an out-of-plane deformation of the membrane. Moreover, the fluidity of the lipid shell allows for strong nanoparticle-membrane interactions to occur even when the ligand density is low. The LPH-membrane avidity is enhanced by the increased stability of each receptor-ligand pair due to the geometric confinement and the cooperative effect arising from multiple binding events. Thus, our results reveal the unique advantages of LPH nanoparticles as active cell-targeting nanocarriers and provide some general principles governing nanoparticle-cell interactions that may aid future design of LPHs with improved affinity and specificity for a given target of interest.

  6. Local anesthetic effects of bupivacaine loaded lipid-polymer hybrid nanoparticles: In vitro and in vivo evaluation.

    PubMed

    Ma, Pengju; Li, Ting; Xing, Huaixin; Wang, Suzhen; Sun, Yingui; Sheng, Xiugui; Wang, Kaiguo

    2017-05-01

    There is a compelling need for prolonged local anesthetic that would be used for analgesia with a single administration. However, due to the low molecular weight of local anesthetics (LA) (lidocaine, bupivacaine, procaine, dibucaine, etc), they present fast systemic absorption. The aim of the present study was to develop and evaluate bupivacaine lipid-polymer hybrid nanoparticles (BVC LPNs), and compared with BVC loaded PLGA nanoparticles (BVC NPs). Their morphology, particle size, zeta potential and drug loading capacity were evaluated. In vitro release study, stability and cytotoxicity were studied. In vivo evaluation of anesthetic effects was performed on animal models. A facile nanoprecipitation and self-assembly method was optimized to obtain BVC LPNs, composed of PLGA, lecithin and DSPE-PEG 2000 , of ∼175nm particle size. Compared to BVC NPs, BVC LPNs exhibited prolonged in vitro release in phosphate-buffered saline (pH=7.4). Further, BVC LPNs displayed enhanced in vitro stability in 10% FBS and lower cytotoxicity (the concentration of BVC ranging from 1.0μM to 20μM). In addition, BVC LPNs exhibited significantly prolonged analgesic duration. These results demonstrate that the LPNs could function as promising drug delivery system for overcoming the drawbacks of poor stability and rapid drug leakage, and prolonging the anesthetic effect with slight toxicity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  7. An alternative choice of lidocaine-loaded liposomes: lidocaine-loaded lipid-polymer hybrid nanoparticles for local anesthetic therapy.

    PubMed

    Wang, Jianguo; Zhang, Laizhu; Chi, Huimin; Wang, Shilei

    2016-05-01

    The skin permeation enhancement of local anesthetics by newer innovative nanotechnologies has been an appealing field recently. However, which nanocarrier is better for drug loading and has better stability? Therefore, the aim of our study was to compare two kinds of nanocarriers: liposomes and lipid-polymer hybrid nanoparticles (LPNs) for lidocaine (LA) delivery. LA-loaded liposomes (LA-LPs) and LPNs (LA-LPNs) were prepared. Two kinds of nanocarriers were characterized in terms of particle size, zeta potential, drug encapsulation efficiency (EE), drug release, and stability. Their in vitro skin permeation was studied using a Franz diffusion cell mounted with depilated mouse skin in vitro. In vivo local anesthetic effects of LA containing formulations were evaluated by tail flick latency (TFL) test using a tail-flick measuring device. Compared with LA-LPs, LA-LPNs showed significantly better in vitro skin permeation ability and in vivo local anesthetic effects. The results demonstrated that LPNs could improve the efficacy of drugs to higher levels than LPs and free drugs, thus could serve as an effective drug system for LA loading for local anesthetic therapy.

  8. Improving polymer/nanocrystal hybrid solar cell performance via tuning ligand orientation at CdSe quantum dot surface.

    PubMed

    Fu, Weifei; Wang, Ling; Zhang, Yanfang; Ma, Ruisong; Zuo, Lijian; Mai, Jiangquan; Lau, Tsz-Ki; Du, Shixuan; Lu, Xinhui; Shi, Minmin; Li, Hanying; Chen, Hongzheng

    2014-11-12

    Achieving superior solar cell performance based on the colloidal nanocrystals remains challenging due to their complex surface composition. Much attention has been devoted to the development of effective surface modification strategies to enhance electronic coupling between the nanocrystals to promote charge carrier transport. Herein, we aim to attach benzenedithiol ligands onto the surface of CdSe nanocrystals in the "face-on" geometry to minimize the nanocrystal-nanocrystal or polymer-nanocrystal distance. Furthermore, the "electroactive" π-orbitals of the benzenedithiol are expected to further enhance the electronic coupling, which facilitates charge carrier dissociation and transport. The electron mobility of CdSe QD films was improved 20 times by tuning the ligand orientation, and high performance poly[2,6-(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']-dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT):CdSe nanocrystal hybrid solar cells were also achieved, showing a highest power conversion efficiency of 4.18%. This research could open up a new pathway to improve further the performance of colloidal nanocrystal based solar cells.

  9. EnVision+, a new dextran polymer-based signal enhancement technique for in situ hybridization (ISH).

    PubMed

    Wiedorn, K H; Goldmann, T; Henne, C; Kühl, H; Vollmer, E

    2001-09-01

    Seventy paraffin-embedded cervical biopsy specimens and condylomata were tested for the presence of human papillomavirus (HPV) by conventional in situ hybridization (ISH) and ISH with subsequent signal amplification. Signal amplification was performed either by a commercial biotinyl-tyramide-based detection system [GenPoint (GP)] or by the novel two-layer dextran polymer visualization system EnVision+ (EV), in which both EV-horseradish peroxidase (EV-HRP) and EV-alkaline phosphatase (EV-AP) were applied. We could demonstrate for the first time, that EV in combination with preceding ISH results in a considerable increase in signal intensity and sensitivity without loss of specificity compared to conventional ISH. Compared to GP, EV revealed a somewhat lower sensitivity, as measured by determination of the integrated optical density (IOD) of the positively stained cells. However, EV is easier to perform, requires a shorter assay time, and does not raise the background problems that may be encountered with biotinyl-tyramide-based amplification systems. (J Histochem Cytochem 49:1067-1071, 2001)

  10. Novel hybrid columns made of ultra-high performance concrete and fiber reinforced polymers

    NASA Astrophysics Data System (ADS)

    Zohrevand, Pedram

    The application of advanced materials in infrastructure has grown rapidly in recent years mainly because of their potential to ease the construction, extend the service life, and improve the performance of structures. Ultra-high performance concrete (UHPC) is one such material considered as a novel alternative to conventional concrete. The material microstructure in UHPC is optimized to significantly improve its material properties including compressive and tensile strength, modulus of elasticity, durability, and damage tolerance. Fiber-reinforced polymer (FRP) composite is another novel construction material with excellent properties such as high strength-to-weight and stiffness-to-weight ratios and good corrosion resistance. Considering the exceptional properties of UHPC and FRP, many advantages can result from the combined application of these two advanced materials, which is the subject of this research. The confinement behavior of UHPC was studied for the first time in this research. The stress-strain behavior of a series of UHPC-filled fiber-reinforced polymer (FRP) tubes with different fiber types and thicknesses were tested under uniaxial compression. The FRP confinement was shown to significantly enhance both the ultimate strength and strain of UHPC. It was also shown that existing confinement models are incapable of predicting the behavior of FRP-confined UHPC. Therefore, new stress-strain models for FRP-confined UHPC were developed through an analytical study. In the other part of this research, a novel steel-free UHPC-filled FRP tube (UHPCFFT) column system was developed and its cyclic behavior was studied. The proposed steel-free UHPCFFT column showed much higher strength and stiffness, with a reasonable ductility, as compared to its conventional reinforced concrete (RC) counterpart. Using the results of the first phase of column tests, a second series of UHPCFFT columns were made and studied under pseudo-static loading to study the effect of column

  11. Mechanical properties of carbon fibre-reinforced polymer/magnesium alloy hybrid laminates

    NASA Astrophysics Data System (ADS)

    Zhou, Pengpeng; Wu, Xuan; Pan, Yingcai; Tao, Ye; Wu, Guoqing; Huang, Zheng

    2018-04-01

    In this study, we prepared fibre metal laminates (FMLs) consisting of high-modulus carbon fibre-reinforced polymer (CFRP) prepregs and thin AZ31 alloy sheets by using hot-pressing technology. Tensile and low-velocity impact tests were performed to evaluate the mechanical properties and fracture behaviour of the magnesium alloy-based FMLs (Mg-FMLs) and to investigate the differences in the fracture behaviour between the Mg-FMLs and traditional Mg-FMLs. Results show that the Mg-FMLs exhibit higher specific tensile strength and specific tensile modulus than traditional Mg-FMLs and that the tensile behaviour of the Mg-FMLs is mainly governed by the CFRP because of the combination of high interlaminar shear properties and thin magnesium alloy layers. The Mg-FMLs exhibit excellent bending stiffness. Hence, no significant difference between the residual displacement d r and indentation depth d i , and the permanent deformation is mainly limited to a small zone surrounding the impact location after the impact tests.

  12. Hydrothermal Synthesis, Crystal Structure and Electrochemical Behavior of 2d Hybrid Coordination Polymer

    NASA Astrophysics Data System (ADS)

    Fan, Weiqiang; Zhu, Lin; Shi, Weidong; Chen, Fuxiao; Bai, Hongye; Song, Shuyan; Yan, Yongsheng

    2013-04-01

    A novel metal-organic coordination polymer [Cu(phen)(L)0.5(H2O)]n (H4L = (N,N‧-5,5‧-bis(isophthalic acid)-p-xylylenediamine, and phen = 1,10-phenanthroline) has been hydrothermally synthesized and characterized by elemental analysis, IR, TGA, and single-crystal X-ray diffraction. The crystallographic data show that the title compound crystallizes in monoclinic space group P21/n with a = 10.682(2), b = 15.682(3), c = 11.909(2) Å, β = 91.39(3)°, V = 1994.3(7) Å3, C24H17CuN3O5, Mr = 490.95, Dc = 1.635 g/cm3, F(000) = 1004, Z = 4, μ(MoKα) = 1.141 mm-1, the final R = 0.0418 and wR = 0.0983 for 3578 observed reflections (I > 2σ(I)). The structural analyses reveal that the title compound exhibits shows a 2D layer structure, which are further linked by hydrogen bonding interactions to form a three-dimensional supramolecular network. In addition, the thermal stability and electrochemical behavior of title compound has been studied. CCDC: 900413.

  13. Asymmetric Hybrid Polymer-Lipid Giant Vesicles as Cell Membrane Mimics.

    PubMed

    Peyret, Ariane; Ibarboure, Emmanuel; Le Meins, Jean-François; Lecommandoux, Sebastien

    2018-01-01

    Lipid membrane asymmetry plays an important role in cell function and activity, being for instance a relevant signal of its integrity. The development of artificial asymmetric membranes thus represents a key challenge. In this context, an emulsion-centrifugation method is developed to prepare giant vesicles with an asymmetric membrane composed of an inner monolayer of poly(butadiene)- b -poly(ethylene oxide) (PBut- b -PEO) and outer monolayer of 1-palmitoyl-2-oleoyl- sn -glycero-3-phosphocholine (POPC). The formation of a complete membrane asymmetry is demonstrated and its stability with time is followed by measuring lipid transverse diffusion. From fluorescence spectroscopy measurements, the lipid half-life is estimated to be 7.5 h. Using fluorescence recovery after photobleaching technique, the diffusion coefficient of 1,2-dioleoyl- sn -glycero-3-phosphoethanolamine- N -(lissamine rhodamine B sulfonyl) (DOPE-rhod, inserted into the POPC leaflet) is determined to be about D = 1.8 ± 0.50 μm 2 s -1 at 25 °C and D = 2.3 ± 0.7 μm 2 s -1 at 37 °C, between the characteristic values of pure POPC and pure polymer giant vesicles and in good agreement with the diffusion of lipids in a variety of biological membranes. These results demonstrate the ability to prepare a cell-like model system that displays an asymmetric membrane with transverse and translational diffusion properties similar to that of biological cells.

  14. Lignin Modification for Biopolymer/Conjugated Polymer Hybrids as Renewable Energy Storage Materials.

    PubMed

    Nilsson, Ting Yang; Wagner, Michal; Inganäs, Olle

    2015-12-07

    Lignin derivatives, which arise as waste products from the pulp and paper industry and are mainly used for heating, can be used as charge storage materials. The charge storage function is a result of the quinone groups formed in the lignin derivative. Herein, we modified lignins to enhance the density of such quinone groups by covalently linking monolignols and quinones through phenolation. The extra guaiacyl, syringyl, and hydroquinone groups introduced by phenolation of kraft lignin derivatives were monitored by (31) P nuclear magnetic resonance and size exclusion chromatography. Electropolymerization in ethylene glycol/tetraethylammonium tosylate electrolyte was used to synthesize the kraft lignin/polypyrrole hybrid films. These modifications changed the phenolic content of the kraft lignin with attachment of hydroquinone units yielding the highest specific capacity (around 70 mA h g(-1) ). The modification of softwood and hardwood lignin derivatives yielded 50 % and 23 % higher charge capacity than the original lignin, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Embroidered polymer-collagen hybrid scaffold variants for ligament tissue engineering.

    PubMed

    Hoyer, M; Drechsel, N; Meyer, M; Meier, C; Hinüber, C; Breier, A; Hahner, J; Heinrich, G; Rentsch, C; Garbe, L-A; Ertel, W; Schulze-Tanzil, G; Lohan, A

    2014-10-01

    Embroidery techniques and patterns used for scaffold production allow the adaption of biomechanical scaffold properties. The integration of collagen into embroidered polylactide-co-caprolactone [P(LA-CL)] and polydioxanone (PDS) scaffolds could stimulate neo-tissue formation by anterior cruciate ligament (ACL) cells. Therefore, the aim of this study was to test embroidered P(LA-CL) and PDS scaffolds as hybrid scaffolds in combination with collagen hydrogel, sponge or foam for ligament tissue engineering. ACL cells were cultured on embroidered P(LA-CL) and PDS scaffolds without or with collagen supplementation. Cell adherence, vitality, morphology and ECM synthesis were analyzed. Irrespective of thread size, ACL cells seeded on P(LA-CL) scaffolds without collagen adhered and spread over the threads, whereas the cells formed clusters on PDS and larger areas remained cell-free. Using the collagen hydrogel, the scaffold colonization was limited by the gel instability. The collagen sponge layers integrated into the scaffolds were hardly penetrated by the cells. Collagen foams increased scaffold colonization in P(LA-CL) but did not facilitate direct cell-thread contacts in the PDS scaffolds. The results suggest embroidered P(LA-CL) scaffolds as a more promising basis for tissue engineering an ACL substitute than PDS due to superior cell attachment. Supplementation with a collagen foam presents a promising functionalization strategy. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Hybrid solar cell based on a-Si/polymer flat heterojunction on flexible substrates

    NASA Astrophysics Data System (ADS)

    Olivares Vargas, A. J.; Mansurova, S.; Cosme, I.; Kosarev, A.; Ospina Ocampo, C. A.; Martinez Mateo, H. E.

    2017-08-01

    In this work, we present the results of investigation of thin film hybrid organic-inorganic photovoltaic structures based on flat heterojunction hydrogenated silicon (a-Si:H) and poly(3,4 ethylene dioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) fabricated on polyethylene naphthalate (PEN). Different thicknesses of transparent AL doped Zn:O (AZO) electrodes have been tested on PEN substrate and studied by atomic force microscopy (AFM). The AZO films on PEN substrate were statistically processed to obtain surface morphological characteristics, such as root mean square roughness RQ, skewness SK and kurtosis KU. Performance characteristics of fabricated photovoltaic structures have been measured and analyzed for different thicknesses of the transparent electrodes under standard illumination (AM 1.5 I0= 100mW/cm2). Structures on flexible substrates show reproducible performance characteristic as their glass substrate counterpart with values of JSC= 6 mA/cm2, VOC= 0.535 V, FF= 43 % and PCE= 1.41%.

  17. Zwitterionic sulfobetaine-grafted poly(vinylidene fluoride) membrane with highly effective blood compatibility via atmospheric plasma-induced surface copolymerization.

    PubMed

    Chang, Yung; Chang, Wan-Ju; Shih, Yu-Ju; Wei, Ta-Chin; Hsiue, Ging-Ho

    2011-04-01

    Development of nonfouling membranes to prevent nonspecific protein adsorption and platelet adhesion is critical for many biomedical applications. It is always a challenge to control the surface graft copolymerization of a highly polar monomer from the highly hydrophobic surface of a fluoropolymer membrane. In this work, the blood compatibility of poly(vinylidene fluoride) (PVDF) membranes with surface-grafted electrically neutral zwitterionic poly(sulfobetaine methacrylate) (PSBMA), from atmospheric plasma-induced surface copolymerization, was studied. The effect of surface composition and graft morphology, electrical neutrality, hydrophilicity and hydration capability on blood compatibility of the membranes were determined. Blood compatibility of the zwitterionic PVDF membranes was systematically evaluated by plasma protein adsorption, platelet adhesion, plasma-clotting time, and blood cell hemolysis. It was found that the nonfouling nature and hydration capability of grafted PSBMA polymers can be effectively controlled by regulating the grafting coverage and charge balance of the PSBMA layer on the PVDF membrane surface. Even a slight charge bias in the grafted zwitterionic PSBMA layer can induce electrostatic interactions between proteins and the membrane surfaces, leading to surface protein adsorption, platelet activation, plasma clotting and blood cell hemolysis. Thus, the optimized PSBMA surface graft layer in overall charge neutrality has a high hydration capability and the best antifouling, anticoagulant, and antihemolytic activities when comes into contact with human blood. © 2011 American Chemical Society

  18. Engineering of budesonide-loaded lipid-polymer hybrid nanoparticles using a quality-by-design approach.

    PubMed

    Leng, Donglei; Thanki, Kaushik; Fattal, Elias; Foged, Camilla; Yang, Mingshi

    2017-08-25

    Chronic obstructive pulmonary disease (COPD) is a complex disease, characterized by persistent airflow limitation and chronic inflammation. The purpose of this study was to design lipid-polymer hybrid nanoparticles (LPNs) loaded with the corticosteroid, budesonide, which could potentially be combined with small interfering RNA (siRNA) for COPD management. Here, we prepared LPNs based on the biodegradable polymer poly(dl-lactic-co-glycolic acid) (PLGA) and the cationic lipid dioleyltrimethylammonium propane (DOTAP) using a double emulsion solvent evaporation method. A quality-by-design (QbD) approach was adopted to define the optimal formulation parameters. The quality target product profile (QTPP) of the LPNs was identified based on risk assessment. Two critical formulation parameters (CFPs) were identified, including the theoretical budesonide loading and the theoretical DOTAP loading. The CFPs were linked to critical quality attributes (CQAs), which included the intensity-based hydrodynamic particle diameter (z-average), the polydispersity index (PDI), the zeta-potential, the budesonide encapsulation efficiency, the actual budesonide loading and the DOTAP encapsulation efficiency. A response surface methodology (RSM) was applied for the experimental design to evaluate the influence of the CFPs on the CQAs, and to identify the optimal operation space (OOS). All nanoparticle dispersions displayed monodisperse size distributions (PDI<0.2) with z-averages of approximately 150nm, suggesting that the size is not dependent on the investigated CFPs. In contrast, the zeta-potential was highly dependent on the theoretical DOTAP loading. Upon increased DOTAP loading, the zeta-potential reached a maximal point, after which it remained stable at the maximum value. This suggests that the LPN surface is covered by DOTAP, and that the DOTAP loading is saturable. The actual budesonide loading of the LPNs was mainly dependent on the initial amount of budesonide, and a clear

  19. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    NASA Astrophysics Data System (ADS)

    Rangari, Vijaya K.; Mohammad, Ghouse M.; Jeelani, Shaik; Hundley, Angel; Vig, Komal; Ram Singh, Shree; Pillai, Shreekumar

    2010-03-01

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of ~ 80 µm size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 µg demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 ± 6.72 mm, 19.4 ± 3.64 mm, 21.9 ± 4.33 mm, and 24.1 ± 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 ± 2.13 mm, 28.6 ± 4.27 mm, 22.6 ± 1.27 mm, and 27.0 ± 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 µg were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial strains tested. Further, the

  20. Nonionic and zwitterionic forms of glycylglycylarginine as a part of spider silk protein: Spectroscopic and theoretical study

    NASA Astrophysics Data System (ADS)

    Arı, Hatice; Özpozan, Talat

    2016-01-01

    Glycylglycylarginine as a part of GGX motif of spider silk spidroin in nonionic (non-GGR) and zwitterionic (zwt-GGR) forms have been examined from theoretical and spectroscopic aspects. The most stable conformational isomers of non-GGR and zwt-GGR were obtained through relaxed scan using the DFT/B3LYP with 6-31G(d) basis set. Nonionic and zwitterionic forms of 310-helix structures of GGR have also been calculated and compared with the most stable conformers obtained as a result of conformer analysis of isolated three peptide structures. This comparison should give an idea about the stability contribution of intermolecular interactions between the 310-helix structured peptide chains. O3LYP and B3PW91 hybrid functionals beside B3LYP have also been used for further calculations of geometry optimization, vibrational analysis, Natural Bond Orbital (NBO) analysis, HOMO-LUMO analysis and hydrogen bonding analysis. Normal Mode Analysis was carried through Potential Energy Distribution (PED) calculations by means of VEDA4 program package. IR and Raman spectra of GGR have also been used to relate the spectroscopic data obtained to electronic and structural features.

  1. Nonionic and zwitterionic forms of glycylglycylarginine as a part of spider silk protein: Spectroscopic and theoretical study.

    PubMed

    Arı, Hatice; Özpozan, Talat

    2016-01-05

    Glycylglycylarginine as a part of GGX motif of spider silk spidroin in nonionic (non-GGR) and zwitterionic (zwt-GGR) forms have been examined from theoretical and spectroscopic aspects. The most stable conformational isomers of non-GGR and zwt-GGR were obtained through relaxed scan using the DFT/B3LYP with 6-31G(d) basis set. Nonionic and zwitterionic forms of 310-helix structures of GGR have also been calculated and compared with the most stable conformers obtained as a result of conformer analysis of isolated three peptide structures. This comparison should give an idea about the stability contribution of intermolecular interactions between the 310-helix structured peptide chains. O3LYP and B3PW91 hybrid functionals beside B3LYP have also been used for further calculations of geometry optimization, vibrational analysis, Natural Bond Orbital (NBO) analysis, HOMO-LUMO analysis and hydrogen bonding analysis. Normal Mode Analysis was carried through Potential Energy Distribution (PED) calculations by means of VEDA4 program package. IR and Raman spectra of GGR have also been used to relate the spectroscopic data obtained to electronic and structural features. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Synthesis of polymer hybrid latex poly(methyl methacrylate-co-butyl acrylate) with organo montmorillonite via miniemulsion polymerization method for barrier paper

    NASA Astrophysics Data System (ADS)

    Chanra, J.; Budianto, E.; Soegijono, B.

    2018-03-01

    Hybrid polymer latex based on combination of organic-inorganic materials, poly(methyl methacrylate-co-butyl acrylate) (PMMBA) and organo-montmorillonite (OMMT) were synthesized via miniemulsion polymerization technique. Modification of montmorillonite (MMT) through the incorporation of myristyltrimethylammonium bromide (MTAB) into the clay’s interlayer spaces were investigated by Small-Angle X-ray Scattering (SAXS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA) and Transmission Electron Microscopy (TEM). Barrier property and thermal stability of polymer latex film sample were investigated through its Water Vapor Transmission Rate (WVTR) and Thermogravimetric Analysis (TGA). The results indicated that addition of OMMT as filler in PMMBA increased the barrier property and thermal stability of the latex film. Addition of 8.0% (wt) OMMT increased the barrier property and thermal stability. Miniemusion polymerization process with higher addition (>8.0 wt%) of OMMT resulting in high latex viscosity, particle size, and high amount of coagulum. The utilization of this hybrid polymer could benefits paper and board industries to produce high quality barrier paper for food packaging.

  3. Wireless Data Transmission at Terahertz Carrier Waves Generated from a Hybrid InP-Polymer Dual Tunable DBR Laser Photonic Integrated Circuit.

    PubMed

    Carpintero, Guillermo; Hisatake, Shintaro; de Felipe, David; Guzman, Robinson; Nagatsuma, Tadao; Keil, Norbert

    2018-02-14

    We report for the first time the successful wavelength stabilization of two hybrid integrated InP/Polymer DBR lasers through optical injection. The two InP/Polymer DBR lasers are integrated into a photonic integrated circuit, providing an ideal source for millimeter and Terahertz wave generation by optical heterodyne technique. These lasers offer the widest tuning range of the carrier wave demonstrated to date up into the Terahertz range, about 20 nm (2.5 THz) on a single photonic integrated circuit. We demonstrate the application of this source to generate a carrier wave at 330 GHz to establish a wireless data transmission link at a data rate up to 18 Gbit/s. Using a coherent detection scheme we increase the sensitivity by more than 10 dB over direct detection.

  4. Gold nanostar-polymer hybrids for siRNA delivery: Polymer design towards colloidal stability and in vitro studies on breast cancer cells.

    PubMed

    Sardo, Carla; Bassi, Barbara; Craparo, Emanuela F; Scialabba, Cinzia; Cabrini, Elisa; Dacarro, Giacomo; D'Agostino, Agnese; Taglietti, Angelo; Giammona, Gaetano; Pallavicini, Piersandro; Cavallaro, Gennara

    2017-03-15

    To overcome the low bioavailability of siRNA (small interfering RNA) and to improve their transfection efficiency, the use of non-viral delivery carriers is today a feasible approach to transform the discovery of these incredibly potent and versatile drugs into clinical practice. Polymer-modified gold nanoconstructs (AuNCs) are currently viewed as efficient and safe intracellular delivery carriers for siRNA, as they have the possibility to conjugate the ability to stably entrap and deliver siRNAs inside cells with the advantages of gold nanoparticles, which can act as theranostic agents and radiotherapy enhancers through laser-induced hyperthermia. In this study, AuNCs were prepared by coating Gold Nano Stars (GNS) with suitable functionalised polymers, to give new insight on the choice of the coating in order to obtain colloidal stability, satisfying in vitro transfection behaviour and reliability in terms of homogeneous results upon GNS type changing. For this goal, GNS synthesized with three different sizes and shapes were coated with two different polymers: i) α-mercapto-ω-amino polyethylene glycol 3000Da (SH-PEG 3000 -NH 2 ), a hydrophilic linear polymer; ii) PHEA-PEG 2000 -EDA-LA (PPE-LA), an amphiphilic hydroxyethylaspartamide copolymer containing a PEG moiety. Both polymers contain SH or SS groups for anchoring on gold surface and NH 2 groups, which can be protonated in order to obtain a positive surface for successive siRNA layering. The effect of the features of the coating polymers on siRNA layering, and the extent of intracellular uptake and luciferase gene silencing effect were evaluated for each of the obtained coated GNS. The results highlight that amphiphilic biocompatible polymers with multi-grafting function are more suitable for ensuring the colloidal stability and the effectiveness of these colloidal systems, compared to the coating with linear PEG. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Hierarchical zwitterionic modification of a SERS substrate enables real-time drug monitoring in blood plasma

    PubMed Central

    Sun, Fang; Hung, Hsiang-Chieh; Sinclair, Andrew; Zhang, Peng; Bai, Tao; Galvan, Daniel David; Jain, Priyesh; Li, Bowen; Jiang, Shaoyi; Yu, Qiuming

    2016-01-01

    Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive analytical technique with molecular specificity, making it an ideal candidate for therapeutic drug monitoring (TDM). However, in critical diagnostic media including blood, nonspecific protein adsorption coupled with weak surface affinities and small Raman activities of many analytes hinder the TDM application of SERS. Here we report a hierarchical surface modification strategy, first by coating a gold surface with a self-assembled monolayer (SAM) designed to attract or probe for analytes and then by grafting a non-fouling zwitterionic polymer brush layer to effectively repel protein fouling. We demonstrate how this modification can enable TDM applications by quantitatively and dynamically measuring the concentrations of several analytes—including an anticancer drug (doxorubicin), several TDM-requiring antidepressant and anti-seizure drugs, fructose and blood pH—in undiluted plasma. This hierarchical surface chemistry is widely applicable to many analytes and provides a generalized platform for SERS-based biosensing in complex real-world media. PMID:27834380

  6. Creation of antifouling microarrays by photopolymerization of zwitterionic compounds for protein assay and cell patterning.

    PubMed

    Sun, Xiuhua; Wang, Huaixin; Wang, Yuanyuan; Gui, Taijiang; Wang, Ke; Gao, Changlu

    2018-04-15

    Nonspecific binding or adsorption of biomolecules presents as a major obstacle to higher sensitivity, specificity and reproducibility in microarray technology. We report herein a method to fabricate antifouling microarray via photopolymerization of biomimetic betaine compounds. In brief, carboxybetaine methacrylate was polymerized as arrays for protein sensing, while sulfobetaine methacrylate was polymerized as background. With the abundant carboxyl groups on array surfaces and zwitterionic polymers on the entire surfaces, this microarray allows biomolecular immobilization and recognition with low nonspecific interactions due to its antifouling property. Therefore, low concentration of target molecules can be captured and detected by this microarray. It was proved that a concentration of 10ngmL -1 bovine serum albumin in the sample matrix of bovine serum can be detected by the microarray derivatized with anti-bovine serum albumin. Moreover, with proper hydrophilic-hydrophobic designs, this approach can be applied to fabricate surface-tension droplet arrays, which allows surface-directed cell adhesion and growth. These light controllable approaches constitute a clear improvement in the design of antifouling interfaces, which may lead to greater flexibility in the development of interfacial architectures and wider application in blood contact microdevices. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Exploration of zwitterionic cellulose acetate antifouling ultrafiltration membrane for bovine serum albumin (BSA) separation.

    PubMed

    Liu, Yang; Huang, Haitao; Huo, Pengfei; Gu, Jiyou

    2017-06-01

    This study focused on the preparation of a new kind of membrane material, zwitterionic cellulose acetate (ZCA), via a three-step procedure consist of oxidization, Schiff base and quaternary amination reaction, and the fabrication of antifouling ZCA ultrafiltration membrane by the non-solvent-induced phase separation method (NIPS). The morphologies, surface chemical structures and compositions of the obtained CA and ZCA membranes were thoroughly characterized by field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray (EDX) spectroscopy, Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS), respectively. Meanwhile, the thermal stability, porosity and average pore size of two investigated membranes were also studied. As a result, the ZCA membrane displayed significantly improved hydrophilicity and water permeability compared with those of the reference CA membrane, despite a slight decrease in the protein rejection ratio. According to the cycle ultrafiltration performance of bovine serum albumin (BSA) solution and protein adsorption experiment, ZCA membrane exhibited better flux recovery property and fouling resistant ability, especially irreversible fouling resistant ability, suggesting superior antifouling performance. This new approach gives polymer-based membrane a long time life and excellent ultrafiltration performance, and seems promising for potential applications in the protein separation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Hierarchical zwitterionic modification of a SERS substrate enables real-time drug monitoring in blood plasma

    NASA Astrophysics Data System (ADS)

    Sun, Fang; Hung, Hsiang-Chieh; Sinclair, Andrew; Zhang, Peng; Bai, Tao; Galvan, Daniel David; Jain, Priyesh; Li, Bowen; Jiang, Shaoyi; Yu, Qiuming

    2016-11-01

    Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive analytical technique with molecular specificity, making it an ideal candidate for therapeutic drug monitoring (TDM). However, in critical diagnostic media including blood, nonspecific protein adsorption coupled with weak surface affinities and small Raman activities of many analytes hinder the TDM application of SERS. Here we report a hierarchical surface modification strategy, first by coating a gold surface with a self-assembled monolayer (SAM) designed to attract or probe for analytes and then by grafting a non-fouling zwitterionic polymer brush layer to effectively repel protein fouling. We demonstrate how this modification can enable TDM applications by quantitatively and dynamically measuring the concentrations of several analytes--including an anticancer drug (doxorubicin), several TDM-requiring antidepressant and anti-seizure drugs, fructose and blood pH--in undiluted plasma. This hierarchical surface chemistry is widely applicable to many analytes and provides a generalized platform for SERS-based biosensing in complex real-world media.

  9. Highly Efficient Flexible Hybrid Photovoltaic Cells Based on Low-Band-Gap Conjugated Polymers Sensitized by Nanoparticle-Grafted Carbon

    DTIC Science & Technology

    2010-09-01

    modeling, synthesis , and characterization of several series functional and processable electro-active conjugated polymers with evolving frontier...tasks as a basic obligation of this award: Task #1. Low Band Gap Polymers The awardee (Professor Sun’s group at NSU) shall design, synthesis , and...design, modeling, synthesis , and characterizations of several series functional and processable electro-active conjugated polymers with evolving

  10. Silicon Nanowire/Polymer Hybrid Solar Cell-Supercapacitor: A Self-Charging Power Unit with a Total Efficiency of 10.5.

    PubMed

    Liu, Ruiyuan; Wang, Jie; Sun, Teng; Wang, Mingjun; Wu, Changsheng; Zou, Haiyang; Song, Tao; Zhang, Xiaohong; Lee, Shuit-Tong; Wang, Zhong Lin; Sun, Baoquan

    2017-07-12

    An integrated self-charging power unit, combining a hybrid silicon nanowire/polymer heterojunction solar cell with a polypyrrole-based supercapacitor, has been demonstrated to simultaneously harvest solar energy and store it. By efficiency enhancement of the hybrid nanowire solar cells and a dual-functional titanium film serving as conjunct electrode of the solar cell and supercapacitor, the integrated system is able to yield a total photoelectric conversion to storage efficiency of 10.5%, which is the record value in all the integrated solar energy conversion and storage system. This system may not only serve as a buffer that diminishes the solar power fluctuations from light intensity, but also pave its way toward cost-effective high efficiency self-charging power unit. Finally, an integrated device based on ultrathin Si substrate is demonstrated to expand its feasibility and potential application in flexible energy conversion and storage devices.

  11. Monolithically Integrated Self-Charging Power Pack Consisting of a Silicon Nanowire Array/Conductive Polymer Hybrid Solar Cell and a Laser-Scribed Graphene Supercapacitor.

    PubMed

    Liu, Hanhui; Li, Mengping; Kaner, Richard B; Chen, Songyan; Pei, Qibing

    2018-05-09

    Owing to the need for portable and sustainable energy sources and the development trend for microminiaturization and multifunctionalization in the electronic components, the study of integrated self-charging power packs has attracted increasing attention. A new self-charging power pack consisting of a silicon nanowire array/poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) hybrid solar cell and a laser-scribed graphene (LSG) supercapacitor has been fabricated. The Si nanowire array/PEDOT:PSS hybrid solar cell structure exhibited a high power conversion efficiency (PCE) of 12.37%. The LSG demonstrated excellent energy storage capability for the power pack, with high current density, energy density, and cyclic stability when compared to other supercapacitor electrodes such as active carbon and conducting polymers. The overall efficiency of the power unit is 2.92%.

  12. Bioinspired Zwitterionic Surface Coatings with Robust Photostability and Fouling Resistance.

    PubMed

    Huang, Chun-Jen; Chu, Sz-Hau; Wang, Lin-Chuan; Li, Chien-Hung; Lee, T Randall

    2015-10-28

    Great care has been paid to the biointerface between a bulk material and the biological environment, which plays a key role in the optimized performance of medical devices. In this work, we report a new superhydrophilic adsorbate, called L-cysteine betaine (Cys-b), having branched zwitterionic groups that give rise to surfaces and nanoparticles with enhanced chemical stability, biofouling resistance, and inertness to environmental changes. Cys-b was synthesized from the amphoteric sulfur-containing amino acid, L-cysteine (Cys), by quaternization of its amino group. Gold surfaces modified with Cys-b exhibited prominent repellence against the nonspecific adsorption of proteins, bacteria, and fibroblast cells. In addition, Cys-b existed in zwitterionic form over a wide pH range (i.e., pH 3.4 to 10.8), and showed excellent suppression in photoinduced oxidation on gold substrates. Furthermore, the modification of hollow Ag@Au nanoshells with Cys-b gave rise to nanoparticles with excellent colloidal stability and resistance to coordinative interaction with Cu(2+). Taken together, the unique features of Cys-b offer a new nanoscale coating for use in a wide spectrum of applications.

  13. Toward highly stable solid-state unconventional thin-film battery-supercapacitor hybrid devices: Interfacing vertical core-shell array electrodes with a gel polymer electrolyte

    NASA Astrophysics Data System (ADS)

    Pandey, Gaind P.; Klankowski, Steven A.; Liu, Tao; Wu, Judy; Li, Jun

    2017-02-01

    A novel solid-state battery-supercapacitor hybrid device is fabricated for high-performance electrical energy storage using a Si anode and a TiO2 cathode in conjunction with a flexible, solid-like gel polymer electrolyte film as the electrolyte and separator. The electrodes were fabricated as three-dimensional nanostructured vertical arrays by sputtering active materials as conformal shells on vertically aligned carbon nanofibers (VACNFs) which serve as the current collector and structural template. Such nanostructured vertical core-shell array-electrodes enable short Li-ion diffusion path and large pseudocapacitive contribution by fast surface reactions, leading to the hybrid features of batteries and supercapacitors that can provide high specific energy over a wide range of power rates. Due to the improved mechanical stability of the infiltrated composite structure, the hybrid cell shows excellent cycling stability and is able to retain more than 95% of the original capacity after 3500 cycles. More importantly, this solid-state device can stably operate in a temperature range from -20 to 60 °C with a very low self-discharge rate and an excellent shelf life. This solid-state architecture is promising for the development of highly stable thin-film hybrid energy storage devices for unconventional applications requiring largely varied power, wider operation temperature, long shelf-life and higher safety standards.

  14. High temperature ultralow water content carbon dioxide-in-water foam stabilized with viscoelastic zwitterionic surfactants.

    PubMed

    Alzobaidi, Shehab; Da, Chang; Tran, Vu; Prodanović, Maša; Johnston, Keith P

    2017-02-15

    Ultralow water content carbon dioxide-in-water (C/W) foams with gas phase volume fractions (ϕ) above 0.95 (that is <0.05 water) tend to be inherently unstable given that the large capillary pressures that cause the lamellar films to thin. Herein, we demonstrate that these C/W foams may be stabilized with viscoelastic aqueous phases formed with a single zwitterionic surfactant at a concentration of only 1% (w/v) in DI water and over a wide range of salinity. Moreover, they are stable with a foam quality ϕ up to 0.98 even for temperatures up to 120°C. The properties of aqueous viscoelastic solutions and foams containing these solutions are examined for a series of zwitterionic amidopropylcarbobetaines, R-ONHC 3 H 6 N(CH 3 ) 2 CH 2 CO 2 , where R is varied from C 12 - 14 (coco) to C 18 (oleyl) to C 22 (erucyl). For the surfactants with long C 18 and C 22 tails, the relaxation times from complex rheology indicate the presence of viscoelastic wormlike micelles over a wide range in salinity and pH, given the high surfactant packing fraction. The apparent viscosities of these ultralow water content foams reached more than 120cP with stabilities more than 30-fold over those for foams formed with the non-viscoelastic C 12 - 14 surfactant. At 90°C, the foam morphology was composed of ∼35μm diameter bubbles with a polyhedral texture. The apparent foam viscosity typically increased with ϕ and then dropped at ϕ values higher than 0.95-0.98. The Ostwald ripening rate was slower for foams with viscoelastic versus non-viscoelastic lamellae as shown by optical microscopy, as a consequence of slower lamellar drainage rates. The ability to achieve high stabilities for ultralow water content C/W foams over a wide temperature range is of interest in various technologies including polymer and materials science, CO 2 enhanced oil recovery, CO 2 sequestration (by greater control of the CO 2 flow patterns), and possibly even hydraulic fracturing with minimal use of water to reduce

  15. Electrochemical performance of a solvent-free hybrid ceramic-polymer electrolyte based on Li7La3Zr2O12 in P(EO)15LiTFSI

    NASA Astrophysics Data System (ADS)

    Keller, Marlou; Appetecchi, Giovanni Battista; Kim, Guk-Tae; Sharova, Varvara; Schneider, Meike; Schuhmacher, Jörg; Roters, Andreas; Passerini, Stefano

    2017-06-01

    The preparation of hybrid ceramic-polymer electrolytes, consisting of 70 wt% of Li+ cation conducting Li7La3Zr2O12 (LLZO) and 30 wt% of P(EO)15LiTFSI polymer electrolyte, through a solvent-free procedure is reported. The LLZO-P(EO)15LiTFSI hybrid electrolytes exhibit remarkable improvement in terms of flexibility and processability with respect to pure LLZO ceramic electrolytes. The physicochemical and electrochemical investigation shows the effect of LLZO annealing, resulting in ion conduction gain. However, slow charge transfer at the ceramic-polymer interface is also observed especially at higher temperatures. Nevertheless, improved compatibility with lithium metal anodes and good Li stripping/plating behavior are exhibited by the LLZO-P(EO)15LiTFSI hybrid electrolytes with respect to P(EO)15LiTFSI.

  16. Smart zwitterionic membranes with on/off behavior for protein transport.

    PubMed

    Su, Yanlei; Zheng, Lili; Li, Chao; Jiang, Zhongyi

    2008-09-25

    Poly(acrylonitrile) (PAN)-based zwitterionic membranes, composed of PAN and poly( N, N-dimethyl- N-methacryloxyethyl- N-(3-sulfopropyl) copolymer, are electrolyte-sensitive smart membranes. The hydrophilicity was increased and protein adsorption was remarkably decreased for the membranes in response to environmental stimuli. FTIR spectroscopic analysis directly provided molecular-level observation of the enhanced dissociation and hydration of zwitterionic sulfobetaine dipoles at higher electrolyte concentrations. The smart PAN-based zwitterionic membranes can close or open channels for protein transport under different NaCl concentrations. The electrolyte-sensitive switch of on/off behavior for protein transport is reversible.

  17. Efficient hybrid white polymer light-emitting devices with electroluminescence covered the entire visible range and reduced efficiency roll-off

    NASA Astrophysics Data System (ADS)

    Hu, Sujun; Zhu, Minrong; Zou, Qinghua; Wu, Hongbin; Yang, Chuluo; Wong, Wai-Yeung; Yang, Wei; Peng, Junbiao; Cao, Yong

    2012-02-01

    We report efficient hybrid white polymer light emitting devices (WPLEDs) fabricated via simple solution-proceeded process from a newly synthesized wide band-gap fluorene-co-dibenzothiophene-S,S-dioxide copolymer, which dually function as fluorescent blue emitter and host material for electrophosphorescent sky-blue, yellow, and saturated-red dyes. The Commission Internationale d'Énclairage coordinates of the best devices are (0.356, 0.334), with electroluminescence covered the entire visible light spectrum from 400 to 780 nm, resulting in a high color rendering index of 90. Incorporation of a bilayer electrode consisting of water/alcohol-soluble conjugated polymer and Al as electron-injection cathode boosts an enhancement of 50% in device efficiency, leading to external quantum efficiency of 12.6%, and peak power efficiency of 21.4 l m W-1 as measured in an integrating sphere. Both the efficiency and the color quality of the obtained device are ranking among one of the highest values for WPLEDs reported to date. Furthermore, as compared with those all-phosphorescent WPLEDs, the hybrid WPLEDs studied here exhibit a significantly reduced efficiency roll-off due to the very low doping concentration.

  18. Wood-Based Nanocomposite Derived by in Situ Formation of Organic-Inorganic Hybrid Polymer within Wood via a Sol-Gel Method.

    PubMed

    Dong, Xiaoying; Zhuo, Xiao; Wei, Jie; Zhang, Gang; Li, Yongfeng

    2017-03-15

    Solid wood materials and wood-plastic composites as two kinds of lightweight materials are attracting great interest from academia and industry due to their green and recycling nature. However, the relatively lower specific strength limits their wider applications. In particular, solid wood is vulnerable to moisture and decay fungi in nature, resulting in its poor durability for effectively long-term utilization. Inspired from the porous structure of wood, we propose a new design to build a wood-based nanocomposite with higher specific strength and satisfactory durability by in situ generation of organic-inorganic hybrid polymer within wood via a sol-gel method. The derived composite has 50-1200% improvement of impact toughness, 56-192% improvement of tensile strength, and 110-291% improvement of flexural strength over those of typical wood-plastic composites, respectively; and even 34% improvement of specific tensile strength than that of 36A steel; 208% enhancement of hardness; and 156% enhancement of compression strength than those of compared solid wood, respectively; as well as significantly improved dimensional stability and decay resistance over those of untreated natural wood. Such materials could be potentially utilized as lightweight and high-strength materials for applications in construction and automotive industries. This method could be extended to constitute other inorganic nanomaterials for novel organic-inorganic hybrid polymer within wood.

  19. Simple and Rapid Immobilization of Coating Polymers on Poly(dimethyl siloxane)-glass Hybrid Microchips by a Vacuum-drying Method.

    PubMed

    Kitagawa, Fumihiko; Nakagawara, Syo; Nukatsuka, Isoshi; Hori, Yusuke; Sueyoshi, Kenji; Otsuka, Koji

    2015-01-01

    A simple and rapid vacuum-drying modification method was applied to several neutral and charged polymers to obtain coating layers for controlling electroosmotic flow (EOF) and suppressing sample adsorption on poly(dimethyl siloxane) (PDMS)-glass hybrid microchips. In the vacuum-dried poly(vinylpyrrolidone) coating, the electroosmotic mobility (μeo) was suppressed from +2.1 to +0.88 × 10(-4) cm(2)/V·s, and the relative standard deviation (RSD) of μeo was improved from 10.2 to 2.5% relative to the bare microchannel. Among several neutral polymers, poly(vinylalcohol) (PVA) and poly(dimethylacrylamide) coatings gave more suppressed and repeatable EOF with RSDs of less than 2.3%. The vacuum-drying method was also applicable to polyanions and polycations to provide accelerated and inversed EOF, respectively, with acceptable RSDs of less than 4.9%. In the microchip electrophoresis (MCE) analysis of bovine serum albumin (BSA) in the vacuum-dried and thermally-treated PVA coating channel, an almost symmetric peak of BSA was obtained, while in the native microchannel a significantly skewed peak was observed. The results demonstrated that the vacuum-dried polymer coatings were effective to control the EOF, and reduced the surface adsorption of proteins in MCE.

  20. Preparation and in vitro evaluation of folate-receptor-targeted SPION-polymer micelle hybrids for MRI contrast enhancement in cancer imaging

    NASA Astrophysics Data System (ADS)

    Mahajan, Shveta; Koul, Veena; Choudhary, Veena; Shishodia, Gauri; Bharti, Alok C.

    2013-01-01

    Polymer-SPION hybrids were investigated for receptor-mediated localization in tumour tissue. Superparamagnetic iron oxide nanoparticles (SPIONs) prepared by high-temperature decomposition of iron acetylacetonate were monodisperse (9.27 ± 3.37 nm), with high saturation magnetization of 76.8 emu g-1. Amphiphilic copolymers prepared from methyl methacrylate and PEG methacrylate by atom transfer radical polymerization were conjugated with folic acid (for folate-receptor specificity). The folate-conjugated polymer had a low critical micellar concentration (0.4 mg l-1), indicating stability of the micellar formulation. SPION-polymeric micelle clusters were prepared by desolvation of the SPION dispersion/polymer solution in water. Magnetic resonance imaging of the formulation revealed very good contrast enhancement, with transverse (T2) relaxivity of 260.4 mM-1 s-1. The biological evaluation of the SPION micelles included cellular viability assay (MTT) and uptake in HeLa cells. These studies demonstrated the potential use of these nanoplatforms for imaging and targeting.

  1. Effect of carbon spacer length on zwitterionic carboxybetaines.

    PubMed

    Shao, Qing; Jiang, Shaoyi

    2013-02-07

    Zwitterionic carboxybetaines (CBs) are ubiquitous in nature and considered promising materials for biological and chemical applications. A thorough understanding of the effect of carbon spacer length (CSL) on molecular properties is important. In this work, using molecular dynamics simulation and quantum chemical calculation, we investigated the effect of CSL on the molecular properties of CB molecules. The hydration number, structure, and dynamics of carboxylic and trimethyl ammonium groups were investigated and found to present different behaviors in regards to the variation of CSL. The simulation results with partial charges developed from quantum chemical calculations were compared with those with partial charges from the OPLS all atom (OPLSAA) force field. The hydration free energy of CB molecules and CB-Na(+) association was also studied as a function of CSL.

  2. Molecular design of high performance zwitterionic liquids for enhanced heavy-oil recovery processes.

    PubMed

    Martínez-Magadán, J M; Cartas-Rosado, A R; Oviedo-Roa, R; Cisneros-Dévora, R; Pons-Jiménez, M; Hernández-Altamirano, R; Zamudio-Rivera, L S

    2018-03-01

    Branched gemini zwitterionic liquids, which contain two zwitterionic moieties of linked quaternary-ammonium and carboxylate groups, are proposed as chemicals to be applied in the Enhanced Oil Recovery (EOR) from fractured carbonate reservoirs. The zwitterionic moieties are bridged between them through an alkyl chain containing 12 ether groups, and each zwitterionic moiety has attached a long alkyl tail including a CC double bond. A theoretical molecular mechanism over which EOR could rest, consisting on both the disaggregation of heavy oil and the reservoir-rock wettability alteration, was suggested. Results show that chemicals can both reduce the viscosity and remove heavy-oil molecules from the rock surface. Copyright © 2018. Published by Elsevier Inc.

  3. A METHOD FOR THE MEASUREMENT OF SITE-SPECIFIC TAUTOMERIC AND ZWITTERIONIC MICROSPECIES EQUILIBRIUM CONSTANTS

    EPA Science Inventory

    We describe a method for the individual measurement of simultaneously occurring, unimolecular, site-specific "microequilibrium" constants as in, for example, prototropic tautomerism and zwitterionic equilibria. Our method represents an elaboration of that of Nygren et al. (Anal. ...

  4. METHOD FOR THE MEASUREMENT OF SITE-SPECIFIC TAUTOMERIC AND ZWITTERIONIC MICROSPECIES EQUILIBRIUM CONSTANTS

    EPA Science Inventory

    We describe a method for the individual measurement of simultaneously occurring, unimolecular, site-specific “microequilibrium” constants as in, for example, prototropic tautomerism and zwitterionic equilibria. Our method represents an elaboration of that of Nygren et al. (Anal. ...

  5. Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

    NASA Astrophysics Data System (ADS)

    Held, Martin; Schießl, Stefan P.; Miehler, Dominik; Gannott, Florentina; Zaumseil, Jana

    2015-08-01

    Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfOx) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states at the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100-300 nF/cm2) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfOx dielectrics.

  6. Polymer/metal oxide hybrid dielectrics for low voltage field-effect transistors with solution-processed, high-mobility semiconductors

    SciT

    Held, Martin; Schießl, Stefan P.; Gannott, Florentina

    Transistors for future flexible organic light-emitting diode (OLED) display backplanes should operate at low voltages and be able to sustain high currents over long times without degradation. Hence, high capacitance dielectrics with low surface trap densities are required that are compatible with solution-processable high-mobility semiconductors. Here, we combine poly(methyl methacrylate) (PMMA) and atomic layer deposition hafnium oxide (HfO{sub x}) into a bilayer hybrid dielectric for field-effect transistors with a donor-acceptor polymer (DPPT-TT) or single-walled carbon nanotubes (SWNTs) as the semiconductor and demonstrate substantially improved device performances for both. The ultra-thin PMMA layer ensures a low density of trap states atmore » the semiconductor-dielectric interface while the metal oxide layer provides high capacitance, low gate leakage and superior barrier properties. Transistors with these thin (≤70 nm), high capacitance (100–300 nF/cm{sup 2}) hybrid dielectrics enable low operating voltages (<5 V), balanced charge carrier mobilities and low threshold voltages. Moreover, the hybrid layers substantially improve the bias stress stability of the transistors compared to those with pure PMMA and HfO{sub x} dielectrics.« less

  7. Improved open-circuit voltage in polymer/oxide-nanoarray hybrid solar cells by formation of homogeneous metal oxide core/shell structures.

    PubMed

    Wu, Fan; Cui, Qi; Qiu, Zeliang; Liu, Changwen; Zhang, Hui; Shen, Wei; Wang, Mingtai

    2013-04-24

    Incorporation of vertically aligned nanorod/nanowire arrays of metal oxide (oxide-NAs) with a polymer can produce efficient hybrid solar cells with an ideal bulk-heterojunction architecture. However, polymer/oxide-NAs solar cells still suffer from a rather low (normally, < 0.4 V) open-circuit voltage (Voc). Here we demonstrate, for the first time, a novel strategy to improve the Voc in polymer/oxide-NAs solar cells by formation of homogeneous core/shell structures and reveal the intrinsic principles involved therein. A feasible hydrothermal-solvothermal combined method is developed for preparing homogeneous core/shell nanoarrays of metal oxides with a single-crystalline nanorod as core and the aggregation layer of corresponding metal oxide quantum dots (QDs) as shell, and the shell thickness (L) is easily controlled by the solvothermal reaction time for growing QDs on the nanorod. The core/shell formation dramatically improves the device Voc up to ca. 0.7-0.8 V depending on L. Based on steady-state and dynamic measurements, as well as modeling by space-charge-limited current method, it is found that the improved Voc originates from the up-shifted conduction band edge in the core by the interfacial dipole field resulting from the decreased mobility difference between photogenerated electrons and holes after the shell growth, which increases the energy difference between the quasi-Fermi levels of photogenerated electrons in the core and holes in the polymer for a higher Voc. Our results indicate that increasing Voc by the core/shell strategy seems not to be dependent on the kinds of metal oxides.

  8. Facilitated preparation of bioconjugatable zwitterionic quantum dots using dual-lipid encapsulation.

    PubMed

    Shrake, Robert; Demillo, Violeta G; Ahmadiantehrani, Mojtaba; Zhu, Xiaoshan; Publicover, Nelson G; Hunter, Kenneth W

    2015-01-01

    Zwitterionic quantum dots prepared through incorporated zwitterionic ligands on quantum dot surfaces, are being paid significant attention in biomedical applications because of their excellent colloidal stability across a wide pH and ionic strength range, antifouling surface, good biocompatibility, etc. In this work, we report a dual-lipid encapsulation approach to prepare bioconjugatable zwitterionic quantum dots using amidosulfobetaine-16 lipids, dipalmitoyl-sn-glycero-3-phosphoethanolamine lipids with functional head groups, and CuInS2/ZnS quantum dots in a tetrahydrofuran/methanol/water solvent system with sonication. Amidosulfobetaine-16 is a zwitterionic lipid and dipalmitoyl-sn-glycero-3-phosphoethanolamine, with its functional head, provides bioconjugation capability. Under sonication, tetrahydrofuran/methanol containing amidosulfobetaine-16, dipalmitoyl-sn-glycero-3-phosphoethanolamine, and hydrophobic quantum dots are dispersed in water to form droplets. Highly water-soluble tetrahydrofuran/methanol in droplets is further displaced by water, which induces the lipid self-assembling on hydrophobic surface of quantum dots and thus forms water soluble zwitterionic quantum dots. The prepared zwitterionic quantum dots maintain colloidal stability in aqueous solutions with high salinity and over a wide pH range. They are also able to be conjugated with biomolecules for bioassay with minimal nonspecific binding. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. Responsive polymer-fluorescent carbon nanoparticle hybrid nanogels for optical temperature sensing, near-infrared light-responsive drug release, and tumor cell imaging

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Ke, Fuyou; Mararenko, Anton; Wei, Zengyan; Banerjee, Probal; Zhou, Shuiqin

    2014-06-01

    Fluorescent carbon nanoparticles (FCNPs) have been successfully immobilized into poly(N-isopropylacrylamide-co-acrylamide) [poly(NIPAM-AAm)] nanogels based on one-pot precipitation copolymerization of NIPAM monomers with hydrogen bonded FCNP-AAm complex monomers in water. The resultant poly(NIPAM-AAm)-FCNP hybrid nanogels can combine functions from each building block for fluorescent temperature sensing, cell imaging, and near-infrared (NIR) light responsive drug delivery. The FCNPs in the hybrid nanogels not only emit bright and stable photoluminescence (PL) and exhibit up-conversion PL properties, but also increase the loading capacity of the nanogels for curcumin drug molecules. The reversible thermo-responsive swelling/shrinking transition of the poly(NIPAM-AAm) nanogel can not only modify the physicochemical environment of the FCNPs to manipulate the PL intensity for sensing the environmental temperature change, but also regulate the releasing rate of the loaded anticancer drug. In addition, the FCNPs embedded in the nanogels can convert the NIR light to heat, thus an exogenous NIR irradiation can further accelerate the drug release and enhance the therapeutic efficacy. The hybrid nanogels can overcome cellular barriers to enter the intracellular region and light up the mouse melanoma B16F10 cells upon laser excitation. The demonstrated hybrid nanogels with nontoxic and optically active FCNPs immobilized in responsive polymer nanogels are promising for the development of a new generation of multifunctional materials for biomedical applications.Fluorescent carbon nanoparticles (FCNPs) have been successfully immobilized into poly(N-isopropylacrylamide-co-acrylamide) [poly(NIPAM-AAm)] nanogels based on one-pot precipitation copolymerization of NIPAM monomers with hydrogen bonded FCNP-AAm complex monomers in water. The resultant poly(NIPAM-AAm)-FCNP hybrid nanogels can combine functions from each building block for fluorescent temperature sensing, cell imaging

  10. Comparative analysis of poly-glycolic acid-based hybrid polymer starter matrices for in vitro tissue engineering.

    PubMed

    Generali, Melanie; Kehl, Debora; Capulli, Andrew K; Parker, Kevin K; Hoerstrup, Simon P; Weber, Benedikt

    2017-10-01

    Biodegradable scaffold matrixes form the basis of any in vitro tissue engineering approach by acting as a temporary matrix for cell proliferation and extracellular matrix deposition until the scaffold is replaced by neo-tissue. In this context several synthetic polymers have been investigated, however a concise systematic comparative analyses is missing. Therefore, the present study systematically compares three frequently used polymers for the in vitro engineering of extracellular matrix based on poly-glycolic acid (PGA) under static as well as dynamic conditions. Ultra-structural analysis was used to examine the polymers structure. For tissue engineering (TE) three human fibroblast cell lines were seeded on either PGA-poly-4-hydroxybutyrate (P4HB), PGA-poly-lactic acid (PLA) or PGA-poly-caprolactone (PCL) patches. These patches were analyzed after 21days of culture qualitative by histology and quantitative by determining the amount of DNA, glycosaminoglycan and hydroxyproline. We found that PGA-P4HB and PGA-PLA scaffolds enhance tissue formation significantly higher than PGA-PCL scaffolds (p<0.05). Polymer remnants were visualized by polarization microscopy. In addition, biomechanical properties of the tissue engineered patches were determined in comparison to native tissue. This study may allow future studies to specifically select certain polymer starter matrices aiming at specific tissue properties of the bioengineered constructs in vitro. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Attomolar electrochemical detection of the BCR/ABL fusion gene based on an amplifying self-signal metal nanoparticle-conducting polymer hybrid composite.

    PubMed

    Avelino, Karen Y P S; Frias, Isaac A M; Lucena-Silva, Norma; Gomes, Renan G; de Melo, Celso P; Oliveira, Maria D L; Andrade, César A S

    2016-12-01

    In the last ten years, conjugated polymers started to be used in the immobilization of nucleic acids via non-covalent interactions. In the present study, we describe the construction and use of an electrochemical DNA biosensor based on a nanostructured polyaniline-gold composite, specifically developed for the detection of the BCR/ABL chimeric oncogene. This chromosome translocation is used as a biomarker to confirm the clinical diagnosis of both chronic myelogenous leukemia (CML) and acute lymphocytic leukemia (ALL). The working principle of the biosensor rests on measuring the conductivity resulting from the non-covalent interactions between the hybrid nanocomposite and the DNA probe. The nanostructured platform exhibits a large surface area that enhances the conductivity. Positive cases, which result from the hybridization between DNA probe and targeted gene, induce changes in the amperometric current and in the charge transfer resistance (R CT ) responses. Atomic force microscopy (AFM) images showed changes in the genosensor surface after exposure to cDNA sample of patient with leukemia, evidencing the hybridization process. This new hybrid sensing-platform displayed high specificity and selectivity, and its detection limit is estimated to be as low as 69.4 aM. The biosensor showed excellent analytical performance for the detection of the BCR/ABL oncogene in clinical samples of patients with leukemia. Hence, this electrochemical sensor appears as a simple and attractive tool for the molecular diagnosis of the BCR/ABL oncogene even in early-stage cases of leukemia and for the monitoring of minimum levels of residual disease. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Phase-Imaging with a Sharpened Multi-Walled Carbon Nanotube AFM Tip: Investigation of Low-k Dielectric Polymer Hybrids

    NASA Technical Reports Server (NTRS)

    Nguyen, Cattien V.; Stevens, Ramsey M.; Meyyappan, M.; Volksen, Willi; Miller, Robert D.

    2005-01-01

    Phase shift tapping mode scanning force microscopy (TMSFM) has evolved into a very powerful technique for the nanoscale surface characterization of compositional variations in heterogeneous samples. Phase shift signal measures the difference between the phase angle of the excitation signal and the phase angle of the cantilever response. The signal correlates to the tip-sample inelastic interactions, identifying the different chemical and/or physical property of surfaces. In general, the resolution and quality of scanning probe microscopic images are highly dependent on the size of the scanning probe tip. In improving AFM tip technology, we recently developed a technique for sharpening the tip of a multi-walled carbon nanotube (CNT) AFM tip, reducing the radius of curvature of the CNT tip to less than 5 nm while still maintaining the inherent stability of multi-walled CNT tips. Herein we report the use of sharpened (CNT) AFM tips for phase-imaging of polymer hybrids, a precursor for generating nanoporous low-k dielectrics for on-chip interconnect applications. Using sharpened CNT tips, we obtained phase-contrast images having domains less than 10 nm. In contrast, conventional Si tips and unsharpened CNT tips (radius greater than 15 nm) were not able to resolve the nanoscale domains in the polymer hybrid films. C1early, the size of the CNT tip contributes significantly to the resolution of phase-contrast imaging. In addition, a study on the nonlinear tapping dynamics of the multi-walled CNT tip indicates that the multi-walled CNT tip is immune to conventional imaging instabilities related to the coexistence of attractive and repulsive tapping regimes. This factor may also contribute to the phase-contrast image quality of multi-walled CNT AFM tips. This presentation will also offer data in support of the stability of the CNT tip for phase shift TMSFM.

  13. Topical delivery of anti-TNFα siRNA and capsaicin via novel lipid-polymer hybrid nanoparticles efficiently inhibits skin inflammation in vivo

    PubMed Central

    Desai, Pinaki R.; Marepally, Srujan; Patel, Apurva R.; Voshavar, Chandrashekhar; Chaudhuri, Arabinda; Singh, Mandip

    2013-01-01

    The barrier properties of the skin pose a significant but not insurmountable obstacle for development of new effective anti-inflammatory therapies. The objective of this study was to design and evaluate therapeutic efficacy of anti-nociception agent Capsaicin (Cap) and anti-TNFα siRNA (siTNFα) encapsulated cyclic cationic head Lipid-Polymer hybrid Nanocarriers (CyLiPns) against chronic skin inflammatory diseases. Physico-chemical characterizations including hydrodynamic size, surface potential and entrapment efficacies of CyLiPns were found to be 163 ± 9 nm, 35.14 ± 8.23 mV and 92% for Cap, respectively. In vitro skin distribution studies revealed that CyLiPns could effectively deliver FITC-siRNA upto 360 µm skin depth. Further, enhanced (p<0.001) Cap permeation from CyLiPns was observed compared to Capsaicin-Solution and Capzasin-HP. Therapeutic efficacies of CyLiPns were assessed using imiquamod induced psoriatic plaque like model. CyLiPns carrying both Cap and siTNFα showed significant reduced expression of TNFα, NF-κB, IL-17, IL-23 and Ki-67 genes compare to either drugs alone (p<0.05) and was in close comparison with Topgraf®;. Collectively these findings support our notion that novel cationic lipid-polymer hybrid nanoparticles can efficiently carry siTNFα and Cap into deeper dermal milieu and Cap with combination of siTNFα show synergism in treating skin inflammation. PMID:23643662

  14. Anharmonic effects in IR, Raman, and Raman optical activity spectra of alanine and proline zwitterions.

    PubMed

    Danecek, Petr; Kapitán, Josef; Baumruk, Vladimír; Bednárová, Lucie; Kopecký, Vladimír; Bour, Petr

    2007-06-14

    The difference spectroscopy of the Raman optical activity (ROA) provides extended information about molecular structure. However, interpretation of the spectra is based on complex and often inaccurate simulations. Previously, the authors attempted to make the calculations more robust by including the solvent and exploring the role of molecular flexibility for alanine and proline zwitterions. In the current study, they analyze the IR, Raman, and ROA spectra of these molecules with the emphasis on the force field modeling. Vibrational harmonic frequencies obtained with 25 ab initio methods are compared to experimental band positions. The role of anharmonic terms in the potential and intensity tensors is also systematically explored using the vibrational self-consistent field, vibrational configuration interaction (VCI), and degeneracy-corrected perturbation calculations. The harmonic approach appeared satisfactory for most of the lower-wavelength (200-1800 cm(-1)) vibrations. Modern generalized gradient approximation and hybrid density functionals, such as the common B3LYP method, provided a very good statistical agreement with the experiment. Although the inclusion of the anharmonic corrections still did not lead to complete agreement between the simulations and the experiment, occasional enhancements were achieved across the entire region of wave numbers. Not only the transitional frequencies of the C-H stretching modes were significantly improved but also Raman and ROA spectral profiles including N-H and C-H lower-frequency bending modes were more realistic after application of the VCI correction. A limited Boltzmann averaging for the lowest-frequency modes that could not be included directly in the anharmonic calculus provided a realistic inhomogeneous band broadening. The anharmonic parts of the intensity tensors (second dipole and polarizability derivatives) were found less important for the entire spectral profiles than the force field anharmonicities (third

  15. Anharmonic effects in IR, Raman, and Raman optical activity spectra of alanine and proline zwitterions

    NASA Astrophysics Data System (ADS)

    Daněček, Petr; Kapitán, Josef; Baumruk, Vladimír; Bednárová, Lucie; Kopecký, Vladimír; Bouř, Petr

    2007-06-01

    The difference spectroscopy of the Raman optical activity (ROA) provides extended information about molecular structure. However, interpretation of the spectra is based on complex and often inaccurate simulations. Previously, the authors attempted to make the calculations more robust by including the solvent and exploring the role of molecular flexibility for alanine and proline zwitterions. In the current study, they analyze the IR, Raman, and ROA spectra of these molecules with the emphasis on the force field modeling. Vibrational harmonic frequencies obtained with 25 ab initio methods are compared to experimental band positions. The role of anharmonic terms in the potential and intensity tensors is also systematically explored using the vibrational self-consistent field, vibrational configuration interaction (VCI), and degeneracy-corrected perturbation calculations. The harmonic approach appeared satisfactory for most of the lower-wavelength (200-1800cm-1) vibrations. Modern generalized gradient approximation and hybrid density functionals, such as the common B3LYP method, provided a very good statistical agreement with the experiment. Although the inclusion of the anharmonic corrections still did not lead to complete agreement between the simulations and the experiment, occasional enhancements were achieved across the entire region of wave numbers. Not only the transitional frequencies of the C-H stretching modes were significantly improved but also Raman and ROA spectral profiles including N-H and C-H lower-frequency bending modes were more realistic after application of the VCI correction. A limited Boltzmann averaging for the lowest-frequency modes that could not be included directly in the anharmonic calculus provided a realistic inhomogeneous band broadening. The anharmonic parts of the intensity tensors (second dipole and polarizability derivatives) were found less important for the entire spectral profiles than the force field anharmonicities (third and

  16. Fabrication of white light-emitting diodes based on UV light-emitting diodes with conjugated polymers-(CdSe/ZnS) quantum dots as hybrid phosphors.

    PubMed

    Jung, Hyunchul; Chung, Wonkeun; Lee, Chang Hun; Kim, Sung Hyun

    2012-07-01

    White light-emitting diodes (LEDs) were fabricated using GaN-based 380-nm UV LEDs precoated with the composite of blue-emitting polymer (poly[(9,9-dihexylfluorenyl-2,7-diyl)-alt-co-(2-methoxy-5-{2-ethylhexyloxy)-1 ,4-phenylene)]), yellow green-emitting polymer (poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-(1,4-benzo-{2,1',3}-thiadiazole)]), and 605-nm red-emitting quantum dots (QDs). CdSe cores were obtained by solvothermal route using CdO, Se precursors and ZnS shells were synthesized by using diethylzinc, and hexamethyldisilathiane precursors. The optical properties of CdSe/ZnS QDs were characterized by UV-visible and photoluminescence (PL) spectra. The structural data and composition of the QDs were transmission electron microscopy (TEM), and EDX technique. The quantum yield and size of the QDs were 58.7% and about 6.7 nm, respectively. Three-band white light was generated by hybridizing blue (430 nm), green (535 nm), and red (605 nm) emission. The color-rendering index (CRI) of the device was extremely improved by introducing the QDs. The CIE-1931 chromaticity coordinate, color temperature, and CRI of a white LED at 20 mA were (0.379, 0.368), 3969 K, and 90, respectively.

  17. Micromechanical analysis of a hybrid composite—effect of boron carbide particles on the elastic properties of basalt fiber reinforced polymer composite

    NASA Astrophysics Data System (ADS)

    Krishna Golla, Sai; Prasanthi, P.

    2016-11-01

    A fiber reinforced polymer (FRP) composite is an important material for structural application. The diversified application of FRP composites has become the center of attention for interdisciplinary research. However, improvements in the mechanical properties of this class of materials are still under research for different applications. The reinforcement of inorganic particles in a composite improves its structural properties due to their high stiffness. The present research work is focused on the prediction of the mechanical properties of the hybrid composites where continuous fibers are reinforced in a micro boron carbide particle mixed polypropylene matrix. The effectiveness of the addition of 30 wt. % of boron carbide (B4C) particle contributions regarding the longitudinal and transverse properties of the basalt fiber reinforced polymer composite at various fiber volume fractions is examined by finite element analysis (FEA). The experimental approach is the best way to determine the properties of the composite but it is expensive and time-consuming. Therefore, the finite element method (FEM) and analytical methods are the viable methods for the determination of the composite properties. The FEM results were obtained by adopting a micromechanics approach with the support of FEM. Assuming a uniform distribution of reinforcement and considering one unit-cell of the whole array, the properties of the composite materials are determined. The predicted elastic properties from FEA are compared with the analytical results. The results suggest that B4C particles are a good reinforcement for the enhancement of the transverse properties of basalt fiber reinforced polypropylene.

  18. Electrospun Conjugated Polymer/Fullerene Hybrid Fibers: Photoactive Blends, Conductivity through Tunneling-AFM, Light Scattering, and Perspective for Their Use in Bulk-Heterojunction Organic Solar Cells

    SciT

    Yang, Zhenhua; Moffa, Maria; Liu, Ying

    Hybrid conjugated polymer/fullerene filaments based on MEH-PPV/PVP/PCBM were prepared by electrospinning, and their properties were assessed by scanning electron, atomic and lateral-force, tunneling, and confocal microscopies, as well as by attenuated-total-reflection Fourier transform infrared spectroscopy, photoluminescence quantum yield, and spatially resolved fluorescence. Highlighted features include the ribbon shape of the realized fibers and the persistence of a network serving as a template for heterogeneous active layers in solar cell devices. A set of favorable characteristics is evidenced in this way in terms of homogeneous charge-transport behavior and formation of effective interfaces for diffusion and dissociation of photogenerated excitons. The interactionmore » of the organic filaments with light, exhibiting specific light-scattering properties of the nanofibrous mat, might also contribute to spreading incident radiation across the active layers, thus potentially enhancing photovoltaic performance. Finally, this method might be applied to other electron donor–electron acceptor material systems for the fabrication of solar cell devices enhanced by nanofibrillar morphologies embedding conjugated polymers and fullerene compounds.« less

  19. Electrospun Conjugated Polymer/Fullerene Hybrid Fibers: Photoactive Blends, Conductivity through Tunneling-AFM, Light Scattering, and Perspective for Their Use in Bulk-Heterojunction Organic Solar Cells

    DOE PAGES

    Yang, Zhenhua; Moffa, Maria; Liu, Ying; ...

    2018-01-25

    Hybrid conjugated polymer/fullerene filaments based on MEH-PPV/PVP/PCBM were prepared by electrospinning, and their properties were assessed by scanning electron, atomic and lateral-force, tunneling, and confocal microscopies, as well as by attenuated-total-reflection Fourier transform infrared spectroscopy, photoluminescence quantum yield, and spatially resolved fluorescence. Highlighted features include the ribbon shape of the realized fibers and the persistence of a network serving as a template for heterogeneous active layers in solar cell devices. A set of favorable characteristics is evidenced in this way in terms of homogeneous charge-transport behavior and formation of effective interfaces for diffusion and dissociation of photogenerated excitons. The interactionmore » of the organic filaments with light, exhibiting specific light-scattering properties of the nanofibrous mat, might also contribute to spreading incident radiation across the active layers, thus potentially enhancing photovoltaic performance. Finally, this method might be applied to other electron donor–electron acceptor material systems for the fabrication of solar cell devices enhanced by nanofibrillar morphologies embedding conjugated polymers and fullerene compounds.« less

  20. Enhanced performance of P(VDF-HFP)-based composite polymer electrolytes doped with organic-inorganic hybrid particles PMMA-ZrO2 for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Xiao, Wei; Wang, Zhiyan; Zhang, Yan; Fang, Rui; Yuan, Zun; Miao, Chang; Yan, Xuemin; Jiang, Yu

    2018-04-01

    To improve the ionic conductivity as well as enhance the mechanical strength of the gel polymer electrolyte, poly(vinylidene fluoride-hexafluoroprolene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with the organic-inorganic hybrid particles poly(methyl methacrylate) -ZrO2 (PMMA-ZrO2) are prepared by phase inversion method, in which PMMA is successfully grafted onto the surface of the homemade nano-ZrO2 particles via in situ polymerization confirmed by FT-IR. XRD and DSC patterns show adding PMMA-ZrO2 particles into P(VDF-HFP) can significantly decrease the crystallinity of the CPE membrane. The CPE membrane doped with 5 wt % PMMA-ZrO2 particles can not only present a homogeneous surface with abundant interconnected micro-pores, but maintain its initial shape after thermal exposure at 160 °C for 1 h, in which the ionic conductivity and lithium ion transference number at room temperature can reach to 3.59 × 10-3 S cm-1 and 0.41, respectively. The fitting results of the EIS plots indicate the doped PMMA-ZrO2 particles can significantly lower the interface resistance and promote lithium ions diffusion rate. The Li/CPE-sPZ/LiCoO2 and Li/CPE-sPZ/Graphite coin cells can deliver excellent rate and cycling performance. Those results suggest the P(VDF-HFP)-based CPE doped with 5 wt % PMMA-ZrO2 particles can become an exciting potential candidate as polymer electrolyte for the lithium ion battery.

  1. Synthesis of a novel molecularly imprinted organic-inorganic hybrid polymer for the selective isolation and determination of fluoroquinolones in tilapia.

    PubMed

    Yang, Xun; Wang, Ruiling; Wang, Weihua; Yan, Hongyuan; Qiu, Mande; Song, Yanxue

    2014-01-15

    A novel molecularly imprinted organic-inorganic hybrid polymer (MI-MAA/APTS) based on a dummy molecular imprinting technique and an organic-inorganic hybrid material technique was synthesised and used as a sorbent in solid-phase extraction for the selective isolation and determination of ofloxacin (OFL), lomefloxacin (LOM), and ciprofloxacin (CIP) in tilapia samples. The MI-MAA/APTS sorbent was prepared from 3-aminopropyltriethoxysilanes (APTS) as an inorganic source and methacrylic acid (MAA) as an organic source and exhibited high mechanical strength and special affinities to the analytes. A comparison of MI-MAA/APTS with other conventional sorbents (C18 and HLB) showed that MI-MAA/APTS displayed good selectivity and affinity for OFL, LOM, and CIP, and the recoveries of the analytes at three spiked levels were in the range of 85.1-101.0%, with the relative standard deviations ≤5.1%. The presented MI-MAA/APTS-SPE-HPLC method could be potentially applied to the determination of fluoroquinolones (FQs) in complex fish samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Ultra-tough and strong, hybrid thin films based on ionically crosslinked polymers and 2D inorganic platelets

    NASA Astrophysics Data System (ADS)

    Ji, Dong Hwan; Choi, Suji; Kim, Jaeyun; nanobiomaterials lab Team

    Integration of high strength and toughness tend to be mutually exclusive and synthesized hybrid films with superior mechanical properties have been difficult to fabricate controllable shapes and various scales. Although diverse synthesized hybrid films consisting of organic matrix and inorganic materials with brick-and-mortar structure, show improved mechanical properties, these films are still limited in toughness and fabrication methods. Herein, we report ultra-tough and strong hybrid thin films with self-assembled uniform microstructures with controllable shapes and various scale based on hydrogel-mediated process. Ca2+-crosslinking in alginate chains and well-aligned alumina platelets in alginate matrix lead to a synergistic enhancement of strength and toughness in the resulting film. Consequentially, Ca2+-crosslinked Alg/Alu films showed outstanding toughness of 29 MJ m-3 and tensile strength of 160 MPa. Furthermore, modifying Alu surface with polyvinylpyrrolidone (PVP), tensile strength was further improved up to 200 MPa. Our results suggest an alternative approach to design and processing of self-assembled hydrogel-mediated hybrid films with outstanding mechanical properties.

  3. Polymer/Nanocrystal Hybrid Solar Cells: Influence of Molecular Precursor Design on Film Nanomorphology, Charge Generation and Device Performance

    PubMed Central

    MacLachlan, Andrew J; Rath, Thomas; Cappel, Ute B; Dowland, Simon A; Amenitsch, Heinz; Knall, Astrid-Caroline; Buchmaier, Christine; Trimmel, Gregor; Nelson, Jenny; Haque, Saif A

    2015-01-01

    In this work, molecular tuning of metal xanthate precursors is shown to have a marked effect on the heterojunction morphology of hybrid poly(3-hexylthiophene-2,5-diyl) (P3HT)/CdS blends and, as a result, the photochemical processes and overall performance of in situ fabricated hybrid solar cells. A series of cadmium xanthate complexes is synthesized for use as in situ precursors to cadmium sulfide nanoparticles in hybrid P3HT/CdS solar cells. The formation of CdS domains is studied by simultaneous GIWAXS (grazing incidence wide-angle X-ray scattering) and GISAXS (grazing incidence small-angle X-ray scattering), revealing knowledge about crystal growth and the formation of different morphologies observed using TEM (transmission electron microscopy). These measurements show that there is a strong relationship between precursor structure and heterojunction nanomorphology. A combination of TAS (transient absorption spectroscopy) and photovoltaic device performance measurements is used to show the intricate balance required between charge photogeneration and percolated domains in order to effectively extract charges to maximize device power conversion efficiencies. This study presents a strong case for xanthate complexes as a useful route to designing optimal heterojunction morphologies for use in the emerging field of hybrid organic/inorganic solar cells, due to the fact that the nanomorphology can be tuned via careful design of these precursor materials. PMID:25866496

  4. Structural analysis of zwitterionic liquids vs. homologous ionic liquids

    NASA Astrophysics Data System (ADS)

    Wu, Boning; Kuroda, Kosuke; Takahashi, Kenji; Castner, Edward W.

    2018-05-01

    Zwitterionic liquids (Zw-ILs) have been developed that are homologous to monovalent ionic liquids (ILs) and show great promise for controlled dissolution of cellulosic biomass. Using both high energy X-ray scattering and atomistic molecular simulations, this article compares the bulk liquid structural properties for novel Zw-ILs with their homologous ILs. It is shown that the significant localization of the charges on Zw-ILs leads to charge ordering similar to that observed for conventional ionic liquids with monovalent anions and cations. A low-intensity first sharp diffraction peak in the liquid structure factor S(q) is observed for both the Zw-IL and the IL. This is unexpected since both the Zw-IL and IL have a 2-(2-methoxyethoxy)ethyl (diether) functional group on the cationic imidazolium ring and ether functional groups are known to suppress this peak. Detailed analyses show that this intermediate range order in the liquid structure arises for slightly different reasons in the Zw-IL vs. the IL. For the Zw-IL, the ether tails in the liquid are shown to aggregate into nanoscale domains.

  5. Mono- and bimetallic zwitterionic chromium(0) and tungsten(0) allenyls.

    PubMed

    Giner, Elena A; Santiago, Alicia; Gómez-Gallego, Mar; Ramírez de Arellano, Carmen; Poulten, Rebecca C; Whittlesey, Michael K; Sierra, Miguel A

    2015-06-01

    A series of stable chiral (racemic), formally neutral, zwitterionic mono- and bimetallic M(CO)5[C(OEt)═C═CR(NHC)] (M = Cr, W) σ-allenyls are ready available by the addition of N-heterocyclic carbenes (NHCs) to Cr(0) and W(0) alkynyl Fischer carbene complexes. Different classes of NHCs, (e.g., 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene, 1,3-bis(2,4,6-trimethylphenyl)imidazolin-2-ylidene, and their six- and seven-membered analogues and 1,3-bis(dimethyl)imidazol-2-ylidene) were employed as nucleophiles in these C-C bond-forming reactions yielding the novel complexes in essentially quantitative yields. A systematic experimental and computational study of the electronic properties of the Cr- and W-allenyls shows that their UV-vis spectra are directly influenced by the structure of the heterocyclic moiety derived from the NHC (ring size, substituents on the N atoms) and by the nature of the metal fragment (Cr/W). The electron-releasing nature of these complexes allows them to participate in electron-transfer reactions in the ground state, leading to a type of charged α,β-unsaturated Fischer carbenes that incorporate an NHC fragment in their structure.

  6. The Modulation of Adaptive Immune Responses by Bacterial Zwitterionic Polysaccharides

    PubMed Central

    Stephen, Tom Li; Groneck, Laura; Kalka-Moll, Wiltrud Maria

    2010-01-01

    The detection of pathogen-derived molecules as foreign particles by adaptive immune cells triggers T and B lymphocytes to mount protective cellular and humoral responses, respectively. Recent immunological advances elucidated that proteins and some lipids are the principle biological molecules that induce protective T cell responses during microbial infections. Polysaccharides are important components of microbial pathogens and many vaccines. However, research concerning the activation of the adaptive immune system by polysaccharides gained interest only recently. Traditionally, polysaccharides were considered to be T cell-independent antigens that did not directly activate T cells or induce protective immune responses. Here, we review several recent advances in “carbohydrate immunobiology”. A group of bacterial polysaccharides that are known as “zwitterionic polysaccharides (ZPSs)” were recently identified as potent immune modulators. The immunomodulatory effect of ZPSs required antigen processing and presentation by antigen presenting cells, the activation of CD4 T cells and subpopulations of CD8 T cells and the modulation of host cytokine responses. In this review, we also discuss the potential use of these unique immunomodulatory ZPSs in new vaccination strategies against chronic inflammatory conditions, autoimmunity, infectious diseases, allergies and asthmatic conditions. PMID:21234388

  7. Diffusion of aqueous solutions of ionic, zwitterionic, and polar solutes

    NASA Astrophysics Data System (ADS)

    Teng, Xiaojing; Huang, Qi; Dharmawardhana, Chamila Chathuranga; Ichiye, Toshiko

    2018-06-01

    The properties of aqueous solutions of ionic, zwitterionic, and polar solutes are of interest to many fields. For instance, one of the many anomalous properties of aqueous solutions is the behavior of water diffusion in different monovalent salt solutions. In addition, solutes can affect the stabilities of macromolecules such as proteins in aqueous solution. Here, the diffusivities of aqueous solutions of sodium chloride, potassium chloride, tri-methylamine oxide (TMAO), urea, and TMAO-urea are examined in molecular dynamics simulations. The decrease in the diffusivity of water with the concentration of simple ions and urea can be described by a simple model in which the water molecules hydrogen bonded to the solutes are considered to diffuse at the same rate as the solutes, while the remainder of the water molecules are considered to be bulk and diffuse at almost the same rate as pure water. On the other hand, the decrease in the diffusivity of water with the concentration of TMAO is apparently affected by a decrease in the diffusion rate of the bulk water molecules in addition to the decrease due to the water molecules hydrogen bonded to TMAO. In other words, TMAO enhances the viscosity of water, while urea barely affects it. Overall, this separation of water molecules into those that are hydrogen bonded to solute and those that are bulk can provide a useful means of understanding the short- and long-range effects of solutes on water.

  8. Using Polymer Electrolyte Membrane Fuel Cells in a Hybrid Surface Ship Propulsion Plant to Increase Fuel Efficiency

    DTIC Science & Technology

    2010-06-01

    cell ( PEMFC ), and the phosphoric acid fuel cell (PAFC). 2.3.1 Solid Oxide Fuel Cells (SOFC) The first type of fuel cell considered is the SOFC. This...durability issues for use within a given application. 2.3.2 Polymer Electrolyte Membrane Fuel Cells ( PEMFC ) The PEMFC operates by passing hydrogen that has...cells. Some advantages of PEMFC operating at such low temperatures is that the fuel cell doesn’t require as meticulous of a support system infrastructure

  9. Zwitterionic PEG-PC Hydrogels Modulate the Foreign Body Response in a Modulus-Dependent Manner.

    PubMed

    Jansen, Lauren E; Amer, Luke D; Chen, Esther Y-T; Nguyen, Thuy V; Saleh, Leila S; Emrick, Todd; Liu, Wendy F; Bryant, Stephanie J; Peyton, Shelly R

    2018-05-15

    Reducing the foreign body response (FBR) to implanted biomaterials will enhance their performance in tissue engineering. Poly(ethylene glycol) (PEG) hydrogels are increasingly popular for this application due to their low cost, ease of use, and the ability to tune their compliance via molecular weight and cross-linking densities. PEG hydrogels can elicit chronic inflammation in vivo, but recent evidence has suggested that extremely hydrophilic, zwitterionic materials and particles can evade the immune system. To combine the advantages of PEG-based hydrogels with the hydrophilicity of zwitterions, we synthesized hydrogels with comonomers PEG and the zwitterion phosphorylcholine (PC). Recent evidence suggests that stiff hydrogels elicit increased immune cell adhesion to hydrogels, which we attempted to reduce by increasing hydrogel hydrophilicity. Surprisingly, hydrogels with the highest amount of zwitterionic comonomer elicited the highest FBR. Lowering the hydrogel modulus (165 to 3 kPa), or PC content (20 to 0 wt %), mitigated this effect. A high density of macrophages was found at the surface of implants associated with a high FBR, and mass spectrometry analysis of the proteins adsorbed to these gels implicated extracellular matrix, immune response, and cell adhesion protein categories as drivers of macrophage recruitment. Overall, we show that modulus regulates macrophage adhesion to zwitterionic-PEG hydrogels, and demonstrate that chemical modifications to hydrogels should be studied in parallel with their physical properties to optimize implant design.

  10. Hybrid materials based on novel 2D lanthanide coordination polymers covalently bonded to amine-modified SBA-15 and MCM-41: assembly, characterization, structural features, thermal and luminescence properties.

    PubMed

    Wang, Jun; Dou, Wei; Kirillov, Alexander M; Liu, Weisheng; Xu, Cailing; Fang, Ran; Yang, Lizi

    2016-11-22

    Three novel 2D coordination polymers [Tb 2 (μ 4 -L) 2 (μ-HL)(μ-HCOO)(DEF)] n (Tb-L), [Eu(μ 4 -L)(L)(H 2 O) 2 ] n (Eu-L), and [Nd(μ 4 -L)(L)(H 2 O) 2 ] n (Nd-L) were assembled from the corresponding lanthanide(iii) nitrates and 5 methoxy-(4-benzaldehyde)-1,3-benzenedicarboxylic acid (H 2 L) as a main multifunctional building block bearing carboxylate and aldehyde functional groups, using H 2 O/DEF {DEF = N,N-diethylformamide} as a reaction medium. The obtained coordination polymers were isolated as stable microcrystalline solids and fully characterized by elemental analysis, FT-IR spectroscopy, TGA, BET, PXRD, and single-crystal X-ray diffraction methods. Their structures feature intricate 2D metal-organic networks, which were topologically classified as underlying layers with the 4,6L26 (for Tb-L) or sql (for Eu-L and Nd-L) topologies. Besides, a novel series of mesoporous hybrid materials wherein the Tb-L, Eu-L, or Nd-L coordination polymers are covalently grafted into the amine-functionalized SBA-15-NH 2 or MCM-41-NH 2 matrices (via the formation of Schiff-base groups) was also synthesized and fully characterized. These hybrid materials show high thermal and photoluminescence stability, as well as remarkable chemical resistance to boiling water, and acidic or alkaline medium. Luminescent properties of the parent coordination polymers and derived hybrid materials are investigated in detail, showing that the latter combine the luminescent characteristics (intense green or red emissions and excellent stability) of lanthanide coordination polymers and structural features of ordered mesoporous silica molecular sieves. Moreover, light emitting devices were assembled, by coating the hybrid materials onto the surface of UV-LED bulbs, and showed excellent light emitting properties.

  11. Rational design on controlled release ion-exchange polymeric microspheres and polymer-lipid hybrid nanoparticles for the delivery of water-soluble drugs through a multidisciplinary approach

    NASA Astrophysics Data System (ADS)

    Li, Yongqiang

    Sulfopropyl dextran sulfate (SP-DS) microspheres and polymer-lipid hybrid nanoparticles (PLN) for the delivery of water-soluble anticancer drugs and P-glycoprotein inhibitors were developed by our group recently and demonstrated effectiveness in local chemotherapy. To optimize the delivery performance of these particulate systems, particularly PLN, an integrated multidisciplinary approach was developed, based on an in-depth understanding of drug-excipient interactions, internal structure, drug loading and release mechanisms, and application of advanced modeling/optimization techniques. An artificial neural networks (ANN) simulator capable of formulation optimization and drug release prediction was developed. In vitro drug release kinetics of SP-DS microspheres, with various drug loading and in different release media, were predicted by ANN. The effects of independent variables on drug release were evaluated. Good modeling performance suggested that ANN is a useful tool to predict drug release from ion-exchange microspheres. To further improve the performance of PLN, drug-polymer-lipid interactions were characterized theoretically and experimentally using verapamil hydrochloride (VRP) as a model drug and dextran sulfate sodium (DS) as a counter-ion polymer. VRP-DS complexation followed a stoichiometric rule and solid-state transformation of VRP were observed. Dodecanoic acid (DA) was identified as the lead lipid carrier material. Based upon the optimized drug-polymer-lipid interactions, PLN with high drug loading capacity (36%, w/w) and sustained release without initial burst release were achieved. VRP remained amorphous and was molecularly dispersed within PLN. H-bonding contributed to the miscibility between the VRP-DS complex and DA. Drug release from PLN was mainly controlled by diffusion and ion-exchange processes. Drug loading capacity and particle size of PLN depend on the formulation factors of the weight ratio of drug to lipid and concentrations of

  12. Achievement of two logical states through a polymer/silicon interface for organic-inorganic hybrid memory

    NASA Astrophysics Data System (ADS)

    Chen, Jianhui; Chen, Bingbing; Shen, Yanjiao; Guo, Jianxin; Liu, Baoting; Dai, Xiuhong; Xu, Ying; Mai, Yaohua

    2017-11-01

    A hysteresis loop of minority carrier lifetime vs voltage is found in polystyrenesulfonate (PSS)/Si organic-inorganic hybrid heterojunctions, implying an interfacial memory effect. Capacitance-voltage and conductance-voltage hysteresis loops are observed and reveal a memory window. A switchable interface state, which can be controlled by charge transfer based on an electrochemical oxidation/deoxidation process, is suggested to be responsible for this hysteresis effect. We perform first-principle total-energy calculations on the influence of external electric fields and electrons or holes, which are injected into interface states on the adsorption energy of PSS on Si. It is demonstrated that the dependence of the interface adsorption energy difference on the electric field is the origin of this two-state switching. These results offer a concept of organic-inorganic hybrid interface memory being optically or electrically readable, low-cost, and compatible with the flexible organic electronics.

  13. Design of water-repellant coating using dual scale size of hybrid silica nanoparticles on polymer surface

    NASA Astrophysics Data System (ADS)

    Conti, J.; De Coninck, J.; Ghazzal, M. N.

    2018-04-01

    The dual-scale size of the silica nanoparticles is commonly aimed at producing dual-scale roughness, also called hierarchical roughness (Lotus effect). In this study, we describe a method to build a stable water-repellant coating with controlled roughness. Hybrid silica nanoparticles are self-assembled over a polymeric surface by alternating consecutive layers. Each one uses homogenously distributed silica nanoparticles of a particular size. The effect of the nanoparticle size of the first layer on the final roughness of the coating is studied. The first layer enables to adjust the distance between the silica nanoparticles of the upper layer, leading to a tuneable and controlled final roughness. An optimal size nanoparticle has been found for higher water-repellency. Furthermore, the stability of the coating on polymeric surface (Polycarbonate substrate) is ensured by photopolymerization of hybridized silica nanoparticles using Vinyl functional groups.

  14. Synthesis of a hybrid polymer-inorganic biomimetic support incorporating in situ pectinase from Aspergillus niger ATCC 9642.

    PubMed

    Bustamante-Vargas, Cindy Elena; Mignoni, Marcelo Luis; de Oliveira, Débora; Venquiaruto, Luciana Dornelles; Valduga, Eunice; Toniazzo, Geciane; Dallago, Rogério Marcos

    2015-08-01

    The hybrid alginate/gelatin/calcium oxalate (AGOCa) support was successfully synthesized through the biomimetic mineralization method for immobilization in situ of a pectinolytic extract from Aspergillus niger ATCC 9642 via entrapment technique. The efficiency of immobilization reached 72.7%. Sodium oxalate buffer (100 mM, pH 5.5) was selected as adjuvant of the immobilization process by allowing the formation of a calcified shell around the calcium alginate capsule, significantly increasing the stability to storage, thermal and recycling of the enzymatic immobilized pectinolytic extract. The pH and temperature for maximum activity were from 5.0 to 6.0 and 60 to 80 °C, respectively. The new hybrid support can be a potential alternative to obtain immobilized pectinases with properties for advantageous industrial applications.

  15. Construction of Metal-Organic Framework/Conductive Polymer Hybrid for All-Solid-State Fabric Supercapacitor.

    PubMed

    Qi, Kai; Hou, Ruizuo; Zaman, Shahid; Qiu, Yubing; Xia, Bao Yu; Duan, Hongwei

    2018-05-30

    Metal-organic frameworks (MOFs) hold promising potential in energy storage but are limited by poor conductivity. In this work, a metal-organic framework/polypyrrole hybrid is constructed by a facile one-pot electrodeposition method in the presence of dopamine. An all-solid-state fabric supercapacitor based on this hybrid demonstrates excellent electrochemical energy-storage performance, which achieves a specific capacitance of 10 mF cm -1 (206 mF cm -2 ), a power density of 132 μW cm -1 (2102 μW cm -2 ), and an energy density of 0.8 μWh cm -1 (12.8 μWh cm -2 ). The stable cycling life and excellent mechanical flexibility over a wide range of working temperature are also achieved, which maintains a capacitance retention of 89% over 10 000 charging/discharging cycles, a capacitance decrease of only 4% after 1000 frizzy (360° bending) cycles, and no obvious capacitance loss under 100 repeated heating (100 °C)/cooling (-15 °C) cycles. This fibrous supercapacitor displays promising potential in wearable textile electronics as it can be easily woven into common cotton cloth. Our strategy may shed some valuable light on the construction of MOF-based hybrids for flexible energy-storage electronics.

  16. Zwitterion formation in titan ice analogs: reaction between HC3N and NH3.

    PubMed

    Couturier-Tamburelli, Isabelle; Sessouma, Bintou; Chiavassa, Thierry; Piétri, Nathalie

    2012-11-08

    A zwitterion is formed in the laboratory at low temperatures in the solid phase from the thermal reaction of HC(3)N and NH(3). We report for the first time its infrared spectrum. We study its reaction using Fourier transform infrared spectroscopy. Its reaction rate is estimated to be k(T) = 2.9 × 10(5) exp(-2.3 ± 0.1 (kJ mol(-1))/RT). Calculations using density functional theory (B3LYP/6-31g**) are used to characterize all the species (complexes, zwitterions, and transition states) and are in good agreement with the infrared spectra. The structure of the zwitterion is determined planar and it is characterized by a N-C bond around 1.5 Å.

  17. Catalytic copolymerization of CO and ethylene with a charge neutral palladium(II) zwitterion.

    PubMed

    Lu, Connie C; Peters, Jonas C

    2002-05-15

    The synthesis of a zwitterionic Pd(II) complex supported by an anionic bis(phosphino)borate ligand, Ph(2)B(CH(2)PPh(2))(2) (abbreviated as [Ph(2)BP(2)]), is reported. The new complex, [Ph(2)BP(2)]PdMe(THF), is active for CO and ethylene copolymerization. The copolymerization activity and polyketone molecular weight for the neutral, zwitterionic system are compared with those for the cationic systems [R(2)E(CH(2)PPh(2))(2)PdMe(THF)][B(C(6)F(5))(4)] where ER(2) = SiPh(2) and CH(2). Surprisingly, the more electron rich zwitterionic system is a catalyst of activity comparable to that of the more conventional cationic systems.

  18. Physiological stability and renal clearance of ultrasmall zwitterionic gold nanoparticles: Ligand length matters

    NASA Astrophysics Data System (ADS)

    Ning, Xuhui; Peng, Chuanqi; Li, Eric S.; Xu, Jing; Vinluan, Rodrigo D.; Yu, Mengxiao; Zheng, Jie

    2017-05-01

    Efficient renal clearance has been observed from ultrasmall zwitterionic glutathione-coated gold nanoparticles (GS-AuNPs), which have broad preclinical applications in cancer diagnosis and kidney functional imaging. However, origin of such efficient renal clearance is still not clear. Herein, we conducted head-to-head comparison on physiological stability and renal clearance of two zwitterionic luminescent AuNPs coated with cysteine and glycine-cysteine (Cys-AuNPs and Gly-Cys-AuNPs), respectively. While both of them exhibited similar surface charges and the same core sizes, additional glycine slightly increased the hydrodynamic diameter of the AuNPs by 0.4 nm but significantly enhanced physiological stability of the AuNPs as well as altered their clearance pathways. These studies indicate that the ligand length, in addition to surface charges and size, also plays a key role in the physiological stability and renal clearance of ultrasmall zwitterionic inorganic NPs.

  19. Proline zwitterion dynamics in solution, glass, and crystalline state.

    PubMed

    Kapitán, Josef; Baumruk, Vladimír; Kopecký, Vladimír; Pohl, Radek; Bour, Petr

    2006-10-18

    Raman and Raman optical activity spectra of L- and D-proline zwitterionic (PROZW) forms were recorded for H(2)O and D(2)O solutions in a wide frequency range and analyzed with respect to the motion of the proline ring and rotation of the carbonyl group. The solution spectra were additionally compared to Raman scattering of glass and crystalline powder proline. Solution and glass spectral band broadenings are similar and reveal information about the extent of internal molecular motion. Two distinct but equally populated flexible forms were found in the glass and the solution. The equal population is consistent with NMR data, temperature, and concentration dependencies. The molecular flexibility is reduced significantly in the crystal, however, where only one conformer is present. Consequently, the crystal bands are narrow and exhibit minor frequency shifts. The spectra were interpreted with the aid of density functional theory computations involving both continuum and explicit solvent. A two-dimensional potential energy surface pertaining to the five-member ring puckering coordinates was constructed and used for dynamical averaging of spectral properties. Comparison of the computed and experimental bandwidths suggests that the puckering is strongly correlated with the carbonyl rotation. An averaging over these two motions produces similar results. The interpretation of the Raman experiments with the aid of the simulation techniques also indicates that the environment modulates properties of the hydrophobic part of the molecule indirectly by interacting with the ionic group. Such behavior may be important for the reactivity and biological activity of proline-containing peptides and proteins.

  20. A potentiometric chiral sensor for L-Phenylalanine based on crosslinked polymethylacrylic acid-polycarbazole hybrid molecularly imprinted polymer.

    PubMed

    Chen, Yu; Chen, Lei; Bi, Ruilin; Xu, Lan; Liu, Yan

    2012-11-19

    A novel chiral molecularly imprinted polymer (MIP) sensor for L-Phenylalanine has been developed, which is constructed by electrochemically driven cross-linking a pendant polymer precursor, poly[2-(N-carbazolyl)ethyl methacrylate-co-meth-acrylic acid]s (PCEMMAs). In this MIP sensing material, the recognition sites, the insulating polymethylacrylic acid (PMAA), were covalently bonded to the conducting polycarbazole which could be used as signal transfer interface between recognition layer and electrode. The mole ratio of copolymerizing monomers, 2-(N-carbazolyl) ethyl methacrylate:methylacrylic acid (CE:MAA), and the scanning cycles of electropolymerization were adjusted during the preparation of MIP sensing material. The optimized conditions, CE:MAA=3:2 and 20 scanning cycles, were obtained. And then the properties of MIP films were characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and water contact angle. Open circuit potential-time technique was used to estimate the enantioselectivity of the MIP sensor. The results indicate that the promising sensor preferentially responses L-Phenylalanine (L-Phe) over D-Phenylalanine (D-Phe) with a selectivity coefficient K(D)(L)=5.75×10(-4) and the limit of detection (LOD) is 1.37μM, which reveals its good enantioselectivity and sensitivity. Crown Copyright © 2012. Published by Elsevier B.V. All rights reserved.

  1. The self-assembling zwitterionic form of L-phenylalanine at neutral pH.

    PubMed

    Mossou, Estelle; Teixeira, Susana C M; Mitchell, Edward P; Mason, Sax A; Adler-Abramovich, Lihi; Gazit, Ehud; Forsyth, V Trevor

    2014-03-01

    The title zwitterion (2S)-2-azaniumyl-1-hydroxy-3-phenylpropan-1-olate, C9H11NO2, also known as L-phenylalanine, was characterized using synchrotron X-rays. It crystallized in the monoclinic space group P21 with four molecules in the asymmetric unit. The 0.62 Å resolution structure is assumed to be closely related to the fibrillar form of phenylalanine, as observed by electron microscopy and electron diffraction. The structure exists in a zwitterionic form in which π-π stacking and hydrogen-bonding interactions are believed to form the basis of the self-assembling properties.

  2. Design of Stomach Acid-Stable and Mucin-Binding Enzyme Polymer Conjugates.

    PubMed

    Cummings, Chad S; Campbell, Alan S; Baker, Stefanie L; Carmali, Sheiliza; Murata, Hironobu; Russell, Alan J

    2017-02-13

    The reduced immunogenicity and increased stability of protein-polymer conjugates has made their use in therapeutic applications particularly attractive. However, the physicochemical interactions between polymer and protein, as well as the effect of this interaction on protein activity and stability, are still not fully understood. In this work, polymer-based protein engineering was used to examine the role of polymer physicochemical properties on the activity and stability of the chymotrypsin-polymer conjugates and their degree of binding to intestinal mucin. Four different chymotrypsin-polymer conjugates, each with the same polymer density, were synthesized using "grafting-from" atom transfer radical polymerization. The influence of polymer charge on chymotrypsin-polymer conjugate mucin binding, bioactivity, and stability in stomach acid was determined. Cationic polymers covalently attached to chymotrypsin showed high mucin binding, while zwitterionic, uncharged, and anionic polymers showed no mucin binding. Cationic polymers also increased chymotrypsin activity from pH 6-8, while zwitterionic polymers had no effect, and uncharged and anionic polymers decreased enzyme activity. Lastly, cationic polymers decreased the tendency of chymotrypsin to structurally unfold at extremely low pH, while uncharged and anionic polymers induced unfolding more quickly. We hypothesized that when polymers are covalently attached to the surface of a protein, the degree to which those polymers interact with the protein surface is the predominant determinant of whether the polymer will stabilize or inactivate the protein. Preferential interactions between the polymer and the protein lead to removal of water from the surface of the protein, and this, we believe, inactivates the enzyme.

  3. Low-voltage organic strain sensor on plastic using polymer/high- K inorganic hybrid gate dielectrics

    NASA Astrophysics Data System (ADS)

    Jung, Soyoun; Ji, Taeksoo; Varadan, Vijay K.

    2007-12-01

    In this paper, gate-induced pentacene semiconductor strain sensors based on hybrid-gate dielectrics using poly-vinylphenol (PVP) and high-K inorganic, Ta IIO 5 are fabricated on flexible substrates, polyethylene naphthalate (PEN). The Ta IIO 5 gate dielectric layer is combined with a thin PVP layer to obtain very smooth and hydrophobic surfaces which improve the molecular structures of pentacene films. The PVP-Ta IIO 5 hybrid-gate dielectric films exhibit a high dielectric capacitance and low leakage current. The sensors adopting thin film transistor (TFT)-like structures show a significantly reduced operating voltage (~6V), and good device characteristics with a field-effect mobility of 1.89 cm2/V•s, a threshold voltage of -0.5 V, and an on/off ratio of 10 3. The strain sensor, one of the practical applications in large-area organic electronics, was characterized with different bending radii of 50, 40, 30, and 20 mm. The sensor output signals were significantly improved with low-operating voltages.

  4. Preparation of hybrid thiol-acrylate emulsion-templated porous polymers by interfacial copolymerization of high internal phase emulsions.

    PubMed

    Langford, Caitlin R; Johnson, David W; Cameron, Neil R

    2015-05-01

    Emulsion-templated highly porous polymers (polyHIPEs), containing distinct regions differing in composition, morphology, and/or properties, are prepared by the simultaneous polymerization of two high internal phase emulsions (HIPEs) contained within the same mould. The HIPEs are placed together in the mould and subjected to thiol-acrylate photopolymerization. The resulting polyHIPE material is found to contain two distinct semicircular regions, reflecting the composition of each HIPE. The original interface between the two emulsions becomes a copolymerized band between 100 and 300 μm wide, which is found to be mechanically robust. The separate polyHIPE layers are distinguished from one another by their differing average void diameter, chemical composition, and extent of contraction upon drying. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Design, Synthesis, and Self-Assembly of Well-Defined Hybrid Materials Including Polymer Amphiphiles and Giant Tetrahedra Molecules Based on Poss Nanoparticles

    NASA Astrophysics Data System (ADS)

    Huang, Mingjun

    "Bottom-up" techniques-based self-assembly are always attracting people's interests since this technology provides relatively low economic cost and fast route to construct organized structures at different scales. Considering unprecedented benefits from polymer materials, self-assemblies utilizing polymer building blocks have been extensively studied to achieve diverse hierarchical structures and various attractive properties. However, precise controls of chemical primary structures and compositions and exact constructions of hierarchal ordered structures in synthetic polymers are far from being fully appreciated. In this dissertation, a novel approach has been utilized to construct diverse well-defined nano-building blocks, giant molecules, via conjugating different, and functionalized molecular nanoparticles (MNPs) which are shape- and volume-persistent nano-objects with precise molecular structure and specific symmetry. The representative examples of the three basic categories of giant molecules, "giant polyhedra", "giant surfactants", and "giant shape amphiphiles" were discussed in details. First, a class of precisely defined, nanosized giant tetrahedra was constructed by placing different polyhedral oligomeric silsesquioxane (POSS) molecular nanoparticles at the vertices of a rigid tetrahedral framework. Designed symmetry breaking of these giant tetrahedra introduces accurate positional interactions and results in diverse selectively assembled, highly ordered supramolecular lattices including a Frank-Kasper (FK) A15 phase. The FK and quasicrystal phases are originally identified in metal alloys and only sporadically observed in soft matters. It remains unclear how to correlate their stability with the chemical composition and molecular topology in the self-assembling systems. We then for this purpose designed and studied the self-assembly phase transition sequences of four series of hybrid giant surfactants based on hydrophilic POSS cages tethered with one to

  6. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes/polymer composite thin film.

    PubMed

    Rajanna, Pramod Mulbagal; Gilshteyn, Evgenia; Yagafarov, Timur; Alekseeva, Alena; Anisimov, Anton; Sergeev, Oleg; Neumueller, Alex; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert

    2018-01-09

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and a thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high quality SWCNTs with an enhanced conductivity by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with different SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit Jsc, open-circuit Voc, and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and efficiency of 3.4% under simulated one-sun AM 1.5G direct illumination. © 2018 IOP Publishing Ltd.

  7. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes and polymer composite thin film.

    PubMed

    Rajanna, Pramod M; Gilshteyn, Evgenia P; Yagafarov, Timur; Aleekseeva, Alena K; Anisimov, Anton S; Neumüller, Alex; Sergeev, Oleg; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert G

    2018-01-31

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high-quality SWCNTs with conductivity enhanced by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with varying SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit J sc , open-circuit V oc , and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and an efficiency of 3.4% under simulated one-sun AM 1.5 G direct illumination.

  8. Enhanced efficiency of hybrid amorphous silicon solar cells based on single-walled carbon nanotubes and polymer composite thin film

    NASA Astrophysics Data System (ADS)

    Rajanna, Pramod M.; Gilshteyn, Evgenia P.; Yagafarov, Timur; Aleekseeva, Alena K.; Anisimov, Anton S.; Neumüller, Alex; Sergeev, Oleg; Bereznev, Sergei; Maricheva, Jelena; Nasibulin, Albert G.

    2018-03-01

    We report a simple approach to fabricate hybrid solar cells (HSCs) based on a single-walled carbon nanotube (SWCNT) film and thin film hydrogenated amorphous silicon (a-Si:H). Randomly oriented high-quality SWCNTs with conductivity enhanced by means of poly(3,4-ethylenedioxythiophene) polystyrene sulfonate are used as a window layer and a front electrode. A series of HSCs are fabricated in ambient conditions with varying SWCNT film thicknesses. The polymethylmethacrylate layer drop-casted on fabricated HSCs reduces the reflection fourfold and enhances the short-circuit J sc , open-circuit V oc , and efficiency by nearly 10%. A state-of-the-art J-V performance is shown for SWCNT/a-Si HSC with an open-circuit voltage of 900 mV and an efficiency of 3.4% under simulated one-sun AM 1.5 G direct illumination.

  9. Investigating the energy harvesting capabilities of a hybrid ZnO nanowires/carbon fiber polymer composite beam.

    PubMed

    Masghouni, N; Burton, J; Philen, M K; Al-Haik, M

    2015-03-06

    Hybrid piezoelectric composite structures that are able to convert mechanical energy into electricity have gained growing attention in the past few years. In this work, an energy harvesting composite beam is developed by growing piezoelectric zinc oxide nanowires on the surface of carbon fiber prior to forming structural composites. The piezoelectric behavior of the composite beam was demonstrated under different vibration sources such as water bath sonicator and permanent magnet vibration shaker. The beam was excited at its fundamental natural frequency (43.2 Hz) and the open circuit voltage and the short circuit current were measured to be 3.1 mV and 23 nA, respectively. Upon connecting an optimal resistor (1.2 kΩ) in series with the beam a maximum power output 2.5 nW was achieved.

  10. Polymeric microcapsules assembled from a cationic/zwitterionic pair of responsive block copolymer micelles.

    PubMed

    Addison, Timothy; Cayre, Olivier J; Biggs, Simon; Armes, Steven P; York, David

    2010-05-04

    Using a layer-by-layer (LbL) approach, this work presents the preparation of hollow microcapsules with a membrane constructed entirely from a cationic/zwitterionic pair of pH-responsive block copolymer micelles. Our previous work with such systems highlighted that, in order to retain the responsive nature of the individual micelles contained within the multilayer membranes, it is important to optimize the conditions required for the selective dissolution of the sacrificial particulate templates. Consequently, here, calcium carbonate particles have been employed as colloidal templates as they can be easily dissolved in aqueous environments with the addition of chelating agents such as ethylenediaminetetraacetic acid (EDTA). Furthermore, the dissolution can be carried out in solutions buffered to a desirable pH so not to adversely affect the pH sensitive micelles forming the capsule membranes. First, we have deposited alternating layers of anionic poly[2-(dimethylamino)ethyl methacrylate-block-poly(2-(diethylamino)ethyl methacrylate)] (PDMA-PDEA) and cationic poly(2-(diethylamino)ethyl)methacrylate-block-poly(methacrylic acid) (PDEA-PMAA) copolymer micelles onto calcium carbonate colloidal templates. After deposition of five micelle bilayers, addition of dilute EDTA solution resulted in dissolution of the calcium carbonate and formation of hollow polymer capsules. The capsules were imaged using atomic force microscopy (AFM) and scanning electron microscopy (SEM), which shows that the micelle/micelle membrane is sufficiently robust to withstand dissolution of the supporting template. Quartz crystal microbalance studies were conducted and provide good evidence that the micelle multilayer structure is retained after EDTA treatment. In addition, a hydrophobic dye was incorporated into the micelle cores prior to adsorption. After dissolution of the particle template, the resulting hollow capsules retained a high concentration of dye, suggesting that the core

  11. Synthetic surfactant- and cross-linker-free preparation of highly stable lipid-polymer hybrid nanoparticles as potential oral delivery vehicles.

    PubMed

    Wang, Taoran; Xue, Jingyi; Hu, Qiaobin; Zhou, Mingyong; Chang, Chao; Luo, Yangchao

    2017-06-05

    The toxicity associated with concentrated synthetic surfactants and the poor stability at gastrointestinal condition are two major constraints for practical applications of solid lipid nanoparticles (SLN) as oral delivery vehicles. In this study, a synthetic surfactant-free and cross-linker-free method was developed to fabricate effective, safe, and ultra-stable lipid-polymer hybrid nanoparticles (LPN). Bovine serum albumin (BSA) and dextran varying in molecular weights were first conjugated through Maillard reaction and the conjugates were exploited to emulsify solid lipid by a solvent diffusion and sonication method. The multilayer structure was formed by self-assembly of BSA-dextran micelles to envelope solid lipid via a pH- and heating-induced facile process with simultaneous surface deposition of pectin. The efficiency of different BSA-dextran conjugates was systematically studied to prepare LPN with the smallest size, the most homogeneous distribution and the greatest stability. The molecular interactions were characterized by Fourier transform infrared and fluorescence spectroscopies. Both nano spray drying and freeze-drying methods were tested to produce spherical and uniform pectin-coated LPN powders that were able to re-assemble nanoscale structure when redispersed in water. The results demonstrated the promise of a synthetic surfactant- and cross-linker-free technique to prepare highly stable pectin-coated LPN from all natural biomaterials as potential oral delivery vehicles.

  12. Codelivery of doxorubicin and triptolide with reduction-sensitive lipid–polymer hybrid nanoparticles for in vitro and in vivo synergistic cancer treatment

    PubMed Central

    Wu, Bo; Lu, Shu-Ting; Zhang, Liu-Jie; Zhuo, Ren-Xi; Xu, Hai-Bo; Huang, Shi-Wen

    2017-01-01

    Codelivery is a promising strategy to overcome the limitations of single chemotherapeutic agents in cancer treatment. Despite progress, codelivery of two or more different functional drugs to increase anticancer efficiency still remains a challenge. Here, reduction-sensitive lipid–polymer hybrid nanoparticles (LPNPs) drug delivery system composed of monomethoxy-poly(ethylene glycol)-S-S-hexadecyl (mPEG-S-S-C16), soybean lecithin, and poly(D,L-lactide-co-glycolide) (PLGA) was used for codelivery of doxorubicin (DOX) and a Chinese herb extract triptolide (TPL). Hydrophobic DOX and TPL could be successfully loaded in LPNPs by self-assembly. More importantly, drug release and cellular uptake experiments demonstrated that the two drugs were reduction sensitive, released simultaneously from LPNPs, and taken up effectively by the tumor cells. DOX/TPL-coloaded LPNPs (DOX/TPL-LPNPs) exhibited a high level of synergistic activation with low combination index (CI) in vitro and in vivo. Moreover, the highest synergistic therapeutic effect was achieved at the ratio of 1:0.2 DOX/TPL. Further experiments showed that TPL enhanced the uptake of DOX by human oral cavity squamous cell carcinoma cells (KB cells). Overall, DOX/TPL-coencapsulated reduction-sensitive nanoparticles will be a promising strategy for cancer treatment. PMID:28331310

  13. Co-delivery of paclitaxel and tetrandrine via iRGD peptide conjugated lipid-polymer hybrid nanoparticles overcome multidrug resistance in cancer cells

    PubMed Central

    Zhang, Jinming; Wang, Lu; Fai Chan, Hon; Xie, Wei; Chen, Sheng; He, Chengwei; Wang, Yitao; Chen, Meiwan

    2017-01-01

    One of the promising strategies to overcome tumor multidrug resistance (MDR) is to deliver anticancer drug along with P-glycoprotein (P-gp) inhibitor simultaneously. To enhance the cancer cellular internalization and implement the controlled drug release, herein an iRGD peptide-modified lipid-polymer hybrid nanosystem (LPN) was fabricated to coload paclitaxel (PTX) and tetrandrine (TET) at a precise combination ratio. In this co-delivery system, PTX was covalently conjugated to poly (D,L-lactide-co-glycolide) polymeric core by redox-sensitive disulfide bond, while TET was physically capsulated spontaneously for the aim to suppress P-gp in advance by the earlier released TET in cancer cells. As a result, the PTX+TET/iRGD LPNs with a core-shell structure possessed high drug loading efficiency, stability and redox-sensitive drug release profiles. Owing to the enhanced cellular uptake and P-gp suppression mediated by TET, significantly more PTX accumulated in A2780/PTX cells treated with PTX+TET/iRGD LPNs than either free drugs or non-iRGD modified LPNs. As expected, PTX+TET/iRGD LPNs presented the highest cytotoxicity against A2780/PTX cells and effectively promoted ROS production, enhanced apoptosis and cell cycle arrests particularly. Taken together, the co-delivery system demonstrated great promise as potential treatment for MDR-related tumors based on the synergistic effects of P-gp inhibition, enhanced endocytosis and intracellular sequentially drug release. PMID:28470171

  14. Co-delivery of pemetrexed and miR-21 antisense oligonucleotide by lipid-polymer hybrid nanoparticles and effects on glioblastoma cells.

    PubMed

    Küçüktürkmen, Berrin; Devrim, Burcu; Saka, Ongun M; Yilmaz, Şükran; Arsoy, Taibe; Bozkir, Asuman

    2017-01-01

    Combination therapy using anticancer drugs and nucleic acid is a more promising strategy to overcome multidrug resistance in cancer and to enhance apoptosis. In this study, lipid-polymer hybrid nanoparticles (LPNs), which contain both pemetrexed and miR-21 antisense oligonucleotide (anti-miR-21), have been developed for treatment of glioblastoma, the most aggressive type of brain tumor. Prepared LPNs have been well characterized by particle size distribution and zeta potential measurements, determination of encapsulation efficiency, and in vitro release experiments. Morphology of LPNs was determined by transmission electron microscopy. LPNs had a hydrodynamic size below 100 nm and exhibited sustained release of pemetrexed up to 10 h. Encapsulation of pemetrexed in LPNs increased cellular uptake from 6% to 78%. Results of confocal microscopy analysis have shown that co-delivery of anti-miR-21 significantly improved accumulation of LPNs in the nucleus of U87MG cells. Nevertheless, more effective cytotoxicity results could not be obtained due to low concentration of anti-miR-21, loaded in LPNs. We expect that the effective drug delivery systems can be obtained with higher concentration of anti-miR-21 for the treatment of glioblastoma.

  15. Codelivery of doxorubicin and triptolide with reduction-sensitive lipid-polymer hybrid nanoparticles for in vitro and in vivo synergistic cancer treatment.

    PubMed

    Wu, Bo; Lu, Shu-Ting; Zhang, Liu-Jie; Zhuo, Ren-Xi; Xu, Hai-Bo; Huang, Shi-Wen

    2017-01-01

    Codelivery is a promising strategy to overcome the limitations of single chemotherapeutic agents in cancer treatment. Despite progress, codelivery of two or more different functional drugs to increase anticancer efficiency still remains a challenge. Here, reduction-sensitive lipid-polymer hybrid nanoparticles (LPNPs) drug delivery system composed of monomethoxy-poly(ethylene glycol)- S - S -hexadecyl (mPEG- S - S -C 16 ), soybean lecithin, and poly(D,L-lactide-co-glycolide) (PLGA) was used for codelivery of doxorubicin (DOX) and a Chinese herb extract triptolide (TPL). Hydrophobic DOX and TPL could be successfully loaded in LPNPs by self-assembly. More importantly, drug release and cellular uptake experiments demonstrated that the two drugs were reduction sensitive, released simultaneously from LPNPs, and taken up effectively by the tumor cells. DOX/TPL-coloaded LPNPs (DOX/TPL-LPNPs) exhibited a high level of synergistic activation with low combination index (CI) in vitro and in vivo. Moreover, the highest synergistic therapeutic effect was achieved at the ratio of 1:0.2 DOX/TPL. Further experiments showed that TPL enhanced the uptake of DOX by human oral cavity squamous cell carcinoma cells (KB cells). Overall, DOX/TPL-coencapsulated reduction-sensitive nanoparticles will be a promising strategy for cancer treatment.

  16. Residue-and-polymer-free graphene transfer: DNA-CTMA/graphene/GaN bio-hybrid photodiode for light-sensitive applications

    NASA Astrophysics Data System (ADS)

    Reddy, M. Siva Pratap; Park, Herie; Lee, Jung-Hee

    2018-02-01

    In this work, we present a residue-and-polymer-free graphene transfer method by using the adhesive force between graphene and a target substrate, the hydrophobic property of graphene, and the surface tension of the solutions. We used an n-type GaN substrate as the target substrate to make a photodiode (PD). Recently, the inclusion of biomolecules in photodetection technology has attracted considerable attention in the electronics and photonics research, particularly due to the rapid evolution of organic-inorganic bio-hybrid PDs (Bio-HPDs). This report presents a significant photoresponse of the bioinspired graphene-based PD fabricated with deoxyribonucleic acid-cetyltrimetylammonium chloride (DNA-CTMA) biomolecules on the n-type GaN substrate. Bio-HPDs respond to the infrared, visible, and ultraviolet wavelengths. Moreover, the Bio-HPDs show photosensitivities (Iphoto/Idark) of 21, 143, and 1194 for infrared, visible, and ultraviolet wavebands, respectively, which can be attributed to the integration of high-mobility graphene and photosensitive DNA-CTMA biomolecules. In addition, the corresponding charge transfer mechanisms in the PDs are explained by energy band diagrams.

  17. Determination of catecholamine in human serum by a fluorescent quenching method based on a water-soluble fluorescent conjugated polymer-enzyme hybrid system.

    PubMed

    Huang, Hui; Gao, Yuan; Shi, Fanping; Wang, Guannan; Shah, Syed Mazhar; Su, Xingguang

    2012-03-21

    In this paper, a sensitive water-soluble fluorescent conjugated polymer biosensor for catecholamine (dopamine DA, adrenaline AD and norepinephrine NE) was developed. In the presence of horse radish peroxidase (HRP) and H(2)O(2), catecholamine could be oxidized and the oxidation product of catecholamine could quench the photoluminescence (PL) intensity of poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylethynylenealt-1,4-poly(phenylene ethynylene)) (PPESO(3)). The quenching PL intensity of PPESO(3) (I(0)/I) was proportional to the concentration of DA, AD and NE in the concentration ranges of 5.0 × 10(-7) to 1.4 × 10(-4), 5.0 × 10(-6) to 5.0 × 10(-4), and 5.0 × 10(-6) to 5.0 × 10(-4) mol L(-1), respectively. The detection limit for DA, AD and NE was 1.4 × 10(-7) mol L(-1), 1.0 × 10(-6) and 1.0 × 10(-6) mol L(-1), respectively. The PPESO(3)-enzyme hybrid system based on the fluorescence quenching method was successfully applied for the determination of catecholamine in human serum samples with good accuracy and satisfactory recovery. The results were in good agreement with those provided by the HPLC-MS method.

  18. 2.5-Gb/s hybridly-integrated tunable external cavity laser using a superluminescent diode and a polymer Bragg reflector.

    PubMed

    Yoon, Ki-Hong; Oh, Su Hwan; Kim, Ki Soo; Kwon, O-Kyun; Oh, Dae Kon; Noh, Young-Ouk; Lee, Hyung-Jong

    2010-03-15

    We presented a hybridly-integrated tunable external cavity laser with 0.8 nm mode spacing 16 channels operating in the direct modulation of 2.5-Gbps for a low-cost source of a WDM-PON system. The tunable laser was fabricated by using a superluminescent diode (SLD) and a polymer Bragg reflector. The maximum output power and the power slope efficiency of the tunable laser were 10.3 mW and 0.132 mW/mA, respectively, at the SLD current of 100 mA and the temperature of 25 degrees C. The directly-modulated tunable laser successfully provided 2.5-Gbps transmissions through 20-km standard single mode fiber. The power penalty of the tunable laser was less than 0.8 dB for 16 channels after a 20-km transmission. The power penalty variation was less than 1.4 dB during the blue-shifted wavelength tuning.

  19. Biomechanical and histologic evaluation of tissue engineered ligaments using chitosan and hyaluronan hybrid polymer fibers: a rabbit medial collateral ligament reconstruction model.

    PubMed

    Irie, Toru; Majima, Tokifumi; Sawaguchi, Naohiro; Funakoshi, Tadanao; Nishimura, Shin-Ichiro; Minami, Akio

    2011-05-01

    In this study, we used a rabbit medial collateral ligament reconstruction model to evaluate a novel chitosan-based hyaluronan hybrid polymer fiber scaffold for ligament tissue engineering and to examine whether mechanical forces exerted in an in vivo model increased extracellular matrix production by seeded fibroblasts. Scaffolds were used 2 weeks after incubation with fibroblasts obtained from the same rabbit in a cell-seeded scaffold (CSS) group and without cells in a noncell-seeded scaffold (NCSS) group. At 3, 6, and 12 weeks after surgery, the failure loads of the engineered ligaments in the CSS groups were significantly greater than those in the NCSS groups. At 6 weeks after surgery, the reconstructed tissue of the CSS group was positive for type I collagen, whereas that in the NCSS group was negative for type I collagen. At 12 weeks after surgery, the reconstructed tissue stained positive for type I collagen in the CSS group, but negative in the NCSS group. Our results indicate that the scaffold material enhanced the production of type I collagen and led to improved mechanical strength in the engineered ligament in vivo. Copyright © 2011 Wiley Periodicals, Inc.

  20. Electrodynamics of Lipid Membrane Interactions in the Presence of Zwitterionic Buffers

    PubMed Central

    Koerner, Megan M.; Palacio, Luis A.; Wright, Johnnie W.; Schweitzer, Kelly S.; Ray, Bruce D.; Petrache, Horia I.

    2011-01-01

    Due to thermal motion and molecular polarizability, electrical interactions in biological systems have a dynamic character. Zwitterions are dipolar molecules that typically are highly polarizable and exhibit both a positive and a negative charge depending on the pH of the solution. We use multilamellar structures of common lipids to identify and quantify the effects of zwitterionic buffers that go beyond the control of pH. We use the fact that the repeat spacing of multilamellar lipid bilayers is a sensitive and accurate indicator of the force balance between membranes. We show that common buffers can in fact charge up neutral membranes. However, this electrostatic effect is not immediately recognized because of the concomitant modification of dispersion (van der Waals) forces. We show that although surface charging can be weak, electrostatic forces are significant even at large distances because of reduced ionic screening and reduced van der Waals attraction. The zwitterionic interactions that we identify are expected to be relevant for interfacial biological processes involving lipid bilayers, and for a wide range of biomaterials, including amino acids, detergents, and pharmaceutical drugs. An appreciation of zwitterionic electrodynamic character can lead to a better understanding of molecular interactions in biological systems and in soft materials in general. PMID:21767488

  1. AN ALTERNATIVE METHOD FOR RELATING MACROSCOPIC TO MICROSCOPIC ACIDITY CONSTANTS WITH ZWITTERIONIC SPECIES

    EPA Science Inventory

    Using the notation of Adams (1916. JACS, 38:1503), zwitterionic microscopic acidity constants defined by: ka = [H+] [+H3NRCOO-]/ [+H3NRCOOH]; kb = [H+] [H2NRCOOH]/ [+H3NRCOOH]; kc = [H+] [H2NRCOO-]/ [+H3NRCOO-]; and kd = [H+] [H2NRCOO-]/ [H2NRCOOH] are historically related to th...

  2. Antifouling enhancement of polyimide membrane by grafting DEDA-PS zwitterions.

    PubMed

    Zhang, Dong Yan; Xiong, Shu; Shi, Yu Sheng; Zhu, Jun; Hu, Qiao Li; Liu, Jie; Wang, Yan

    2018-05-01

    In order to improve the water flux and antifouling property of polyimide (PI) membrane, zwitterions are grafted on PI membrane surface via a two-step modification route by reactions with N,N-diethylethylenediamine (DEDA) and 1,3-propane sultone (PS) sequentially. The reaction mechanism and physicochemical properties of membranes are confirmed via various characterization techniques. The anti-biofouling performance of the zwitterion-grafted PI membranes is evaluated by bacterial suspension immersion tests in Escherichia coli (E. coli) and staphylococcus aureus (S. aureus) solutions. The antifouling property is assessed via the filtration test using the bovine serum albumin (BSA) and dodecyl trimethyl ammonium bromide (DTAB) aqueous feed solutions. The effect of the reaction time with DEDA in the zwitterion-grafted process on the antifouling property is further investigated systematically. The results show that both the anti-biofouling and antifouling performances of zwitterion-grafted PI membranes are significantly improved. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Superior Antifouling Performance of a Zwitterionic Peptide Compared to an Amphiphilic, Non-Ionic Peptide.

    PubMed

    Ye, Huijun; Wang, Libing; Huang, Renliang; Su, Rongxin; Liu, Boshi; Qi, Wei; He, Zhimin

    2015-10-14

    The aim of this study was to explore the influence of amphiphilic and zwitterionic structures on the resistance of protein adsorption to peptide self-assembled monolayers (SAMs) and gain insight into the associated antifouling mechanism. Two kinds of cysteine-terminated heptapeptides were studied. One peptide had alternating hydrophobic and hydrophilic residues with an amphiphilic sequence of CYSYSYS. The other peptide (CRERERE) was zwitterionic. Both peptides were covalently attached onto gold substrates via gold-thiol bond formation. Surface plasmon resonance analysis results showed that both peptide SAMs had ultralow or low protein adsorption amounts of 1.97-11.78 ng/cm2 in the presence of single proteins. The zwitterionic peptide showed relatively higher antifouling ability with single proteins and natural complex protein media. We performed molecular dynamics simulations to understand their respective antifouling behaviors. The results indicated that strong surface hydration of peptide SAMs contributes to fouling resistance by impeding interactions with proteins. Compared to the CYSYSYS peptide, more water molecules were predicted to form hydrogen-bonding interactions with the zwitterionic CRERERE peptide, which is in agreement with the antifouling test results. These findings reveal a clear relation between peptide structures and resistance to protein adsorption, facilitating the development of novel peptide-containing antifouling materials.

  4. Influence of Zwitterions on Thermomechanical Properties and Morphology of Acrylic Copolymers: Implications for Electroactive Applications

    DTIC Science & Technology

    2011-09-30

    transducers from branched sulfonated polysulfones.7 The mechanical strength of the membranes drastically decreased upon introduction of ionic liquids to... liquids ,8 and zwitterionomers maintained mechanical strengths upon swelling with 10 wt % ionic liquid . Zwitterions are chargedmolecules that contain...water purification5 to biotechnology.6 A unique combination of physical properties of ionomeric membranes is the ionic con- ductivity of lowmolar mass

  5. Microscopic insight into the DNA condensation process of a zwitterion-functionalized polycation.

    PubMed

    Sun, Hui; Zhou, Li; Chen, Xiaolu; Han, Xia; Wang, Rui; Liu, Honglai

    2016-11-01

    Zwitterion-functionalized polycations are ideal gene carriers with long circulation, high cellular uptaking and low cell viability. However, the trade-off between the DNA condensation efficiency and the cell viability must be addressed. The purpose of this study is to provide a microscopic insight into the DNA condensation process and to explore the effect of a zwitterionic block of zwitterion-functionalized polycation, which is of great significance in designing novel gene delivery systems. Poly[2-(dimethylamino)ethyl methacrylate-b-(sulfobetaine methacrylate)] (PDMAEMA-b-PSBMA) copolymers were synthesized and used as the model systems. Different from the conventional concept that the PSBMA zwitterionic block act only as the "stealthy" groups, the subtle differences in physical and colloidal characteristics between the polycation/DNA polyplexes show that the PSBMA segment is capable of wrapping DNA attributed to the quaternary ammonium cations, without compromising the DNA condensation capability. On the other hand, the incorporation of PSBMA block reduces the surface charge of the polyplexes, which substantially result in the inefficient transfection and the reduced cytotoxicity. © 2016 Wiley Periodicals, Inc.

  6. Tetrakis(1-imidazolyl) borate (BIM4) based zwitterionic and related molecules used as electron injection layers

    DOEpatents

    Li, Huaping; Xu, Yunhua; Bazan, Guillermo C

    2013-02-05

    Tetrakis(1-imidazolyl)borate (BIm4) based zwitterionic and/or related molecules for the fabrication of PLEDs is provided. Device performances with these materials approaches that of devices with Ba/Al cathodes for which the cathode contact is ohmic. Methods of producing such materials, and electron injection layers and devices containing these materials are also provided.

  7. A novel approach for synthesis of zwitterionic polyurethane coating with protein resistance.

    PubMed

    Wang, Chunhua; Ma, Chunfeng; Mu, Changdao; Lin, Wei

    2014-11-04

    We have developed a novel approach to introduce zwitterions into polyurethane for the preparation of antibiofouling coating. First, the thiol-ene click reaction between 2-(dimethylamino)ethyl methacrylate (DMAEMA) and 3-mercapto-1,2-propanediol (TPG) is used to synthesize dihydroxy-terminated DMAEMA (DMA(OH)2) under UV catalysis. The product has been proved by gel permeation chromatography (GPC), Fourier transform infrared spectrum (FT-IR), proton nuclear magnetic resonance ((1)H NMR), and high resolution mass spectrometry (HRMS). DMA(OH)2 is then incorporated into polyurethane as side groups by polyaddition with diisocyanate and further reacts with 1,3-propane sultone to obtain the zwitterionic polyurethanes. The presence of sulfobetaine zwitterions side groups has been demonstrated by FT-IR and X-ray photoelectron spectroscopy (XPS). Thermal analysis indicates that the thermal stability is decreased with the increasing content of zwitterionions. The antibiofouling property of polyurethanes has been investigated by the measurement of adsorption of fibrinogen, bovine serum albumin (BSA), and lysozyme on the polyurethanes surface using quartz crystal microbalance with dissipation (QCM-D). The results show that the polyurethane coatings exhibit effective nonspecific protein resistance at higher content of zwitterionic side groups.

  8. Zwitterionic Antifouling Coatings for the Purification of High-Salinity Shale Gas Produced Water.

    PubMed

    Yang, Rong; Goktekin, Esma; Gleason, Karen K

    2015-11-03

    Fouling refers to the undesirable attachment of organic molecules and microorganisms to submerged surfaces. It is an obstacle to the purification of shale gas produced water and is currently without an effective solution due to the highly contaminated nature of produced water. Here, we demonstrate the direct vapor application of a robust zwitterionic coating to a variety of substrates. The coating remains unprecedentedly hydrophilic, smooth, and effectively antifouling in extremely high salinity solutions (with salt concentration of 200,000 ppm). The fouling resistance is assessed rapidly and quantitatively with a molecular force spectroscopy-based method and corroborated using quartz crystal microbalance system with dissipation monitoring. Grazing angle attenuated total reflectance Fourier transform infrared is used in combination with X-ray photoelectron spectroscopy, atomic force microscope, and in situ spectroscopic ellipsometry to lend insight into the underlying mechanism for the exceptional stability and effectiveness of the zwitterionic coating under high-salinity conditions. A unique coating architecture, where the surface is concentrated with mobile zwitterionic moieties while the bulk is cross-linked to enhance coating durability, was discovered to be the origin of its stable fouling resistance under high salinity. Combined with previously reported exceptional stability in highly oxidative environments and strong fouling resistance to oil and grease, the zwitterionic surface here has the potential to enable low-cost, membrane-based techniques for the purification of produced water and to eventually balance the favorable economics and the concerning environmental impacts of the hydraulic fracturing industry.

  9. Chain Conformation of Phosphorycholine-based Zwitterionic Polymer Brushes in Aqueous Solutions

    NASA Astrophysics Data System (ADS)

    Mao, Jun; Yu, Jing; Lee, Sungsik; Yuan, Guangcui; Satija, Sushil; Chen, Wei; Tirrell, Matthew

    Polyzwitterionic brushes are resistant to nonspecific accumulation of proteins and microorganisms, making them excellent candidates for antifouling applications. It is well-known that polyzwitterions exhibit the so-called antipolyelectrolyte effect: Polyzwitterionic brushes would adopt a collapsed conformation at a low ionic strength due to the electrostatic inter/intra-chain association; whereas at a high ionic strength, they would exhibit an extended conformation because the electrostatic inter/intra-chain dipole-dipole interaction is weakened. However, poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) is a unique member in polyzwitterionic families. Its ultrahigh affinity to water leads to no detectable shrinks in aqueous solutions even at low ionic strengths. In this study, we synthesized highly dense PMPC brushes via surface initiated radical polymerization and systematically investigate their conformational behaviors at solid-liquid interfaces in the presence of multivalent counterions, combining X-ray and neutron scattering and force measurements. We have demonstrated that despite no obvious changes of the entire lengths of extended PMPC brushes in aqueous solutions, the chain conformations including, but not limited to, polyzwitterion distribution and charge correlation, varied, dependent on salt types, ionic strengths and ion valences.

  10. Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix.

    PubMed

    Xia, Zhangxun; Wang, Suli; Jiang, Luhua; Sun, Hai; Liu, Shuang; Fu, Xudong; Zhang, Bingsen; Sheng Su, Dang; Wang, Jianqiang; Sun, Gongquan

    2015-11-05

    The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demonstrate for the first time a design that allocates platinum nanoparticles (Pt NPs) at the boundaries with dual-functions of conducting both electrons by aid of polypyrrole and protons via Nafion(®) ionomer within hierarchical nanoarrays. By mimicking enzymes functionally, an impressive ORR activity and stability is achieved. Using this brand new electrode architecture as the cathode and the anode of a PEMFC, a high mass specific power density of 5.23 W mg(-1)Pt is achieved, with remarkable durability. These improvements are ascribed to not only the electron decoration and the anchoring effects from the Nafion(®) ionomer decorated PPy substrate to the supported Pt NPs, but also the fast charge and mass transport facilitated by the electron and proton pathways within the electrode architecture.

  11. Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix

    PubMed Central

    Xia, Zhangxun; Wang, Suli; Jiang, Luhua; Sun, Hai; Liu, Shuang; Fu, Xudong; Zhang, Bingsen; Sheng Su, Dang; Wang, Jianqiang; Sun, Gongquan

    2015-01-01

    The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demonstrate for the first time a design that allocates platinum nanoparticles (Pt NPs) at the boundaries with dual-functions of conducting both electrons by aid of polypyrrole and protons via Nafion® ionomer within hierarchical nanoarrays. By mimicking enzymes functionally, an impressive ORR activity and stability is achieved. Using this brand new electrode architecture as the cathode and the anode of a PEMFC, a high mass specific power density of 5.23 W mg−1Pt is achieved, with remarkable durability. These improvements are ascribed to not only the electron decoration and the anchoring effects from the Nafion® ionomer decorated PPy substrate to the supported Pt NPs, but also the fast charge and mass transport facilitated by the electron and proton pathways within the electrode architecture. PMID:26537781

  12. Bio-inspired Construction of Advanced Fuel Cell Cathode with Pt Anchored in Ordered Hybrid Polymer Matrix

    NASA Astrophysics Data System (ADS)

    Xia, Zhangxun; Wang, Suli; Jiang, Luhua; Sun, Hai; Liu, Shuang; Fu, Xudong; Zhang, Bingsen; Sheng Su, Dang; Wang, Jianqiang; Sun, Gongquan

    2015-11-01

    The significant use of platinum for catalyzing the cathodic oxygen reduction reactions (ORRs) has hampered the widespread use of polymer electrolyte membrane fuel cells (PEMFCs). The construction of well-defined electrode architecture in nanoscale with enhanced utilization and catalytic performance of Pt might be a promising approach to address such barrier. Inspired by the highly efficient catalytic processes in enzymes with active centers embedded in charge transport pathways, here we demonstrate for the first time a design that allocates platinum nanoparticles (Pt NPs) at the boundaries with dual-functions of conducting both electrons by aid of polypyrrole and protons via Nafion® ionomer within hierarchical nanoarrays. By mimicking enzymes functionally, an impressive ORR activity and stability is achieved. Using this brand new electrode architecture as the cathode and the anode of a PEMFC, a high mass specific power density of 5.23 W mg-1Pt is achieved, with remarkable durability. These improvements are ascribed to not only the electron decoration and the anchoring effects from the Nafion® ionomer decorated PPy substrate to the supported Pt NPs, but also the fast charge and mass transport facilitated by the electron and proton pathways within the electrode architecture.

  13. Achieving 15% Tandem Polymer Solar Cells

    DTIC Science & Technology

    2015-06-23

    solar cell structures – both polymer only and hybrid tandem cells to constantly pushing the envelope of solution processed solar cell ...performance – 11.6% polymer tandem cell , 7% transparent tandem polymer cell , and over 10% PCE hybrid tandem solar cells were achieved. In addition, AFOSR’s...final support also enabled us to explore novel hybrid perovskite solar cells in depth. For example, single junction cell efficiency

  14. Thermally stable hybrid polyarylidene(azomethine-ether)s polymers (PAAP): an ultrasensitive arsenic(III) sensor approach

    PubMed Central

    Rahman, Mohammed M.; Hussein, Mahmoud A.; Aly, Kamal I.; Asiri, Abdullah M.

    2018-01-01

    ABSTRACT A new category of thermally stable hybrid polyarylidene(azomethine-ether)s and copolyarylidene(azomethine-ether)s (PAAP) based on diarylidenecycloalkanones has been synthesized using solution polycondensation method. For potential cationic sensor development, a thin layer of PAAP onto a flat glassy carbon electrode (GCE, surface area: 0.0316 cm2) was prepared with conducting nafion (5%) coating agent to fabricate a sensitive and selective arsenic (III) [As3+] ion in short response time in neutral buffer system. The fabricated cationic sensor was measured the analytical performances such as higher sensitivity, linear dynamic range, detection limit, reproducibility, and long-term stability towards As3+ ions. The sensitivity and detection limit were calculated as 2.714 μAμM−1cm−2 and 6.8 ± 0.1 nM (SNR of 3; 3N/S) respectively from the calibration curve. This novel approach can be initiated a well-organized route of an efficient development of heavy selective arsenic sensor for hazardous pollutants in biological, environmental, and health care fields. Real sample analysis for various environmental sample was performed with PAAP-modified-GCE. PMID:29844770

  15. Molecular Design of Antifouling Polymer Brushes Using Sequence-Specific Peptoids.

    PubMed

    Lau, King Hang Aaron; Sileika, Tadas S; Park, Sung Hyun; Sousa, Ana Maria Leal; Burch, Patrick; Szleifer, Igal; Messersmith, Phillip B

    2015-01-07

    Material systems that can be used to flexibly and precisely define the chemical nature and molecular arrangement of a surface would be invaluable for the control of complex biointerfacial interactions. For example, progress in antifouling polymer biointerfaces that prevent non-specific protein adsorption and cell attachment, which can significantly improve the performance of an array of biomedical and industrial applications, is hampered by a lack of chemical models to identify the molecular features conferring their properties. Poly(N-substituted glycine) "peptoids" are peptidomimetic polymers that can be conveniently synthesized with specific monomer sequences and chain lengths, and are presented as a versatile platform for investigating the molecular design of antifouling polymer brushes. Zwitterionic antifouling polymer brushes have captured significant recent attention, and a targeted library of zwitterionic peptoid brushes with a different charge densities, hydration, separations between charged groups, chain lengths, and grafted chain densities, is quantitatively evaluated for their antifouling properties through a range of protein adsorption and cell attachment assays. Specific zwitterionic brush designs were found to give rise to distinct but subtle differences in properties. The results also point to the dominant roles of the grafted chain density and chain length in determining the performance of antifouling polymer brushes.

  16. Molecular Design of Antifouling Polymer Brushes Using Sequence-Specific Peptoids

    DOE PAGES

    Lau, King Hang Aaron; Sileika, Tadas S.; Park, Sung Hyun; ...

    2014-11-26

    Material systems that can be used to flexibly and precisely define the chemical nature and molecular arrangement of a surface would be invaluable for the control of complex biointerfacial interactions. For example, progress in antifouling polymer biointerfaces that prevents nonspecific protein adsorption and cell attachment, which can significantly improve the performance of an array of biomedical and industrial applications, is hampered by a lack of chemical models to identify the molecular features conferring their properties. Poly(N-substituted glycine) “peptoids” are peptidomimetic polymers that can be conveniently synthesized with specific monomer sequences and chain lengths, and are presented as a versatile platformmore » for investigating the molecular design of antifouling polymer brushes. Zwitterionic antifouling polymer brushes have captured significant recent attention, and a targeted library of zwitterionic peptoid brushes with different charge densities, hydration, separations between charged groups, chain lengths, and grafted chain densities, is quantitatively evaluated for their antifouling properties through a range of protein adsorption and cell attachment assays. Specific zwitterionic brush designs are found to give rise to distinct but subtle differences in properties. In conclusion, the results also point to the dominant roles of the grafted chain density and chain length in determining the performance of antifouling polymer brushes.« less

  17. Fabrication and Characterization of Novel Electrothermal Self-Healing Microcapsules with Graphene/Polymer Hybrid Shells for Bitumenious Material.

    PubMed

    Wang, Xinyu; Guo, Yandong; Su, Junfeng; Zhang, Xiaolong; Wang, Yingyuan; Tan, Yiqiu

    2018-06-09

    Self-healing bituminous material has been a hot research topic in self-healing materials, and this smart self-healing approach is a promising a revolution in pavement material technology. Bitumen has a self-healing naturality relating to temperature, healing time, and aging degree. To date, heat induction and microencapsulation rejuvenator are two feasible approaches, which have been put into real applications. However, both methods have disadvantages limiting their practical results and efficiency. It will be an ideal method combining the advantages and avoiding the disadvantages of the above two methods at the same time. The aim of this work was to synthesize and characterize electrothermal self-healing microcapsules containing bituminous rejuvenator with graphene/organic nanohybrid structure shells. The microcapsules owned electric conductivity capability because of the advent of graphene, and realized the self-healing through the two approaches of heat induction and rejuvenation. The microcapsule shells were fabricated using a strength hexamethoxymethylmelamine (HMMM) resin and graphene by two-step hybrid polymerization. Experimental tests were carried out to character the morphology, integrity, and shell structure. It was found that the electric charge balance determined the graphene/HMMM microstructure. The graphene content in shells could not be greatly increased under an electrostatic balance in emulsion. X-ray photoelectron spectroscopy (XPS), Energy dispersive spectrometer (EDS), Transmission electron microscope (TEM) and Atomic force microscopy (AFM) results indicated that the graphene had deposited on shells. TGA/DTG tests implied that the thermal decomposition temperature of microcapsules with graphene had increased to about 350 °C. The thermal conductivity of microcapsules had been sharply increased to about 8.0 W/m²·K with 2.0 wt % graphene in shells. At the same time, electrical resistivity of microcapsules/bitumen samples had a decrease

  18. Polymer-Based Black Phosphorus (bP) Hybrid Materials by in Situ Radical Polymerization: An Effective Tool To Exfoliate bP and Stabilize bP Nanoflakes

    PubMed Central

    2018-01-01

    Black phosphorus (bP) has been recently investigated for next generation nanoelectronic multifunctional devices. However, the intrinsic instability of exfoliated bP (the bP nanoflakes) toward both moisture and air has so far overshadowed its practical implementation. In order to contribute to fill this gap, we report here the preparation of new hybrid polymer-based materials where bP nanoflakes (bPn) exhibit a significantly improved stability. The new materials have been prepared by different synthetic paths including: (i) the mixing of conventionally liquid-phase exfoliated bP (in dimethyl sulfoxide, DMSO) with poly(methyl methacrylate) (PMMA) solution; (ii) the direct exfoliation of bP in a polymeric solution; (iii) the in situ radical polymerization after exfoliating bP in the liquid monomer (methyl methacrylate, MMA). This last methodology concerns the preparation of stable suspensions of bPn–MMA by sonication-assisted liquid-phase exfoliation (LPE) of bP in the presence of MMA followed by radical polymerization. The hybrids characteristics have been compared in order to evaluate the bP dispersion and the effectiveness of the bPn interfacial interactions with polymer chains aimed at their long-term environmental stabilization. The passivation of the bPn is particularly effective when the hybrid material is prepared by in situ polymerization. By using this synthetic methodology, the nanoflakes, even if with a gradient of dispersion (size of aggregates), preserve their chemical structure from oxidation (as proved by both Raman and 31P-solid state NMR studies) and are particularly stable to air and UV light exposure. The feasibility of this approach, capable of efficiently exfoliating bP while protecting the bPn, has been then verified by using different vinyl monomers (styrene and N-vinylpyrrolidone), thus obtaining hybrids where the nanoflakes are embedded in polymer matrices with a variety of intriguing thermal, mechanical, and solubility characteristics.

  19. A strong adjuvant based on glycol-chitosan-coated lipid-polymer hybrid nanoparticles potentiates mucosal immune responses against the recombinant Chlamydia trachomatis fusion antigen CTH522.

    PubMed

    Rose, Fabrice; Wern, Jeanette Erbo; Gavins, Francesca; Andersen, Peter; Follmann, Frank; Foged, Camilla

    2018-02-10

    Induction of mucosal immunity with vaccines is attractive for the immunological protection against pathogen entry directly at the site of infection. An example is infection with Chlamydia trachomatis (Ct), which is the most common sexually transmitted infection in the world, and there is an unmet medical need for an effective vaccine. A vaccine against Ct should elicit protective humoral and cell-mediated immune (CMI) responses in the genital tract mucosa. We previously designed an antibody- and CMI-inducing adjuvant based on poly(dl-lactic-co-glycolic acid) (PLGA) nanoparticles modified with the cationic surfactant dimethyldioctadecylammonium bromide and the immunopotentiator trehalose-6,6'-dibehenate. Here we show that immunization with these lipid-polymer hybrid nanoparticles (LPNs) coated with the mucoadhesive polymer chitosan enhances mucosal immune responses. Glycol chitosan (GC)-modified LPNs were engineered using an oil-in-water single emulsion solvent evaporation method. The nanoparticle design was optimized in a highly systematic way by using a quality-by-design approach to define the optimal operating space and to gain maximal mechanistic information about the GC coating of the LPNs. Cryo-transmission electron microscopy revealed a PLGA core coated with one or several concentric lipid bilayers. The GC coating of the surface was identified as a saturable, GC concentration-dependent increase in particle size and a reduction of the zeta-potential, and the coating layer could be compressed upon addition of salt. Increased antigen-specific mucosal immune responses were induced in the lungs and the genital tract with the optimized GC-coated LPN adjuvant upon nasal immunization of mice with the recombinant Ct fusion antigen CTH522. The mucosal responses were characterized by CTH522-specific IgG/IgA antibodies, together with CTH522-specific interferon γ-producing Th1 cells. This study demonstrates that mucosal administration of CTH522 adjuvanted with chitosan

  20. Synthesis of hydrazide-functionalized hydrophilic polymer hybrid graphene oxide for highly efficient N-glycopeptide enrichment and identification by mass spectrometry.

    PubMed

    Bai, Haihong; Pan, Yiting; Guo, Cong; Zhao, Xinyuan; Shen, Bingquan; Wang, Xinghe; Liu, Zeyuan; Cheng, Yuanguo; Qin, Weijie; Qian, Xiaohong

    2017-08-15

    Protein N-glycosylation is one of the most important post-translational modifications, participating in many key biological and pathological processes. Large-scale and precise identification of N-glycosylated proteins and peptides is especially beneficial for understanding their biological functions and for discovery of new clinical biomarkers and therapeutic drug targets. However, protein N-glycosylation is microheterogeneous and low abundant in living organisms, therefore specific enrichment of N-glycosylated proteins/peptides before mass spectrometry analysis is a prerequisite. In this work, we developed a new type of polymer hybrid graphene oxide (GO) by in situ growth of hydrazide-functionalized hydrophilic polymer chains on the GO surface (GO-PAAH) for selective N-glycopeptide enrichment and identification by mass spectrometry. The densely attached and low steric hindrance hydrazide groups as well as the highly hydrophilic nature of GO-PAAH facilitate N-glycopeptide enrichment by the combination of hydrazide capturing and HILIC interaction. Taking advantage of the unique features of GO-PAAH, all of the three N-glycopeptides of bovine fetuin were successfully enriched and identified with significantly enhanced signal intensities from a digest mixture of bovine fetuin and bovine serum albumin at a mass ratio of 1:100, demonstrating the excellent enrichment selectivity of GO-PAAH. Furthermore, a total of 507 N-glycosylation sites and 480 N-glycopeptides in 232 N-glycoproteins were enriched and identified from 10μL of human serum by three replicates using this novel enrichment material, which is nearly two times higher than the commercial hydrazide resin based method (280 N-glycosylation sites, 261 N-glycopeptides and 144 N-glycoproteins in three experiments). Among the identified, 95 N-glycosylation sites were not reported in the Uniprot database, and 106 N-glycoproteins were disease related in the Nextprot database, indicating the potential of this new

  1. Cyclic behavior, development, and characteristics of a ductile hybrid fiber-reinforced polymer (DHFRP) for reinforced concrete members

    NASA Astrophysics Data System (ADS)

    Hampton, Francis Patrick

    Reinforced concrete (R/C) structures especially pavements and bridge decks that constitute vital elements of the infrastructure of all industrialized societies are deteriorating prematurely. Structural repair and upgrading of these structural elements have become a more economical option for constructed facilities especially in the United States and Canada. One method of retrofitting concrete structures is the use of advanced materials. Fiber reinforced polymer (FRP) composite materials typically are in the form of fabric sheets or reinforcing bars. While the strength and stiffness of the FRP is high, composites are inherently brittle, with limited or no ductility. Conventional FRP systems cannot currently meet ductility demand, and therefore, may fail in a catastrophic failure mode. The primary goal of this research was to develop an optimized prototype 10-mm diameter DHFRP bar. The behavior of the bar under full load reversals to failure was investigated. However, this bar first needed to be designed and manufactured in the Fibrous Materials Research at Drexel University. Material properties were determined through testing to categorize the strength properties of the DHFRP. Similitude was used to demonstrate the scaling of properties from the original model bars. The four most important properties of the DHFRP bars are sufficient strength and stiffness, significant ductility for plasticity to develop in the R/C section, and sufficient bond strength for the R/C section to develop its full strength. Once these properties were determined the behavior of reinforced concrete members was investigated. This included the testing of prototype-size beams under monotonic loading and model and prototype beam-columns under reverse cyclic loading. These tests confirmed the large ductility exhibited by the DHFRP. Also the energy absorption capacity of the bar was demonstrated by the hysteretic behavior of the beam-columns. Displacement ductility factors in the range of 3

  2. Redox-Active Hydrogel Polymer Electrolytes with Different pH Values for Enhancing the Energy Density of the Hybrid Solid-State Supercapacitor.

    PubMed

    Tang, Xiaohui; Lui, Yu Hui; Merhi, Abdul Rahman; Chen, Bolin; Ding, Shaowei; Zhang, Bowei; Hu, Shan

    2017-12-27

    To enhance the energy density of solid-state supercapacitors, a novel solid-state cell, made of redox-active poly(vinyl alcohol) (PVA) hydrogel electrolytes and functionalized carbon nanotube-coated cellulose paper electrodes, was investigated in this work. Briefly, acidic PVA-[BMIM]Cl-lactic acid-LiBr and neutral PVA-[BMIM]Cl-sodium acetate-LiBr hydrogel polymer electrolytes are used as catholyte and anolyte, respectively. The acidic condition of the catholyte contributes to suppression of the undesired irreversible reaction of Br - and extension of the oxygen evolution reaction potential to a higher value than that of the redox potential of Br - /Br 3 - reaction. The observed Br - /Br 3 - redox activity at the cathode contributes to enhance the cathode capacitance. The neutral condition of the anolyte helps extend the operating voltage window of the supercapacitor by introducing hydrogen evolution reaction overpotential to the anode. The electrosorption of nascent H on the negative electrode also increases the anode capacitance. As a result, the prepared solid-state hybrid supercapacitor shows a broad voltage window of 1.6 V, with a high Coulombic efficiency of 97.6% and the highest energy density of 16.3 Wh/kg with power density of 932.6 W/kg at 2 A/g obtained. After 10 000 cycles of galvanostatic charge and discharge tests at the current density of 10 A/g, it exhibits great cyclic stability with 93.4% retention of the initial capacitance. In addition, a robust capacitive performance can also be observed from the solid-state supercapacitor at different bending angles, indicating its great potential as a flexible energy storage device.

  3. Functionalized Lipid-Polymer Hybrid Nanoparticles Mediated Codelivery of Methotrexate and Aceclofenac: A Synergistic Effect in Breast Cancer with Improved Pharmacokinetics Attributes.

    PubMed

    Garg, Neeraj K; Tyagi, Rajeev K; Sharma, Gajanand; Jain, Ashay; Singh, Bhupinder; Jain, Sanyog; Katare, O P

    2017-06-05

    The present study was aimed to coencapsulate methotrexate (MTX) and aceclofenac (ACL) in fucose anchored lipid-polymer hybrid nanoparticles (Fu-LPHNPs) to achieve target specific and controlled delivery for developing therapeutic interventions against breast cancer. The effective combination therapy requires coadministration of drugs to achieve synergistic effect on tumor with minimum adverse effects. Present study investigates the potential of codelivery of MTX and ACL through LPHNPs in MCF-7 and triple negative breast cancer cells (MDA-MB-231). We obtained LPHNPs in the nanosize range (<150 nm) with better particle size distribution (<0.3). The entrapment and loading efficiency of MTX and ACL was calculated as 85-90% and 10-12%, respectively. The coumarin-6 LPHNP formulations showed rapid internalization within 2 h incubation with MCF-7 and MDA-MB-231 cells. With 8-10 times, greater bioavailability of drug-loaded LPHNPs than free MTX and ACL was obtained. Also, antitumor efficacy of MTX- and ACL-loaded LPHNPs was determined on DMBA-induced experimental breast cancer mouse model. This model showed better control over tumor growth with MTX- and ACL-loaded LPHNPs than the combination of MTX and ACL or MTX alone. ACL-loaded LPHNPs showed prophylactic and anticancer activity in DMBA-induced mouse model at higher dose (10 mg/kg). ACL-LPHNPs confer synergistic anticancer effect when administered in combination with MTX. In conclusion, ACL enhances the therapeutic and anticancer efficacy of MTX, when coencapsulated into fucose-anchored LPHNPs, as confirmed by cell viability and serum angiogenesis (IL-6, TNF-α, IL-1β, COX2, and MMP1) at both transcript and proteome level.

  4. Design and preparation of bi-functionalized short-chain modified zwitterionic nanoparticles.

    PubMed

    Hu, Fenglin; Chen, Kaimin; Xu, Hong; Gu, Hongchen

    2018-05-01

    An ideal nanomaterial for use in the bio-medical field should have a distinctive surface capable of effectively preventing nonspecific protein adsorption and identifying target bio-molecules. Recently, the short-chain zwitterion strategy has been suggested as a simple and novel approach to create outstanding anti-fouling surfaces. In this paper, the carboxyl end group of short-chain zwitterion-coated silica nanoparticles (SiO 2 -ZWS) was found to be difficult to functionalize via a conventional EDC/NHS strategy due to its rapid hydrolysis side-reactions. Hence, a series of bi-functionalized silica nanoparticles (SiO 2 -ZWS/COOH) were designed and prepared by controlling the molar ratio of 3-aminopropyltriethoxysilane (APTES) to short-chain zwitterionic organosiloxane (ZWS) in order to achieve above goal. The synthesized SiO 2 -ZWS/COOH had similar excellent anti-fouling properties compared with SiO 2 -ZWS, even in 50% fetal bovine serum characterized by DLS and turbidimetric titration. Subsequently, SiO 2 -ZWS/COOH 5/1 was chosen as a representative and then demonstrated higher detection signal intensity and more superior signal-to-noise ratios compare with the pure SiO 2 -COOH when they were used as a bio-carrier for chemiluminescence enzyme immunoassay (CLEIA). These unique bi-functionalized silica nanoparticles have many potential applications in the diagnostic and therapeutic fields. Reducing nonspecific protein adsorption and enhancing the immobilized efficiency of specific bio-probes are two of the most important issues for bio-carriers, particularly for a nanoparticle based bio-carrier. Herein, we designed and prepared a bi-functional nanoparticle with anti-fouling property and bio conjugation capacity for further bioassay by improving the short-chain zwitterionic modification strategy we have proposed previously. The heterogeneous surface of this nanoparticle showed effective anti-fouling properties both in model protein solutions and fetal bovine serum

  5. Zwitterionic versus canonical amino acids over the various defects in zeolites: A two-layer ONIOM calculation

    PubMed Central

    Yang, Gang; Zhou, Lijun

    2014-01-01

    Defects are often considered as the active sites for chemical reactions. Here a variety of defects in zeolites are used to stabilize zwitterionic glycine that is not self-stable in gas phase; in addition, effects of acidic strengths and zeolite channels on zwitterionic stabilization are demonstrated. Glycine zwitterions can be stabilized by all these defects and energetically prefer to canonical structures over Al and Ga Lewis acidic sites rather than Ti Lewis acidic site, silanol and titanol hydroxyls. For titanol (Ti-OH), glycine interacts with framework Ti and hydroxyl sites competitively, and the former with Lewis acidity predominates. The transformations from canonical to zwitterionic glycine are obviously more facile over Al and Ga Lewis acidic sites than over Ti Lewis acidic site, titanol and silanol hydroxyls. Charge transfers that generally increase with adsorption energies are found to largely decide the zwitterionic stabilization effects. Zeolite channels play a significant role during the stabilization process. In absence of zeolite channels, canonical structures predominate for all defects; glycine zwitterions remain stable over Al and Ga Lewis acidic sites and only with synergy of H-bonding interactions can exist over Ti Lewis acidic site, while automatically transform to canonical structures over silanol and titanol hydroxyls. PMID:25307449

  6. Reaction of iminopropadienones with amines--formation of zwitterionic intermediates, ketenes, and ketenimines.

    PubMed

    Veedu, Rakesh Naduvile; Kokas, Okanya J; Couturier-Tamburelli, Isabelle; Koch, Rainer; Aycard, Jean-Pierre; Borget, Fabien; Wentrup, Curt

    2008-10-09

    Five aryliminopropadienones 4a- d have been synthesized by flash vacuum thermolysis (FVT) by using two different precursors in each case. These compounds were deposited at 50 K at a pressure of ca. 10(-6) mbar together with three different nucleophiles, namely, trimethylamine (TMA), dimethylamine (DMA), and diethylamine (DEA), in order to study their reactions as neat solids during warm-up by FTIR spectroscopy. The reaction with TMA showed that a zwitterionic species (5 and/or 6) was formed in all the cases. With DMA and DEA, an alpha-oxoketenimine and/or an imidoylketene (7 and 8 or 9 and 10) was formed as the final product. In addition, several bands were observed, which can be assigned to zwitterionic intermediates (11 or 12). Optimized structures and vibrational spectra for all products were calculated at the B3LYP/6-31G(d) level of theory by using the polarizable continuum model (epsilon = 5).

  7. Development of Low Fouling and High Fouling-release Zwitterionic Marine Coatings

    DTIC Science & Technology

    2016-01-04

    amount, pigment , crosslinker type and catalyst amount. The details are shown below, 1. PDMS coating with zwitterionic copolymer incorporated. PDMS...onto aluminum panels. The coating can be cured within 3.5 hours. 2. PDMS coating with pigment incorporated. Various amount of the pigment cadmium...stirred vigorously until all the solid were dispersed uniformly. The obtained viscous liquid was then mixed with 3 g PDMS crosslinker, and applied onto

  8. Hollow Fiber Membrane Modification with Functional Zwitterionic Macromolecules for Improved Thromboresistance in Artificial Lungs

    PubMed Central

    Ye, Sang-Ho; Arazawa, David T.; Zhu, Yang; Shankarraman, Venkat; Malkin, Alexander D.; Kimmel, Jeremy D.; Gamble, Lara J.; Ishihara, Kazuhiko; Federspiel, William J.; Wagner, William R.

    2015-01-01

    Respiratory assist devices seek optimized performance in terms of gas transfer efficiency and thromboresistance to minimize device size and reduce complications associated with inadequate blood biocompatibility. The exchange of gas with blood occurs at the surface of the hollow fiber membranes (HFMs) used in these devices. In this study, three zwitterionic macromolecules were attached to HFM surfaces to putatively improve thromboresistance: (1) carboxyl-functionalized zwitterionic phosphorylcholine (PC) and (2) sulfobetaine (SB) macromolecules (mPC or mSB-COOH) prepared by a simple thiol-ene radical polymerization and (3) a low-molecular weight sulfobetaine (SB)-co-methacrylic acid (MA) block copolymer (SBMAb-COOH) prepared by reversible addition–fragmentation chain transfer (RAFT) polymerization. Each macromolecule type was covalently immobilized on an aminated commercial HFM (Celg-A) by a condensation reaction, and HFM surface composition changes were analyzed by X-ray photoelectron spectroscopy. Thrombotic deposition on the HFMs was investigated after contact with ovine blood in vitro. The removal of CO2 by the HFMs was also evaluated using a model respiratory assistance device. The HFMs conjugated with zwitterionic macromolecules (Celg-mPC, Celg-mSB, and Celg-SBMAb) showed expected increases in phosphorus or sulfur surface content. Celg-mPC and Celg-SBMAb experienced rates of platelet deposition significantly lower than those of unmodified (Celg-A, >95% reduction) and heparin-coated (>88% reduction) control HFMs. Smaller reductions were seen with Celg-mSB. The CO2 removal rate for Celg-SBMAb HFMs remained comparable to that of Celg-A. In contrast, the rate of removal of CO2 for heparin-coated HFMs was significantly reduced. The results demonstrate a promising approach to modifying HFMs using zwitterionic macromolecules for artificial lung devices with improved thromboresistance without degradation of gas transfer. PMID:25669307

  9. Silica Nanoparticles Functionalized with Zwitterionic Sulfobetaine Siloxane for Application as a Versatile Antifouling Coating System.

    PubMed

    Knowles, Brianna R; Wagner, Pawel; Maclaughlin, Shane; Higgins, Michael J; Molino, Paul J

    2017-06-07

    The growing need to develop surfaces able to effectively resist biological fouling has resulted in the widespread investigation of nanomaterials with potential antifouling properties. However, the preparation of effective antifouling coatings is limited by the availability of reactive surface functional groups and our ability to carefully control and organize chemistries at a materials' interface. Here, we present two methods of preparing hydrophilic low-fouling surface coatings through reaction of silica-nanoparticle suspensions and predeposited silica-nanoparticle films with zwitterionic sulfobetaine (SB). Silica-nanoparticle suspensions were functionalized with SB across three pH conditions and deposited as thin films via a simple spin-coating process to generate hydrophilic antifouling coatings. In addition, coatings of predeposited silica nanoparticles were surface functionalized via exposure to zwitterionic solutions. Quartz crystal microgravimetry with dissipation monitoring was employed as a high throughput technique for monitoring and optimizing reaction to the silica-nanoparticle surfaces. Functionalization of nanoparticle films was rapid and could be achieved over a wide pH range and at low zwitterion concentrations. All functionalized particle surfaces presented a high degree of wettability and resulted in large reductions in adsorption of bovine serum albumin protein. Particle coatings also showed a reduction in adhesion of fungal spores (Epicoccum nigrum) and bacteria (Escherichia coli) by up to 87 and 96%, respectively. These results indicate the potential for functionalized nanosilicas to be further developed as versatile fouling-resistant coatings for widespread coating applications.

  10. Modification of silicone elastomer with zwitterionic silane for durable antifouling properties.

    PubMed

    Yeh, Shiou-Bang; Chen, Chien-Sheng; Chen, Wen-Yih; Huang, Chun-Jen

    2014-09-30

    Biofouling on medical devices generally causes adverse complications, such as thrombosis, infection, and pathogenic calcification. Silicone is a widely used material for medical applications. Its surface modification typically encounters undesirable "hydrophobic recovery", leading to deterioration of surface engineering. In this study, we developed a stable superhydrophilic zwitterionic interface on polydimethylsiloxane (PDMS) elastomer by covalent silanization of sulfobetaine silane (SBSi) to resist nonspecific adsorption of bacteria, proteins, and lipids. SBSi is a zwitterionic organosilane assembly, enabling resisting surface reconstruction by forming a cross-linked network and polar segregation. Surface elemental composition was confirmed by X-ray photoelectron spectroscopy (XPS), and the long-term stability of modification was accessed using a contact angle goniometer. The biofouling tests were carried out by exposing substrates to bacterial, protein, and lipid solutions, revealing the excellent bioinertness of SBSi-tailored PDMS, even after 30 day storage in ambient. For the real-world application, we modified commercially available silicone hydrogel contact lenses with developed zwitterionic silane, presenting its antibacterial adhesion property. Moreover, the cytotoxicity of SBSi was accessed with NIH-3T3 fibroblast by the MTT assay, showing negligible cytotoxicity up to a concentration of 5 mM. Consequently, the strategy of surface engineering in this work can effectively retard the "hydrophobic recovery" occurrence and can be applied to other silicone-based medical devices in a facile way.

  11. Fabrication of a Quartz-Crystal-Microbalance/Surface-Plasmon-Resonance Hybrid Sensor and Its Use for Detection of Polymer Thin-Film Deposition and Evaluation of Moisture Sorption Phenomena

    NASA Astrophysics Data System (ADS)

    Shinbo, Kazunari; Ishikawa, Hiroshi; Baba, Akira; Ohdaira, Yasuo; Kato, Keizo; Kaneko, Futao

    2012-03-01

    We fabricated a hybrid sensor utilizing quartz crystal microbalance (QCM) and surface plasmon resonance (SPR) spectroscopy. We confirmed its effectiveness by observing QCM frequency shifts and SPR wavelength changes for two processes: deposition of various transparent polymer thin films and moisture sorption. For thin-film deposition, the relationship between the QCM frequency and SPR wavelength was found to depend on the refractive index of the film material. For moisture sorption, the direction of SPR wavelength shift depended on the film thickness. This was estimated to be caused by film swelling and decrease in refractive index induced by moisture.

  12. Hybrid Lipid/Polymer Nanoparticles for Pulmonary Delivery of siRNA: Development and Fate Upon In Vitro Deposition on the Human Epithelial Airway Barrier.

    PubMed

    d'Angelo, Ivana; Costabile, Gabriella; Durantie, Estelle; Brocca, Paola; Rondelli, Valeria; Russo, Annapina; Russo, Giulia; Miro, Agnese; Quaglia, Fabiana; Petri-Fink, Alke; Rothen-Rutishauser, Barbara; Ungaro, Francesca

    2017-10-16

    Nowadays, the downregulation of genes involved in the pathogenesis of severe lung diseases through local siRNA delivery appears an interesting therapeutic approach. In this study, we propose novel hybrid lipid-polymer nanoparticles (hNPs) consisting of poly(lactic-co-glycolic) acid (PLGA) and dipalmitoyl phosphatidylcholine (DPPC) as siRNA inhalation system. A panel of DPPC/PLGA hNPs was prepared by emulsion/solvent diffusion and fully characterized. A combination of model siRNAs against the sodium transepithelial channel (ENaC) was entrapped in optimized hNPs comprising or not poly(ethylenimine) (PEI) as third component. siRNA-loaded hNPs were characterized for encapsulation efficiency, release kinetics, aerodynamic properties, and stability in artificial mucus (AM). The fate and cytotoxicity of hNPs upon aerosolization on a triple cell co-culture model (TCCC) mimicking human epithelial airway barrier were assessed. Finally, the effect of siRNA-loaded hNPs on ENaC protein expression at 72 hours was evaluated in A549 cells. Optimized muco-inert hNPs encapsulating model siRNA with high efficiency were produced. The developed hNPs displayed a hydrodynamic diameter of ∼150 nm, a low polydispersity index, a negative ζ potential close to -25 mV, and a peculiar triphasic siRNA release lasting for 5 days, which slowed down in the presence of PEI. siRNA formulations showed optimal in vitro aerosol performance after delivery with a vibrating mesh nebulizer. Furthermore, small-angle X-ray scattering analyses highlighted an excellent stability upon incubation with AM, confirming the potential of hNPs for direct aerosolization on mucus-lined airways. Studies in TCCC confirmed that fluorescent hNPs are internalized inside airway epithelial cells and do not exert any cytotoxic or acute proinflammatory effect. Finally, a prolonged inhibition of ENaC protein expression was observed in A549 cells upon treatment with siRNA-loaded hNPs. Results demonstrate the great potential

  13. Polymers in separation processes

    NASA Astrophysics Data System (ADS)

    Wieszczycka, Karolina; Staszak, Katarzyna

    2017-05-01

    Application of polymer materials as membranes and ion-exchange resins was presented with a focus on their use for the recovery of metal ions from aqueous solutions. Several membrane techniques were described including reverse osmosis, nanofiltration, ultrafiltration, diffusion and Donnan dialysis, electrodialysis and membrane extraction system (polymer inclusion and supported membranes). Moreover, the examples of using ion-exchange resins in metal recovery were presented. The possibility of modification of the resin was discussed, including hybrid system with metal cation or metal oxide immobilized on polymer matrices or solvent impregnated resin.

  14. Polymer films

    DOEpatents

    Granick, Steve; Sukhishvili, Svetlana A.

    2004-05-25

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  15. Polymer films

    DOEpatents

    Granick, Steve [Champaign, IL; Sukhishvili, Svetlana A [Maplewood, NJ

    2008-12-30

    A film contains a first polymer having a plurality of hydrogen bond donating moieties, and a second polymer having a plurality of hydrogen bond accepting moieties. The second polymer is hydrogen bonded to the first polymer.

  16. Synergistic effects on enantioselectivity of zwitterionic chiral stationary phases for separations of chiral acids, bases, and amino acids by HPLC.

    PubMed

    Hoffmann, Christian V; Pell, Reinhard; Lämmerhofer, Michael; Lindner, Wolfgang

    2008-11-15

    In an attempt to overcome the limited applicability scope of earlier proposed Cinchona alkaloid-based chiral weak anion exchangers (WAX) and recently reported aminosulfonic acid-based chiral strong cation exchangers (SCX), which are conceptionally restricted to oppositely charged solutes, their individual chiral selector (SO) subunits have been fused in a combinatorial synthesis approach into single, now zwitterionic, chiral SO motifs. The corresponding zwitterionic ion-exchange-type chiral stationary phases (CSPs) in fact combined the applicability spectra of the parent chiral ion exchangers allowing for enantioseparations of chiral acids and amine-type solutes in liquid chromatography using polar organic mode with largely rivaling separation factors as compared to the parent WAX and SCX CSPs. Furthermore, the application spectrum could be remarkably expanded to various zwitterionic analytes such as alpha- and beta-amino acids and peptides. A set of structurally related yet different CSPs consisting of either a quinine or quinidine alkaloid moiety as anion-exchange subunit and various chiral or achiral amino acids as cation-exchange subunits enabled us to derive structure-enantioselectivity relationships, which clearly provided strong unequivocal evidence for synergistic effects of the two oppositely charged ion-exchange subunits being involved in molecular recognition of zwitterionic analytes by zwitterionic SOs driven by double ionic coordination.

  17. The relative abundance of dimethylsulfoniopropionate (DMSP) among other zwitterions in branching coral at Heron Island, southern Great Barrier Reef.

    PubMed

    Swan, Hilton B; Deschaseaux, Elisabeth S M; Jones, Graham B; Eyre, Bradley D

    2017-07-01

    Dimethylsulfoniopropionate (DMSP) and eleven other target zwitterions were quantified in the branch tips of six Acropora species and Stylophora pistillata hard coral growing on the reef flat surrounding Heron Island in the southern Great Barrier Reef (GBR), Australia. Hydrophilic interaction liquid chromatography mass spectrometry (HILIC-MS) was used for sample analysis with isotope dilution MS applied to quantify DMSP. The concentration of DMSP was ten times greater in A. aspera than A. valida, with this difference being maintained throughout the spring, summer and winter seasons. In contrast, glycine betaine was present in significantly higher concentrations in these species during the summer than the winter. Exposure of branch tips of A. aspera to air and hypo-saline seawater for up to 1 h did not alter the concentrations of DMSP present in the coral when compared with control samples. DMSP was the most abundant target zwitterion in the six Acropora species examined, ranging from 44-78% of all target zwitterions in A. millepora and A. aspera, respectively. In contrast, DMSP only accounted for 7% in S. pistillata, with glycine betaine and stachydrine collectively accounting for 88% of all target zwitterions in this species. The abundance of DMSP in the six Acropora species examined points to Acropora coral being an important source for the biogeochemical cycling of sulfur throughout the GBR, since this reef-building branching coral dominates the coral cover of the GBR. Graphical Abstract HILIC-MS extracted ion chromatogram showing zwitterionic metabolites from the branching coral Acropora isopora.

  18. The Influence of the Polymer Amount on the Biological Properties of PCL/ZrO2 Hybrid Materials Synthesized via Sol-Gel Technique

    PubMed Central

    Tranquillo, Elisabetta; Illiano, Michela; Sapio, Luigi; Spina, Annamaria; Naviglio, Silvio

    2017-01-01

    Organic/inorganic hybrid materials are attracting considerable attention in the biomedical area. The sol-gel process provides a convenient way to produce many bioactive organic–inorganic hybrids. Among those, poly(e-caprolactone)/zirconia (PCL/ZrO2) hybrids have proved to be bioactive with no toxic materials. The aim of this study was to investigate the effects of these materials on the cellular response as a function of the PCL content, in order to evaluate their potential use in the biomedical field. For this purpose, PCL/ZrO2 hybrids containing 6, 12, 24, and 50 wt % of PCL were synthesized by the sol-gel method. The effects of their presence on the NIH-3T3 fibroblast cell line carrying out direct cell number counting, MTT, cell damage assays, flow cytometry-based analysis of cell-cycle progression, and immunoblotting experiments. The results confirm and extend the findings that PCL/ZrO2 hybrids are free from toxicity. The hybrids containing 12 and 24 wt % PCL, (more than 6 and 50 wt % ones) enhance cell proliferation when compared to pure ZrO2 by affecting cell cycle progression. The finding that the content of PCL in PCL/ZrO2 hybrids differently supports cell proliferation suggests that PCL/ZrO2 hybrids could be useful tools with different potential clinical applications. PMID:29039803

  19. Synthesis and characterization of aminated perfluoro polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Page-Belknap, Zachary Stephan Glenn

    g -1. The low OH- conductivities and IEC were attributed to the formation of a predominately zwitterionic polymer when exposed to a strong base. Removal of the sulfonamide proton following counterion exchange with a strong base and formation of a zwitterion was confirmed by FTIR with the absence of a primary amine stretch between 3000-3600 cm-1. 1H NMR analysis of small molecule analogues established that the sulfonamide site was not methylated during quaternization as evident by the exclusion of a strong singlet around 2.9 ppm. pH indication tests with Thymolphthalein illuminated the slight presence of free OH- ions within the polymer following counterion exchange thus validating the low IEC and formation of a predominately zwitterionic polymer. Recommended future work with this polymer electrolyte consists of fine tuning the polymer to be less or completely zwitterionic, pKa analysis of the sulfonamide linkage with small molecule analogues, implementation into microbial fuel cell and biological separation processes for pH regulation, and development as a support infrastructure for ionic liquids.

  20. Quantum chemical characterization of zwitterionic structures: Supramolecular complexes for modifying the wettability of oil-water-limestone system.

    PubMed

    Lopez-Chavez, Ernesto; Garcia-Quiroz, Alberto; Gonzalez-Garcia, Gerardo; Orozco-Duran, Gabriela E; Zamudio-Rivera, Luis S; Martinez-Magadan, José M; Buenrostro-Gonzalez, Eduardo; Hernandez-Altamirano, Raul

    2014-06-01

    In this work, we present a quantum chemical study pertaining to some supramolecular complexes acting as wettability modifiers of oil-water-limestone system. The complexes studied are derived from zwitterionic liquids of the types N'-alkyl-bis, N-alquenil, N-cycloalkyl, N-amyl-bis-beta amino acid or salts acting as sparkling agents. We studied two molecules of zwitterionic liquids (ZL10 and ZL13), HOMO and LUMO levels, and the energy gap between them, were calculated, as well as the electron affinity (EA) and ionization potential (IP), chemical potential, chemical hardness, chemical electrophilicity index and selectivity descriptors such Fukui indices. In this work, electrochemical comparison was realized with cocamidopropyl betaine (CPB), which is a structure zwitterionic liquid type, nowadays widely applied in enhanced recovery processes. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Efficient CO2 capture by tertiary amine-functionalized ionic liquids through Li+-stabilized zwitterionic adduct formation

    PubMed Central

    Yang, Zhen-Zhen

    2014-01-01

    Summary Highly efficient CO2 absorption was realized through formation of zwitterionic adducts, combining synthetic strategies to ionic liquids (ILs) and coordination. The essence of our strategy is to make use of multidentate cation coordination between Li+ and an organic base. Also PEG-functionalized organic bases were employed to enhance the CO2-philicity. The ILs were reacted with CO2 to form the zwitterionic adduct. Coordination effects between various lithium salts and neutral ligands, as well as the CO2 capacity of the chelated ILs obtained were investigated. For example, the CO2 capacity of PEG150MeBu2N increased steadily from 0.10 to 0.66 (mol CO2 absorbed per mol of base) through the formation of zwitterionic adducts being stabilized by Li+. PMID:25246955

  2. Biomimetic synthesis of raspberry-like hybrid polymer-silica core-shell nanoparticles by templating colloidal particles with hairy polyamine shell.

    PubMed

    Pi, Mengwei; Yang, Tingting; Yuan, Jianjun; Fujii, Syuji; Kakigi, Yuichi; Nakamura, Yoshinobu; Cheng, Shiyuan

    2010-07-01

    The nanoparticles composed of polystyrene core and poly[2-(diethylamino)ethyl methacrylate] (PDEA) hairy shell were used as colloidal templates for in situ silica mineralization, allowing the well-controlled synthesis of hybrid silica core-shell nanoparticles with raspberry-like morphology and hollow silica nanoparticles by subsequent calcination. Silica deposition was performed by simply stirring a mixture of the polymeric core-shell particles in isopropanol, tetramethyl orthosilicate (TMOS) and water at 25 degrees C for 2.5h. No experimental evidence was found for nontemplated silica formation, which indicated that silica deposition occurred exclusively in the PDEA shell and formed PDEA-silica hybrid shell. The resulting hybrid silica core-shell particles were characterized by transmission electron microscopy (TEM), thermogravimetry, aqueous electrophoresis, and X-ray photoelectron spectroscopy. TEM studies indicated that the hybrid particles have well-defined core-shell structure with raspberry morphology after silica deposition. We found that the surface nanostructure of hybrid nanoparticles and the composition distribution of PDEA-silica hybrid shell could be well controlled by adjusting the silicification conditions. These new hybrid core-shell nanoparticles and hollow silica nanoparticles would have potential applications for high-performance coatings, encapsulation and delivery of active organic molecules. 2010 Elsevier B.V. All rights reserved.

  3. Functionalizable and ultra stable nanoparticles coated with zwitterionic poly(carboxybetaine) in undiluted blood serum.

    PubMed

    Yang, Wei; Zhang, Lei; Wang, Shanlin; White, Andrew D; Jiang, Shaoyi

    2009-10-01

    A new surface chemistry presenting an abundance of functional groups for ligand immobilization in an ultra-low fouling background all in one material for nanoparticles was introduced. This surface platform, as demonstrated by zwitterionic poly(carboxybetaine acrylamide) (polyCBAA) coated nanoparticles, is not only ultra stable in undiluted human blood serum, but also can be conjugated to biomolecules conveniently and effectively. Thus, this surface chemistry is ideal to create multi-functional nanoparticles for targeted delivery and diagnostics. In addition, this work clearly shows that 10% blood serum commonly used to evaluate the stability of nanoparticles is insufficient and a new evaluation criterion with undiluted blood serum is recommended.

  4. Isolation of a Moderately Stable but Sensitive Zwitterionic Diazonium Tetrazolyl-1,2,3-triazolate.

    PubMed

    Klapötke, Thomas M; Krumm, Burkhard; Pflüger, Carolin

    2016-07-15

    An unexpected formation of a diazonium compound was observed by nitration of an amino substituted triazolyl tetrazole with mixed acid. The crystal structure determination revealed a zwitterionic diazonium tetrazolyl-1,2,3-triazolate, whose constitution was supported by NMR and vibrational spectroscopic analysis. The thermal stability and sensitivity toward impact and friction were determined. In contrast, diazotriazoles are rather unstable and are mainly handled in solution and/or low temperatures, which is not the case for this diazonium tetrazolyl-1,2,3-triazolate, being stable at ambient temperature.

  5. Synthesis of zwitterionic salts of pyridinium-Meldrum acid and barbiturate through unique four-component reactions.

    PubMed

    Wang, Qi-Fang; Hui, Li; Hou, Hong; Yan, Chao-Guo

    2010-03-08

    An efficient synthetic procedure for the preparation of the unusual charge-separated pyridinium-Meldrum acid and N,N-dimethylbarbiturate acid zwitterionic salts was developed though a unique one-pot four-component reaction involving pyridine, aromatic aldehyde, Meldrum acid or N,N-dimethylbarbituric acid, and p-nitrobenzyl bromide in acetonitrile. By varying combinations of four components involving nitrogen-containing heterocycles, we conveniently established reactive alpha-halomethylene compounds, aldehydes and beta-dicarbonyl compounds a library of zwitterionic salts.

  6. Induction of cell self-organization on weakly positively charged surfaces prepared by the deposition of polyion complex nanoparticles of thermoresponsive, zwitterionic copolymers.

    PubMed

    Iwai, Ryosuke; Haruki, Ryota; Nemoto, Yasushi; Nakayama, Yasuhide

    2017-07-01

    We have developed inducible cell self-organization through weakly positively charged culture surfaces. In this study, a thermoresponsive and zwitterionic copolymer comprised of N,N-dimethylaminoethyl methacrylate (DMAEMA) and methacrylic acid (MA) (PDMAEMA-co-PMA; Mn: ∼9.7 × 10 4 g/mol; PDMAEMA/PMA ratio: 10) was designed for inducing cell self-organization. The copolymer formed single polymer-derived polyion complex (sPIC) nanoparticles following dissolution in an aqueous solution. The sPIC nanoparticles had a positive charge (ca. 25 mV). Self-organization occurred in adipose-derived vascular stromal cell monolayers cultivated on sPIC-deposited surfaces. There were dramatic morphological changes of these cells with the formation of capillary-like networks and single-cell aggregates with little cytotoxicity. This was a significant improvement compared with cells grown on previously developed surfaces deposited with PIC, a mixture of PDMAEMA and plasmid DNA. Thus, sPICs of PDMAEMA-co-PMA may allow for the accurate evaluation of a variety of cell behaviors with less cytotoxicity, and may facilitate additional potential medical applications such as cell-based therapy and drug discovery. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1009-1015, 2017. © 2016 Wiley Periodicals, Inc.

  7. Highly Selective Enrichment of Glycopeptides Based on Zwitterionically Functionalized Soluble Nanopolymers

    NASA Astrophysics Data System (ADS)

    Cao, Weiqian; Huang, Jiangming; Jiang, Biyun; Gao, Xing; Yang, Pengyuan

    2016-07-01

    Efficient glycopeptides enrichment prior to mass spectrometry analysis is essential for glycoproteome study. ZIC-HILIC (zwitterionic hydrophilic interaction liquid chromatography) based glycopeptides enrichment approaches have been attracting more attention for several benefits like easy operating, high enrichment specificity and intact glycopeptide retained. In this study, Poly (amidoamine) dendrimer (PAMAM) was adopted for the synthesis of zwitterionically functionalized (ZICF) materials for glycopeptide enrichment. The multiple branched structure and good solubility of ZICF-PAMAM enables a sufficient interaction with glycopeptides. The ZICF-PAMAM combined with the FASP-mode enrichment strategy exhibits more superior performance compared with the existing methods. It has the minimum detectable concentration of femtomolar level and high recovery rate of over 90.01%, and can efficiently enrich glycopeptides from complex biological samples even for merely 0.1 μL human serum. The remarkable glycopeptides enrichment capacity of ZICF-PAMAM highlights the potential application in in-depth glycoproteome research, which may open up new opportunities for the development of glycoproteomics.

  8. Highly Selective Enrichment of Glycopeptides Based on Zwitterionically Functionalized Soluble Nanopolymers.

    PubMed

    Cao, Weiqian; Huang, Jiangming; Jiang, Biyun; Gao, Xing; Yang, Pengyuan

    2016-07-14

    Efficient glycopeptides enrichment prior to mass spectrometry analysis is essential for glycoproteome study. ZIC-HILIC (zwitterionic hydrophilic interaction liquid chromatography) based glycopeptides enrichment approaches have been attracting more attention for several benefits like easy operating, high enrichment specificity and intact glycopeptide retained. In this study, Poly (amidoamine) dendrimer (PAMAM) was adopted for the synthesis of zwitterionically functionalized (ZICF) materials for glycopeptide enrichment. The multiple branched structure and good solubility of ZICF-PAMAM enables a sufficient interaction with glycopeptides. The ZICF-PAMAM combined with the FASP-mode enrichment strategy exhibits more superior performance compared with the existing methods. It has the minimum detectable concentration of femtomolar level and high recovery rate of over 90.01%, and can efficiently enrich glycopeptides from complex biological samples even for merely 0.1 μL human serum. The remarkable glycopeptides enrichment capacity of ZICF-PAMAM highlights the potential application in in-depth glycoproteome research, which may open up new opportunities for the development of glycoproteomics.

  9. Synchronized Regulation of Different Zwitterionic Metabolites in the Osmoadaption of Phytoplankton

    PubMed Central

    Gebser, Björn; Pohnert, Georg

    2013-01-01

    The ability to adapt to different seawater salinities is essential for cosmopolitan marine phytoplankton living in very diverse habitats. In this study, we examined the role of small zwitterionic metabolites in the osmoadaption of two common microalgae species Emiliania huxleyi and Prorocentrum minimum. By cultivation of the algae under salinities between 16‰ and 38‰ and subsequent analysis of dimethylsulfoniopropionate (DMSP), glycine betaine (GBT), gonyol, homarine, trigonelline, dimethylsulfonioacetate, trimethylammonium propionate, and trimethylammonium butyrate using HPLC-MS, we could reveal two fundamentally different osmoadaption mechanisms. While E. huxleyi responded with cell size reduction and a nearly constant ratio between the major metabolites DMSP, GBT and homarine to increasing salinity, osmolyte composition of P. minimum changed dramatically. In this alga DMSP concentration remained nearly constant at 18.6 mM between 20‰ and 32‰ but the amount of GBT and dimethylsulfonioacetate increased from 4% to 30% of total investigated osmolytes. Direct quantification of zwitterionic metabolites via LC-MS is a powerful tool to unravel the complex osmoadaption and regulation mechanisms of marine phytoplankton. PMID:23774888

  10. Microwave-assisted micellar extraction of organic and inorganic iodines using zwitterionic surfactants.

    PubMed

    Wang, Shu-Ling; Yi, Ling; Ye, Li-Hong; Cao, Jun; Du, Li-Jing; Peng, Li-Qing; Xu, Jing-Jing; Zhang, Qi-Dong

    2017-08-04

    Zwitterionic surfactant, used as extractant in microwave-assisted extraction (MAE) was investigated for the first time to extract organic and inorganic iodines from kelp samples. Optimized conditions for the MAE were 200W of microwave irradiation power, 100°C of extraction temperature, 10min of microwave irradiation time, 1g of sample, and 20mL of solvent volume. Ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) was used for the quantitative and qualitative analyses of the iodines. Under the optimum experimental conditions, KI, MIT and DIT were identified in kelp samples, the limits of detection of these analytes were ranged between 3.39 and 6.31ng/mL. The recoveries for spiked samples obtained from different areas were all higher than 92.48%. Compared with the ultrasound-assisted extraction, the proposed method is faster and more effective. Thus, the combination of zwitterionic surfactant-MAE and UHPLC-Q-TOF/MS made up a simple, rapid and effective approach for extraction and determination of iodine compounds in complex seaweed materials. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Light-Induced Gelling in a Micellar Fluid Based on a Zwitterionic Surfactant.

    NASA Astrophysics Data System (ADS)

    Kumar, Rakesh; Raghavan, Srinivasa

    2007-03-01

    Fluids with photoresponsive rheological properties (i.e. photorheological or PR fluids) can be useful in a range of applications, such as in dampers, sensors, and valves for microfluidic or MEMS devices. Previously, we have demonstrated a cationic surfactant-based PR fluid whose viscosity can be rapidly decreased by UV irradiation. This viscosity decrease was not reversible. Here, we describe a different formulation based on a zwitterionic surfactant that shows a rapid increase in viscosity (gelling) upon exposure to UV radiation. The formulation consists of the zwitterionic surfactant and a photosensitive cinnamic acid derivative. Initially, the viscosity of the fluid is low indicating the presence of small micelles. Upon UV irradiation, the cinnamic acid derivative is photoisomerized from trans to cis. In turn, the small micelles transform into long wormlike micelles, thus increasing the solution viscosity by more than five orders of magnitude. Small angle neutron scattering (SANS) data confirms the dramatic increase in micelle length. Possible reasons for such changes in micelle dimensions will be discussed.

  12. Anti-Fouling Double-Skinned Forward Osmosis Membrane with Zwitterionic Brush for Oily Wastewater Treatment.

    PubMed

    Ong, Chi Siang; Al-Anzi, Bader; Lau, Woei Jye; Goh, Pei Sean; Lai, Gwo Sung; Ismail, Ahmad Fauzi; Ong, Yue Seong

    2017-07-31

    Despite its attractive features for energy saving separation, the performance of forward osmosis (FO) has been restricted by internal concentration polarization and fast fouling propensity that occur in the membrane sublayer. These problems have significantly affected the membrane performance when treating highly contaminated oily wastewater. In this study, a novel double-skinned FO membrane with excellent anti-fouling properties has been developed for emulsified oil-water treatment. The double-skinned FO membrane comprises a fully porous sublayer sandwiched between a highly dense polyamide (PA) layer for salt rejection and a fairly loose dense bottom zwitterionic layer for emulsified oil particle removal. The top dense PA layer was synthesized via interfacial polymerization meanwhile the bottom layer was made up of a zwitterionic polyelectrolyte brush - (poly(3-(N-2-methacryloxyethyl-N,N-dimethyl) ammonatopropanesultone), abbreviated as PMAPS layer. The resultant double-skinned membrane exhibited a high water flux of 13.7 ± 0.3 L/m 2 .h and reverse salt transport of 1.6 ± 0.2 g/m 2 .h under FO mode using 2 M NaCl as the draw solution and emulsified oily solution as the feed. The double-skinned membrane outperforms the single-skinned membrane with much lower fouling propensity for emulsified oil-water separation.

  13. Controllable self-assembly of sodium caseinate with a zwitterionic vitamin-derived bolaamphiphile.

    PubMed

    Sun, Li-Hui; Sun, Yu-Long; Yang, Li-Jun; Zhang, Jian; Chen, Zhong-Xiu

    2013-11-06

    The control of self-assembly of sodium caseinate (SC) including the formation of mixed layers, microspheres, or nanoparticles is highly relevant to the microstructure of food and the design of promising drug delivery systems. In this paper, we designed a structure-switchable zwitterionic bolaamphiphile, 1,12-diaminododecanediorotate (DDO), from orotic acid, which has special binding sites and can guide the self-assembly of SC. Complexation between SC and DDO was investigated using dynamic light scattering, transmission electron microscopy, differential scanning calorimetry, and fluorescence spectra measurements. Monomeric DDO was bound to the negatively charged sites on the SC micelle and made the structure of SC more compact with decreased electrostatic repulsion between the head groups. Vesicular DDO led to reassociation of vesicles with enlarged size via preferable hydrophobic interactions. Moreover, the aggregation between SC and DDO was found to be temperature-dependent and reversible. This research provides an effective way to control the reversible self-assembly of SC by the zwitterionic vitamin-derived bolaamphiphile.

  14. Chromatographic behavior of zwitterionic enalapril-exploring the conditions for lipophilicity assessment.

    PubMed

    Gikas, Spyros; Tsopelas, Fotios; Giaginis, Costas; Dimitrakopoulos, John; Livadara, Theodora; Archontaki, Helen; Tsantili-Kakoulidou, Anna

    2008-11-04

    The chromatographic behavior of enalapril was investigated under different stationary and mobile phase conditions in an effort to unravel interferences in the underlying retention mechanism, which would affect its relation to octanol-water partitioning. Extrapolated retention factors, logk(w), were used as relevant chromatographic indices. The retention/pH profile was established and the peak split phenomenon, associated with cis/trans interconversion, was also monitored as a function of pH. The pH at maximum retention and minimum peak split occurrence was chosen for further investigation, so that the presence of zwitterionic structure was guaranteed and any effect of cis/trans interconversion could be ignored. Retention of zwitterionic enalapril was found to be very sensitive to mobile phase conditions in regard to organic modifier as well to the aqueous component. The use of morpholine-propanesulfonic acid (MOPS) as buffer and the presence of n-octanol as mobile phase additive proved critical factors for maximum suppression of secondary interactions. Nevertheless, the corresponding extrapolated retention factor was considerably larger than octanol-water logD value at the isoelectric point. However, logk(w) could be successfully converted to logD by means of a calibration equation established for ionized acidic compounds.

  15. Electrophoretic separations in poly(dimethylsiloxane) microchips using a mixture of ionic and zwitterionic surfactants

    PubMed Central

    Guan, Qian; Noblitt, Scott D.; Henry, Charles S.

    2012-01-01

    The use of mixtures of ionic and zwitterionic surfactants in poly(dimethylsiloxane) (PDMS) microchips is reported. The effect of surfactant concentration on EOF was studied for a single anionic surfactant (sodium dodecyl sulfate, SDS), a single zwitterionic surfactant (N-tetradecylammonium-N,N-dimethyl-3-ammonio-1-propanesulfonate, TDAPS), and a mixed SDS/TDAPS surfactant system. SDS increased the EOF as reported previously while TDAPS showed an initial increase in EOF followed by a reduction at higher concentrations. When TDAPS was added to a solution containing SDS, the EOF decreased in a concentration dependent manner. The EOF for all three surfactant systems followed expected pH trends, with increasing EOF at higher pH. The mixed surfactant system allowed tuning of the EOF across a range of pH and concentration conditions. After establishing the EOF behavior, the adsorption/desorption kinetics were measured and showed a slower adsorption/desorption rate for TDAPS than SDS. Finally, the separation and electrochemical detection of model catecholamin