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Sample records for hybrid conducting polymer

  1. 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.

  2. Conducting Polymers and Their Hybrids as Organic Thermoelectric Materials

    NASA Astrophysics Data System (ADS)

    Toshima, Naoki; Ichikawa, Shoko

    2015-01-01

    Conducting polymers have received much attention recently as organic thermoelectric materials, because of such advantages as plentiful resources, easy synthesis, easy processing, low cost, low thermal conductivity, and easy fabrication of flexible, light, and printable devices with large area. Many reports on organic thermoelectric materials have recently been published. We have studied conducting polymers as organic thermoelectric materials since 1999. During these investigations, we found that the thermal conductivity of conducting polymers did not increase even though electrical conductivity increased; this was a major advantage of conducting polymers as organic thermoelectric materials. We also observed that molecular alignment was one of the most important factors for improvement of the thermoelectric performance of conducting polymers. Stretching of conducting polymers or their precursors was one of the most common techniques used to achieve good molecular alignment. Recently, alignment of the clusters of conducting polymers by treatment with solvents has been proposed as a means of achieving high electrical conductivity. Hybridization of conducting polymers with inorganic nanoparticles has also been found to improve thermoelectric performance. Here we present a brief history and discuss recent progress of research on conducting polymers as organic thermoelectric materials, and describe the techniques used to improve thermoelectric performance by treatment of conducting polymers with solvents and hybridization of conducting polymers with Bi2Te3 and gold nanoparticles.

  3. High ion conducting polymer nanocomposite electrolytes using hybrid nanofillers.

    PubMed

    Tang, Changyu; Hackenberg, Ken; Fu, Qiang; Ajayan, Pulickel M; Ardebili, Haleh

    2012-03-14

    There is a growing shift from liquid electrolytes toward solid polymer electrolytes, in energy storage devices, due to the many advantages of the latter such as enhanced safety, flexibility, and manufacturability. The main issue with polymer electrolytes is their lower ionic conductivity compared to that of liquid electrolytes. Nanoscale fillers such as silica and alumina nanoparticles are known to enhance the ionic conductivity of polymer electrolytes. Although carbon nanotubes have been used as fillers for polymers in various applications, they have not yet been used in polymer electrolytes as they are conductive and can pose the risk of electrical shorting. In this study, we show that nanotubes can be packaged within insulating clay layers to form effective 3D nanofillers. We show that such hybrid nanofillers increase the lithium ion conductivity of PEO electrolyte by almost 2 orders of magnitude. Furthermore, significant improvement in mechanical properties were observed where only 5 wt % addition of the filler led to 160% increase in the tensile strength of the polymer. This new approach of embedding conducting-insulating hybrid nanofillers could lead to the development of a new generation of polymer nanocomposite electrolytes with high ion conductivity and improved mechanical properties. © 2012 American Chemical Society

  4. Functionalised hybrid materials of conducting polymers with individual wool fibers.

    PubMed

    Kelly, Fern M; Johnston, James H; Borrmann, Thomas; Richardson, Michael J

    2008-04-01

    Composites of natural protein materials, such as merino wool, with the conducting polymers polypyrrole (PPy) and polyaniline (PAn) have been successfully synthesised. In doing so, hybrid materials have been produced in which the mechanical strength and flexibility of the fibers is retained whilst also incorporating the desired chemical and electrical properties of the polymer. Scanning electron microscopy shows PPy coatings to comprise individual polymer spheres, approximately 100 to 150 nm in diameter. The average size of the polymer spheres of PAn was observed to be approximately 50 to 100 nm in diameter. These spheres fuse together in a continuous sheet to coat the fibers in their entirety. The reduction of silver ions to silver metal nanoparticles onto the redox active polymer surface has also been successful and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterisation of such products has been undertaken through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrical conductivity, cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and the testing of their anti-microbial activity.

  5. Processable enzyme-hybrid conductive polymer composites for electrochemical biosensing.

    PubMed

    Liu, Yu; Turner, Anthony P F; Zhao, Maojun; Mak, Wing Cheung

    2017-09-18

    A new approach for the facile fabrication of electrochemical biosensors using a biohybrid conducting polymer was demonstrated using glucose oxidase (GOx) and poly (3, 4-ethylenedioxythiophene) (PEDOT) as a model. The biohybrid conducting polymer was prepared based on a template-assisted chemical polymerisation leading to the formation of PEDOT microspheres (PEDOT-MSs), followed by in-situ deposition of platinum nanoparticles (PtNPs) and electrostatic immobilisation of glucose oxidase (GOx) to form water processable GOx-PtNPs-PEDOT-MSs. The morphology, chemical composition and electrochemical performance of the GOx-PtNPs-PEDOT-MS-based glucose biosensor were characterised using scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDS), Fourier transform infrared (FTIR) spectroscopy, zeta potential and electrochemical measurements, respectively. The biosensor delivered a linear response for glucose over the range 0.1-10mM (R(2) = 0.9855) with a sensitivity of 116.25µAmM(-1)cm(-2), and limit of detection of 1.55µM (3×SD/sensitivity). The sensitivity of the developed PEDOT-MS based biosensor is significantly higher (2.7 times) than the best reported PEDOT-based glucose biosensor in the literature. The apparent Michaelis-Menten constant (Km(app)) of the GOx-PtNPs-PEDOT-MS-based biosensors was calculated as 7.3mM. Moreover, the biosensor exhibited good storage stability, retaining 97% of its sensitivity after 12 days storage. This new bio-hybrid conducting polymer combines the advantages of micro-structured morphology, compatibility with large-scale manufacturing processes, and intrinsic biocatalytic activity and conductivity, thus demonstrating its potential as a convenient material for printed bioelectronics and sensors. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. 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

  7. Conductive Polymer-Inorganic Hybrid Materials through Synergistic Mutual Doping of the Constituents.

    PubMed

    Wang, Weike; Chen, Chaoqiu; Tollan, Christopher; Yang, Fan; Beltrán, Mikel; Qin, Yong; Knez, Mato

    2017-08-23

    Polymer-matrix-based inorganic-organic hybrid materials are at the cutting edge of current research for their great promise of merging properties of soft and hard solids in one material. Infiltration of polymers with vapors of reactive metal organics is a pathway for postsynthetic blending of the polymer with inorganic materials. Here, we show that this process is also an excellent method for fabricating conductive hybrid materials. Polyaniline (PANI) was infiltrated with ZnO and the initially insulating polymer was converted to a PANI/ZnO hybrid with conductivities as high as 18.42 S/cm. The conductivity is based on a synergistic effect of the constituting materials, where the inorganic and the polymeric fractions mutually act as dopants for the counterpart. The process temperature is a very important factor for successful infiltration, and the number of applied infiltration cycles allows tuning the level of conductivity of the resulting PANI/ZnO.

  8. Selective sensing of volatile organic compounds using novel conducting polymer-metal nanoparticle hybrids

    NASA Astrophysics Data System (ADS)

    Vaddiraju, Sreeram; Gleason, Karen K.

    2010-03-01

    Conducting polymer-metal nanoparticle hybrids, fabricated by assembling metal nanoparticles on top of functionalized conducting polymer film surfaces using conjugated linker molecules, enable the selective sensing of volatile organic compounds (VOCs). In these conducting polymer-metal nanoparticle hybrids, selectivity is achieved by assembling different metals on the same conducting polymer film. This eliminates the need to develop either different polymers chemistries or device configurations for each specific analyte. In the hybrids, chemisorption of the analyte vapor induces charge redistribution in the metal nanoparticles and changes their work function. The conjugated linker molecule causes this change in the work function of the tethered nanoparticles to affect the electronic states in the underlying conducting polymer film. The result is an easily measurable change in the resistance of the hybrid structure. The fabrication of these sensing elements involved the covalent assembly of nickel (Ni) and palladium (Pd) metal nanoparticles on top of poly(3,4-ethylenedioxythiophene-co-thiophene-3-acetic acid), poly(EDOT-co-TAA), films using 4-aminothiophenol linker molecules. The change in resistance of hybrid Pd/poly(EDOT-co-TAA) and Ni/poly(EDOT-co-TAA) hybrid films to acetone and toluene, respectively, is observed to be in proportion to their concentrations. The projected detection limits are 2 and 10 ppm for toluene and acetone, respectively. A negligible response (resistance change) of the Pd/poly(EDOT-co-TAA) films to toluene exposure confirmed its selectivity for detecting acetone. Similarly, lack of response to acetone confirmed the selectivity of the Ni/poly(EDOT-co-TAA) stacks for detecting toluene. It is anticipated that the assembly of other metals such as Ag, Au and Cu on top of poly(EDOT-co-TAA) would provide selectivity for detecting and discriminating other VOCs.

  9. A Cytocompatible Robust Hybrid Conducting Polymer Hydrogel for Use in a Magnesium Battery.

    PubMed

    Yu, Changchun; Wang, Caiyun; Liu, Xiao; Jia, Xiaoteng; Naficy, Sina; Shu, Kewei; Forsyth, Maria; Wallace, Gordon G

    2016-11-01

    A cytocompatible robust hybrid conducting-polymer hydrogel, polypyrrole/poly(3,4-ethylenedioxythiophene) is developed. This hydrogel is suitable for electrode-cellular applications. It demonstrates a high battery performance when coupled with a bioresorbable Mg alloy in phosphate-buffered saline. A combination of suitable mechanical and electrochemical properties makes this hydrogel a promising material for bionic applications.

  10. 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.

  11. Enhancing the electrical conductivity of a hybrid POSS-PCL/graphene nanocomposite polymer.

    PubMed

    Nezakati, Toktam; Tan, Aaron; Seifalian, Alexander M

    2014-12-01

    An electrically conductive polymer using polyhedral oligomeric silsesquioxane (POSS) nanocage incorporated into a modified poly [caprolactone based urea-urethane] (PCL)/graphene hybrid nanocomposite is described. Multilayer graphene flakes (8nm) were homogeneously dispersed into POSS-PCL at 0.1, 2, 5, and 10wt.% concentrations. This dispersion process of the graphene flakes was achieved by the use of stable dimethylacetamide (DMAc), via solution intercalation with POSS-PCL nanocomposites. The impedance spectroscopy of 5.0wt.% and higher concentration of graphene in POSS-PCL represented major improvement in conductivity over pristine POSS-PCL. The percolation threshold occurred at 5.0wt.% graphene concentration, converting the insulator POSS-PCL into a conductive POSS-PCL/graphene hybrid nanocomposite. The structures of the obtained hybrid materials were characterized with atomic force microscopy (AFM), Fourier transform infra-red (FT-IR), and Raman spectroscopy. The conductivity of the resultant nanocomposite polymer was investigated with electrochemical impedance spectroscopy (EIS). Herein, for the first time, we demonstrate a facile method of synthesizing, and describe the electrical properties of a conductive POSS-PCL/graphene nanocomposite polymer.

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

    PubMed

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

    2016-01-05

    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.

  13. 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

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

    DOE PAGES

    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 Li+/Li. X-raymore » 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

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

    SciTech Connect

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

    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 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.

  16. Conducting metallopolymers as precursors to fabricate palladium nanoparticle/polymer hybrids for oxygen reduction.

    PubMed

    Edelman, Kate R; Stevenson, Keith J; Holliday, Bradley J

    2012-04-13

    The novel conducting metallopolymer [N,N'-((2,2'-dimethyl)propyl)bis(5-(2,2'-bithiophene-5-yl)salcylideniminato-palladium(II)](n) prepared by electropolymerization provides a polymer matrix in which the palladium metal centers are evenly distributed. The metal centers embedded directly in the conducting metallopolymer backbone serve as seed points for size-controlled palladium nanoparticle (NP) growth of 3.8 to 4.9 nm NPs within the conducting metallopolymer film. The palladium NP/conducting metallopolymer hybrid material has demonstrated electrocatalytic behavior toward oxygen reduction with peak current densities around 400 μA/cm(2) in acidic aqueous conditions. These results demonstrate a promising new method for the production of electrocatalytically active hybrid materials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Novel conducting polymer-heteropoly acid hybrid material for artificial photosynthetic membranes.

    PubMed

    McDonald, Michael B; Freund, Michael S

    2011-04-01

    Artificial photosynthetic (AP) approaches to convert and store solar energy will require membranes capable of conducting both ions and electrons while remaining relatively transparent and chemically stable. A new approach is applied herein involving previously described in situ chemical polymerization of electronically conducting poly(3,4-ethylenedioxythiophene) (PEDOT) in the presence of proton conducting heteropoly acid (HPA) phosphomolybdic acid (PMA). The electrochemical behaviour of the PEDOT/PMA hybrid material was investigated and it was found that the conducting polymer (CP) is susceptible to irreversible oxidative processes at potentials where water is oxidized. This will be problematic in AP devices should the process occur in very close proximity to a conducting polymer-based membrane. It was found that PEDOT grants the system good electrical performance in terms of conductivity and stability over a large pH window; however, the presence of PMA was not found to provide sufficient proton conductivity. This was addressed in an additional study by tuning the ionic (and in turn, electronic) conductivity in creating composites with the proton-permselective polymer Nafion. It was found that a material of this nature with near-equal conductivity for optimal chemical conversion efficiency will consist of roughly three parts Nafion and one part PEDOT/PMA.

  18. Current-dependent anisotropic conductivity of locally assembled silver nanoparticles in hybrid polymer films.

    PubMed

    Goel, Pooja; Vinokur, Rostislav; Weichold, Oliver

    2010-12-15

    The electrical behaviour of hybrid poly(ethylene terephthalate) films containing localised, percolating networks of silver nanoparticles separated by pure polymer is studied. The films resemble an array of parallel wires in the submicron range and, thus, exhibit anisotropic conductivity. In the high-conductivity direction at low amplitudes, the films show Ohmic behaviour, while at moderate voltage, non-linearity and a decreasing resistance is observed. The samples were found to heat up during the measurements and the deviation from Ohm's law coincides with the Tg of the polymer. Microstructural analysis of the samples revealed an irreversible agglomeration of the particles at moderate voltages leading to the formation of filaments with higher metallic character than the random particle network.

  19. 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.

  20. High Seebeck effects from conducting polymer: Poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) based thin-film device with hybrid metal/polymer/metal architecture

    SciTech Connect

    Stanford, Michael G; Wang, Hsin; Ivanov, Ilia N; Hu, Bin

    2012-01-01

    Conductive polymers are of particular interest for thermoelectric applications due to their low thermal conductivity and relatively high electrical conductivity. In this study, commercially available conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) was used in a hybrid metal/polymer/metal thin film design in order to achieve a high Seebeck coefficient with the value of 252lV/k on a relatively low temperature scale. Polymer film thickness was varied in order to investigate its influence on the Seebeck effect. The high Seebeck coefficient indicates that the metal/polymer/metal design can develop a large entropy difference in internal energy of charge carriers between high and low-temperature metal electrodes to develop electrical potential due to charge transport in conducting polymer film through metal/polymer interface. Therefore, the metal/polymer/metal structure presents a new design to combine inorganic metals and organic polymers in thin-film form to develop Seebeck devices

  1. Electrochemical co-deposition of conductive polymer-silica hybrid thin films.

    PubMed

    Raveh, Moran; Liu, Liang; Mandler, Daniel

    2013-07-14

    Conductive polymers, such as polypyrrole (ppy), have been the subject of numerous studies due to their promising applications in organic solar cells, flexible electronics, electrochromic devices, super capacitors, etc. Yet, their application is still limited as a result of poor processability. Silica has been reported to improve the mechanical strength and adhesion of conductive polymer films. In this work, we propose a controllable electrochemical approach for preparing ppy-silica hybrid thin films from a solution containing both pyrrole and silane monomers. It is known that pyrrole can be electropolymerised using anodic potentials, while silica can be electrodeposited under cathodic potentials. Thus, we studied the formation of ppy-silica hybrid thin films on a stainless steel surface by applying alternating potentials, i.e. cathodic followed by anodic pulses (denoted C + A) or anodic followed by cathodic pulses (denoted A + C). We show that by controlling the deposition potential and time for the cathodic and anodic pulses, the film thickness and composition can be manipulated well as analysed using profilometry and EDX. The element depth profile of the films was characterized using secondary ion mass spectroscopy (SIMS). In essence, for the C + A process, pyrrole diffuses through the cathodically electrodeposited wet silica gel layer and undergoes anodic polymerisation on the substrate, while for the A + C process, silane can be electrodeposited both on top of the anodically electrodeposited conductive ppy films as well as on the stainless steel through the pinholes in the ppy film. This offers a simple approach for tuning the structure of conductive polymer-sol-gel composite films.

  2. Hybrid solar cells with conducting polymers and vertically aligned silicon nanowire arrays: The effect of silicon conductivity

    NASA Astrophysics Data System (ADS)

    Woo, Sungho; Hoon Jeong, Jae; Kun Lyu, Hong; Jeong, Seonju; Hyoung Sim, Jun; Hyun Kim, Wook; Soo Han, Yoon; Kim, Youngkyoo

    2012-08-01

    Organic/inorganic hybrid solar cells, based on vertically aligned n-type silicon nanowires (n-Si NWs) and p-type conducting polymers (PEDOT:PSS), were investigated as a function of Si conductivity. The n-Si NWs were easily prepared from the n-Si wafer by employing a silver nanodot-mediated micro-electrochemical redox reaction. This investigation shows that the photocurrent-to-voltage characteristics of the n-Si NW/PEDOT:PSS cells clearly exhibit a stable rectifying diode behavior. The increase in current density and fill factor using high conductive silicon is attributed to an improved charge transport towards the electrodes achieved by lowering the device's series resistance. Our results also show that the surface area of the nanowire that can form heterojunction domains significantly influences the device performance.

  3. Conducting polymer-coated Physarum polycephalum towards the synthesis of bio-hybrid electronic devices

    NASA Astrophysics Data System (ADS)

    de Lacy Costello, B. J. P.; Mayne, R.; Adamatzky, A.

    2015-04-01

    This paper presents a generic method for the production of functionalized coatings on biological substrates. The specific method described involves the functionalization of the living plasmodial stage of Physarum polycephalum with the conducting organic polymer polypyrrole. The simple method involves localized treatment of tube sections with a solution of ferric chloride, followed by exposure to the vapour or a liquid solution of the pyrrole monomer. This technique enables the production of surface-coated conducting plasmodial tubes of certain lengths to be formed at specific points. Measurement of the electrical resistance of a 1 cm functionalized tube gave a value of 100 k? . The use of this selective functionalization technique means that the majority of the growing plasmodium remains unfunctionalized and living; thus, a true hybrid device is formed. It can be seen how a range of functionalized polymers and materials whereby a chemical activator, for the formation of the product (or the pre-cursor) can be added to P. polycephalum (or other organisms) followed by reaction to form a hybrid material.

  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. 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.

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

    PubMed

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

    2016-03-04

    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 PdCl4(-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.

  7. Electrochemical impedance sensing of DNA hybridization on conducting polymer film-modified diamond.

    PubMed

    Gu, Huiru; Su, Xiao di; Loh, Kian Ping

    2005-07-21

    The impedimetric sensing of DNA hybridization on polyaniline/polyacrylate (PANI/PAA)-modified boron-doped diamond (BDD) electrode has been investigated. An ultrathin film of PANI-PAA copolymer was electropolymerized onto the diamond surfaces to provide carboxylic groups for tethering to DNA sensing probes. The electrochemical impedance and the intrinsic electroactivity of the polymer-diamond interface were analyzed after the hybridization reaction with target and non-target DNA. The impedance measurement shows changes in the impedance modulus as well as electron-transfer resistance at the stage of probe DNA immobilization (single-strand), as well as after hybridization with target DNA (double-strand). DNA hybridization increases the capacitance of the polymer-DNA layer and reduces the overall impedance of the DNA-polymer-diamond stack significantly. The polymer-modified BDD electrode shows no detectable nonspecific adsorption, with good selectivity between the complementary DNA targets and the one-base mismatch targets. The detection limit was measured to be 2 x 10(-8) M at 1000 Hz. Denaturing test on the hybridized probe and subsequent reuse of the probe indicates chemical robustness of the sensor. Our results suggest that electropolymerization followed by the immobilization of biomolecules is a simple and effective way of creating a functional biomolecular scaffold on the diamond surface. In addition, label-free electrochemical impedance method can provide direct and noninvasive sensing of DNA hybridization on BDD.

  8. A Conductive Self-Healing Hybrid Gel Enabled by Metal-Ligand Supramolecule and Nanostructured Conductive Polymer.

    PubMed

    Shi, Ye; Wang, Ming; Ma, Chongbo; Wang, Yaqun; Li, Xiaopeng; Yu, Guihua

    2015-09-09

    Self-healing materials emerge as a fascinating class of materials important for various technological applications. However, achieving the synergistic characteristics of high conductivity, room-temperature self-healing ability, and decent mechanical properties still remains a critical challenge. Here we develop for the first time a hybrid gel based on self-assembled supramolecular gel and nanostructured polypyrrole that synergizes the dynamic assembly/disassembly nature of metal-ligand supramolecule and the conductive nanostructure of polypyrrole hydrogel and exhibits features of high conductivity (12 S m(-1)), appealing mechanical and electrical self-healing property without any external stimuli, and enhanced mechanical strength and flexibility. The attractive characteristics of the hybrid gel are further demonstrated by a flexible yet self-healable electrical circuit. Our work shows the great potential of self-healing hybrid gel system in flexible electronics and provides a useful strategy to design multifunctional self-healing materials.

  9. Highly conductive, capacitive, flexible and soft electrodes based on a 3D graphene-nanotube-palladium hybrid and conducting polymer.

    PubMed

    Kim, Hyun-Jun; Randriamahazaka, Hyacinthe; Oh, Il-Kwon

    2014-12-29

    Highly conductive, capacitive and flexible electrodes are fabricated by employing 3D graphene-nanotube-palladium nanostructures and a PEDOT:PSS conducting polymer. The fabricated flexible electrodes, without any additional metallic current collectors, exhibit increased charge mobility and good mechanical properties; they also allow greater access to the electrolyte ions and hence are suitable for flexible energy storage applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Silver Nanowire-IZO-Conducting Polymer Hybrids for Flexible and Transparent Conductive Electrodes for Organic Light-Emitting Diodes

    PubMed Central

    Yun, Ho Jun; Kim, Se Jung; Hwang, Ju Hyun; Shim, Yong Sub; Jung, Sun-Gyu; Park, Young Wook; Ju, Byeong-Kwon

    2016-01-01

    Solution-processed silver nanowire (AgNW) has been considered as a promising material for next-generation flexible transparent conductive electrodes. However, despite the advantages of AgNWs, some of their intrinsic drawbacks, such as large surface roughness and poor interconnection between wires, limit their practical application in organic light-emitting diodes (OLEDs). Herein, we report a high-performance AgNW-based hybrid electrode composed of indium-doped zinc oxide (IZO) and poly (3,4-ethylenediowythiophene):poly(styrenesulfonate) [PEDOT:PSS]. The IZO layer protects the underlying AgNWs from oxidation and corrosion and tightly fuses the wires together and to the substrate. The PEDOT:PSS effectively reduces surface roughness and increases the hybrid films’ transmittance. The fabricated electrodes exhibited a low sheet resistance of 5.9 Ωsq−1 with high transmittance of 86% at 550 nm. The optical, electrical, and mechanical properties of the AgNW-based hybrid films were investigated in detail to determine the structure-property relations, and whether optical or electrical properties could be controlled with variation in each layer’s thickness to satisfy different requirements for different applications. Flexible OLEDs (f-OLEDs) were successfully fabricated on the hybrid electrodes to prove their applicability; their performance was even better than those on commercial indium doped tin oxide (ITO) electrodes. PMID:27703182

  11. Silver Nanowire-IZO-Conducting Polymer Hybrids for Flexible and Transparent Conductive Electrodes for Organic Light-Emitting Diodes

    NASA Astrophysics Data System (ADS)

    Yun, Ho Jun; Kim, Se Jung; Hwang, Ju Hyun; Shim, Yong Sub; Jung, Sun-Gyu; Park, Young Wook; Ju, Byeong-Kwon

    2016-10-01

    Solution-processed silver nanowire (AgNW) has been considered as a promising material for next-generation flexible transparent conductive electrodes. However, despite the advantages of AgNWs, some of their intrinsic drawbacks, such as large surface roughness and poor interconnection between wires, limit their practical application in organic light-emitting diodes (OLEDs). Herein, we report a high-performance AgNW-based hybrid electrode composed of indium-doped zinc oxide (IZO) and poly (3,4-ethylenediowythiophene):poly(styrenesulfonate) [PEDOT:PSS]. The IZO layer protects the underlying AgNWs from oxidation and corrosion and tightly fuses the wires together and to the substrate. The PEDOT:PSS effectively reduces surface roughness and increases the hybrid films’ transmittance. The fabricated electrodes exhibited a low sheet resistance of 5.9 Ωsq‑1 with high transmittance of 86% at 550 nm. The optical, electrical, and mechanical properties of the AgNW-based hybrid films were investigated in detail to determine the structure-property relations, and whether optical or electrical properties could be controlled with variation in each layer’s thickness to satisfy different requirements for different applications. Flexible OLEDs (f-OLEDs) were successfully fabricated on the hybrid electrodes to prove their applicability; their performance was even better than those on commercial indium doped tin oxide (ITO) electrodes.

  12. Silver Nanowire-Conducting Polymer-ITO Hybrids for Flexible and Transparent Conductive Electrodes with Excellent Durability.

    PubMed

    Yoo, Ji Hoon; Kim, Yunkyung; Han, Mi Kyoung; Choi, Seonghwa; Song, Ki Yong; Chung, Kwang Choon; Kim, Ji Man; Kwak, Jeonghun

    2015-07-29

    Solution-processed silver nanowire (AgNW) films have attracted attention as transparent and conductive electrodes for flexible optoelectronic devices and touch screens, to replace sputtered indium-tin-oxide (ITO) films. However, the mechanical flexibility, environmental durability, and the optical (such as transparency and a haze) and electrical properties of the AgNW films should be improved for their practical application. In this work, high-performance and roll-to-roll processed AgNW-based hybrid electrodes comprising poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) ( PSS) and/or ITO are introduced. The optical and electrical properties of the AgNW films combined with PSS, ITO, or both of them were systematically examined. Among the films, the AgNW-PEDOT:PSS-ITO hybrid film exhibits a high transmittance (88%) and a low sheet resistance (44 Ω sq(-1)) with a small haze (1.9%). Moreover, the hybrid films show excellent durability to a variety of environmental stresses. By virtues of the high performance and durability, it is believed that the AgNW-PEDOT:PSS-ITO hybrid electrodes are highly suitable for practical use.

  13. Transparent and flexible conducting hybrid film combined with 3-Aminopropyltriethoxysilane-coated polymer and graphene

    NASA Astrophysics Data System (ADS)

    Jung, Daesung; Ko, Yong-Hun; Cho, Jumi; Adhikari, Prashanta Dhoj; Lee, Su Il; Kim, Yooseok; Song, Wooseok; Jung, Min Wook; Jang, Sung Won; Lee, Seung Youb; An, Ki-Seok; Park, Chong-Yun

    2015-12-01

    A simple approach to fabricate graphene hybrid film consisted of Graphene/3-aminopropyltriethoxysilane (APTES)/polyethylene terephthalate (PET) is presented, using self-assembled monolayers (SAMs) for enhancement of conductivity. The SAMs of APTES was prepared on ultraviolet-ozone (UVO)-irradiated PET films via wet chemical technique. The density of APTES was saturated after UV treatment time of 1 h for PET films; the carrier density and the optical transmittance were 9.3 × 10 12/cm2 and 82% for pristine graphene and 1.16 × 1013/cm2 and 86% for graphene hybrid films, respectively, and experienced at inflection point at 30 min in UV treatment time. This behavior can be explained by surface morphology transition due to coalescence or clustering of mobile and low-molecular-weight oxidized components of PET.

  14. Breaking through the Solid/Liquid Processability Barrier: Thermal Conductivity and Rheology in Hybrid Graphene-Graphite Polymer Composites.

    PubMed

    Varenik, Maxim; Nadiv, Roey; Levy, Idan; Vasilyev, Gleb; Regev, Oren

    2017-03-01

    Thermal conductivity (TC) enhancement of an insulating polymer matrix at low filler concentration is possible through the loading of a high aspect ratio, thermally conductive single filler. Unfortunately, the dispersion of high-aspect-ratio particles greatly influences the rheological behavior of the polymer host at relatively low volume fractions, which makes further polymer processing or mixing difficult. A possible remedy is using two (hybrid) fillers, differing in their aspect ratios: (1) a plate-like filler, which sharply increases both viscosity and TC, and (2) an isotropic filler, which gradually increases these properties. We examine this hypothesis in a thermosetting silicone rubber by loading it with different ratios, (1)/(2), of graphene nanoplatelets (GNPs) (1) and graphite powder (2). We constructed a "phase diagram" delineating two composite processability regions: solid-like (moldable) or fluid-like (pourable). This diagram may be employed to tailor the mixture's viscosity to a desired TC value by varying the fillers' volume fraction. The phase diagram highlights the low volume fraction value, above which the composite is solid-like (low processability) for a single high-aspect-ratio nanofiller. By using hybrid filling, one can overcome this limit and prepare a fluid-like composite at a desired TC, not accessible by the single nanofiller. Thus, it provides an indicative tool for polymer processing, especially in applications such as the encapsulation of electronic devices. This approach was demonstrated for a heat source (resistor) potted by silicon rubber graphene-graphite composites, for which a desired TC was obtained in both solid- and liquid-like regions.

  15. Covalent organic/inorganic hybrid proton-conductive membrane with semi-interpenetrating polymer network: Preparation and characterizations

    NASA Astrophysics Data System (ADS)

    Fu, Rong-Qiang; Woo, Jung-Je; Seo, Seok-Jun; Lee, Jae-Suk; Moon, Seung-Hyeon

    2008-05-01

    A series of new covalent organic/inorganic hybrid proton-conductive membranes, each with a semi-interpenetrating polymer network (semi-IPN), for direct methanol fuel cell (DMFC) applications is prepared through the following sequence: (i) copolymerization of impregnated styrene (St), p-vinylbenzyl chloride (VBC) and divinylbenzene (DVB) within a supporting polyvinyl chloride (PVC) film; (ii) reaction of the chloromethyl group with 3-(methylamine)propyl-trimethoxysilane (MAPTMS); (ii) a sol-gel process under acidic conditions; (iv) a sulfonation reaction. The developed membranes are characterized in terms of Fourier transform infrared/attenuated total reflectance (FTIR/ATR), scanning electron microscopy/energy-dispersive X-ray analysis (SEM/EDXA), elemental analysis (EA) and thermogravimetric analysis (TGA), which confirm the formation of the target membranes. The developed copolymer chains are interpenetrating with the PVC matrix to form the semi-IPN structure, and the inorganic silica is covalently bound to the copolymers. These features provide the membranes with high mechanical strength. The effect of silica content is investigated. As the silica content increases, proton conductivity and water content decrease, whereas oxidative stability is improved. In particular, methanol permeability and methanol uptake are reduced largely by the silica. The ratio of proton conductivity to methanol permeability for the hybrid membranes is higher than that of Nafion 117. All these properties make the hybrid membranes a potential candidate for DMFC applications.

  16. Polymers that Conduct Electricity.

    ERIC Educational Resources Information Center

    Edelson, Edward

    1983-01-01

    Although polymers are regarded as electrical insulators, it was discovered that they can be made to conduct electricity. This discovery has opened vast new practical and theoretical areas for exploration by physicists and chemists. Research studies with these conducting polymers and charge-transfer salts as well as possible applications are…

  17. Thermally conductive polymers

    NASA Technical Reports Server (NTRS)

    Byrd, N. R.; Jenkins, R. K.; Lister, J. L. (Inventor)

    1971-01-01

    A thermally conductive polymer is provided having physical and chemical properties suited to use as a medium for potting electrical components. The polymer is prepared from hydroquinone, phenol, and formaldehyde, by conventional procedures employed for the preparation of phenol-formaldehyde resins. While the proportions of the monomers can be varied, a preferred polymer is formed from the monomers in a 1:1:2.4 molar or ratio of hydroquinone:phenol:formaldehyde.

  18. Highly Efficient Microwave Absorption of Magnetic Nanospindle-Conductive Polymer Hybrids by Molecular Layer Deposition.

    PubMed

    Yan, Lili; Wang, Xixi; Zhao, Shichao; Li, Yunqin; Gao, Zhe; Zhang, Bin; Cao, Maosheng; Qin, Yong

    2017-03-16

    Oxidative molecular layer deposition (oMLD) was applied to fabricate conductive polymer-magnetic material core-shell microwave absorbers in this work. One dimensional Fe3O4-poly(3,4-ethylenedioxythiophene) (PEDOT) nanospindles with controllable PEDOT thickness were successfully synthesized. Their absorption performance was evaluated in the 2-18 GHz frequency range. With the advantage of oMLD, PEDOT shell thicknesses can be controlled precisely. Because the permittivity of Fe3O4-PEDOT nanospindles obviously increases while their permeability decreases slightly with the PEDOT cycles, the properties can be tuned effectively by only adjusting the PEDOT cycle number. With a proper PEDOT shell thickness, excellent reflection characteristics can be obtained. Remarkably high absorption strength (-55.0 dB at 16.2 GHz) and good absorption bandwidth (4.34 GHz less than -10 dB) were realized. Such excellent performance is better than that reported previously for most magnetic material-based absorbers. Considering the precise controllability and excellent absorption performance of the prepared microwave absorbers, we believe that oMLD is a facile synthetic route for microwave absorbers.

  19. Electrical conductive coordination polymers.

    PubMed

    Givaja, Gonzalo; Amo-Ochoa, Pilar; Gómez-García, Carlos J; Zamora, Félix

    2012-01-07

    Coordination polymers are currently one of the hottest topics in Inorganic and Supramolecular Chemistry. This critical review summarizes the current state-of-the-art on electrical conductive coordination polymers (CPs), also named metal-organic frameworks (MOFs). The data were collected following two sort criteria of the CPs structure: dimensionality and bridging ligands (151 references). This journal is © The Royal Society of Chemistry 2012

  20. Conducting polymer-metal hybrid materials: Towards tunable redox control over transition metal properties?

    NASA Astrophysics Data System (ADS)

    Weinberger, Dana Alise

    2000-10-01

    Terthienyl-based redox-switchable hemilabile ligands, 3' -(2-diphenylphosphinoethyl)-5,5″-dimethyl-2,2 ': 5',2″-terthiophene and 3'-(2-diphenylphosphinoethyl)-2,2':5,2 ″-terthiophene have been synthesized and fully characterized. Mononuclear, dinuclear, and polymeric Ru(II) complexes formed from these ligands demonstrate that this class of ligand provides electrochemical control over the electronic properties, coordination environments, and reactivities of bound transition metals. Specifically, [CpRuCO(kappa2-3 '-(2-diphenylphosphinoethyl)-5,5″-dimethyl-2,2 ':5',2″-terthiophene)][B(C 6H3-3,5-(CF3)2)4] ( 4a) exhibits a three order of magnitude increase in binding affinity for acetonitrile upon terthienyl-based oxidation. FT-IR spectroelectrochemical experiments on 4a indicate that terthienyl-based oxidation removes electron density from the metal center, equivalent to approximately 11--17% of the electronic change that occurs upon direct oxidation of Ru(II) to Ru(III) in analogous complexes. The FT-IR spectroelectrochemical responses of 4a were compared to those of dimeric and polymeric analogues of 4a. The spectroelectrochemistry of the dimer is consistent with two, sequential, one-electron ligand-based oxidations, compared to only one in 4a. In contrast, the polymer exhibits spectroelectrochemical behavior similar to that of 4a. The polymer spectroelectrochemistry shows changes in the metal center electronic properties between two different states, reflective of two discrete oxidation states of the polymeric ligand backbone. We propose that the polymer backbone does not allow one to vary the electronic properties of the metal center through a continuous range of oxidation states due to charge localization within the metallated films. The oxidation state dependent coordination chemistries of 4a and 4a + with a variety of substrates were studied. Dip-Pen Nanolithography (DPN) has been used to deposit monolayer-based resists with micron to sub-100 nm

  1. Organic-inorganic hybrid thin film solar cells using conducting polymer and gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Hwan Jung, Hyung; Ho Kim, Dong; Su Kim, Chang; Bae, Tae-Sung; Bum Chung, Kwun; Yoon Ryu, Seung

    2013-05-01

    We employed poly(styrenesulfonate)-doped poly (3,4-ethylenedioxythiophene) (PEDOT:PSS) as a p-layer on textured fluorine-tin-oxide (FTO) glass in pin-type hydrogenated amorphous silicon solar cells (a-Si:H SCs). An amorphous tungsten oxide (WO3) layer and gold nanoparticles (Au-NPs) 10 nm in size were included to prevent the degradation and to increase short-circuit current by the Plasmon effect, respectively, between the PEDOT:PSS and intrinsic-Si layer. The energy band between PEDOT:PSS and WO3 was meaningfully adjusted by Au-NPs. The p-type PEDOT:PSS layer in these organic-inorganic hybrid a-Si:H SCs results in an increased conversion efficiency from ˜2.42% to ˜5.49% and an increased open-circuit voltage from ˜0.29 V to ˜0.56 V. PEDOT:PSS on textured FTO glass is sufficiently showing that it can replace the p-type Si layer in pin-type a-Si:H SCs.

  2. Thermoelectric Properties of Conducting Polymers

    DTIC Science & Technology

    1994-07-01

    polyphenylene sulfide , all of which are made conductive by addition of carbon. Polymers made conductive in this way do not have a high Seebeck...merit. KEYWORDS: Polyaniline, conducting polymer, conductive vinyl, conductive nylon, conductive polyphenylene sulfide , polyoctylthiophene, Schiff’s...directions. Polyphenylene sulfide (Ryton) A conductive form of this material, which is commercially available, is made conductive by the presence of carbon

  3. Conducting polymer ultracapacitor

    DOEpatents

    Shi, Steven Z.; Davey, John R.; Gottesfeld, Shimshon; Ren, Xiaoming

    2002-01-01

    A sealed ultracapacitor assembly is formed with first and second electrodes of first and second conducting polymers electrodeposited on porous carbon paper substrates, where the first and second electrodes each define first and second exterior surfaces and first and second opposing surfaces. First and second current collector plates are bonded to the first and second exterior surfaces, respectively. A porous membrane separates the first and second opposing surfaces, with a liquid electrolyte impregnating the insulating membrane. A gasket formed of a thermoplastic material surrounds the first and second electrodes and seals between the first and second current collector plates for containing the liquid electrolyte.

  4. Transparent conducting hybrid thin films fabricated by layer-by-layer assembly of single-wall carbon nanotubes and conducting polymers

    NASA Astrophysics Data System (ADS)

    Sim, Jun-Bo; Yang, Hyun-Ho; Lee, Min-Jae; Yoon, Jun-Bo; Choi, Sung-Min

    2012-08-01

    The effect of conducting polymers on the performance of transparent conducting SWNT thin films fabricated by the layer-by-layer (LBL) assembly has been investigated. Transparent conducting SWNT thin films were fabricated by the LBL assembly in two ways, one using conducting polymers, PEDOT-PEG, and the other using non-conducting polymers, PAH, and their electrical and optical properties were compared. The sheet resistance of (PSS-SWNT/PEDOT-PEG) n films is more than thrice lower than that of (PSS-SWNT/PAH) n films for the same n while the decrease of optical transmittance due to the absorbance of PEDOT-PEG is fairly small (ca. 2 % at n=30). The conductivity ratio of the (PSS-SWNT/PEDOT-PEG)30 is 3.3 times larger than that of the (PSS-SWNT/PAH)30. These figures indicate that the performance of the transparent conducting SWNT thin films fabricated by the LBL assembly is highly improved by using conducting polymers instead of non-conducting ones.

  5. Program for Research on Conducting Polymers

    DTIC Science & Technology

    1991-07-17

    material derived from all monomers). Unfortunately the copper is tenaciously entrained in these materials So that new approaches to couple I hybridized ...characterization of new conducting polymers, processing of these conducting polymers into highly oriented fibers and films, and measurement of the electrical and...is now clear (largely as a result of the effort at UCSB) that the desired combination of properties is available: Electrical and Optical Properties

  6. Electrical conduction in polymer dielectrics

    NASA Technical Reports Server (NTRS)

    Cotts, D. B.

    1985-01-01

    The use of polymer dielectrics with moderate resistivities could reduce or eliminate problems associated with spacecraft charging. The processes responsible for conduction and the properties of electroactive polymers are reviewed, and correlations drawn between molecular structure and electrical conductivity. These structure-property relationships led to the development of several new electroactive polymer compositions and the identification of several systems that have the requisite thermal, mechanical, environmental and electrical properties for use in spacecraft.

  7. Processable Electronically Conducting Polymers

    DTIC Science & Technology

    1991-01-01

    is also evident in the electronic spectra of the polymer as the (CH)x formed in this manner has a band gap (absorption onset) at -1.9 eV (650 nm) and...an absorption maximum at 2.8 eV (440 nm) (compared to a band gap of 1.4 eV (885 nm) for Shirakawa (CH)x). As is the case with Durham (CH)x, orientation...annulated ring system locks the polymer into a stable conformation, and thus the optical band gaps of the mono- and disubstituted species are at

  8. Nanocomposite of p-type conductive polymer/functionalized graphene oxide nanosheets as novel and hybrid electrodes for highly capacitive pseudocapacitors.

    PubMed

    Ehsani, A; Mohammad Shiri, H; Kowsari, E; Safari, R; Torabian, J; Kazemi, S

    2016-09-15

    An effective approach for increasing the life cycle of poly ortho aminophenol (POAP) as a p-type conductive polymers is combining conventional conductive polymers and nanomaterials to fabricate hybrid electrodes. In this paper, functionalized graphene oxide (FGO) has first been synthesized using a chemical approach. Hybrid POAP/FGO films have then been fabricated by POAP electropolymerization in the presence of FGO nanoparticles as active electrodes for electrochemical supercapacitors. Based on the atomic scale study results, it seems that H3PO4(-) oxygen atoms and terminal pyridine ring nitrogen atoms play a crucial role in the intramolecular charge and energy transfer in the FGO molecular systems. Theoretical studies, surface and electrochemical analyses have been used for characterization of POAP/FGO composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. This work introduces new nanocomposite materials for electrochemical redox capacitors with such advantages as the ease of synthesis, high active surface area and stability in an aqueous electrolyte.

  9. Conducting polymer-hydrogels for medical electrode applications

    PubMed Central

    Green, Rylie A; Baek, Sungchul; Poole-Warren, Laura A; Martens, Penny J

    2010-01-01

    Conducting polymers hold significant promise as electrode coatings; however, they are characterized by inherently poor mechanical properties. Blending or producing layered conducting polymers with other polymer forms, such as hydrogels, has been proposed as an approach to improving these properties. There are many challenges to producing hybrid polymers incorporating conducting polymers and hydrogels, including the fabrication of structures based on two such dissimilar materials and evaluation of the properties of the resulting structures. Although both fabrication and evaluation of structure–property relationships remain challenges, materials comprised of conducting polymers and hydrogels are promising for the next generation of bioactive electrode coatings. PMID:27877322

  10. Conductive polymer-based material

    DOEpatents

    McDonald, William F.; Koren, Amy B.; Dourado, Sunil K.; Dulebohn, Joel I.; Hanchar, Robert J.

    2007-04-17

    Disclosed are polymer-based coatings and materials comprising (i) a polymeric composition including a polymer having side chains along a backbone forming the polymer, at least two of the side chains being substituted with a heteroatom selected from oxygen, nitrogen, sulfur, and phosphorus and combinations thereof; and (ii) a plurality of metal species distributed within the polymer. At least a portion of the heteroatoms may form part of a chelation complex with some or all of the metal species. In many embodiments, the metal species are present in a sufficient concentration to provide a conductive material, e.g., as a conductive coating on a substrate. The conductive materials may be useful as the thin film conducting or semi-conducting layers in organic electronic devices such as organic electroluminescent devices and organic thin film transistors.

  11. Conductive Polymers via Reactive Aligomer.

    DTIC Science & Technology

    1987-01-30

    properties are presumably due to the formation of dibenzothiophene units 7 .! 9 NADC-87038-60 and intermolecular crosslinking(1 6). Frommer and...2), 280, (1984). 17. J.E. Frommer and R.R. Chance, "Electrically Conductive Polymers", Encycoedia of Polymer Science and Engineering. V. 5, Second

  12. Temperature-responsive polymer/carbon nanotube hybrids: smart conductive nanocomposite films for modulating the bioelectrocatalysis of NADH.

    PubMed

    Zhao, Xin; Liu, Yang; Lu, Jin; Zhou, Jianhua; Li, Jinghong

    2012-03-19

    A temperature-sensitive polymer/carbon nanotube interface with switchable bioelectrocatalytic capability was fabricated by self-assembly of poly(N-isopropylacrylamide)-grafted multiwalled carbon nanotubes (MWNT-g-PNIPAm) onto the PNIPAm-modified substrate. Electron microscopy and electrochemical measurements revealed that these fairly thick (>6 μm) and highly porous nanocomposite films exhibited high conductivity and electrocatalytic activity. The morphological transitions in both the tethered PNIPAm chains on a substrate and those polymers wrapping around the MWNT surface resulted in the opening, closing, or tuning of its permeability, and simultaneously an electron-transfer process took place through the channels formed in the nanostructure in response to temperature change. By combining the good electron-transfer and electrochemical catalysis capabilities, the large surface area, and good biocompatibility of MWNTs with the responsive features of PNIPAm, reversible temperature-controlled bioelectrocatalysis of 1,4-dihydro-β-nicotinamide adenine dinucleotide with improved sensitivity has been demonstrated by cyclic voltammetry and electrochemical impedance spectroscopy measurements. The mechanism behind this approach was studied by Raman spectroscopy, in situ attenuated total reflection FTIR spectroscopy, and contact angle measurements. The results also suggested that the synergetic or cooperative interactions of PNIPAm with MWNTs gave rise not only to an increase in surface wettability, but also to the enhancement of the interfacial thermoresponsive behavior. This bioelectrocatalytic "smart" system has potential applications in the design of biosensors and biofuel cells with externally controlled activity. Furthermore, this concept might be proposed for biomimetics, interfacial engineering, bioelectronic devices, and so forth.

  13. 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.

  14. 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 (RCT) 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.

  15. Conducting polymers: Synthesis and industrial applications

    SciTech Connect

    Gottesfeld, S.

    1997-04-01

    The Conducting Polymer project funded by the AIM Program has developed new methods for the synthesis of conducting polymers and evaluated new industrial applications for these materials which will result in significant reductions in energy usage or industrial waste. The applications specifically addressed during FY 1996 included two ongoing efforts on membranes for gas separation and on electrochemical capacitors and a third new application: electrochemical reactors (ECRs) based on polymeric electrolytes. As a gas separation membrane, conducting polymers offer high selectivity and the potential to chemically or electrically adapt the membrane for specific gas combinations. Potential energy savings in the US for this application are estimated at 1 to 3 quads/yr. As an active material in electrochemical capacitors, electronically conducting polymers have the potential of storing large amounts of electric energy in low cost materials. Potential energy savings estimated at 1 quad/yr would result from introduction of electrochemical capacitors as energy storage devices in power trains of electric and hybrid vehicles, once such vehicles reach 20% of the total transportation market in the US. In the chlor-alkali industry, electrochemical reactors based on polymer electrolyte membranes consume around 1 % of the total electric power in the US. A new activity, started in FY 1996, is devoted to energy efficient ECRs. In the case of the chlor-alkali industry, energy savings as high as 50% seem possible with the novel ECR technology demonstrated by the author in 1996.

  16. Hybrid polymer microspheres

    NASA Technical Reports Server (NTRS)

    Rembaum, A.

    1980-01-01

    Techniques have been successfully tested for bonding polymeric spheres, typically 0.1 micron in diameter, to spheres with diameter up to 100 microns. Hybrids are being developed as improved packing material for ion-exchange columns, filters, and separators.

  17. Electrospun porous conductive polymer membranes

    NASA Astrophysics Data System (ADS)

    Wang, Jingwen; Naguib, Hani E.; Bazylak, Aimy

    2012-04-01

    In this work, two methodologies were used in fabricating conductive electrospun polymer fibers with nano features. We first investigated the addition of multiwall carbon nanotubes (MWCNT) as conductive fillers at concentrations ranging from 1 to 10% into a polystyrene (PS) matrix. Electrospinning conditions were tailored to produce fibers with minimal beads. Next, we investigated the effects of coating electrospun fibers with nano structured conductive polymer. Oxidant (FeCl3) fibers were electrospun in PS and then exposed to a pyrrole (Py) monomer in a vacuum chamber. As a result, polypyrrole (PPy) was coated on the fibers creating conductive pathways. In both methods, the electrospun conductive fibers were characterized in terms of their morphologies, thermal stability and electrical conductivity. Strong correlations were found among PPy coating nanostructures, oxidant concentration and polymerization time. Electrospun fibrous membranes with conductive polymer coating exhibit much higher electrical conductivities compare to fibers with conductive fillers. Highest conductivity achieved was 9.5E-4 S/cm with 40% FeCl3/PS fibers polymerized with Py for 140 min.

  18. 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.

  19. 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.

  20. New Directions in Conductive Polymers

    DTIC Science & Technology

    1988-08-15

    0 TIC FILE CO~h o Final Technical Report0(August 15, 1988) N Office of Naval Research N00014-85-K-0098 I0 New Directions in Conductive Polymers...statement of the success of this funding, we note that the National Sciemce Foundation has initiated a Materials Research Group within the Institute for

  1. Conducting polymer electrodes for electroencephalography.

    PubMed

    Leleux, Pierre; Badier, Jean-Michel; Rivnay, Jonathan; Bénar, Christian; Hervé, Thierry; Chauvel, Patrick; Malliaras, George G

    2014-04-01

    Conducting polymer electrodes are developed on a flexible substrate for electroencephalography applications. These electrodes yield higher quality recordings than dry electrodes made from metal. Their performance is equivalent to commercial gel-assisted electrodes, paving the way for non-invasive, long-term monitoring of the human brain.

  2. 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.

  3. The Workshop on Conductive Polymers: Final Report

    DOE R&D Accomplishments Database

    1985-10-01

    Reports are made by groups on: polyacetylene, polyphenylene, polyaniline, and related systems; molecular, crystallographic, and defect structures in conducting polymers; heterocyclic polymers; synthesis of new and improved conducting polymers; future applications possibilities for conducting polymers; and challenges for improved understanding of properties. (DLC)

  4. The workshop on conductive polymers: Final report

    SciTech Connect

    Not Available

    1985-01-01

    Reports are made by groups on: polyacetylene, polyphenylene, polyaniline, and related systems; molecular, crystallographic, and defect structures in conducting polymers; heterocyclic polymers; synthesis of new and improved conducting polymers; future applications possibilities for conducting polymers; and challenges for improved understanding of properties. (DLC)

  5. Water-soluble conductive polymers

    DOEpatents

    Aldissi, Mahmoud

    1990-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  6. Water-soluble conductive polymers

    DOEpatents

    Aldissi, Mahmoud

    1989-01-01

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  7. Water-soluble conductive polymers

    DOEpatents

    Aldissi, M.

    1988-02-12

    Polymers which are soluble in water and are electrically conductive. The monomer repeat unit is a thiophene or pyrrole molecule having an alkyl group substituted for the hydrogen atom located in the beta position of the thiophene or pyrrole ring and having a surfactant molecule at the end of the alkyl chain. Polymers of this class having 8 or more carbon atoms in the alkyl chain exhibit liquid crystalline behavior, resulting in high electrical anisotropy. The monomer-to-monomer bonds are located between the carbon atoms which are adjacent to the sulfur or nitrogen atoms. The number of carbon atoms in the alkyl group may vary from 1 to 20 carbon atoms. The surfactant molecule consists of a sulfonate group, or a sulfate group, or a carboxylate group, and hydrogen or an alkali metal. Negative ions from a supporting electrolyte which may be used in the electrochemical synthesis of a polymer may be incorporated into the polymer during the synthesis and serve as a dopant to increase the conductivity.

  8. Composites incorporated a conductive polymer nanofiber network

    DOEpatents

    Pozzo, Lilo Danielle; Newbloom, Gregory

    2017-04-11

    Methods of forming composites that incorporate networks of conductive polymer nanofibers are provided. Networks of less-than conductive polymers are first formed and then doped with a chemical dopant to provide networks of conductive polymers. The networks of conductive polymers are then incorporated into a matrix in order to improve the conductivity of the matrix. The formed composites are useful as conductive coatings for applications including electromagnetic energy management on exterior surfaces of vehicles.

  9. Electrically conductive polymer concrete coatings

    DOEpatents

    Fontana, Jack J.; Elling, David; Reams, Walter

    1990-01-01

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  10. Electrically conductive polymer concrete coatings

    DOEpatents

    Fontana, J.J.; Elling, D.; Reams, W.

    1990-03-13

    A sprayable electrically conductive polymer concrete coating for vertical d overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt % calcined coke breeze, 40 wt % vinyl ester with 3.5 wt % modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag.

  11. Electrically conductive polymer concrete coatings

    DOEpatents

    Fontana, J.J.; Elling, D.; Reams, W.

    1988-05-26

    A sprayable electrically conductive polymer concrete coating for vertical and overhead applications is described. The coating is permeable yet has low electrical resistivity (<10 ohm-cm), good bond strength to concrete substrates, and good weatherability. A preferred formulation contains about 60 wt% calcined coke breeze, 40 wt% vinyl ester resin with 3.5 wt% modified bentonite clay. Such formulations apply evenly and provide enough rigidity for vertical or overhead structures so there is no drip or sag. 4 tabs.

  12. Ion-Conducting Organic/Inorganic Polymers

    NASA Technical Reports Server (NTRS)

    Kinder, James D.; Meador, Mary Ann B.

    2007-01-01

    Ion-conducting polymers that are hybrids of organic and inorganic moieties and that are suitable for forming into solid-electrolyte membranes have been invented in an effort to improve upon the polymeric materials that have been used previously for such membranes. Examples of the prior materials include perfluorosulfonic acid-based formulations, polybenzimidazoles, sulfonated polyetherketone, sulfonated naphthalenic polyimides, and polyethylene oxide (PEO)-based formulations. Relative to the prior materials, the polymers of the present invention offer greater dimensional stability, greater ease of formation into mechanically resilient films, and acceptably high ionic conductivities over wider temperature ranges. Devices in which films made of these ion-conducting organic/inorganic polymers could be used include fuel cells, lithium batteries, chemical sensors, electrochemical capacitors, electrochromic windows and display devices, and analog memory devices. The synthesis of a polymer of this type (see Figure 1) starts with a reaction between an epoxide-functionalized alkoxysilane and a diamine. The product of this reaction is polymerized by hydrolysis and condensation of the alkoxysilane group, producing a molecular network that contains both organic and inorganic (silica) links. The silica in the network contributes to the ionic conductivity and to the desired thermal and mechanical properties. Examples of other diamines that have been used in the reaction sequence of Figure 1 are shown in Figure 2. One can use any of these diamines or any combination of them in proportions chosen to impart desired properties to the finished product. Alternatively or in addition, one could similarly vary the functionality of the alkoxysilane to obtain desired properties. The variety of available alkoxysilanes and diamines thus affords flexibility to optimize the organic/inorganic polymer for a given application.

  13. Electrosynthesis of neodymium oxide nanorods and its nanocomposite with conjugated conductive polymer as a hybrid electrode material for highly capacitive pseudocapacitors.

    PubMed

    Mohammad Shiri, Hamid; Ehsani, Ali

    2017-06-01

    Herein, we report for the first time a facile and cost-efficient synthesis of metal oxide nanostructures comprised of nanorods type without the use of any additive. Nd(OH)3 and Nd2O3 nanorods were obtained by ultrasound wave assisted pulse electrochemical deposition in a Nd(NO3)3·6H2O nitrate bath. In addition, the interconnected nanorods were mesoporous leading to large electrochemical active sites for the redox reaction and fast ion transport within the Nd2O3 nanorods. Furthermore, for improving the electrochemical performance of conductive polymer, hybrid POAP/Nd2O3 films have then been fabricated by POAP electropolymerization in the presence of Nd2O3 nanorods as active electrodes for electrochemical supercapacitors. Surface and electrochemical analyses have been used for characterization of Nd2O3 and POAP/Nd2O3 composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. Prepared composite film exhibited a significantly high specific capacity, high rate capability and excellent cycling stability. Importantly, electrochemical investigation show that POAP/Nd2O3 nanorods composite material has better properties than POAP without Nd2O3 nanorods, suggesting it can be used as supercapacitor electrode material with excellent specific capacitance (379Fg(-1)) which indicates this material is a promising electrode material for energy storage applications in high-performance pseudocapacitors.

  14. Conductivity fluctuations in polymer's networks

    NASA Astrophysics Data System (ADS)

    Samukhin, A. N.; Prigodin, V. N.; Jastrabík, L.

    1998-01-01

    A Polymer network is treated as an anisotropic fractal with fractional dimensionality D = 1 + ε close to one. Percolation model on such a fractal is studied. Using real space renormalization group approach of Migdal and Kadanoff, we find the threshold value and all the critical exponents in the percolation model to be strongly nonanalytic functions of ε, e.g. the critical exponent of the conductivity was obtained to be ε-2 exp (-1 - 1/ε). The main part of the finite-size conductivities distribution function at the threshold was found to be universal if expressed in terms of the fluctuating variable which is proportional to a large power of the conductivity, but with ε-dependent low-conductivity cut-off. Its reduced central momenta are of the order of e -1/ε up to a very high order.

  15. 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

  16. Electronically Conductive Composite Polymer Membranes.

    DTIC Science & Technology

    1985-09-20

    coats the individual fibers which make up the webs. Clearly, at this loading level ( 10 w/w S Nafion in the Gr), only a small fraction of the...NOO014-82K-0612 Task No. NR 627-838 cc TECHNICAL REPORT NO. 10 Mn Electronically Conductive Composite Polymer Membranes I- I by 0 Reginald M. Penner... 10 of Document Control Data - DO Form 1473. Copies of form available from cognizant contract administrator 85 IV, 03 O88 UNCLASSI FIED SECURITY

  17. Electrically conducting polymers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. R.; Meador, Michael A.

    1991-01-01

    Current research on electrically conducting polymers from 1974 to the present is reviewed focusing on the development of materials for aeronautic and space applications. Problems discussed include extended pi-systems, pyrolytic polymers, charge-transfer systems, conductive matrix resins for composite materials, and prospects for the use of conducting polymers in space photovoltaics.

  18. Electrically conducting polymers for aerospace applications

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. R.; Meador, Michael A.

    1991-01-01

    Current research on electrically conducting polymers from 1974 to the present is reviewed focusing on the development of materials for aeronautic and space applications. Problems discussed include extended pi-systems, pyrolytic polymers, charge-transfer systems, conductive matrix resins for composite materials, and prospects for the use of conducting polymers in space photovoltaics.

  19. Hybrid silicon nanocone-polymer solar cells.

    PubMed

    Jeong, Sangmoo; Garnett, Erik C; Wang, Shuang; Yu, Zongfu; Fan, Shanhui; Brongersma, Mark L; McGehee, Michael D; Cui, Yi

    2012-06-13

    Recently, hybrid Si/organic solar cells have been studied for low-cost Si photovoltaic devices because the Schottky junction between the Si and organic material can be formed by solution processes at a low temperature. In this study, we demonstrate a hybrid solar cell composed of Si nanocones and conductive polymer. The optimal nanocone structure with an aspect ratio (height/diameter of a nanocone) less than two allowed for conformal polymer surface coverage via spin-coating while also providing both excellent antireflection and light trapping properties. The uniform heterojunction over the nanocones with enhanced light absorption resulted in a power conversion efficiency above 11%. Based on our simulation study, the optimal nanocone structures for a 10 μm thick Si solar cell can achieve a short-circuit current density, up to 39.1 mA/cm(2), which is very close to the theoretical limit. With very thin material and inexpensive processing, hybrid Si nanocone/polymer solar cells are promising as an economically viable alternative energy solution.

  20. Direct writing of conducting polymers.

    PubMed

    Aydemir, Nihan; Parcell, James; Laslau, Cosmin; Nieuwoudt, Michel; Williams, David E; Travas-Sejdic, Jadranka

    2013-08-01

    Described herein is a new printing method-direct writing of conducting polymers (CPs)-based on pipette-tip localized continuous electrochemical growth. A single barrel micropipette containing a metal wire (Pt) is filled with a mixture of monomer, supporting electrolyte, and an appropriate solvent. A droplet at the tip of the pipette contacts the substrate, which becomes the working electrode of a micro-electrochemical cell confined to the tip droplet and the pipette. The metallic wire in the pipette acts as both counter and reference electrode. Electropolymerization forms the CP on the working electrode in a pattern controlled by the movement of the pipette. In this study, various width poly(pyrrole) 2D and 3D structures are extruded and characterized in terms of microcyclic voltammetry, Raman spectroscopy, and scanning electron microscopy.

  1. Conductive hydrogels: mechanically robust hybrids for use as biomaterials.

    PubMed

    Green, Rylie A; Hassarati, Rachelle T; Goding, Josef A; Baek, Sungchul; Lovell, Nigel H; Martens, Penny J; Poole-Warren, Laura A

    2012-04-01

    A hybrid system for producing conducting polymers within a doping hydrogel mesh is presented. These conductive hydrogels demonstrate comparable electroactivity to conventional conducting polymers without requiring the need for mobile doping ions which are typically used in literature. These hybrids have superior mechanical stability and a modulus significantly closer to neural tissue than materials which are commonly used for medical electrodes. Additionally they are shown to support the attachment and differentiation of neural like cells, with improved interaction when compared to homogeneous hydrogels. The system provides flexibility such that biologic incorporation can be tailored for application.

  2. Nanostructured conducting polymers and their biomedical applications.

    PubMed

    Wang, G W; Lu, Y N; Wang, L P; Wang, H J; Wang, J Y

    2014-01-01

    Much attention has been paid to nanostructured conducting polymers due to their unique properties, which arise from their nanoscale size, such as their large surface area, high electrical conductivity, electrochemical stability and quantum effects. This article reviews three methods to synthesize nanostructured conducting polymers and their applications in the biomedical field, focusing specifically on neural probes, biosensors, artificial muscles or actuators and controlled drug release. Challenges and future directions of these nanostructured conducting polymer are also discussed.

  3. Conducting Polymers for Neutron Detection

    SciTech Connect

    Kimblin, Clare; Miller, Kirk; Vogel, Bob; Quam, Bill; McHugh, Harry; Anthony, Glen; Mike, Grover

    2007-12-01

    Conjugated polymers have emerged as an attractive technology for large-area electronic applications. As organic semiconductors, they can be used to make large-area arrays of diodes or transistors using fabrication techniques developed for polymer coatings, such as spraying and screen-printing. We have demonstrated both neutron and alpha detection using diodes made from conjugated polymers and have done preliminary work to integrate a boron carbide layer into the conventional polymer device structure to capture thermal neutrons. The polymer devices appear to be insensitive to gamma rays, due to their small physical thickness and low atomic number.

  4. Carbon Redox-Polymer-Gel Hybrid Supercapacitors

    NASA Astrophysics Data System (ADS)

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

    2016-02-01

    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.

  5. Nanostructured polymer membranes for proton conduction

    DOEpatents

    Balsara, Nitash Pervez; Park, Moon Jeong

    2013-06-18

    Polymers having an improved ability to entrain water are characterized, in some embodiments, by unusual humidity-induced phase transitions. The described polymers (e.g., hydrophilically functionalized block copolymers) have a disordered state and one or more ordered states (e.g., a lamellar state, a gyroid state, etc.). In one aspect, the polymers are capable of undergoing a disorder-to-order transition while the polymer is exposed to an increasing temperature at a constant relative humidity. In some aspects the polymer includes a plurality of portions, wherein a first portion forms proton-conductive channels within the membrane and wherein the channels have a width of less than about 6 nm. The described polymers are capable of entraining and preserving water at high temperature and low humidity. Surprisingly, in some embodiments, the polymers are capable of entraining greater amounts of water with the increase of temperature. The polymers can be used in Polymer Electrolyte Membranes in fuel cells.

  6. Dipole Engineering for Conducting Polymers

    NASA Astrophysics Data System (ADS)

    McClain, William Edward

    A method for the growth of a TiO2 adhesion layer on PEDOT:PSS (poly[3,4- ethylenedioxythiophene]: poly[styrenesulfonate]) and for further functionalization with self-assembled monolayers of phosphonates (SAMPs) was developed. The TiO2 adhesion layer was grown via chemical vapor deposition using a titanium(IV) t-butoxide precursor, and was characterized by goniometry and X-ray photoelectron spectroscopy. TiO 2 grown on a model system, H-terminated silicon, indicated that the surface was t-butoxide terminated. Phenylphosphonic acids were synthesized with a variety of molecular dipoles and were used to change the work function of PEDOT:PSS through the formation of an aggregate surface dipole. Good correlation was found between the z-component of the molecular dipole and the change in work function, indicating that the film was well-ordered and dense. The magnitude of the changes in work function and goniometry measurements were similar to measurements on ITO, a substrate on which phosphonates form well-ordered monolayers. As-grown PEDOT:PSS/TiO 2 electrodes showed a lower work function compared to PEDOT:PSS, which is attributed to residual t-butoxide groups on the TiO 2 surface. UPS measurements revealed that reductions in work function in the modified electrodes lowered the difference in energy between the Fermi energy (EF) of the conducting polymer and the LUMO of PCBM ([6,6]-phenyl-C 61-butyric acid methyl ester). A reduction of this energy difference should translate into increased electron injection in electron-only diodes; however, devices with modified electrodes showed decreased current densities. UPS/IPES measurements show that TiO2 grown using this method has a much larger band gap than bulk or nanocrystalline TiO2, which is likely responsible for this decrease in device currents. At high bias, device currents increase dramatically, and the effects of the phosphonates or t-butoxide terminated TiO2 vanish. This is attributed to a reduction of the TiO2 to

  7. Conducting polymers in electronic chemical sensors.

    PubMed

    Janata, Jiri; Josowicz, Mira

    2003-01-01

    Conducting organic polymers have found two main kinds of application in electronics so far: as materials for construction of various devices and as selective layers in chemical sensors. In either case, interaction with ambient gases is critical. It may compromise the performance of a device based on conducting polymers, whereas it is beneficial in a sensor. Conductivity has been the primary property of interest. Work function--related to conductivity, but in principle a different property--has received only scant attention. Our aim here is to discuss the usability of conducting polymers in both types of electronic applications in light of these two parameters.

  8. Biochemical synthesis of water soluble conducting polymers

    NASA Astrophysics Data System (ADS)

    Bruno, Ferdinando F.; Bernabei, Manuele

    2016-05-01

    An efficient biomimetic route for the synthesis of conducting polymers/copolymers complexed with lignin sulfonate and sodium (polystyrenesulfonate) (SPS) will be presented. This polyelectrolyte assisted PEG-hematin or horseradish peroxidase catalyzed polymerization of pyrrole (PYR), 3,4 ethyldioxithiophene (EDOT) and aniline has provided a route to synthesize water-soluble conducting polymers/copolymers under acidic conditions. The UV-vis, FTIR, conductivity and cyclic voltammetry studies for the polymers/copolymer complex indicated the presence of a thermally stable and electroactive polymers. Moreover, the use of water-soluble templates, used as well as dopants, provided a unique combination of properties such as high electronic conductivity, and processability. These polymers/copolymers are nowadays tested/evaluated for antirust features on airplanes and helicopters. However, other electronic applications, such as photovoltaics, for transparent conductive polyaniline, actuators, for polypyrrole, and antistatic films, for polyEDOT, will be proposed.

  9. Biochemical synthesis of water soluble conducting polymers

    SciTech Connect

    Bruno, Ferdinando F.; Bernabei, Manuele

    2016-05-18

    An efficient biomimetic route for the synthesis of conducting polymers/copolymers complexed with lignin sulfonate and sodium (polystyrenesulfonate) (SPS) will be presented. This polyelectrolyte assisted PEG-hematin or horseradish peroxidase catalyzed polymerization of pyrrole (PYR), 3,4 ethyldioxithiophene (EDOT) and aniline has provided a route to synthesize water-soluble conducting polymers/copolymers under acidic conditions. The UV-vis, FTIR, conductivity and cyclic voltammetry studies for the polymers/copolymer complex indicated the presence of a thermally stable and electroactive polymers. Moreover, the use of water-soluble templates, used as well as dopants, provided a unique combination of properties such as high electronic conductivity, and processability. These polymers/copolymers are nowadays tested/evaluated for antirust features on airplanes and helicopters. However, other electronic applications, such as photovoltaics, for transparent conductive polyaniline, actuators, for polypyrrole, and antistatic films, for polyEDOT, will be proposed.

  10. Ionic conduction in polymer composite electrolytes

    NASA Astrophysics Data System (ADS)

    Dam, Tapabrata; Tripathy, Satya N.; Paluch, M.; Jena, S.; Pradhan, D. K.

    2016-05-01

    Conductivity and structural relaxation has been explored from modulus and dielectric loss formalisms respectively for a series of polymer composite electrolytes with zirconia as filler. The temperature dependence of conductivity followed Vogel-Tamman-Fulcher (VTF) behavior, which suggested a close correlation between conductivity and the segmental relaxation process in polymer electrolytes. Vogel temperature (T0) plays significant role in ion conduction process in these kind of materials.

  11. Nanostructured conductive polymers for advanced energy storage.

    PubMed

    Shi, Ye; Peng, Lele; Ding, Yu; Zhao, Yu; Yu, Guihua

    2015-10-07

    Conductive polymers combine the attractive properties associated with conventional polymers and unique electronic properties of metals or semiconductors. Recently, nanostructured conductive polymers have aroused considerable research interest owing to their unique properties over their bulk counterparts, such as large surface areas and shortened pathways for charge/mass transport, which make them promising candidates for broad applications in energy conversion and storage, sensors, actuators, and biomedical devices. Numerous synthetic strategies have been developed to obtain various conductive polymer nanostructures, and high-performance devices based on these nanostructured conductive polymers have been realized. This Tutorial review describes the synthesis and characteristics of different conductive polymer nanostructures; presents the representative applications of nanostructured conductive polymers as active electrode materials for electrochemical capacitors and lithium-ion batteries and new perspectives of functional materials for next-generation high-energy batteries, meanwhile discusses the general design rules, advantages, and limitations of nanostructured conductive polymers in the energy storage field; and provides new insights into future directions.

  12. Charge-transport model for conducting polymers

    NASA Astrophysics Data System (ADS)

    Dongmin Kang, Stephen; Jeffrey Snyder, G.

    2016-11-01

    The growing technological importance of conducting polymers makes the fundamental understanding of their charge transport extremely important for materials and process design. Various hopping and mobility edge transport mechanisms have been proposed, but their experimental verification is limited to poor conductors. Now that advanced organic and polymer semiconductors have shown high conductivity approaching that of metals, the transport mechanism should be discernible by modelling the transport like a semiconductor with a transport edge and a transport parameter s. Here we analyse the electrical conductivity and Seebeck coefficient together and determine that most polymers (except possibly PEDOT:tosylate) have s = 3 and thermally activated conductivity, whereas s = 1 and itinerant conductivity is typically found in crystalline semiconductors and metals. The different transport in polymers may result from the percolation of charge carriers from conducting ordered regions through poorly conducting disordered regions, consistent with what has been expected from structural studies.

  13. Charge-transport model for conducting polymers

    NASA Astrophysics Data System (ADS)

    Dongmin Kang, Stephen; Jeffrey Snyder, G.

    2017-02-01

    The growing technological importance of conducting polymers makes the fundamental understanding of their charge transport extremely important for materials and process design. Various hopping and mobility edge transport mechanisms have been proposed, but their experimental verification is limited to poor conductors. Now that advanced organic and polymer semiconductors have shown high conductivity approaching that of metals, the transport mechanism should be discernible by modelling the transport like a semiconductor with a transport edge and a transport parameter s. Here we analyse the electrical conductivity and Seebeck coefficient together and determine that most polymers (except possibly PEDOT:tosylate) have s = 3 and thermally activated conductivity, whereas s = 1 and itinerant conductivity is typically found in crystalline semiconductors and metals. The different transport in polymers may result from the percolation of charge carriers from conducting ordered regions through poorly conducting disordered regions, consistent with what has been expected from structural studies.

  14. Morphology in electrochemically grown conducting polymer films

    DOEpatents

    Rubinstein, Israel; Gottesfeld, Shimshon; Sabatani, Eyal

    1992-01-01

    A conducting polymer film with an improved space filling is formed on a metal electrode surface. A self-assembling monolayer is formed directly on the metal surface where the monolayer has a first functional group that binds to the metal surface and a second chemical group that forms a chemical bonding site for molecules forming the conducting polymer. The conducting polymer is then conventioonally deposited by electrochemical deposition. In one example, a conducting film of polyaniline is formed on a gold electrode surface with an intermediate monolayer of p-aminothiophenol.

  15. Morphology in electrochemically grown conducting polymer films

    DOEpatents

    Rubinstein, I.; Gottesfeld, S.; Sabatani, E.

    1992-04-28

    A conducting polymer film with an improved space filling is formed on a metal electrode surface. A self-assembling monolayer is formed directly on the metal surface where the monolayer has a first functional group that binds to the metal surface and a second chemical group that forms a chemical bonding site for molecules forming the conducting polymer. The conducting polymer is then conventionally deposited by electrochemical deposition. In one example, a conducting film of polyaniline is formed on a gold electrode surface with an intermediate monolayer of p-aminothiophenol. 2 figs.

  16. Dual function conducting polymer diodes

    DOEpatents

    Heeger, Alan J.; Yu, Gang

    1996-01-01

    Dual function diodes based on conjugated organic polymer active layers are disclosed. When positively biased the diodes function as light emitters. When negatively biased they are highly efficient photodiodes. Methods of preparation and use of these diodes in displays and input/output devices are also disclosed.

  17. Electronically conducting polymers with silver grains

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor); Hodko, Dolibor (Inventor)

    1999-01-01

    The present invention provides electronically conducting polymer films formed from photosensitive formulations of pyrrole and an electron acceptor that have been selectively exposed to UV light, laser light, or electron beams. The formulations may include photoinitiators, flexibilizers, solvents and the like. These solutions can be used in applications including printed circuit boards and through-hole plating and enable direct metallization processes on non-conducting substrates. After forming the conductive polymer patterns, a printed wiring board can be formed by sensitizing the polymer with palladium and electrolytically depositing copper.

  18. Morphological Studies of Conductive Polymers.

    DTIC Science & Technology

    1987-05-31

    order in the polypyrrole (PPY)- tenside salts, seen along the polypyrrole chains axis. The simple black lines represent the PPY chains; the zig-zag...lines symbolize the alkyl chains of the tensides and the black circles stand for the ionic -S03 or -0S03 groups; for d(n) ............ 4 4Polypyrrole 2...has examined films of polypyrrole tensides by x-ray diffraction and speculated that the polymer chains form a kind of double-layered structure as shown

  19. Application of conducting polymers to electroanalysis

    SciTech Connect

    Josowicz, M.A.

    1994-04-01

    Conducting polymers can be used as sensitive layers in chemical microsensors leading to new applications of theses devices. They offer the potential for developing material properties that are critical to the sensor sensitivity, selectivity and fabrication. The advantages and limitations of the use of thin polymer layers in electrochemical sensors are discussed.

  20. Conductive Polymer Waving in Liquid Nitrogen.

    PubMed

    Mao, Jifu; Li, Chaojing; Park, Hyun Jin; Rouabhia, Mahmoud; Zhang, Ze

    2017-09-12

    The poor mechanical properties and processability of pristine heterocyclic conductive polymers represent the most notable scientific and technological challenges that have greatly limited the application of these polymers. We report a soft and mechanically processable free-standing pristine polypyrrole (PPy) membrane (PPy-N) that is as soft in liquid nitrogen (-196 °C) as it is at room temperature, despite a glass transition temperature (Tg) above 100 °C. This PPy membrane also displays a highly attractive combination of properties, including mechanical processability, lightweight (9 g m(-2)), large surface area (14.5 m(2) g(-1)), stable electrothermal behavior, amphiphilicity, excellent cytocompatibility, and easy synthesis, at virtually any size. This discovery demonstrates an approach to changing the mechanical property of heterocyclic conductive polymer with no chemical alterations or compounding and may enhance the development of inherently conducting polymers for applications in energy storage and biomedicine and as lightweight conducting and heating materials.

  1. Electrochemical sensor based on conductive polymer electrolyte

    SciTech Connect

    Ribes, C.; Cisneros, B.; Noding, S.A.; Ribes, A.J.

    1995-12-31

    A novel conductive polymer film has been incorporated into an electrochemical sensor for the determination of toxic gases. The conductive film consists of an inert polymer, a completing agent, and a salt. A variety of gases can be determined with this sensor. The specific detection of sulfuryl fluoride (SO{sub 2}F{sub 2}) in air will be discussed as an example of the capability and flexibility of technology.

  2. 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

  3. Controlled isotropic or anisotropic nanoscale growth of coordination polymers: formation of hybrid coordination polymer particles.

    PubMed

    Lee, Hee Jung; Cho, Yea Jin; Cho, Won; Oh, Moonhyun

    2013-01-22

    The ability to fabricate multicompositional hybrid materials in a precise and controlled manner is one of the primary goals of modern materials science research. In addition, an understanding of the phenomena associated with the systematic growth of one material on another can facilitate the evolution of multifunctional hybrid materials. Here, we demonstrate precise manipulation of the isotropic and/or anisotropic nanoscale growth of various coordination polymers (CPs) to obtain heterocompositional hybrid coordination polymer particles. Chemical composition analyses conducted at every growth step reveal the formation of accurately assembled hybrid nanoscale CPs, and microscopy images are used to examine the morphology of the particles and visualize the hybrid structures. The dissimilar growth behavior, that is, growth in an isotropic or anisotropic fashion, is found to be dependent on the size of the metal ions involved within the CPs.

  4. 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%.

  5. Engineering thermal conductivity in polymer blends

    NASA Astrophysics Data System (ADS)

    Rashidi, Vahid; Coyle, Eleanor; Kieffer, John; Pipe, Kevin

    Weak inter-chain bonding in polymers is believed to be a bottleneck for both thermal conductivity and mechanical strength. Most polymers have low thermal conductivity (~0.1 W/mK), hindering their performance in applications for which thermal management is critical (e.g., electronics packaging). In this work, we use computational methods to study how hydrogen bonding between polymer chains as well as water content can be used to engineer thermal transport in bulk polymers. We examine how changes in the number of hydrogen bonds, chain elongation, density, and vibrational density of states correlate with changes in thermal conductivity for polymer blends composed of different relative constituent fractions. We also consider the effects of bond strength, tacticity, and polymer chain mass. For certain blend fractions, we observe large increases in thermal conductivity, and we analyze these increases in terms of modifications to chain chemistry (e.g., inter-chain bonding) and chain morphology (e.g., chain alignment and radius of gyration). We observe that increasing the number of hydrogen bonds in the system results in better packing as well as better chain alignment and elongation that contribute to enhanced thermal conductivity. The Air Force Office of Scientific Research, Grant No. FA9550-14-1-0010.

  6. Ionic conductivity in crystalline polymer electrolytes.

    PubMed

    Gadjourova, Z; Andreev, Y G; Tunstall, D P; Bruce, P G

    2001-08-02

    Polymer electrolytes are the subject of intensive study, in part because of their potential use as the electrolyte in all-solid-state rechargeable lithium batteries. These materials are formed by dissolving a salt (for example LiI) in a solid host polymer such as poly(ethylene oxide) (refs 2, 3, 4, 5, 6), and may be prepared as both crystalline and amorphous phases. Conductivity in polymer electrolytes has long been viewed as confined to the amorphous phase above the glass transition temperature, Tg, where polymer chain motion creates a dynamic, disordered environment that plays a critical role in facilitating ion transport. Here we show that, in contrast to this prevailing view, ionic conductivity in the static, ordered environment of the crystalline phase can be greater than that in the equivalent amorphous material above Tg. Moreover, we demonstrate that ion transport in crystalline polymer electrolytes can be dominated by the cations, whereas both ions are generally mobile in the amorphous phase. Restriction of mobility to the lithium cation is advantageous for battery applications. The realization that order can promote ion transport in polymers is interesting in the context of electronically conducting polymers, where crystallinity favours electron transport.

  7. Thermally conducting electron transfer polymers

    NASA Technical Reports Server (NTRS)

    Byrd, N. R.; Jenkins, R. K.; Lister, J. L.

    1969-01-01

    New polymeric material exhibits excellent physical shock protection, high electrical resistance, and thermal conductivity. It is especially useful for electronic circuitry, such as subminiaturization of components and modular construction of circuits.

  8. On the high conductivity of nonconjugated polymers

    SciTech Connect

    Lachinov, A. N. Kornilov, V. M.; Zagurenko, T. G.; Zherebov, A. Yu.

    2006-04-15

    The mechanism of charge transfer in a metal-electroactive polymer-metal structure has been experimentally studied near the threshold of the uniaxial-pressure-induced transition into a high-conductivity state in the polymer. The dynamics of the I-V curve is investigated as a function of the applied pressure. The data obtained are analyzed in terms of the model of injection currents using the concepts of possible scanning of a quasi-Fermi level near an injection level. Our estimates suggest that a narrow band made of deep trap states located near the Fermi level forms in the polymer film in the pretransition pressure range. In the immediate vicinity of the transition range, a narrow band of coherent charge transfer appears from these states; this band can be responsible for the high metal-type conductivity of thin polymer films, which has been repeatedly observed by many researchers.

  9. 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.

  10. Liquid crystal-templated conducting organic polymers

    DOEpatents

    Stupp, Samuel I.; Hulvat, James F.

    2004-01-20

    A method of preparing a conductive polymeric film, includes providing a liquid crystal phase comprising a plurality of hydrophobic cores, the phase on a substrate, introducing a hydrophobic component to the phase, the component a conductive polymer precursor, and applying an electric potential across the liquid crystal phase, the potential sufficient to polymerize the said precursor.

  11. Multifunctional Nanostructured Conductive Polymer Gels: Synthesis, Properties, and Applications.

    PubMed

    Zhao, Fei; Shi, Ye; Pan, Lijia; Yu, Guihua

    2017-07-18

    Conductive polymers have attracted significant interest over the past few decades because they synergize the advantageous features of conventional polymeric materials and organic conductors. With rationally designed nanostructures, conductive polymers can further exhibit exceptional mechanical, electrical, and optical properties because of their confined dimensions at the nanoscale level. Among various nanostructured conductive polymers, conductive polymer gels (CPGs) with synthetically tunable hierarchical 3D network structures show great potential for a wide range of applications, such as bioelectronics, and energy storage/conversion devices owing to their structural features. CPGs retain the properties of nanosized conductive polymers during the assembly of the nanobuilding blocks into a monolithic macroscopic structure while generating structure-derived features from the highly cross-linked network. In this Account, we review our recent progress on the synthesis, properties, and novel applications of dopant cross-linked CPGs. We first describe the synthetic strategies, in which molecules with multiple functional groups are adopted as cross-linkers to cross-link conductive polymer chains into a 3D molecular network. These cross-linking molecules also act as dopants to improve the electrical conductivity of the gel network. The microstructure and physical/chemical properties of CPGs can be tuned by controlling the synthetic conditions such as species of monomers and cross-linkers, reaction temperature, and solvents. By incorporating other functional polymers or particles into the CPG matrix, hybrid gels have been synthesized with tailored structures. These hybrid gel materials retain the functionalities from each component, as well as enable synergic effects to improve mechanical and electrical properties of CPGs. We then introduce the unique structure-derived properties of the CPGs. The network facilitates both electronic and ionic transport owing to the

  12. Hybrid electronics and electrochemistry with conjugated polymers.

    PubMed

    Inganäs, Olle

    2010-07-01

    In this critical review, we discuss the history and development of polymer devices wherein manipulation of the electronic conductivity by electrochemical redox processes in a conjugated polymer is used to form new functions. The devices employed are an electrochemical transistor, an electrolyte-gated field-effect transistor and light-emitting electrochemical cells, all of which combine doping/undoping of a conjugated polymer with modification of electronic transport (130 references).

  13. Three dimensional polymer waveguide using hybrid lithography.

    PubMed

    Wang, Huanran; Liu, Yu; Jiang, Minghui; Chen, Changming; Wang, Xibin; Wang, Fei; Zhang, Daming; Yi, Yunji

    2015-10-01

    A three dimensional polymer waveguide with taper structure was demonstrated and fabricated by a reliable and effective hybrid lithography. The hybrid lithography consists of lithography to fabricate a polymer waveguide and gray scale lithography to fabricate a polymer taper structure. Laser ablation and shadow aluminum evaporation were designed for gray scale lithography. The length of the gray scale region ranging from 20 to 400 μm could be controlled by the laser power, the ablation speed, and the aluminum thickness. The slope angle was determined by the length of the gray scale region and the thickness of the photoresist. The waveguide taper structure could be transferred to the lower layer by the etching method. The taper structure can be used for integration of the waveguide with different dimensions.

  14. Conducting polymers: Synthesis and industrial applications

    SciTech Connect

    Gottesfeld, S.

    1995-05-01

    The Conducting Polymer project funded by the AIM Materials Program is developing new methods for the synthesis of electronically conducting polymers and is evaluating new industrial applications for these materials which will result in significant reductions in energy usage or industrial waste. The applications specifically addressed during FY 1994 are electrochemical capacitors and membranes for gas separation. As an active material in electrochemical capacitors, conducting polymers have the potential of storing large amounts of electrical energy in low cost materials. Such devices are needed in electronics for power failure back-up and peak power, in power supplies for filtering, and in electric vehicles for peak power and load leveling. As a gas electrically adapt the membrane for specific gas combinations. Potential energy savings in the US. for this application are estimated at 1 to 3 quads/yr.

  15. Hybrid high refractive index polymer coatings

    NASA Astrophysics Data System (ADS)

    Wang, Yubao; Flaim, Tony; Mercado, Ramil; Fowler, Shelly; Holmes, Douglas; Planje, Curtis

    2005-04-01

    Thermally curable hybrid high refractive index polymer solutions have been developed. These solutions are stable up to 6 months under room temperature storage conditions and can be easily spin-coated onto a desired substrate. When cured at elevated temperature, the hybrid polymer coating decomposes to form a metal oxide-rich film that has a high refractive index. The resulting films have refractive indices higher than 1.90 in the entire visible region and achieve film thicknesses of 300-900 nm depending on the level of metal oxide loading, cure temperature being used, and number of coatings. The formed films show greater than 90% internal transmission in the visible wavelength (400-700 nm). These hybrid high refractive index films are mechanically robust, are stable upon exposure to both heat and UV radiation, and are currently being investigated for microlithographic patterning potential.

  16. Conducting polymer for high power ultracapacitor

    DOEpatents

    Shi, Steven Z.; Gottesfeld, Shimshon

    2002-01-01

    In accordance with the purposes of the present invention, as embodied and broadly described herein, the present invention is directed to an electrode having a conducting polymer active material for use in an ultracapacitor. The conducting polymer active material is electropolymerized onto a carbon paper substrate from a mixed solution of a dimer of (3,3' bithiophene) (BT) and a monomer that is selected from the group of thiophenes derived in the 3-position, having an aryl group attached to thiophene in the 3-position or having aryl and alkly groups independently attached to thiophene in the 3 and 4 positions.

  17. Conductivity of carbon nanotube polymer composites

    SciTech Connect

    Wescott, J T; Kung, P; Maiti, A

    2006-11-20

    Dissipative Particle Dynamics (DPD) simulations were used to investigate methods of controlling the assembly of percolating networks of carbon nanotubes (CNTs) in thin films of block copolymer melts. For suitably chosen polymers the CNTs were found to spontaneously self-assemble into topologically interesting patterns. The mesoscale morphology was projected onto a finite-element grid and the electrical conductivity of the films computed. The conductivity displayed non-monotonic behavior as a function of relative polymer fractions in the melt. Results are compared and contrasted with CNT dispersion in small-molecule fluids and mixtures.

  18. Polymer hybrid nano/micro composites

    SciTech Connect

    Dzenis, Y.A.; Reneker, D.H.

    1994-12-31

    Nanocomposites based on ceramic and metal matrices attracted considerable attention during the past decade. Polymer based nanocomposites are much less well-known. Recently, a method of electrospinning of thin polymer fibers has been developed. Continuous, oriented fibers with diameters ranging from 50 nanometers to several microns have been prepared from over 30 different synthetic and natural polymers, including high temperature high modulus polyimide and polyaramid (Kevlar) fibers. The possible applications of these small fibers in hybrid polymer hierarchical composites are discussed. Micromechanics models of hybrid composites are developed based on the models for two component composites and on the principle of effective homogeneity. Effective thermoviscoelastic characteristics of nano and microfiber composite as well as nanofiber and microparticulate composites are calculated. ``Strong`` hybrid effects are observed in the dependence of effective moduli, loss factor, creep factor, and thermal expansion coefficient on fractional content of fibers of different diameters. The extrema are located at the higher fractions of larger reinforcing elements. Similarities of composite microstructures having synergistic ``extremal`` properties with some biological composites are noted.

  19. Mechanically stiff, electrically conductive composites of polymers and carbon nanotubes

    SciTech Connect

    Worsley, Marcus A.; Kucheyev, Sergei O.; Baumann, Theodore F.; Kuntz, Joshua D.; Satcher, Jr., Joe H.; Hamza, Alex V.

    2015-07-21

    Using SWNT-CA as scaffolds to fabricate stiff, highly conductive polymer (PDMS) composites. The SWNT-CA is immersing in a polymer resin to produce a SWNT-CA infiltrated with a polymer resin. The SWNT-CA infiltrated with a polymer resin is cured to produce the stiff and electrically conductive composite of carbon nanotube aerogel and polymer.

  20. Preparation of Conductive Polymer Graphite (PG) Composites

    NASA Astrophysics Data System (ADS)

    Munirah Abdullah, Nur; Saddam Kamarudin, M.; Rus, Anika Zafiah M.; Abdullah, M. F. L.

    2017-08-01

    The preparation of conductive polymer graphite (PG) composites thin film is described. The thickness of the PG composites due to slip casting method was set approximately ~0.1 mm. The optical microscope (OM) and fourier transform infra-red spectroscopy (FTIR) has been operated to distinguish the structure-property relationships scheme of PG composites. It shows that the graphite is homogenously dispersed in polymer matrix composites. The electrical characteristics of the PG composite were measured at room temperature and the electrical conductivity (σ) was discovered with respect of its resistivity (Ω). By achieving conductivity of 103 S/m, it is proven that at certain graphite weight loading (PG20, PG25 and PG30) attributes to electron pathway in PG composites.

  1. Polymer hybrid materials for planar optronic systems

    NASA Astrophysics Data System (ADS)

    Körner, Martin; Prucker, Oswald; Rühe, Jürgen

    2015-09-01

    Planar optronic systems made entirely from polymeric functional materials on polymeric foils are interesting architectures for monitoring and sensing applications. Key components in this regard are polymer hybrid materials with adjustable optical properties. These materials can then be processed into optical components such as waveguides for example by using embossing techniques. However, the resulting microstructures have often low mechanical or thermal stability which quickly leads to a degradation of the microstructures accompanied often by a complete loss of function. A simple and versatile way to increase the thermal and mechanical stability of polymers is to connect the individual chains to a polymer network by using thermally or photochemically reactive groups. Upon excitation, these groups form reactive intermediates such as radicals or nitrenes which then crosslink with adjacent C-H-groups through a C,H insertion reaction (CHic = C,H insertion based crosslinking). To generate waveguide structures a PDMS stamp is filled with the waveguide core material e.g. poly(methylmethacrylate) (PMMA), which is modified with a few mol% of the thermal crosslinker and hot embossed onto a foil substrate e.g. PMMA. In this one-step hot embossing process polymer ridge waveguides are formed and simultaneously the polymer becomes crosslinked. Due to the reaction across the boundary between waveguide and substrate it is also possible to combine initially incompatible polymers for the waveguide and the substrate foil. The thermomechanical properties of the obtained materials are studied.

  2. Structure and Conductivity of Semiconducting Polymer Hydrogels

    SciTech Connect

    Huber, Rachel C.; Ferreira, Amy S.; Aguirre, Jordan C.; Kilbride, Daniel; Toso, Daniel B.; Mayoral, Kenny; Zhou, Z. Hong; Kopidakis, Nikos; Rubin, Yves; Schwartz, Benjamin J.; Mason, Thomas G.; Tolbert, Sarah H.

    2016-07-07

    Poly(fluorene-alt-thiophene) (PFT) is a conjugated polyelectrolyte that self-assembles into rod-like micelles in water, with the conjugated polymer backbone running along the length of the micelle. At modest concentrations (-10 mg/mL in aqueous solutions), PFT forms hydrogels, and this work focuses on understanding the structure and intermolecular interactions in those gel networks. The network structure can be directly visualized using cryo electron microscopy. Oscillatory rheology studies further tell us about connectivity within the gel network, and the data are consistent with a picture where polymer chains bridge between micelles to hold the network together. Addition of tetrahydrofuran (THF) to the gels breaks those connections, but once the THF is removed, the gel becomes stronger than it was before, presumably due to the creation of a more interconnected nanoscale architecture. Small polymer oligomers can also passivate the bridging polymer chains, breaking connections between micelles and dramatically weakening the hydrogel network. Fits to solution-phase small-angle X-ray scattering data using a Dammin bead model support the hypothesis of a bridging connection between PFT micelles, even in dilute aqueous solutions. Finally, time-resolved microwave conductivity measurements on dried samples show an increase in carrier mobility after THF annealing of the PFT gel, likely due to increased connectivity within the polymer network.

  3. Physical theory of excitons in conducting polymers.

    PubMed

    Brazovskii, Serguei; Kirova, Natasha

    2010-07-01

    In this tutorial review, we cover the solid state physics approach to electronic and optical properties of conducting polymers. We attempt to bring together languages and advantages of the solid state theory for polymers and of the quantum chemistry for monomers. We consider polymers as generic one-dimensional semiconductors with features of strongly correlated electronic systems. Our model combines the long range electron-hole Coulomb attraction with a specific effect of strong intra-monomer electronic correlations, which results in effective intra-monomer electron-hole repulsion. Our approach allows to go beyond the single-chain picture and to compare excitons for polymers in solutions and in films. The approach helps connecting such different questions as shallow singlet and deep triplet excitons, stronger binding of interchain excitons in films, crossings of excitons' branches, 1/N energies shifts in oligomers. We describe a strong suppression of the luminescence from free charge carriers by long-range Coulomb interactions. Main attention is devoted to the most requested in applications phenyl based polymers. The specifics of the benzene ring monomer give rise to existence of three possible types of excitons: Wannier-Mott, Frenkel and intermediate ones. We discuss experimental manifestations of various excitons and of their transformations. We touch effects of the time-resolved self-trapping by libron modes leading to formation of torsion polarons.

  4. Fabrication, Modelling and Application of Conductive Polymer Composites

    NASA Astrophysics Data System (ADS)

    Price, Aaron David

    electroactive actuation response inherent to conductive polymer trilayer actuators. The main contribution of this investigation was the proposal and development of a new hybrid model that unifies concepts from charge transport and electrochemomechanical models. The output of the proposed model was compared with published data and shown to be accurate to within 10%. Finally, Chapter 6 demonstrated the application of these materials for use as precision mirror positioners in adaptive optical systems.

  5. Actuator device utilizing a conductive polymer gel

    DOEpatents

    Chinn, Douglas A.; Irvin, David J.

    2004-02-03

    A valve actuator based on a conductive polymer gel is disclosed. A nonconductive housing is provided having two separate chambers separated by a porous frit. The conductive polymer is held in one chamber and an electrolyte solution, used as a source of charged ions, is held in the second chamber. The ends of the housing a sealed with a flexible elastomer. The polymer gel is further provide with electrodes with which to apply an electrical potential across the gel in order to initiate an oxidation reaction which in turn drives anions across the porous frit and into the polymer gel, swelling the volume of the gel and simultaneously contracting the volume of the electrolyte solution. Because the two end chambers are sealed the flexible elastomer expands or contracts with the chamber volume change. By manipulating the potential across the gel the motion of the elastomer can be controlled to act as a "gate" to open or close a fluid channel and thereby control flow through that channel.

  6. Thermal conductivity and multiferroics of electroactive polymers and polymer composites

    NASA Astrophysics Data System (ADS)

    Jin, Jiezhu

    Electronically conducting polymers and electromechanical polymers are the two important branches of the cutting-edge electroactive polymers. They have shown significant impact on many modern technologies such as flat panel display, energy transport, energy conversion, sensors and actuators. To utilize conducting polymers in microelectronics, optoelectronics and thermoelectrics, it is necessary to have a comprehensive study of their thermal conductivity since thermal conductivity is a fundamental materials property that is particularly important and sometimes a determining factor of the device performance. For electromechanical polymers, larger piezoelectric effect will contribute to the improvement of magnetoelectric (ME) coupling efficiency in their multiferroic composites. This dissertation is devoted to characterizing electronically conducting polymers for their electrical and thermal conductivity, and developing new classes of electromechanical polymers and strain-mediated electromechanical polymer-based multiferroic ME composites. Conducting polymers opened up new possibilities for devices combining novel electrical and thermal properties, but there has been limited understanding of the length-scale effect of the electrical and thermal conductivity, and the mechanism underlying the electricity and heat transport behavior. In this dissertation, the analytical model and experimental technique are presented to measure the in-plane thermal conductivity of polyaniline thin films. For camphorsulfonic acid doped polyaniline patterned on silicon oxide/silicon substrate using photolithography and reactive ion etching, the thermal conductivity of the film with thickness of 20 nm is measured to be 0.0406 W/m˙K, which significantly deviates from their bulk (> 0.26 W/m˙K). The size effect on thermal conductivity at this scale is attributed to the significant phonon boundary scattering. When the film goes up to 130 nm thick, the thermal conductivity increases to 0.166 W

  7. Morphology tailoring of nano/micro-structured conductive polymers, composites and their applications in chemical sensors.

    PubMed

    Ma, Xingfa; Gao, Mingjun; He, Xiaochun; Li, Guang

    2010-11-01

    Conductive polymer is one of the important multi-functional materials. It has many applications in light-emitting diodes, chemical sensors, biosensors, et al. This paper provides a relatively comprehensive review on the progress of conductive polymer and composite as sensitive film for sensors to chemical vapors including patents, papers and our preliminary research results. Especially, the feature of conjugated polymers, the processing technology, doping characteristics and some factors affecting gas responses are discussed. Otherwise, the developments of nanostructured conductive polymer and organic-inorganic hybrid film sensor with high sensitivity and rapid response to vapors are also described, and some suggestions are proposed.

  8. Conducting polymer electrodes for visual prostheses.

    PubMed

    Green, R A; Devillaine, F; Dodds, C; Matteucci, P; Chen, S; Byrnes-Preston, P; Poole-Warren, L A; Lovell, N H; Suaning, G J

    2010-01-01

    Conducting polymers (CPs) have the potential to provide superior neural interfaces to conventional metal electrodes by introducing more efficient charge transfer across the same geometric area. In this study the conducting polymer poly(ethylene dioxythiophene) (PEDOT) was coated on platinum (Pt) microelectrode arrays. The in vitro electrical characteristics were assessed during biphasic stimulation regimes applied between electrode pairs. It was demonstrated that PEDOT could reduce the potential excursion at a Pt electrode interface by an order of magnitude. The charge injection limit of PEDOT was found to be 15 x larger than Pt. Additionally, PEDOT coated electrodes were acutely implanted in the suprachoroidal space of a cat retina. It was demonstrated that PEDOT coated electrodes also had lower potential excursions in vivo and electrically evoked potentials (EEPs) could be detected within the vision cortex.

  9. Insulator to semimetallic transition in conducting polymers

    NASA Astrophysics Data System (ADS)

    Muñoz, W. A.; Singh, Sandeep Kumar; Franco-Gonzalez, J. F.; Linares, M.; Crispin, X.; Zozoulenko, I. V.

    2016-11-01

    We report a multiscale modeling of electronic structure of a conducting polymer poly(3,4-ethylenedioxythiopehene) (PEDOT) based on a realistic model of its morphology. We show that when the charge carrier concentration increases, the character of the density of states (DOS) gradually evolves from the insulating to the semimetallic, exhibiting a collapse of the gap between the bipolaron and valence bands with the drastic increase of the DOS between the bands. The origin of the observed behavior is attributed to the effect of randomly located counterions giving rise to the states in the gap. These results are discussed in light of recent experiments. The method developed in this work is general and can be applied to study the electronic structure of other conducting polymers.

  10. Gas Sensors Based on Conducting Polymers

    PubMed Central

    Bai, Hua; Shi, Gaoquan

    2007-01-01

    The gas sensors fabricated by using conducting polymers such as polyaniline (PAni), polypyrrole (PPy) and poly (3,4-ethylenedioxythiophene) (PEDOT) as the active layers have been reviewed. This review discusses the sensing mechanism and configurations of the sensors. The factors that affect the performances of the gas sensors are also addressed. The disadvantages of the sensors and a brief prospect in this research field are discussed at the end of the review.

  11. The Organic Chemistry of Conducting Polymers

    SciTech Connect

    Tolbert, Laren Malcolm

    2014-12-01

    For the last several years, we have examined the fundamental principles of conduction in one-dimensional systems, i.e., molecular “wires”. It is, of course, widely recognized that such systems, as components of electronically conductive materials, function in a two- and three-dimensional milieu. Thus interchain hopping and grain-boundary resistivity are limiting conductivity factors in highly conductive materials, and overall conductivity is a function of through-chain and boundary hopping. We have given considerable attention to the basic principles underlying charge transport (the “rules of the game”) in two-dimensional systems by using model systems which allow direct observation of such processes, including the examination of tunneling and hopping as components of charge transfer. In related work, we have spent considerable effort on the chemistry of conjugated heteropolymers, most especially polythiophens, with the aim of using these most efficient of readily available electroactive polymers in photovoltaic devices.

  12. 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

  13. 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.

  14. Polymer-metal hybrid transparent electrodes for flexible electronics.

    PubMed

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

    2015-03-19

    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.

  15. Example Transfers of Corn-Hybrid Polymer (CHP) Blasting Technology

    DTIC Science & Technology

    2008-05-01

    Example Transfers of Corn -Hybrid Polymer (CHP) Blasting Technology Joint Services Environmental Management Conference May 5-8, 2008 Bill Thomas...00-00-2008 4. TITLE AND SUBTITLE Example Transfers of Corn -Hybrid Polymer (CHP) Blasting Technology 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...Transfer History  Example Transfers  Conclusion * - for additional details, see JSEM presentation: B Yallay, “ Corn Hybrid Polymer Media for

  16. A highly stretchable, transparent, and conductive polymer

    DOE PAGES

    Wang, Yue; Zhu, Chenxin; Pfattner, Raphael; ...

    2017-03-10

    Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm undermore » 100% strain—among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire– or carbon nanotube–based stretchable conductor films. As a result, the combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects.« less

  17. A highly stretchable, transparent, and conductive polymer

    PubMed Central

    Wang, Yue; Zhu, Chenxin; Pfattner, Raphael; Yan, Hongping; Jin, Lihua; Chen, Shucheng; Molina-Lopez, Francisco; Lissel, Franziska; Liu, Jia; Rabiah, Noelle I.; Chen, Zheng; Chung, Jong Won; Linder, Christian; Toney, Michael F.; Murmann, Boris; Bao, Zhenan

    2017-01-01

    Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm under 100% strain—among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire– or carbon nanotube–based stretchable conductor films. The combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects. PMID:28345040

  18. A highly stretchable, transparent, and conductive polymer.

    PubMed

    Wang, Yue; Zhu, Chenxin; Pfattner, Raphael; Yan, Hongping; Jin, Lihua; Chen, Shucheng; Molina-Lopez, Francisco; Lissel, Franziska; Liu, Jia; Rabiah, Noelle I; Chen, Zheng; Chung, Jong Won; Linder, Christian; Toney, Michael F; Murmann, Boris; Bao, Zhenan

    2017-03-01

    Previous breakthroughs in stretchable electronics stem from strain engineering and nanocomposite approaches. Routes toward intrinsically stretchable molecular materials remain scarce but, if successful, will enable simpler fabrication processes, such as direct printing and coating, mechanically robust devices, and more intimate contact with objects. We report a highly stretchable conducting polymer, realized with a range of enhancers that serve a dual function: (i) they change morphology and (ii) they act as conductivity-enhancing dopants in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). The polymer films exhibit conductivities comparable to the best reported values for PEDOT:PSS, with over 3100 S/cm under 0% strain and over 4100 S/cm under 100% strain-among the highest for reported stretchable conductors. It is highly durable under cyclic loading, with the conductivity maintained at 3600 S/cm even after 1000 cycles to 100% strain. The conductivity remained above 100 S/cm under 600% strain, with a fracture strain of 800%, which is superior to even the best silver nanowire- or carbon nanotube-based stretchable conductor films. The combination of excellent electrical and mechanical properties allowed it to serve as interconnects for field-effect transistor arrays with a device density that is five times higher than typical lithographically patterned wavy interconnects.

  19. Synthesis and characterization of soluble conducting polymers and conducting adhesives

    NASA Astrophysics Data System (ADS)

    Oztemiz, Serhan

    With the demanding nature of the technology today, scientists are looking for new materials in order to decrease the cost, increase the efficiency of the use of the materials, and decrease time-consuming steps in order to increase the speed of production. New materials are being studied to decrease the weight of cars, planes and space vehicles; surface properties are being modified to decrease the drag coefficient; new technologies are being introduced for speeding up applications in production and assembly lines. In this research we address the needs of different technological applications from a conductivity perspective. In the first part of the thesis, the synthesis of soluble conducting polymers in order to make them more processable for potential electronic and photovoltaic applications is presented. Soluble conducting polymers of 3-hexylthiophene, 3-octylthiophene, 3-decylthiophene and 3-dodecylthiophene were synthesized electrochemically and thus, doped during synthesis. It was found that the conductivities; molecular weights and degrees of polymerization of the polymers strongly depend on the side chain's length. The substitution of alkyl side chains decreases the reactivity of the growing chain, and with an increasing side-chain length, all of these properties show a decrease. The hexyl substituent, being the shortest of the four side chains, causes the least distortion in the background, has the highest conjugation, and has the highest shift in the UV spectrum when it polymerizes. As the length of the side chain increases, the shift in the UV spectrum decreases, too. Decrease in the pi-stacking, conjugation and delocalization decreases the conductivity. This gives the material an opportunity to be used in photovoltaic applications. In the second part of the thesis, a conducting adhesive formulation that eliminates the need for heat or other expensive and rather bothersome application methods to activate the adhesive is investigated. Using the quick

  20. Conducting polymer electrodes for auditory brainstem implants

    PubMed Central

    Guex, Amélie A.; Vachicouras, Nicolas; Hight, Ariel E.; Brown, M. Christian; Lee, Daniel J.; Lacour, Stéphanie P.

    2015-01-01

    The auditory brainstem implant (ABI) restores hearing in patients with damaged auditory nerves. One of the main ideas to improve the efficacy of ABIs is to increase spatial specificity of stimulation, in order to minimize extra-auditory side-effects and to maximize the tonotopy of stimulation. This study reports on the development of a microfabricated conformable electrode array with small (100 μm diameter) electrode sites. The latter are coated with a conducting polymer, PEDOT:PSS, to offer high charge injection properties and to safely stimulate the auditory system with small stimulation sites. We report on the design and fabrication of the polymer implant, and characterize the coatings in physiological conditions in vitro and under mechanical deformation. We characterize the coating electrochemically and during bending tests. We present a proof of principle experiment where the auditory system is efficiently activated by the flexible polymeric interface in a rat model. These results demonstrate the potential of using conducting polymer coatings on small electrode sites for electrochemically safe and efficient stimulation of the central auditory system. PMID:26207184

  1. Electrochemical Analysis of Conducting Polymer Thin Films

    PubMed Central

    Vyas, Ritesh N.; Wang, Bin

    2010-01-01

    Polyelectrolyte multilayers built via the layer-by-layer (LbL) method has been one of the most promising systems in the field of materials science. Layered structures can be constructed by the adsorption of various polyelectrolyte species onto the surface of a solid or liquid material by means of electrostatic interaction. The thickness of the adsorbed layers can be tuned precisely in the nanometer range. Stable, semiconducting thin films are interesting research subjects. We use a conducting polymer, poly(p-phenylene vinylene) (PPV), in the preparation of a stable thin film via the LbL method. Cyclic voltammetry and electrochemical impedance spectroscopy have been used to characterize the ionic conductivity of the PPV multilayer films. The ionic conductivity of the films has been found to be dependent on the polymerization temperature. The film conductivity can be fitted to a modified Randle’s circuit. The circuit equivalent calculations are performed to provide the diffusion coefficient values. PMID:20480052

  2. Hybrid nanorod-polymer solar cells.

    PubMed

    Huynh, Wendy U; Dittmer, Janke J; Alivisatos, A Paul

    2002-03-29

    We demonstrate that semiconductor nanorods can be used to fabricate readily processed and efficient hybrid solar cells together with polymers. By controlling nanorod length, we can change the distance on which electrons are transported directly through the thin film device. Tuning the band gap by altering the nanorod radius enabled us to optimize the overlap between the absorption spectrum of the cell and the solar emission spectrum. A photovoltaic device consisting of 7-nanometer by 60-nanometer CdSe nanorods and the conjugated polymer poly-3(hexylthiophene) was assembled from solution with an external quantum efficiency of over 54% and a monochromatic power conversion efficiency of 6.9% under 0.1 milliwatt per square centimeter illumination at 515 nanometers. Under Air Mass (A.M.) 1.5 Global solar conditions, we obtained a power conversion efficiency of 1.7%.

  3. Synthesis of novel electrically conducting polymers: Potential conducting Langmuir-Blodgett films and conducting polymers on defined surfaces

    NASA Technical Reports Server (NTRS)

    Zimmer, Hans

    1993-01-01

    Based on previous results involving thiophene derived electrically conducting polymers in which it was shown that thiophene, 3-substituted thiophenes, furans, and certain oligomers of these compounds showed electrical conductivity after polymerization. The conductivity was in the order of up to 500 S/cm. In addition, these polymers showed conductivity without being doped and most of all they were practically inert toward ambient conditions. They even could be used in aqueous media. With these findings as a guide, a number of 3-long-chain-substituted thiophenes and 1-substituted-3-long-chain substituted pyrrols were synthesized as monomers for potential polymeric electrically conducting Langmuir-Blodgett films.

  4. Hybrid polymer-nanocrystal materials for photovoltaic applications.

    PubMed

    Zhou, Renjia; Xue, Jiangeng

    2012-07-16

    Hybrid polymer-nanocrystal photovoltaic (PV) cells have received much attention during the past decade as promising low-cost solar energy harvesting devices, and showed significant progress with power conversion efficiency reaching 5% recently. This review starts from the introduction of hybrid materials to their application in electronic devices, with particular focus on bulk-heterojunction hybrid polymer-nanocrystal PV devices. The synthesis, surface chemistry, and electronic properties of colloidal inorganic nanocrystals are described. The recent development of hybrid PV devices will be discussed from the perspective of tailoring both inorganic nanocrystals and conjugated polymers, controlling polymer-nanocrystal hybrid morphology, engineering polymer-nanocrystal interface, and optimizing device architecture. Finally, future directions for further advancing hybrid PV technology to potential commercialization are also discussed.

  5. Electrochemical characterization of aminated acrylic conducting polymer

    SciTech Connect

    Rashid, Norma Mohammad; Heng, Lee Yook; Ling, Tan Ling

    2015-09-25

    New attempt has been made to synthesize aminated acrylic conducting polymer (AACP) using precursor of phenylvinylsulfoxide (PVS). The process was conducted via the integration of microemulsion and photopolymerization techniques. It has been utilized for covalent immobilization of amino groups by the adding of N-achryiloxisuccinimide (NAS). Thermal eliminating of benzene sulfenic acids from PVS has been done at 250 °C to form electroactive polyacetylene (PA) segment. Characterization of AACP has been conducted using fourier transform infrared (FTIR), scanning electron microscopy (SEM) and linear sweep cyclic voltammetry (CV). A range of 0.3-1.25μm particle size obtained from SEM characterization. A quasi-reversible system performed as shown in electrochemical study.

  6. Highly stretchable electrospun conducting polymer nanofibers

    NASA Astrophysics Data System (ADS)

    Boubée de Gramont, Fanny; Zhang, Shiming; Tomasello, Gaia; Kumar, Prajwal; Sarkissian, Andranik; Cicoira, Fabio

    2017-08-01

    Biomedical electronics research targets both wearable and biocompatible electronic devices easily adaptable to specific functions. To achieve such goals, stretchable organic electronic materials are some of the most intriguing candidates. Herein, we develop highly stretchable poly-(3,4-ethylenedioxythiphene) (PEDOT) doped with tosylate (PEDOT:Tos) nanofibers. A two-step process involving electrospinning of a carrier polymer (with oxidant) and vapor phase polymerization was used to produce fibers on a polydimethylsiloxane substrate. The fibers can be stretched up to 140% of the initial length maintaining high conductivity.

  7. A novel high energy hybrid Li-ion capacitor with a three-dimensional hierarchical ternary nanostructure of hydrogen-treated TiO2 nanoparticles/conductive polymer/carbon nanotubes anode and an activated carbon cathode

    NASA Astrophysics Data System (ADS)

    Tang, Gang; Cao, Liujun; Xiao, Peng; Zhang, Yunhuai; Liu, Hao

    2017-07-01

    Lithium ion capacitors (LICs) are considered to be high-performance energy storage devices that have stimulated intense attention to bridge the gap between lithium ion battery and supercapacitor. Currently, the major challenge for LICs has been to improve the energy density without sacrificing the high rate of power output performance. Herein, we designed a three-dimensional (3D) hierarchical porous nanostructure of hydrogen-treated TiO2 nanoparticles wrapped conducting polymer polypyrrole (PPy) framework with single-walled carbon nanotubes (SWCNTs) hybrid (denoted as, H-TiO2/PPy/SWCNTs) anode material for LICs through a conventional and green approach. Such a unique network can offer continuous electron transport and reduce the diffusion length of lithium ions. A greatly lithium storage specific capacity is achieved with reversible discharge capacity ∼213 mA h g-1 (based on the mass of TiO2) over 50 cycles (@ 0.1 A g-1), which is almostly three times compared with raw TiO2 (a commercial TiO2 nanoparticles powder). In addition, coupled with commercial activated carbon (AC) cathode, the fully assembled H-TiO2/PPy/SWCNTs//AC LICs delivers a maximum energy and power densities of 31.3 Wh kg-1 and 4 kW kg-1, a reasonably good cycling stability (∼77.8% retention after 3000 cycles) within the voltage range of 1.0-3.0 V.

  8. Conductive inks for metalization in integrated polymer microsystems

    DOEpatents

    Davidson, James Courtney; Krulevitch, Peter A.; Maghribi, Mariam N.; Benett, William J.; Hamilton, Julie K.; Tovar, Armando R.

    2006-02-28

    A system of metalization in an integrated polymer microsystem. A flexible polymer substrate is provided and conductive ink is applied to the substrate. In one embodiment the flexible polymer substrate is silicone. In another embodiment the flexible polymer substrate comprises poly(dimethylsiloxane).

  9. Thermoelectric transport in hybrid materials incorporating metallic nanowires in polymer matrix

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Lu, Tingyu; Wang, Biao; Liu, Jun; Nakayama, Tsuneyoshi; Zhou, Jun; Li, Baowen

    2017-03-01

    We propose a type of thermoelectric materials incorporating metallic nanowires in insulating polymers. It is shown that the hybridization of poor thermoelectric materials such as metal and polymer can achieve high performance of thermoelectricity. The electrical conductivity of such hybrid materials is controllable by the volume fraction of metallic nanowires which is above a percolation critical value. Meanwhile, the Seebeck coefficient shows a weak dependence on the volume fraction. Low thermal conductivities required for achieving the high figure of merit can be fulfilled from both the low thermal conductivity of polymer and the interfacial thermal resistance between nanowires and polymer. In this regard, we propose the concept "electron-percolation thermal-insulator," providing a guide to design efficient hybrid thermoelectric materials.

  10. Active media for tunable lasers based on hybrid polymers

    SciTech Connect

    Kopylova, T N; Eremina, N S; Vaitulevich, E A; Samsonova, L G; Maier, G V; Tel'minov, E N; Solodova, T A; Solodov, A M

    2008-02-28

    The lasing properties of rhodamine 6G (chloride and perchlorate) in synthesised hybrid polymers based on an organic polymer (methyl methacrylate with hydroxyethyl methacrylate) and an inorganic precursor (tetraethoxysilane) are studied. Rhodamine 6G samples were transversely pumped by the second harmonic of a Nd{sup 3+}:YAG laser. It is found that the active media based on hybrid polymers have a considerably longer service life compared to the active media based on organic polymers. The structure of the hybrid polymer is studied by the methods of IR Fourier spectroscopy, X-ray diffraction, and thermogravimetry. It is shown that the longer service life of hybrid-polymer active media is explained by the formation of an inorganic nanostructure network in them, which improves the thermooptic properties of the material and reduces the efficiency of thermal decomposition of active molecules. (lasers. amplifiers)

  11. Inorganic/polymer hybrid nanoparticles for sensing applications.

    PubMed

    Sierra-Martin, Benjamin; Fernandez-Barbero, Antonio

    2016-07-01

    This paper reviews a wide set of sensing applications based on the special properties associated with inorganic/polymer composite nanoparticles. We first describe optical sensing applications performed with hybrid nanoparticles and hybrid microgels with special emphasis on photoluminescence detection and imaging. Analyte detection with molecularly imprinted polymers and HPLC-based sensing using hybrid nanoparticles as stationary phase is also summarized. The final part is devoted to the study of ultra-sensitive molecule detection by surface-enhanced Raman spectroscopy using core-shell hybrid materials composed of noble metal nanoparticles and cross-linked polymers.

  12. Stretchable and Conductive Polymer Films Prepared by Solution Blending.

    PubMed

    Li, Pengcheng; Sun, Kuan; Ouyang, Jianyong

    2015-08-26

    Stretchable and conductive materials can have important application in many areas, such as wearable electronics and healthcare devices. Conducting polymers have very limited elasticity because of their rigid conjugated backbone. In this work, highly stretchable and conductive polymer films are prepared by coating or casting aqueous solution of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate ( PSS) and a soft polymer, including poly(ethylene glycol), poly(ethylene oxide), or poly(vinyl alcohol). The soft polymers can greatly improve the stretchability and the conductivity of PSS. The elongation at break can be increased from 2% up to 55%. The soft polymers can also enhance the conductivity of PSS from 0.2 up to 75 S cm(-1). The conductivity is further enhanced by adding dimethyl sulfoxide (DMSO) or ethylene glycol (EG) into the aqueous solutions of the polymer blends. Polymer blends with an elongation at break of close to 50% and a conductivity of 172 S cm(-1) are attained.

  13. Catalytic synthesis of metal crystals using conductive polymers

    DOEpatents

    Wang, Hsing-Lin; Li, Wenguang

    2008-01-15

    A method of forming metal nanoparticles using a polymer colloid that includes at least one conductive polymer and at least one polyelectrolyte. Metal ions are reduced in water by the conductive polymer to produce the nanoparticles, which may be then incorporated in the colloidal structure to form a colloid composite. The method can also be used to separate selected metal ions from aqueous solutions.

  14. Chemical synthesis of chiral conducting polymers

    DOEpatents

    Wang, Hsing-Lin; Li, Wenguang

    2009-01-13

    An process of forming a chiral conducting polymer, e.g., polyaniline, is provided including reacting a monomer, e.g., an aniline monomer, in the presence of a chiral dopant acid to produce a first reaction mixture by addition of a solution including a first portion of an oxidizing agent, the first portion of oxidizing agent characterized as insufficient to allow complete reaction of the monomer, and further reacting the first reaction mixture in the presence of the chiral dopant acid by addition of a solution including a second portion of the oxidizing agent, the second portion of oxidizing agent characterized as insufficient to allow complete reaction of the monomer, and repeating the reaction by addition of further portions of the oxidizing agent until the monomer reaction is complete to produce a chiral conducting polymer, e.g., polyaniline. A preferred process includes addition of a catalyst during the reaction, the catalyst selected from among the group consisting of phenylene diamine, aniline oligomers and amino-capped aniline oligomers and metal salts.The processes of the present invention further provide a resultant polyaniline product having a chirality level defined by a molar ellipticity of from about 40.times.10.sup.3 degree-cm.sup.2/decimole to about 700.times.10.sup.3 degree-cm.sup.2/decimole. The processes of the present invention further provide a resultant polyaniline product having a nanofiber structure with a diameter of from about 30 nanometers to about 120 nanometers and from about 1 micron to about 5 microns in length.

  15. Chemical synthesis of chiral conducting polymers

    DOEpatents

    Wang, Hsing-Lin; Li, Wenguang

    2006-07-11

    An process of forming a chiral conducting polymer, e.g., polyaniline, is provided including reacting a monomer, e.g., an aniline monomer, in the presence of a chiral dopant acid to produce a first reaction mixture by addition of a solution including a first portion of an oxidizing agent, the first portion of oxidizing agent characterized as insufficient to allow complete reaction of the monomer, and further reacting the first reaction mixture in the presence of the chiral dopant acid by addition of a solution including a second portion of the oxidizing agent, the second portion of oxidizing agent characterized as insufficient to allow complete reaction of the monomer, and repeating the reaction by addition of further portions of the oxidizing agent until the monomer reaction is complete to produce a chiral conducting polymer, e.g., polyaniline. A preferred process includes addition of a catalyst during the reaction, the catalyst selected from among the group consisting of phenylene diamine, aniline oligomers and amino-capped aniline oligomers and metal salts. The processes of the present invention further provide a resultant polyaniline product having a chirality level defined by a molar ellipticity of from about 40.times.103 degree-cm2/decimole to about 700.times.103 degree-cm2/decimole. The processes of the present invention further provide a resultant polyaniline product having a nanofiber structure with a diameter of from about 30 nanometers to about 120 nanometers and from about 1 micron to about 5 microns in length.

  16. Improved thermally conducting electron transfer polymers

    NASA Technical Reports Server (NTRS)

    Jenkins, R. K.; Byrd, N. R.; Lister, J. L.

    1972-01-01

    Development of polymers with improved heat transfer coefficients for use in encapsulating electronic modules is discussed. Chemical reactions for synthesizing the polymers are described and thermodynamic and physical properties are analyzed.

  17. Hybrid Silicon Nanostructures with Conductive Ligands and Their Microscopic Conductivity

    NASA Astrophysics Data System (ADS)

    Bian, Tiezheng; Peck, Jamie N.; Cottrell, Stephen P.; Jayasooriya, Upali A.; Chao, Yimin

    2016-09-01

    Silicon nanoparticles (SiNPs) functionalized with conjugated molecules are a promising potential pathway for generating an alternative category of thermoelectric materials. While the thermoelectric performance of materials based on phenylacetylene-capped SiNPs has been proven, their low conductivity is still a problem for their general application. A muon study of phenylacetylene-capped SiNPs was recently carried out using the HIFI spectrometer at the Rutherford Appleton Laboratory, measuring the avoided level-crossing spectra as a function of temperature. The results show a reduction in the measured line width of the resonance above room temperature, suggesting an activated behaviour for this system. This study shows that the muon study could be a powerful method for investigating microscopic conductivity of hybrid thermoelectric materials.

  18. Nanostructured conducting polymers for energy applications: towards a sustainable platform.

    PubMed

    Ghosh, Srabanti; Maiyalagan, Thandavarayan; Basu, Rajendra N

    2016-04-07

    Recently, there has been tremendous progress in the field of nanodimensional conducting polymers with the objective of tuning the intrinsic properties of the polymer and the potential to be efficient, biocompatible, inexpensive, and solution processable. Compared with bulk conducting polymers, conducting polymer nanostructures possess a high electrical conductivity, large surface area, short path length for ion transport and superior electrochemical activity which make them suitable for energy storage and conversion applications. The current status of polymer nanostructure fabrication and characterization is reviewed in detail. The present review includes syntheses, a deeper understanding of the principles underlying the electronic behavior of size and shape tunable polymer nanostructures, characterization tools and analysis of composites. Finally, a detailed discussion of their effectiveness and perspectives in energy storage and solar light harvesting is presented. In brief, a broad overview on the synthesis and possible applications of conducting polymer nanostructures in energy domains such as fuel cells, photocatalysis, supercapacitors and rechargeable batteries is described.

  19. Nanostructured conducting polymers for energy applications: towards a sustainable platform

    NASA Astrophysics Data System (ADS)

    Ghosh, Srabanti; Maiyalagan, Thandavarayan; Basu, Rajendra N.

    2016-03-01

    Recently, there has been tremendous progress in the field of nanodimensional conducting polymers with the objective of tuning the intrinsic properties of the polymer and the potential to be efficient, biocompatible, inexpensive, and solution processable. Compared with bulk conducting polymers, conducting polymer nanostructures possess a high electrical conductivity, large surface area, short path length for ion transport and superior electrochemical activity which make them suitable for energy storage and conversion applications. The current status of polymer nanostructure fabrication and characterization is reviewed in detail. The present review includes syntheses, a deeper understanding of the principles underlying the electronic behavior of size and shape tunable polymer nanostructures, characterization tools and analysis of composites. Finally, a detailed discussion of their effectiveness and perspectives in energy storage and solar light harvesting is presented. In brief, a broad overview on the synthesis and possible applications of conducting polymer nanostructures in energy domains such as fuel cells, photocatalysis, supercapacitors and rechargeable batteries is described.

  20. Electrochemical post-functionalization of conducting polymers.

    PubMed

    Inagi, Shinsuke; Fuchigami, Toshio

    2014-05-01

    This article summarizes recent progress in the post-functionalization of conjugated polymers by electrochemical methods. These electrochemical polymer reactions typically proceed via electrochemical doping of a conjugated polymer film, followed by chemical transformation. Examples include the quantitative oxidative fluorination of polyfluorenes and oxidative halogenation of polythiophenes, as well as the reductive hydrogenation of polyfluorenones. The degree of functionalization, otherwise known as the reaction ratio, can be controlled by varying the charge passed through the polymer, allowing the optoelectronic properties of the conjugated polymers to be tailored. Wireless bipolar electrodes with an in-plane potential distribution are also useful with regard to the electrochemical doping and reaction of conjugated polymers and allow the synthesis of films exhibiting composition gradients. Such bipolar electrochemistry can induce multiple reaction sites during electrochemical polymer reactions.

  1. Conducting Polymer Nanostructures: Template Synthesis and Applications in Energy Storage

    PubMed Central

    Pan, Lijia; Qiu, Hao; Dou, Chunmeng; Li, Yun; Pu, Lin; Xu, Jianbin; Shi, Yi

    2010-01-01

    Conducting polymer nanostructures have received increasing attention in both fundamental research and various application fields in recent decades. Compared with bulk conducting polymers, conducting polymer nanostructures are expected to display improved performance in energy storage because of the unique properties arising from their nanoscaled size: high electrical conductivity, large surface area, short path lengths for the transport of ions, and high electrochemical activity. Template methods are emerging for a sort of facile, efficient, and highly controllable synthesis of conducting polymer nanostructures. This paper reviews template synthesis routes for conducting polymer nanostructures, including soft and hard template methods, as well as its mechanisms. The application of conducting polymer mesostructures in energy storage devices, such as supercapacitors and rechargeable batteries, are discussed. PMID:20717527

  2. Smart conducting polymer composites having zero temperature coefficient of resistance

    NASA Astrophysics Data System (ADS)

    Chu, Kunmo; Lee, Sung-Chul; Lee, Sangeui; Kim, Dongearn; Moon, Changyoul; Park, Sung-Hoon

    2014-12-01

    Zero temperature coefficient of resistance (TCR) is essential for the precise control of temperature in heating element and sensor applications. Many studies have focused on developing zero-TCR systems with inorganic compounds; however, very few have dealt with developing zero-TCR systems with polymeric materials. Composite systems with a polymer matrix and a conducting filler show either a negative (NTC) or a positive temperature coefficient (PTC) of resistance, depending on several factors, e.g., the polymer nature and the filler shape. In this study, we developed a hybrid conducting zero-TCR composite having self-heating properties for thermal stability and reliable temperature control. The bi-layer composites consisted of a carbon nanotube (CNT)-based layer having an NTC of resistance and a carbon black (CB)-based layer having a PTC of resistance which was in direct contact with electrodes to stabilize the electrical resistance change during electric Joule heating. The composite showed nearly constant resistance values with less than 2% deviation of the normalized resistance until 200 °C. The CB layer worked both as a buffer and as a distributor layer against the current flow from an applied voltage. This behavior, which was confirmed both experimentally and theoretically, has been rarely reported for polymer-based composite systems.Zero temperature coefficient of resistance (TCR) is essential for the precise control of temperature in heating element and sensor applications. Many studies have focused on developing zero-TCR systems with inorganic compounds; however, very few have dealt with developing zero-TCR systems with polymeric materials. Composite systems with a polymer matrix and a conducting filler show either a negative (NTC) or a positive temperature coefficient (PTC) of resistance, depending on several factors, e.g., the polymer nature and the filler shape. In this study, we developed a hybrid conducting zero-TCR composite having self

  3. Water-Processable Polymer-Nanocrystal Hybrids for Thermoelectrics

    DTIC Science & Technology

    2010-10-05

    thermoelectric characterization of composite nanocrystals composed of a tellurium core functionalized with the conducting polymer poly(3,4...composed of a tellurium core functionalized with the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Solution...thermoelectric characterization of composite nanocrystals composed of a tellurium core functionalized with the conducting polymer poly(3,4-ethylenedioxythiophene

  4. Hybrid materials and polymer electrolytes for electrochromic device applications.

    PubMed

    Thakur, Vijay Kumar; Ding, Guoqiang; Ma, Jan; Lee, Pooi See; Lu, Xuehong

    2012-08-08

    Electrochromic (EC) materials and polymer electrolytes are the most imperative and active components in an electrochromic device (ECD). EC materials are able to reversibly change their light absorption properties in a certain wavelength range via redox reactions stimulated by low direct current (dc) potentials of the order of a fraction of volts to a few volts. The redox switching may result in a change in color of the EC materials owing to the generation of new or changes in absorption band in visible region, infrared or even microwave region. In ECDs the electrochromic layers need to be incorporated with supportive components such as electrical contacts and ion conducting electrolytes. The electrolytes play an indispensable role as the prime ionic conduction medium between the electrodes of the EC materials. The expected applications of the electrochromism in numerous fields such as reflective-type display and smart windows/mirrors make these materials of prime importance. In this article we have reviewed several examples from our research work as well as from other researchers' work, describing the recent advancements on the materials that exhibit visible electrochromism and polymer electrolytes for electrochromic devices. The first part of the review is centered on nanostructured inorganic and conjugated polymer-based organic-inorganic hybrid EC materials. The emphasis has been to correlate the structures, morphologies and interfacial interactions of the EC materials to their electronic and ionic properties that influence the EC properties with unique advantages. The second part illustrates the perspectives of polymer electrolytes in electrochromic applications with emphasis on poly (ethylene oxide) (PEO), poly (methyl methacrylate) (PMMA) and polyvinylidene difluoride (PVDF) based polymer electrolytes. The requirements and approaches to optimize the formulation of electrolytes for feasible electrochromic devices have been delineated. Copyright © 2012 WILEY

  5. Multifunctional Nanofibers Comprised of Conducting and Ferroelectric Polymer Composites

    DTIC Science & Technology

    2015-08-04

    SECURITY CLASSIFICATION OF: Work on this proposal concentrated on studying the following polymers : poly(vinylidene fluoride-trifluoroethylene) (PVDF...prepare thin films and electrospinning to prepare fine fibers of these polymers . The goal was to make devices and sensors. Using an atomic force...2014 Approved for Public Release; Distribution Unlimited Multifunctional nanofibers comprised of conducting and ferroelectric polymer composites The

  6. Chemical anchoring of organic conducting polymers to semiconducting surfaces

    DOEpatents

    Frank, Arthur J.; Honda, Kenji

    1984-01-01

    According to the present invention, an improved method of coating electrodes with conductive polymer films and/or preselected catalysts is provided. The charge-conductive polymer is covalently or coordinatively attached to the electrode surface to strengthen the adhesion characteristics of the polymer to the electrode surface or to improve charge-conductive properties between the conductive polymer and the electrode surface. Covalent or coordinative attachment is achieved by a number of alternative methods including covalently or coordinatively attaching the desired monomer to the electrode by means of a suitable coupling reagent and, thereafter, electrochemically polymerizing the monomer in situ.

  7. Chemical anchoring of organic conducting polymers to semiconducting surfaces

    DOEpatents

    Frank, A.J.; Honda, K.

    1984-01-01

    According to the present invention, an improved method of coating electrodes with conductive polymer films and/or preselected catalysts is provided. The charge conductive polymer is covalently or coordinatively attached to the electrode surface to strengthen the adhesion characteristics of the polymer to the electrode surface or to improve charge conductive properties between the conductive polymer and the electrode surface. Covalent or coordinative attachment is achieved by a number of alternative methods including covalently or coordinatively attaching the desired monomer to the electrode by means of a suitable coupling reagent and, thereafter, electrochemically polymerizing the monomer in situ.

  8. Electrochemical Impedance Spectroscopy of Conductive Polymer Coatings

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; MacDowell, Louis G.

    1996-01-01

    Electrochemical impedance spectroscopy (EIS) was used to investigate the corrosion protection performance of twenty nine proprietary conductive polymer coatings for cold rolled steel under immersion in 3.55 percent NaCl. Corrosion potential as well as Bode plots of the data were obtained for each coating after one hour immersion, All coatings, with the exception of one, have a corrosion potential that is higher in the positive direction than the corrosion potential of bare steel under the same conditions. Group A consisted of twenty one coatings with Bode plots indicative of the capacitive behavior characteristic of barrier coatings. An equivalent circuit consisting of a capacitor in series with a resistor simulated the experimental EIS data for these coatings very well. Group B consisted of eight coatings that exhibited EIS spectra showing an inflection point which indicates that two time constants are present. This may be caused by an electrochemical process taking place which could be indicitive of coating failing. These coatings have a lower impedance that those in Group A.

  9. Proton Conducting Polymer Electrolyte Based on Pva-Pan

    NASA Astrophysics Data System (ADS)

    Devi, S. Siva; Selvasekarapandian, S.; Rajeswari, N.; Genova, F. Kingslin Mary; Karthikeyan, S.; Raja, C. Sanjeevi

    2013-07-01

    Proton conducting polymer electrolytes based on blend polymer using Poly Vinyl Alcohol (PVA) and Poly Acrylo Nitrile (PAN) doped with ammonium nitrate have been prepared by solution casting method. The highest conductivity at room temperature (305K) has been found to be 1.8×10-3 S cm-1 for 15 mole % NH4NO3 doped PVA-PAN system. X ray Diffraction pattern of the doped and the undoped blend polymer electrolyte confirms the amorphous nature of blend polymer, when salt is added. The complex formation between the blend polymer and the salt has been confirmed by Fourier transform infrared spectroscopy.

  10. Anion-conducting polymer, composition, and membrane

    DOEpatents

    Pivovar, Bryan S [Los Alamos, NM; Thorn, David L [Los Alamos, NM

    2011-11-22

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  11. Anion-Conducting Polymer, Composition, and Membrane

    DOEpatents

    Pivovar, Bryan S.; Thorn, David L.

    2008-10-21

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  12. Anion-conducting polymer, composition, and membrane

    DOEpatents

    Pivovar, Bryan S.; Thorn, David L.

    2010-12-07

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  13. Anion-conducting polymer, composition, and membrane

    DOEpatents

    Pivovar, Bryan S.; Thorn, David L.

    2009-09-01

    Anion-conducing polymers and membranes with enhanced stability to aqueous alkali include a polymer backbone with attached sulfonium, phosphazenium, phosphazene, and guanidinium residues. Compositions also with enhanced stability to aqueous alkali include a support embedded with sulfonium, phosphazenium, and guanidinium salts.

  14. Tunnelling conductive hybrid films of gold nanoparticles and cellulose and their applications as electrochemical electrodes.

    PubMed

    Liu, Zhiming; Wang, Xuefeng; Li, Mei; Wu, Wenjian

    2015-11-20

    Conductive hybrid films of metal nanoparticles and polymers have practical applications in the fields of sensing, microelectronics and catalysis, etc. Herein, we present the electrochemical availability of tunnelling conductive hybrid films of gold nanoparticles (GNPs) and cellulose.The hybrid films were provided with stable tunnelling conductive properties with 12 nm GNPs of 12.7% (in weight). For the first time, the conductive hybrid films were used as substrates of electrochemical electrodes to load calmodulin (CaM) proteins for sensing of calcium cations.The electrodes of hybrid films with 20 nm GNPs of 46.7% (in weight) exhibited stable electrochemical properties, and showed significant responses to calcium cations with concentrations as low as 10(−9) M after being loaded with CaM proteins.

  15. Tunnelling conductive hybrid films of gold nanoparticles and cellulose and their applications as electrochemical electrodes

    NASA Astrophysics Data System (ADS)

    Liu, Zhiming; Wang, Xuefeng; Li, Mei; Wu, Wenjian

    2015-11-01

    Conductive hybrid films of metal nanoparticles and polymers have practical applications in the fields of sensing, microelectronics and catalysis, etc. Herein, we present the electrochemical availability of tunnelling conductive hybrid films of gold nanoparticles (GNPs) and cellulose. The hybrid films were provided with stable tunnelling conductive properties with 12 nm GNPs of 12.7% (in weight). For the first time, the conductive hybrid films were used as substrates of electrochemical electrodes to load calmodulin (CaM) proteins for sensing of calcium cations. The electrodes of hybrid films with 20 nm GNPs of 46.7% (in weight) exhibited stable electrochemical properties, and showed significant responses to calcium cations with concentrations as low as 10-9 M after being loaded with CaM proteins.

  16. 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.

  17. Corn Hybrid Polymer Media for Coatings Removal from Delicate Substrates

    DTIC Science & Technology

    2008-05-01

    Corn Hybrid Polymer Media for Coatings Removal from Delicate Substrates Brian Yallaly, NDCEE The NDCEE is operated by: NDCEE National Defense Center...3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Corn Hybrid Polymer Media for Coatings Removal from Delicate Substrates 5a... Corn -based blasting media – Provides acceptable stripping rates – Does not damage delicate substrates – Generates biodegradable and recyclable

  18. 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.

  19. Nanoscale hybrid protein/polymer functionalized materials

    NASA Astrophysics Data System (ADS)

    Ho, Dean; Chu, Ben; Lee, Hyeseung; Montemagno, Carlo D.

    2004-07-01

    Block copolymer-based membrane technology represents a versatile class of nanoscale materials in which biomolecules, such as membrane proteins, can be reconstituted. Our work has demonstrated the fabrication of large-area, protein- enhanced membranes that possess significant performance improvements in protein functionality. Among its many advantages over conventional lipid-based membrane systems, block copolymers can mimic natural cell biomembrane environments in a single chain, enabling large-area membrane fabrication using methods like Langmuir-Blodgett (LB) deposition, or spontaneous protein-functionalized nano-vesicle formation. The membrane protein, Bacteriorhodopsin (BR), found in Halobacterium Halobium, is a light-actuated proton pump that develops gradients towards the demonstration of coupled functionality with other membrane proteins to effect ATP production, or production of electricity through Bacteriorhodopsin activity-dependent reversal of Cytochrome C Oxidase (COX), found in Rhodobacter Sphaeroides. Using quantum dot-labeled, engineered protein constructs, we have demonstrated large-scale insertion of proteins into block copolymer Langmuir-Blodgett (LB) films as well as measurable pH changes based upon light-actuated proton pumping. Light actuated-activity across the protein-functionalized membrane when fully enclosed in a sol-gel matrix has also been observed using impedance spectroscopy. Initial data has suggested a significant pH change of up to 1.75 in a volume of 100 mL and surface area of 0.317cm2, a level that is capable of powering a number of proton-gradient dependent proteins towards the buildup of a robust, hybrid protein/polymer device. Recent atomic force microscopy studies of the protein-embedded polymer film samples have revealed the formation of protein aggregate-based pattern generation with very uniform torus-shaped rings. Current work focused towards characterizing the effects that various pattern formations can have on the

  20. Electrically Conductive Metal Nanowire Polymer Nanocomposites

    NASA Astrophysics Data System (ADS)

    Luo, Xiaoxiong

    This thesis investigates electrically conductive polymer nanocomposites formulated with metal nanowires for electrostatic discharge and electromagnetic interference shielding. Copper nanowires (CuNWs) of an average length of 1.98 mum and diameter of 25 +/- 4 nm were synthesized. The oxidation reaction of the CuNWs in air can be divided into two stages at weight of 111.2% on TGA curves. The isoconversional activation energies determined by Starink method were used to fit the different master plots. Johnson-Mehl-Avrami (JMA) equation gave the best fit. The surface atoms of the CuNWs are the sites for the random nucleation and the crystallite strain in the CuNWs is the driving force for the growth of nuclei mechanism during the oxidation process. To improve the anti-oxidation properties of the CuNWs, silver was coated onto the surface of the CuNWs in Ag-amine solution. The prepared silver coated CuNWs (AgCuNWs) with silver content of 66.52 wt. %, diameter of 28--33 nm exhibited improved anti-oxidation behavior. The electrical resistivity of the AgCuNW/low density polyethylene (LDPE) nanocomposites is lower than that of the CuNW/LDPE nanocomposites with the same volume percentage of fillers. The nanocomposites formulated with CuNWs and polyethylenes (PEs) were compared to study the different interaction between the CuNWs and the different types of PE matrices. The electrical conductivity of the different PE matrices filled with the same concentrations of CuNWs correlated well with the level of the CuNW dispersion. The intermolecular force and entanglement resulting from the different macromolecular structures such as molecular weight and branching played an important role in the dispersion, electrical properties and rheological behaviour of the CuNW/PE nanocomposites. Ferromagnetic polycrystalline nickel nanowires (NiNWs) were synthesized with uniform diameter of ca. 38 nm and an average length of 2.68 mum. The NiNW linear low density polyethylene (LLDPE

  1. Synthesis and characterization of conducting polymer inserted carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Choi, A. Jeong; Nam, Young Woo; Park, Yung Woo

    2008-03-01

    The carbon nanotubes filled with the photo-conducting polymer poly(N-vinyl carbazole) and the conducting polymer polypyrrole were prepared by polymerizing the monomers inside the nanotubes using the supercritical carbon dioxide. The endohedral nanotubes were characterized by HRTEM and ^1H NMR, which confirmed that the inserted material was indeed the conducting polymer [1]. I-V characteristics of the polymer inserted carbon nanotubes are presented. [1] Johannes Steinmetz, Soyoung Kwon, Hyun-Jung Lee, Edy Abou-Hamad, Robert Almairac, Christophe Goze-Bac, Hwayong Kim, Yung-Woo Park,, Chem. Phys. Lett., 431, 139 (2006)

  2. Polymer-polymer and hybrid clay-polymer complexes at liquid-liquid interfaces

    NASA Astrophysics Data System (ADS)

    Wang, Yuhao; Sukhishvili, Svetlana

    2014-03-01

    We report on polymer-polymer and hybrid clay-polymer complex formation at oil-water interfaces. The complexes were composed of poly(methacrylic acid) (PMAA) and poly(N-isopropylacrylamide) (PNIPAM) or PNIPAM modified Laponite (L@PN). Interfacial surface tension, confocal laser scanning microscopy (CLSM) and cryogenic scanning electron microscopy (cryo-SEM) measurements were performed at various ratios of complex components and as a function of solution pH. The results reveal that interfacial PNIPAM/PMAA and L@PN/PMAA complexes are significantly more stable across the pH scale than their solution counterparts, probably because of the suppressed ionization of PMAA at the oil-water interface. In addition, we will discuss the effect of interfacial complex formation on PMAA chain dynamics, as measured by fluorescence-correlation spectroscopy (FCS), and demonstrate the use of these systems to control emulsion stability via changes in solution pH or temperature.

  3. 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.

  4. Enzymatic biosensors based on SWCNT-conducting polymer electrodes.

    PubMed

    Le Goff, Alan; Holzinger, Michael; Cosnier, Serge

    2011-04-07

    This short review is focused on recent advances in the combination of conducting polymers and SWCNTs for the fabrication of electrochemical biosensors. The different properties of conducting polymers and SWCNTs are discussed in respect of their use in immobilizing and wiring biomolecules on electrode surfaces. We further describe the functionalization techniques used in the fabrication of these devices and their associated biosensing performances.

  5. Nanostructured conducting polymer hydrogels for energy storage applications.

    PubMed

    Shi, Ye; Peng, Lele; Yu, Guihua

    2015-08-14

    Conducting polymer hydrogels are emerging as a promising class of polymeric materials for various technological applications, especially for energy storage devices due to their unique combination of advantageous features of conventional polymers and organic conductors. To overcome the drawbacks of conventional synthesis, new synthetic routes in which acid molecules are adopted as both crosslinkers and dopants have been developed for conducting polymer hydrogels with unique 3D hierarchical porous nanostructures, resulting in high electrical conductivity, large surface area, structural tunability and hierarchical porosity for rapid mass/charge transport. The newly developed conducting polymer hydrogels exhibit high performance when applied as active electrode materials for electrochemical capacitors or as functional binder materials for high-energy lithium-ion batteries. This feature article summarizes the synthesis of conducting polymer hydrogels, presents their applications in energy storage, and discusses further opportunities and challenges.

  6. Nanostructured conducting polymer hydrogels for energy storage applications

    NASA Astrophysics Data System (ADS)

    Shi, Ye; Peng, Lele; Yu, Guihua

    2015-07-01

    Conducting polymer hydrogels are emerging as a promising class of polymeric materials for various technological applications, especially for energy storage devices due to their unique combination of advantageous features of conventional polymers and organic conductors. To overcome the drawbacks of conventional synthesis, new synthetic routes in which acid molecules are adopted as both crosslinkers and dopants have been developed for conducting polymer hydrogels with unique 3D hierarchical porous nanostructures, resulting in high electrical conductivity, large surface area, structural tunability and hierarchical porosity for rapid mass/charge transport. The newly developed conducting polymer hydrogels exhibit high performance when applied as active electrode materials for electrochemical capacitors or as functional binder materials for high-energy lithium-ion batteries. This feature article summarizes the synthesis of conducting polymer hydrogels, presents their applications in energy storage, and discusses further opportunities and challenges.

  7. Mesoscopic modelling of conducting and semiconducting polymers

    NASA Astrophysics Data System (ADS)

    Stoneham, A. M.; Ramos, Marta M. D.

    2001-03-01

    We present generalized Monte Carlo calculations to assess the effects of texture and related key factors on the properties of polymer-based light emitting diodes. We describe one class of mesoscopic model giving specific realizations of the polymer network. The model, with simple physically based rules, shows the effects of polymer structural order on current flow, trapping and radiative and non-radiative charge recombination within the polymer layer. Interactions between charges are included explicitly, as are image interactions with the electrodes. It is important that these Coulomb interactions are not simplified to an averaged space charge, since the local interactions can lead to effective trapping of charge, even in the absence of defective chains or impurity trapping. There proves to be an important role for trapping, in which charges are localized for times long compared with transit times. The competition between current flow, trapping and radiative and non-radiative charge recombination means that some of the trends are not intuitively obvious. For example, if radiative recombination occurs only on short polymer chains, as is the case for certain polymer systems, the internal efficiency appears to saturate for a concentration of these shorter luminescent chains of about 20-30%. As the proportion of shorter chains increases, trapping increases, whereas current efficiency decreases. Our approach provides a natural link between atomistic models of individual polymer molecules and the macroscopic descriptions of device modelling. Such mesoscopic models provide a means to design better film structures, and hence to optimize the effectiveness of new organic materials in a range of applications.

  8. Nuclear alkylated pyridine aldehyde polymers and conductive compositions thereof

    NASA Technical Reports Server (NTRS)

    Rembaum, A.; Singer, S. (Inventor)

    1970-01-01

    A thermally stable, relatively conductive polymer was disclosed. The polymer was synthesized by condensing in the presence of catalyst a 2, 4, or 6 nuclear alklylated 2, 3, or 4 pyridine aldehyde or quaternary derivatives thereof to form a polymer. The pyridine groups were liked by olefinic groups between 2-4, 2-6, 2-3, 3-4, 3-6 or 4-6 positions. Conductive compositions were prepared by dissolving the quaternary polymer and an organic charge transfer complexing agent such as TCNQ in a mutual solvent such as methanol.

  9. Polyvinyl alcohol as photoluminescent conductive polymer

    NASA Astrophysics Data System (ADS)

    Ruiz-Limón, B.; Wetzel, G. B. J.; Olivares-Pérez, A.; Ponce-Lee, E. L.; Hernández-Garay, M. P.; Páez-Trujillo, G.; Toxqui-López, S.; Fuentes-Tapia, I.

    2007-02-01

    We synthesized a photoluminescent conductor polymer composed of polyvinyl alcohol, which was doped with nickel chloride to decrease its resistivity (300 Ωcm) and benzalkonium chloride to obtain photoluminescence properties, when it is radiated with a green laser beam (532 nm). We compared its absorbance curve and its energy emitted curve to observe the amount energy that is taken advantage of this process. Besides we research the photoluminescence behavior when an electric currant is applied in our conductor polymer, obtaining a modulation capacity.

  10. Organometallics for Conducting Polymer Synthesis and Starburst Polymer Synthesis

    DTIC Science & Technology

    1991-05-16

    Polymers for Electronic and Photonic Applications. (B) Metal(0) Deposition in Sol-Gel Materials for Heterogeneous Catalysis . Dow Coming Corporation...Deposition in Sol-Gel Materials for Heterogeneous Catalysis . Shell Development Company, Westhollow Research Center, Houston, Texas, March 16, 1991

  11. Patterning of conducting polymers using charged self-assembled monolayers.

    PubMed

    Jung, Mi-Hee; Lee, Hyoyoung

    2008-09-02

    We introduce a new approach to pattern conducting polymers by combining oppositely charged conducting polymers on charged self-assembled monolayers (SAMs). The polymer resist pattern behaves as a physical barrier, preventing the formation of SAMs. The patterning processes were carried out using commercially available conducting polymers: a negatively charged PEDOT/PSS (poly(3,4-ethylene-dioxythiophene)/poly(4-stylenesulphonic acid)) and a positively charged polypyrrole (PPy). A bifunctional NH 2 (positively charged) or COOH (negatively charged) terminated alkane thiol or silane was directly self-assembled on a substrate (Au or SiO 2). A suspension of the conducting polymers (PEDOT/PSS and PPy) was then spin-coated on the top surface of the SAMs and allowed to adsorb on the oppositely charged SAMs via an electrostatic driving force. After lift-off of the polymer resist, i.e., poly(methyl methacrylate, PMMA), using acetone, the conducting polymers remained on the charged SAMs surface. Optical microscopy, Auger electron spectroscopy, and atomic force microscopy reveal that the prepared nanolines have low line edge roughness and high line width resolution. Thus, conducting polymer patterns with high resolution could be produced by simply employing charged bifunctional SAMs. It is anticipated that this versatile new method can be applied to device fabrication processes of various nano- and microelectronics.

  12. Conductive polymers: towards a smart biomaterial for tissue engineering.

    PubMed

    Balint, Richard; Cassidy, Nigel J; Cartmell, Sarah H

    2014-06-01

    Developing stimulus-responsive biomaterials with easy-to-tailor properties is a highly desired goal of the tissue engineering community. A novel type of electroactive biomaterial, the conductive polymer, promises to become one such material. Conductive polymers are already used in fuel cells, computer displays and microsurgical tools, and are now finding applications in the field of biomaterials. These versatile polymers can be synthesised alone, as hydrogels, combined into composites or electrospun into microfibres. They can be created to be biocompatible and biodegradable. Their physical properties can easily be optimized for a specific application through binding biologically important molecules into the polymer using one of the many available methods for their functionalization. Their conductive nature allows cells or tissue cultured upon them to be stimulated, the polymers' own physical properties to be influenced post-synthesis and the drugs bound in them released, through the application of an electrical signal. It is thus little wonder that these polymers are becoming very important materials for biosensors, neural implants, drug delivery devices and tissue engineering scaffolds. Focusing mainly on polypyrrole, polyaniline and poly(3,4-ethylenedioxythiophene), we review conductive polymers from the perspective of tissue engineering. The basic properties of conductive polymers, their chemical and electrochemical synthesis, the phenomena underlying their conductivity and the ways to tailor their properties (functionalization, composites, etc.) are discussed. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  13. Raising the conductivity of crystalline polymer electrolytes by aliovalent doping.

    PubMed

    Zhang, Chuhong; Staunton, Edward; Andreev, Yuri G; Bruce, Peter G

    2005-12-28

    Polymer electrolytes, salts dissolved in solid polymers, hold the key to realizing all solid-state devices such as rechargeable lithium batteries, electrochromic displays, or SMART windows. For 25 years conductivity was believed to be confined to amorphous polymer electrolytes, all crystalline polymer electrolytes were thought to be insulators. However, recent results have demonstrated conductivity in crystalline polymer electrolytes, although the levels at room temperature are too low for application. Here we show, for the first time, that it is possible to raise significantly the level of ionic conductivity by aliovalent doping. The conductivity may be raised by 1.5 orders of magnitude if the SbF6- ion in the crystalline conductor poly(ethylene oxide)6:LiSbF6 is replaced by less than 5 mol % SiF6(2-), thus introducing additional, mobile, Li+ ions into the structure to maintain electroneutrality.

  14. Conducting polymer as smart interfaces for cultured neurons

    NASA Astrophysics Data System (ADS)

    Ahluwalia, Arti; Mauricio, Ines; Mazzoldi, Alberto; Serra, Giorgio; Bianchi, Francesca

    2005-05-01

    This work is part of a research project aimed at realising conducting polymer matrices for interfacing with cultured neurons. The polymer matrix has a dual function, one as a medium for recording electrical activity; the other is chemical stimulation through the release of bioactive molecules. In this work we use poly-3-hexylthiophene as a conducting polymer matrix. To test the polymer"s ability to release molecules upon the application of a potential it was doped with glutamate (GA). GA is an important neurotransmitter, and its controlled release can be important in several medical and tissue engineering applications. Diffusional and controlled release of GA from the polymer were assessed. Biocompatibility of the samples was evaluated at each stage using neuroblastoma cell cultures.

  15. Thermophysical Properties of Polymer Materials with High Thermal Conductivity

    NASA Astrophysics Data System (ADS)

    Lebedev, S. M.; Gefle, O. S.; Dneprovskii, S. N.; Amitov, E. T.

    2015-06-01

    Results of studies on the main thermophysical properties of new thermally conductive polymer materials are presented. It is shown that modification of polymer dielectrics by micron-sized fillers allows thermally conductive materials with thermal conductivity not less than 2 W/(m K) to be produced, which makes it possible to use such materials as cooling elements of various electrical engineering and semiconductor equipment and devices.

  16. Intrinsically Electrically Conducting Polymers as Corrosion Inhibiting Coatings.

    DTIC Science & Technology

    1998-04-01

    work on corrosion protection has focused on polyaniline ( PANI ) (References 42 through 46), but also has been extended to other conjugated polymers...of conducting polymers as corrosion-protective coatings. On a historical note, polyaniline was first made as far back as 1862 by Letheby (Reference 1...Conjugated Polymers in Their Respective Neutral Forms. Polyaniline is usually obtained by protonation of what is called the emeraldine base form

  17. Research Trends of Soft Actuators based on Electroactive Polymers and Conducting Polymers

    NASA Astrophysics Data System (ADS)

    Kaneto, K.

    2016-04-01

    Artificial muscles (or soft actuators) based on electroactive polymers (EAPs) are attractive power sources to drive human-like robots in place of electrical motor, because they are quiet, powerful, light weight and compact. Among EAPs for soft actuators, conducting polymers are superior in strain, stress, deformation form and driving voltage compared with the other EAPs. In this paper, the research trends of EAPs and conducting polymers are reviewed by retrieval of the papers and patents. The research activity of EAP actuators showed the maximum around 2010 and somehow declining now days. The reasons for the reducing activity are found to be partly due to problems of conducting polymer actuators for the practical application. The unique characteristics of conducting polymer actuators are mentioned in terms of the basic mechanisms of actuation, creeping, training effect and shape retention under high tensile loads. The issues and limitation of conducting polymer soft actuators are discussed.

  18. The effect of ultrasonic waves in conducting polymer solution.

    PubMed

    de Azevedo, W M; de Oliveira Luna, A J H; Silva, E F V B N; Silva, R O

    2006-07-01

    The effects of ultrasonic wave on the conducting polymer polyaniline dissolved in DMSO were observed. The UV-visible, infrared and NMR analysis show that the polymer undergo a redox and doping transition when the ultrasound wave interacts with the polymer dissolved into the solvent. The proposed mechanism to explain these effects is based on the solvent's hygroscopicity properties. The interaction with the ultrasonic wave, homolitically dissociates the water molecule producing radical species, and these species interact with the dissolved conducting polymer changing its oxidation and doped state. The resulting effects of that interaction are the modification of oxidation state of the conducting polymer and the decrease of the amount of water molecule in the solvent. From those results, we have proposed one straightforward method to eliminate water contamination in the solvent DMSO using ultrasonic waves.

  19. Making Conductive Polymers By Arc Tracking

    NASA Technical Reports Server (NTRS)

    Daech, Alfred F.

    1992-01-01

    Experimental technique for fabrication of electrically conductive polymeric filaments based on arc tracking, in which electrical arc creates conductive carbon track in material that initially was insulator. Electrically conductive polymeric structures made by arc tracking aligned along wire on which formed. Alignment particularly suited to high conductivity and desirable in materials intended for testing as candidate superconductors.

  20. Making Conductive Polymers By Arc Tracking

    NASA Technical Reports Server (NTRS)

    Daech, Alfred F.

    1992-01-01

    Experimental technique for fabrication of electrically conductive polymeric filaments based on arc tracking, in which electrical arc creates conductive carbon track in material that initially was insulator. Electrically conductive polymeric structures made by arc tracking aligned along wire on which formed. Alignment particularly suited to high conductivity and desirable in materials intended for testing as candidate superconductors.

  1. Affordable, Lightweight, Highly Conductive Polymer Composite Electronic Packaging Structures

    DTIC Science & Technology

    1996-06-01

    matrix composite materials and how various material designs can be utilized in various structural/thermal configurations to produce electronic housings and...conductive polymer composite electronic packaging (i.e., electronic housings and heat sinks). The research will center on predominately polymer

  2. 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.

  3. 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.

  4. Anisotropic Thermal Conduction in Polymers and its Molecular Origins

    NASA Astrophysics Data System (ADS)

    Schieber, Jay; Venerus, David; Gupta, Sahil

    2013-03-01

    The strong coupling of mechanical and thermal effects in polymer flows have a significant impact on both the processing and final properties of the material. Simple molecular arguments suggest that Fourier's law must be generalized to allow for anisotropic thermal conductivity in polymers subjected to deformation. In our laboratory we have developed a novel application of the optical technique known as Forced Rayleigh Scattering to obtain quantitative measurements of components of the thermal diffusivity (conductivity) tensor in polymers subjected to deformations. We report measurements of anisotropic thermal diffusivity and stress in molten, cross-linked and solid polymers subjected to several types of flows. The deformed samples have significant anisotropy in polymer chain orientation that results in significant anisotropy in thermal conductivity. Stress and thermal conductivity data support the validity of the stress-thermal rule, which is analogous to the well-known stress-optic rule. We also report measurements on solid polymers with isotropic polymer chain orientation that are under stress, which display rather unexpected behavior. These measurements are used to develop an understanding of the molecular origins of anisotropic thermal conduction in polymeric material NSF-DMR-706582

  5. Conducting Polymer Electrodes for Gel Electrophoresis

    PubMed Central

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D.

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation. PMID:24586761

  6. Conducting polymer electrodes for gel electrophoresis.

    PubMed

    Bengtsson, Katarina; Nilsson, Sara; Robinson, Nathaniel D

    2014-01-01

    In nearly all cases, electrophoresis in gels is driven via the electrolysis of water at the electrodes, where the process consumes water and produces electrochemical by-products. We have previously demonstrated that π-conjugated polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) can be placed between traditional metal electrodes and an electrolyte to mitigate electrolysis in liquid (capillary electroosmosis/electrophoresis) systems. In this report, we extend our previous result to gel electrophoresis, and show that electrodes containing PEDOT can be used with a commercial polyacrylamide gel electrophoresis system with minimal impact to the resulting gel image or the ionic transport measured during a separation.

  7. 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

  8. Electropolymerized Conducting Polymer as Actuator and Sensor Device

    ERIC Educational Resources Information Center

    Cortes, Maria T.; Moreno, Juan C.

    2005-01-01

    A study demonstrates the potential application of conducting polymers to convert electrical energy into mechanical energy at low voltage or current. The performance of the device is explained using electrochemistry and solid-state chemistry.

  9. Current Trends in Sensors Based on Conducting Polymer Nanomaterials

    PubMed Central

    Yoon, Hyeonseok

    2013-01-01

    Conducting polymers represent an important class of functional organic materials for next-generation electronic and optical devices. Advances in nanotechnology allow for the fabrication of various conducting polymer nanomaterials through synthesis methods such as solid-phase template synthesis, molecular template synthesis, and template-free synthesis. Nanostructured conducting polymers featuring high surface area, small dimensions, and unique physical properties have been widely used to build various sensor devices. Many remarkable examples have been reported over the past decade. The enhanced sensitivity of conducting polymer nanomaterials toward various chemical/biological species and external stimuli has made them ideal candidates for incorporation into the design of sensors. However, the selectivity and stability still leave room for improvement. PMID:28348348

  10. Properties of polymer blends filled with mixtures of conductive fillers

    NASA Astrophysics Data System (ADS)

    Thongruang, Wiriya

    2001-11-01

    High-density polyethylene (HDPE), ultrahigh molecular weight polyethylene (UHMWPE) and blends thereof are used to produce ternary and quaternary conductive polymer composites (CPCs) containing carbon black (CB), carbon graphite (G), carbon fiber (CF) and selected mixtures thereof to discern if polymer blends and mixed fillers yield appreciable advantages over CPCs composed of single polymers and/or single fillers. The effects of polymer blend composition and filler type, concentration and composition on electrical conductivity, composite morphology, mechanical properties and thermal behavior have been examined and correlated to establish meaningful structure-property relationships that can facilitate the rational design of efficient CPCs. Enhanced conductivity due to double-percolation is observed in ternary CPCs containing CB or G, whereas the concept of bridged double percolation is proposed to explain substantial conductivity increases in quaternary composites.

  11. Current Trends in Sensors Based on Conducting Polymer Nanomaterials.

    PubMed

    Yoon, Hyeonseok

    2013-08-27

    Conducting polymers represent an important class of functional organic materials for next-generation electronic and optical devices. Advances in nanotechnology allow for the fabrication of various conducting polymer nanomaterials through synthesis methods such as solid-phase template synthesis, molecular template synthesis, and template-free synthesis. Nanostructured conducting polymers featuring high surface area, small dimensions, and unique physical properties have been widely used to build various sensor devices. Many remarkable examples have been reported over the past decade. The enhanced sensitivity of conducting polymer nanomaterials toward various chemical/biological species and external stimuli has made them ideal candidates for incorporation into the design of sensors. However, the selectivity and stability still leave room for improvement.

  12. Electropolymerized Conducting Polymer as Actuator and Sensor Device

    ERIC Educational Resources Information Center

    Cortes, Maria T.; Moreno, Juan C.

    2005-01-01

    A study demonstrates the potential application of conducting polymers to convert electrical energy into mechanical energy at low voltage or current. The performance of the device is explained using electrochemistry and solid-state chemistry.

  13. Enhanced Photoresponse of Conductive Polymer Nanowires Embedded with Au Nanoparticles.

    PubMed

    Zhang, Junchang; Zhong, Liubiao; Sun, Yinghui; Li, Anran; Huang, Jing; Meng, Fanben; Chandran, Bevita K; Li, Shuzhou; Jiang, Lin; Chen, Xiaodong

    2016-04-20

    A conductive polymer nanowire embedded with a 1D Au nanoparticle chain with defined size, shape, and interparticle distance is fabricated which demonstrates enhanced photoresponse behavior. The precise and controllable positioning of 1D Au nanoparticle chain in the conductive polymer nanowire plays a critical role in modulating the photoresponse behavior by excitation light wavelength or power due to the coupled-plasmon effect of 1D Au nanoparticle chain.

  14. Unusually conductive carbon-inherently conducting polymer (ICP) composites: Synthesis and characterization

    NASA Astrophysics Data System (ADS)

    Bourdo, Shawn Edward

    Two groups of materials that have recently come to the forefront of research initiatives are carbon allotropes, especially nanotubes, and conducting polymers-more specifically inherently conducting polymers. The terms conducting polymers and inherently conducting polymers sometimes are used interchangeably without fully acknowledging a major difference in these terms. Conducting polymers (CPs) and inherently conducting polymers (ICPs) are both polymeric materials that conduct electricity, but the difference lies in how each of these materials conducts electricity. For CPs of the past, an electrically conductive filler such as metal particles, carbon black, or graphite would be blended into a polymer (insulator) allowing for the CP to carry an electric current. An ICP conducts electricity due to the intrinsic nature of its chemical structure. The two materials at the center of this research are graphite and polyaniline. For the first time, a composite between carbon allotropes (graphite) and an inherently conducting polymer (PANI) has exhibited an electrical conductivity greater than either of the two components. Both components have a plethora of potential applications and therefore the further investigation could lead to use of these composites in any number of technologies. Touted applications that use either conductive carbons or ICPs exist in a wide range of fields, including electromagnetic interference (EMI) shielding, radar evasion, low power rechargeable batteries, electrostatic dissipation (ESD) for anti-static textiles, electronic devices, light emitting diodes (LEDs), corrosion prevention, gas sensors, super capacitors, photovoltaic cells, and resistive heating. The main motivation for this research has been to investigate the connection between an observed increase in conductivity and structure of composites. Two main findings have resulted from the research as related to the observed increase in conductivity. The first was the structural evidence from

  15. Li conductivity in siloxane-based polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Stacy, Eric; Fan, Fei; Feng, Hongbo; Gainaru, Catalin; Mays, Jimmy; Sokolov, Alexei

    Polymer electrolytes containing lithium ions are ideal candidates for electrochemical devices and energy storage applications. Understanding their ionic transport mechanism is the key for rational designing of highly conductive polymer matrices. Complementing dielectric spectroscopy investigations by results from rheology and differential scanning calorimetry we focused on the interplay between dynamics of lithium ions and the polymer matrix based on polysiloxane backbone. Our results demonstrate that the conductivity and the degree of decoupling between ion dynamics and structural relaxation depend strongly not only on the ions concentration, but also on the polarity and size of the polymeric side-groups. Chemical Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States.

  16. High thermal conductivity in electrostatically engineered amorphous polymers

    PubMed Central

    Shanker, Apoorv; Li, Chen; Kim, Gun-Ho; Gidley, David; Pipe, Kevin P.; Kim, Jinsang

    2017-01-01

    High thermal conductivity is critical for many applications of polymers (for example, packaging of light-emitting diodes), in which heat must be dissipated efficiently to maintain the functionality and reliability of a system. Whereas uniaxially extended chain morphology has been shown to significantly enhance thermal conductivity in individual polymer chains and fibers, bulk polymers with coiled and entangled chains have low thermal conductivities (0.1 to 0.4 W m−1 K−1). We demonstrate that systematic ionization of a weak anionic polyelectrolyte, polyacrylic acid (PAA), resulting in extended and stiffened polymer chains with superior packing, can significantly enhance its thermal conductivity. Cross-plane thermal conductivity in spin-cast amorphous films steadily grows with PAA degree of ionization, reaching up to ~1.2 W m−1 K−1, which is on par with that of glass and about six times higher than that of most amorphous polymers, suggesting a new unexplored molecular engineering strategy to achieve high thermal conductivities in amorphous bulk polymers. PMID:28782022

  17. Conducting Polymers and Their Applications in Diabetes Management

    PubMed Central

    Zhao, Yu; Cao, Luyao; Li, Lanlan; Cheng, Wen; Xu, Liangliang; Ping, Xinyu; Pan, Lijia; Shi, Yi

    2016-01-01

    Advances in conducting polymers (CPs) have promoted the development of diabetic monitoring and treatment, which is of great significance in human healthcare and modern medicine. CPs are special polymers with physical and electrochemical features resembling metals, inorganic semiconductors and non-conducting polymers. To improve and extend their properties, the fabrication of CPs and CP composites has attracted intensive attention in recent decades. Some CPs are biocompatible and suitable for biomedical use. Thus, the intriguing properties of CPs make wearable, noninvasive, continuous diabetes managing devices and other potential applications in diabetes possible in the near future. To highlight the recent advances of CPs and their derived materials (especially in conducting polymer hydrogels), here we discuss their fabrication and characterization, review the current state-of-the-art research in diabetes management based on these materials and describe current challenges as well as future potential research directions. PMID:27792179

  18. Versatile solution for growing thin films of conducting polymers

    PubMed Central

    D’Arcy, Julio M.; Tran, Henry D.; Tung, Vincent C.; Tucker-Schwartz, Alexander K.; Wong, Rain P.; Yang, Yang; Kaner, Richard B.

    2010-01-01

    The method employed for depositing nanostructures of conducting polymers dictates potential uses in a variety of applications such as organic solar cells, light-emitting diodes, electrochromics, and sensors. A simple and scalable film fabrication technique that allows reproducible control of thickness, and morphological homogeneity at the nanoscale, is an attractive option for industrial applications. Here we demonstrate that under the proper conditions of volume, doping, and polymer concentration, films consisting of monolayers of conducting polymer nanofibers such as polyaniline, polythiophene, and poly(3-hexylthiophene) can be produced in a matter of seconds. A thermodynamically driven solution-based process leads to the growth of transparent thin films of interfacially adsorbed nanofibers. High quality transparent thin films are deposited at ambient conditions on virtually any substrate. This inexpensive process uses solutions that are recyclable and affords a new technique in the field of conducting polymers for coating large substrate areas. PMID:21041676

  19. Amine-functionalized polypyrrole: inherently cell adhesive conducting polymer

    PubMed Central

    Lee, Jae Y.; Schmidt, Christine E.

    2014-01-01

    Electrically conducting polymers have been recognized as novel biomaterials that can electrically communicate with biological systems. For their tissue engineering applications, conducting polymers have been modified to promote cell adhesion for improved interactions between biomaterials and cells/tissues. Conventional approaches to improve cell adhesion involve the surface modification of conducting polymers with biomolecules, such as physical adsorption of cell adhesive proteins and polycationic polymers, or their chemical immobilization; however, these approaches require additional multiple modification steps with expensive biomolecules. In this study, as a simple and effective alternative to such additional biomolecule treatment, we synthesized amine-functionalized polypyrrole (APPy) that inherently presents cell adhesion-supporting positive charges under physiological conditions. The synthesized APPy provides electrical activity in a moderate range and a hydrophilic surface compared to regular polypyrrole (PPy) homopolymers. Under both serum and serum-free conditions, APPy exhibited superior attachment of human dermal fibroblasts and Schwann cells compared to PPy homopolymer controls. Moreover, Schwann cell adhesion onto the APPy copolymer was at least similar to that on poly-L-lysine treated PPy controls. Our results indicate that amine-functionalized conducting polymer substrates will be useful to achieve good cell adhesion and potentially electrically stimulate various cells. In addition, an amine functionality present on conducting polymers can further serve as a novel and flexible platform to chemically tether various bioactive molecules, such as growth factors, antibodies, and chemical drugs. PMID:25294089

  20. Multilevel conductance switching in polymer films

    NASA Astrophysics Data System (ADS)

    Lauters, M.; McCarthy, B.; Sarid, D.; Jabbour, G. E.

    2006-07-01

    Multilevel conductance switching in poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene] (MEH-PPV) films is demonstrated. A thin-film structure, ITO-coated glass/MEH-PPV/Al, has shown the ability to store a continuum of conductance states. These states are nonvolatile and can be switched reproducibly by applying appropriate programing biases above a certain threshold voltage. The electrical conductivity of the highest and lowest states can differ by five orders of magnitude. Furthermore, these devices exhibit good cyclic switching characteristics and retention times of several weeks.

  1. Flexible Polymer/Metal/Polymer and Polymer/Metal/Inorganic Trilayer Transparent Conducting Thin Film Heaters with Highly Hydrophobic Surface.

    PubMed

    Kang, Tae-Woon; Kim, Sung Hyun; Kim, Cheol Hwan; Lee, Sang-Mok; Kim, Han-Ki; Park, Jae Seong; Lee, Jae Heung; Yang, Yong Suk; Lee, Sang-Jin

    2017-09-27

    Polymer/metal/polymer and polymer/metal/inorganic trilayer-structured transparent electrodes with fluorocarbon plasma polymer thin film heaters have been proposed. The polymer/metal/polymer and polymer/metal/inorganic transparent conducting thin films fabricated on a large-area flexible polymer substrate using a continuous roll-to-roll sputtering process show excellent electrical properties and visible-light transmittance. They also exhibit water-repelling surfaces to prevent wetting and to remove contamination. In addition, the adoption of a fluorocarbon/metal/fluorocarbon film permits an outer bending radius as small as 3 mm. These films have a sheet resistance of less than 5 Ω sq(-1), sufficient to drive light-emitting diode circuits. The thin film heater with the fluorocarbon/Ag/SiNx structure exhibits excellent heating characteristics, with a temperature reaching 180 °C under the driving voltage of 13 V. Therefore, the proposed polymer/metal/polymer and polymer/metal/inorganic transparent conducting electrodes using polymer thin films can be applied in flexible and rollable displays as well as automobile window heaters and other devices.

  2. Template Synthesis of Electronically Conductive Polymers

    DTIC Science & Technology

    1993-12-01

    polyace.ylene (7), and polyaniline (8). This enhancement in conductivity results from enhancements in molecular and supermolecular order in the template...present conductivity data for polyaniline tubules synthesized within these membranes. The monomer solution was 0.325 M in aniline and 1 M in HCI. The...polymerization, the polyaniline surface layers were removed by polishing the faces of the membrane with alumina powder, and the tubule-impregnated membrane

  3. Reactive template synthesis of polypyrrole nanotubes for fabricating metal/conducting polymer nanocomposites.

    PubMed

    Zhang, Jun; Liu, Xianghong; Zhang, Lixue; Cao, Bingqiang; Wu, Shihua

    2013-03-25

    Unique nanocomposites of polypyrrole/Au and polypyrrole/Pt hybrid nanotubes are synthesized employing polypyrrole (PPy) nanotubes as an advanced support by solution reduction. The conducting polymer PPy nanotubes are fabricated by using pre-prepared MnO2 nanowires as the reactive templates. MnO2 nanowires induce the 1D polymerization of pyrrole monomers and the simultaneous dissolution of the templates affords the hollow tube-like structure. The loading content of metal nanoparticles in the nanocomposites could be adjusted by simply changing the amount of metal precursors. This work provides an efficient approach to fabricate an important kind of metal/conducting polymer hybrid nanotubes that are potentially useful for electrocatalyst and sensor materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Effect of PEDOT band structure on conductive polymer-insulator-silicon junctions

    NASA Astrophysics Data System (ADS)

    Demtchenko, S.; Tarr, N. G.; McGarry, S.

    2017-08-01

    The effect of replacing a conventional metal with an organic conductive polymer in a metal-insulator-semiconductor (MIS) diode is examined theoretically and experimentally. Two sets of MIS diodes, one with gold and the other with poly(3,4-ethylenedioxythiophene) as the top "metal", have been manufactured in parallel. Despite the two conductors having similar reported work functions of 5.1 eV to 5.2 eV, the hybrid devices exhibited far lower current densities as compared to their inorganic counterparts. Simulating the device behaviour reveals the limited width of the energy bands in the conductive polymer as the reason for low current density in the hybrid MIS.

  5. Measurement of in-plane thermal conductivity in polymer films

    NASA Astrophysics Data System (ADS)

    Wei, Qingshuo; Uehara, Chinatsu; Mukaida, Masakazu; Kirihara, Kazuhiro; Ishida, Takao

    2016-04-01

    Measuring the in-plane thermal conductivity of organic thermoelectric materials is challenging but is critically important. Here, a method to study the in-plane thermal conductivity of free-standing films (via the use of commercial equipment) based on temperature wave analysis is explored in depth. This subject method required a free-standing thin film with a thickness larger than 10 μm and an area larger than 1 cm2, which are not difficult to obtain for most solution-processable organic thermoelectric materials. We evaluated thermal conductivities and anisotropic ratios for various types of samples including insulating polymers, undoped semiconducting polymers, doped conducting polymers, and one-dimensional carbon fiber bulky papers. This approach facilitated a rapid screening of in-plane thermal conductivities for various organic thermoelectric materials.

  6. Enhanced dielectric performance in polymer composite films with carbon nanotube-reduced graphene oxide hybrid filler.

    PubMed

    Kim, Jin-Young; Kim, TaeYoung; Suk, Ji Won; Chou, Harry; Jang, Ji-Hoon; Lee, Jong Ho; Kholmanov, Iskandar N; Akinwande, Deji; Ruoff, Rodney S

    2014-08-27

    The electrical conductivity and the specific surface area of conductive fillers in conductor-insulator composite films can drastically improve the dielectric performance of those films through changing their polarization density by interfacial polarization. We have made a polymer composite film with a hybrid conductive filler material made of carbon nanotubes grown onto reduced graphene oxide platelets (rG-O/CNT). We report the effect of the rG-O/CNT hybrid filler on the dielectric performance of the composite film. The composite film had a dielectric constant of 32 with a dielectric loss of 0.051 at 0.062 wt% rG-O/CNT filler and 100 Hz, while the neat polymer film gave a dielectric constant of 15 with a dielectric loss of 0.036. This is attributed to the increased electrical conductivity and specific surface area of the rG-O/CNT hybrid filler, which results in an increase in interfacial polarization density between the hybrid filler and the polymer.

  7. Low-Dimensional Conduction Mechanisms in Highly Conductive and Transparent Conjugated Polymers.

    PubMed

    Ugur, Asli; Katmis, Ferhat; Li, Mingda; Wu, Lijun; Zhu, Yimei; Varanasi, Kripa K; Gleason, Karen K

    2015-08-19

    Electronic conduction in conjugated polymers is of emerging technological interest for high-performance optoelectronic and thermoelectric devices. A completely new aspect and understanding of the conduction mechanism on conducting polymers is introduced, allowing the applicability of materials to be optimized. The charge-transport mechanism is explained by direct experimental evidence with a very well supported theoretical model. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Intercalation of ionically conductive polymers into Lithium Hectorite

    NASA Astrophysics Data System (ADS)

    Saada, Iskandar

    Renewable energy sources such as wind and solar have become appealing sources of energy with low environmental impact. However, the challenge with using these energy sources is their intermittent and unpredictable power generation. In order to overcome this challenge, energy storage mechanisms such as lithium-ion batteries are dependable systems for such applications. The purpose of this project is intended to synthesize environmentally benign and safe materials which can be used as electrolytes in lithium-ion batteries. The ionically conductive polymers POEGO, POMOE, and MEEP were successfully intercalated into the two-dimensional layered structure Lithium Hectorite. The goal of the project was to synthesize a series of nanocomposites with increasing polymer molar ratios to Lithium Hectorite, and investigate the thermal and ionic conductivity properties of the synthesized nanocomposites. A second series of nanocomposites using the same polymer molar ratio to Lithium Hectorite were synthesized after the polymers were complexed with lithium triflate. The salt-complexed nanocomposites were compared to the pristine nanocomposites based on thermal stability, polymer flexibility, as well as their ionic conductivity. The synthesized polymers, nanocomposites, and salt-complexed materials were characterized using powder X-ray diffraction, attenuated total reflectance spectroscopy, thermogravimetric analysis, and differential scanning calorimetry. Ionic conductivity data was investigated using AC impedance spectroscopy.

  9. Conductivity percolation in polyiodide/polymer complexes

    SciTech Connect

    Forsyth, M.; Shriver, D.F.; Ratner, M.A.; DeGroot, D.C.; Kannewurf, C.R. )

    1993-08-01

    Variable-temperature four-probe conductivity measurements and Raman spectroscopy were investigated for iodine in poly(propylene oxide) (PPO) and NaI[sub 3] in PPO. The Raman spectra indicate the presence of both triiodide and polyiodide species in samples of I[sub 2]-doped PPO. The conductivity of these PPO/I[sub 2] samples increased with increasing I[sub 2] concentration and reached a plateau at approximately 12 vol % iodine. Raman spectra at 20 [degrees]C indicate that, at concentrations less than 23 vol% I[sup [minus][sub 3

  10. Dielectric Properties of Aligned Conducting Polymers

    DTIC Science & Technology

    1991-10-01

    It has been demonstrated that aligned polyacetylene and polyaniline possess remarkably enhanced conductivities. The increase in crystallinity and...and thermal stability compared to other CPs such as polyacetylenes, polythiophenes, and polyaniline . These favorable properties and the commercial...stretch-orientation of BF4- doped PPy films electrochemically deposited at -30,C, 7 pyrrole electropolymerization at a xylene/water interface, 8 and

  11. Method of forming electronically conducting polymers on conducting and nonconducting substrates

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor); Hodko, Dalibor (Inventor); Clarke, Eric T. (Inventor); Miller, David L. (Inventor); Parker, Donald L. (Inventor)

    2001-01-01

    The present invention provides electronically conducting polymer films formed from photosensitive formulations of pyrrole and an electron acceptor that have been selectively exposed to UV light, laser light, or electron beams. The formulations may include photoinitiators, flexibilizers, solvents and the like. These solutions can be used in applications including printed circuit boards and through-hole plating and enable direct metallization processes on non-conducting substrates. After forming the conductive polymer patterns, a printed wiring board can be formed by sensitizing the polymer with palladium and electrolytically depositing copper.

  12. Hybrid microfluidic systems: combining a polymer microfluidic toolbox with biosensors

    NASA Astrophysics Data System (ADS)

    Gärtner, Claudia; Kirsch, Stefanie; Anton, Birgit; Becker, Holger

    2007-01-01

    In this paper we present polymer based microfluidic chips which contain functional elements (electrodes, biosensors) made out of a different material (metals, silicon, organic semiconductors). These hybrid microfluidic devices allow the integration of additional functionality other than the simple manipulation of liquids in the chip and have been developed as a reaction to the increasing requirement for functional integration in microfluidics.

  13. 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.

  14. Electrochemically driven actuators from conducting polymers, hydrogels, and carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Spinks, Geoffrey M.; Wallace, Gordon G.; Lewis, Trevor W.; Fifield, Leonard S.; Dai, Liming; Baughman, Ray H.

    2001-04-01

    The mechanisms of actuation operating in polymeric actuators are reviewed along with a comparison of actuator performance. Polymer hydrogel actuators show very large dimensional changes, but relatively low response times. The mechanism of actuation involves several processes including electro-osmosis and electrochemical effects. Conducting polymer actuators operate by Faradaic reactions causing oxidation and reduction of the polymer backbone. Associated ion movements produce dimensional changes of typically up to 3%. The maximum stress achieved to date from conducting polymers is not more than 10 MPA. Carbon nanotubes have recently been demonstrated as new actuator materials. The nanotubes undergo useful dimensional changes (approximately 1%) but have the capacity to respond very rapidly (kHz) and generate giant stresses (600 MPa). The advantages of nanotube actuators stem from their exceptional mechanical properties and the non-Faradaic actuation mechanism.

  15. Recent developments of hybrid nanocrystal/polymer bulk heterojunction solar cells.

    PubMed

    Tang, Aiwei; Qu, Shengchun; Teng, Feng; Hou, Yanbing; Wang, Yongsheng; Wang, Zhanguo

    2011-11-01

    Hybrid nanocrystal/polymer bulk heterojunction (BHJ) solar cells consisting of colloidal inorganic semiconductor nanocrystals as electron acceptors and conjugated polymers as electron donors have been extensively investigated in the past few decades, which take advantage of the strongpoints of the inorganic semiconductor nanocrystals and the conjugated polymers. Currently, power conversion efficiency over 3% for the hybrid nanocrystal/polymer BHJ solar cells has been achieved. Although the development of hybrid nanocrystal/polymer BHJ solar cells lacks behind the international level, great progress in this research field has been made in China. In this article, we first review the general fabrication techniques and general working principles of hybrid nanocrystal/polymer BHJ solar cells. Secondly, we highlight the international and national developments of hybrid nanocrystal/polymer BHJ solar cells based on different types of semiconductor nanocrystals and conjugated polymers. Finally, we give a future outlook for the hybrid nanocrystal/polymer BHJ solar cells in the worldwide.

  16. Phase diagram of hopping conduction mechanisms in polymer nanofiber network

    SciTech Connect

    Li, Jeng-Ting; Lu, Yu-Cheng; Jiang, Shiau-Bin; Zhong, Yuan-Liang; Yeh, Jui-Ming

    2015-12-07

    Network formation by nanofiber crosslinking is usually in polymer materials as application in organic semiconductor devices. Electron hopping transport mechanisms depend on polymer morphology in network. Conducting polymers morphology in a random network structure is modeled by a quasi-one-dimensional system coupled of chains or fibers. We observe the varying hopping conduction mechanisms in the polyaniline nanofibers of the random network structure. The average diameter d of the nanofibers is varied from approximately 10 to 100 nm. The different dominant hopping mechanisms including Efros-Shklovskii variable-range hopping (VRH), Mott VRH, and nearest-neighbor hopping are dependent on temperature range and d in crossover changes. The result of this study is first presented in a phase diagram of hopping conduction mechanisms based on the theories of the random network model. The hopping conduction mechanism is unlike in normal semiconductor materials.

  17. Rapid synthesis of flexible conductive polymer nanocomposite films

    NASA Astrophysics Data System (ADS)

    Blattmann, C. O.; Sotiriou, G. A.; Pratsinis, S. E.

    2015-03-01

    Polymer nanocomposite films with nanoparticle-specific properties are sought out in novel functional materials and miniaturized devices for electronic and biomedical applications. Sensors, capacitors, actuators, displays, circuit boards, solar cells, electromagnetic shields and medical electrodes rely on flexible, electrically conductive layers or films. Scalable synthesis of such nanocomposite films, however, remains a challenge. Here, flame aerosol deposition of metallic nanosliver onto bare or polymer-coated glass substrates followed by polymer spin-coating on them leads to rapid synthesis of flexible, free-standing, electrically conductive nanocomposite films. Their electrical conductivity is determined during their preparation and depends on substrate composition and nanosilver deposition duration. Accordingly, thin (<500 nm) and flexible nanocomposite films are made having conductivity equivalent to metals (e.g. 5 × 104 S cm-1), even during repetitive bending.

  18. Mediating conducting polymer growth within hydrogels by controlling nucleation

    NASA Astrophysics Data System (ADS)

    Patton, A. J.; Green, R. A.; Poole-Warren, L. A.

    2015-01-01

    This study examines the efficacy of primary and secondary nucleation for electrochemical polymerisation of conductive polymers within poly(vinyl alcohol) methacrylate hydrogels. The two methods of nucleation investigated were a primary heterogeneous mechanism via introduction of conductive bulk metallic glass (Mg64Zn30Ca5Na1) particles and a secondary mechanism via introduction of "pre-polymerised" conducting polymer within the hydrogel (PEDOT:PSS). Evidence of nucleation was not seen in the bulk metallic glass loaded gels, however, the PEDOT:PSS loaded gels produced charge storage capacities over 15 mC/cm2 when sufficient polymer was loaded. These studies support the hypothesis that secondary nucleation is an efficient approach to producing stand-alone conducting hydrogels.

  19. Designing Non-charging Surfaces from Non-conductive Polymers.

    PubMed

    Zhang, Xuan; Huang, Xu; Kwok, Sen Wai; Soh, Siowling

    2016-04-20

    Polymers that prevent the generation of static charge by contact electrification can be fabricated by copolymerizing an appropriate proportion of a molecule that has the tendency to charge positively, and a molecule that has the tendency to charge negatively, against a reference material. These non-conductive polymers resist charging by contact or rubbing, and prevent the adhesion of microscopic particles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Charge transport in conducting polymers: insights from impedance spectroscopy.

    PubMed

    Rubinson, Judith F; Kayinamura, Yohani P

    2009-12-01

    This tutorial review gives a brief introduction to impedance spectroscopy and discusses how it has been used to provide insight into charge transport through conducting polymers, particularly when the polymers are used as electrodes for solution studies or the design of electrodes for biomedical applications. As such it provides both an introduction to the topic and references to both classic and contemporary work for the more advanced reader.

  1. Electrical characterization of proton conducting polymer electrolyte based on bio polymer with acid dopant

    SciTech Connect

    Kalaiselvimary, J.; Pradeepa, P.; Sowmya, G.; Edwinraj, S.; Prabhu, M. Ramesh

    2016-05-06

    This study describes the biodegradable acid doped films composed of chitosan and Perchloric acid with different ratios (2.5 wt %, 5 wt %, 7.5 wt %, 10 wt %) was prepared by the solution casting technique. The temperature dependence of the proton conductivity of complex electrolytes obeys the Arrhenius relationship. Proton conductivity of the prepared polymer electrolyte of the bio polymer with acid doped was measured to be approximately 5.90 × 10{sup −4} Scm{sup −1}. The dielectric data were analyzed using Complex impedance Z*, Dielectric loss ε’, Tangent loss for prepared polymer electrolyte membrane with the highest conductivity samples at various temperature.

  2. Electrical characterization of proton conducting polymer electrolyte based on bio polymer with acid dopant

    NASA Astrophysics Data System (ADS)

    Kalaiselvimary, J.; Pradeepa, P.; Sowmya, G.; Edwinraj, S.; Prabhu, M. Ramesh

    2016-05-01

    This study describes the biodegradable acid doped films composed of chitosan and Perchloric acid with different ratios (2.5 wt %, 5 wt %, 7.5 wt %, 10 wt %) was prepared by the solution casting technique. The temperature dependence of the proton conductivity of complex electrolytes obeys the Arrhenius relationship. Proton conductivity of the prepared polymer electrolyte of the bio polymer with acid doped was measured to be approximately 5.90 × 10-4 Scm-1. The dielectric data were analyzed using Complex impedance Z*, Dielectric loss ɛ', Tangent loss for prepared polymer electrolyte membrane with the highest conductivity samples at various temperature.

  3. 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.

  4. Hierarchically structured vanadium pentoxide-polymer hybrid materials.

    PubMed

    Tritschler, Ulrich; Zlotnikov, Igor; Zaslansky, Paul; Fratzl, Peter; Schlaad, Helmut; Cölfen, Helmut

    2014-05-27

    Biomimetic composite materials consisting of vanadium pentoxide (V2O5) and a liquid crystal (LC) "gluing" polymer were manufactured exhibiting six structural levels of hierarchy, formed through LC phases. The organic matrix was a polyoxazoline with pendant cholesteryl and carboxyl units, forming a lyotropic phase with the same structural orientation extending up to hundreds of micrometers upon shearing, and binding to V2O5 via hydrogen bridges. Composites consisting of V2O5-LC polymer hybrid fibers with a pronounced layered structuring were obtained. The V2O5-LC polymer hybrid fibers consist of aligned V2O5 ribbons, composed of self-assembled V2O5 sheets, encasing a chiral nematic polymer matrix. The structures of the V2O5-LC polymer composites strongly depend on the preparation method, i.e., the phase-transfer method from aqueous to organic medium, in which the polymer forms LC phases. Notably, highly defined micro- and nanostructures were obtained when initiating the synthesis using V2O5 tactoids with preoriented nanoparticle building units, even when using isotropic V2O5 dispersions. Shear-induced hierarchical structuring of the composites was observed, as characterized from the millimeter and micrometer down to the nanometer length scales using complementary optical and electron microscopy, SAXS, μCT, and mechanical nanoindentation.

  5. Corrosion resistant coatings from conducting polymers

    SciTech Connect

    Wrobleski, D.A.; Benicewicz, B.C.; Thompson, K.G.; Bryan, C.J.

    1993-12-01

    Cr-based corrosion resistant undercoatings will have to be replaced because of environmental and health concerns. A coating system of a conducting polyaniline primer layer topcoated with epoxy or polyurethane, is being evaluated for corrosion resistance on mild steel in 0.1 M HCl or in a marine setting. Results of both laboratory and Beach Site testing indicate that this coating is very effective; even when the coatings are scratched to expose bare metal, the coated samples show very little signs of corrosion in the exposed area. 3 figs, 6 refs.

  6. Preparation of Conducting Polymers by Electrochemical Methods and Demonstration of a Polymer Battery

    ERIC Educational Resources Information Center

    Goto, Hiromasa; Yoneyama, Hiroyuki; Togashi, Fumihiro; Ohta, Reina; Tsujimoto, Akitsu; Kita, Eiji; Ohshima, Ken-ichi

    2008-01-01

    The electrochemical polymerization of aniline and pyrrole, and demonstrations of electrochromism and the polymer battery effect, are presented as demonstrations suitable for high school and introductory chemistry at the university level. These demonstrations promote student interest in the electrochemical preparation of conducting polymers, where…

  7. Preparation of Conducting Polymers by Electrochemical Methods and Demonstration of a Polymer Battery

    ERIC Educational Resources Information Center

    Goto, Hiromasa; Yoneyama, Hiroyuki; Togashi, Fumihiro; Ohta, Reina; Tsujimoto, Akitsu; Kita, Eiji; Ohshima, Ken-ichi

    2008-01-01

    The electrochemical polymerization of aniline and pyrrole, and demonstrations of electrochromism and the polymer battery effect, are presented as demonstrations suitable for high school and introductory chemistry at the university level. These demonstrations promote student interest in the electrochemical preparation of conducting polymers, where…

  8. Highly Conductive Water-Based Polymer/Graphene Nanocomposites for Printed Electronics.

    PubMed

    Koutsioukis, Apostolos; Georgakilas, Vasilios; Belessi, Vassiliki; Zboril, Radek

    2017-06-16

    The preparation and characterization of highly conductive carbon inks is described based on nanocomposites that combine a polystyrene-acrylic resin or water-soluble polymers with a hydrophilic graphene/carbon nanotube hybrid. The water-based carbon inks showed high electrical conductivity and could be effectively used in advanced technologies such as gravure printing for printed electronics. Moreover, the conductivity was shown to be increased with a power law of the nanohybrid volume fraction, with an exponent close to that predicted from the percolation theory, indicating a limited impact of the polymer tunneling barrier on the electrical conductivity of such nanocomposites. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Electric conductivity of polymer films filled with magnetic nanoparticles

    NASA Astrophysics Data System (ADS)

    Rumyantsev, B. M.; Bibikov, S. B.; Bychkova, A. V.; Leontiev, V. G.; Berendyaev, V. I.; Sorokina, O. N.; Kovarskii, A. L.

    2016-12-01

    The conductivity of polymer composites with magnetic nanoparticles (MNP) containing magnetite and other MNP (Ni, Cu-Ni) in the layers and planar cells with Al electrodes is studied. For soluble polymers (polyvinylpyrrolidone and polyvinyl alcohol) containing 1-10 wt % of magnetite MNP, a substantial effect of MNP on surface conductivity is detected over a wide range (from 10-10 to 10-3 Ω-1). It is shown that the addition of magnetite MNP not only results in a considerable change in cell conductivity, but also leads to its partially irreversible variation (by an order of magnitude or more) via minor modifications of the experimental conditions (temperature, electric field). For high-resistance samples with low probabilities of conducting chain formation, temperature current peaks are observed upon moderate heating (up to 350 K). These peaks are similar to the maxima observed upon polymer electret thermodischarges when the charges are captured by the deep centers associated with separate MNP or MNP aggregates. The type and position of the maxima are determined by the characteristics of the polymer matrix. For polyvinylpyrrolidone composites, the maxima are observed some time after heating (the echo effect). With composites based on solventborne polymers (polyalkanesterimides, soluble polyimide) and Ni, Cu-Ni MNP, no change in film conductivity measured electrophotographically is observed, due to the formation of a dielectric coating formed by polymer macromolecules adsorbed on the MNP surface. An explanation based on the possible formation of magnetic aggregates of magnetite MNP and conducting chains is proposed. Magnetic aggregation IPM is proposed as one way of controlling cell conductivity.

  10. Studies on conducting polymer and conducting polymerinorganic composite electrodes prepared via a new cathodic polymerization method

    NASA Astrophysics Data System (ADS)

    Singh, Nikhilendra

    A novel approach for the electrodeposition of conducting polymers and conducting polymer-inorganic composite materials is presented. The approach shows that conducting polymers, such as polypyrrole (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) can be electrodeposited by the application of a cathodic bias that generates an oxidizing agent, NO+, via the in-situ reduction of nitrate anions. This new cathodic polymerization method allows for the deposition of PPy and PEDOT as three dimensional, porous films composed of spherical polymer particles. The method is also suitable for the co-deposition of inorganic species producing conducting polymer-inorganic composite electrodes. Such composites are used as high surface area electrodes in Li-ion batteries, electrochemical hydrogen evolution and in the development of various other conducting polymer-inorganic composite electrodes. New Sn-PPy and Sb-PPy composite electrodes where Sn and Sb nanoparticles are well dispersed among the PPy framework are reported. These structures allow for decreased stress during expansion and contraction of the active material (Sn, Sb) during the alloying and de-alloying processes of a Li-ion battery anode, significantly alleviating the loss of active material due to pulverization processes. The new electrochemical synthesis mechanism allows for the fabrication of Sn-PPy and Sb-PPy composite electrodes directly from a conducting substrate and eliminates the use of binding materials and conducting carbon used in modern battery anodes, which significantly simplifies their fabrication procedures. Platinum (Pt) has long been identified as the most efficient catalyst for electrochemical water splitting, while nickel (Ni) is a cheaper, though less efficient alternative to Pt. A new morphology of PPy attained via the aforementioned cathodic deposition method allows for the use of minimal quantities of Pt and Ni dispersed over a very high surface area PPy substrate. These composite electrodes

  11. Highly conductive self-assembled nanoribbons of coordination polymers.

    PubMed

    Welte, Lorena; Calzolari, Arrigo; Di Felice, Rosa; Zamora, Felix; Gómez-Herrero, Julio

    2010-02-01

    Organic molecules can self-assemble into well-ordered structures, but the conductance of these structures is limited, which is a disadvantage for applications in molecular electronics. Conductivity can be improved by using coordination polymers-in which metal centres are incorporated into a molecular backbone-and such structures have been used as molecular wires by self-assembling them into ordered films on metal surfaces. Here, we report electrically conductive nanoribbons of the coordination polymer [Pt(2)I(S(2)CCH(3))(4)](n) self-assembled on an insulating substrate by direct sublimation of polymer crystals. Conductance atomic force microscopy is used to probe the electrical characteristics of a few polymer chains ( approximately 10) within the nanoribbons. The observed currents exceed those previously sustained in organic and metal-organic molecules assembled on surfaces by several orders of magnitude and over much longer distances. These results, and the results of theoretical calculations based on density functional theory, confirm coordination polymers as candidate materials for applications in molecular electronics.

  12. Hybrid polymer photonic crystal fiber with integrated chalcogenide glass nanofilms

    PubMed Central

    Markos, Christos; Kubat, Irnis; Bang, Ole

    2014-01-01

    The combination of chalcogenide glasses with polymer photonic crystal fibers (PCFs) is a difficult and challenging task due to their different thermo-mechanical material properties. Here we report the first experimental realization of a hybrid polymer-chalcogenide PCF with integrated As2S3 glass nanofilms at the inner surface of the air-channels of a poly-methyl-methacrylate (PMMA) PCF. The integrated high refractive index glass films introduce distinct antiresonant transmission bands in the 480–900 nm wavelength region. We demonstrate that the ultra-high Kerr nonlinearity of the chalcogenide glass makes the polymer PCF nonlinear and provides a possibility to shift the transmission band edges as much as 17 nm by changing the intensity. The proposed fabrication technique constitutes a new highway towards all-fiber nonlinear tunable devices based on polymer PCFs, which at the moment is not possible with any other fabrication method. PMID:25317501

  13. Ionic conductivity enhancement of polymer electrolytes with ceramic nanowire fillers.

    PubMed

    Liu, Wei; Liu, Nian; Sun, Jie; Hsu, Po-Chun; Li, Yuzhang; Lee, Hyun-Wook; Cui, Yi

    2015-04-08

    Solid-state electrolytes provide substantial improvements to safety and electrochemical stability in lithium-ion batteries when compared with conventional liquid electrolytes, which makes them a promising alternative technology for next-generation high-energy batteries. Currently, the low mobility of lithium ions in solid electrolytes limits their practical application. The ongoing research over the past few decades on dispersing of ceramic nanoparticles into polymer matrix has been proved effective to enhance ionic conductivity although it is challenging to form the efficiency networks of ionic conduction with nanoparticles. In this work, we first report that ceramic nanowire fillers can facilitate formation of such ionic conduction networks in polymer-based solid electrolyte to enhance its ionic conductivity by three orders of magnitude. Polyacrylonitrile-LiClO4 incorporated with 15 wt % Li0.33La0.557TiO3 nanowire composite electrolyte exhibits an unprecedented ionic conductivity of 2.4 × 10(-4) S cm(-1) at room temperature, which is attributed to the fast ion transport on the surfaces of ceramic nanowires acting as conductive network in the polymer matrix. In addition, the ceramic-nanowire filled composite polymer electrolyte shows an enlarged electrochemical stability window in comparison to the one without fillers. The discovery in the present work paves the way for the design of solid ion electrolytes with superior performance.

  14. Poly(p-Phenylene Sulfide) Hexafluoroarsenate: A Novel Conducting Polymer.

    DTIC Science & Technology

    1981-07-28

    attributed to absorptions due to states introduced into the band gap by the doping process. It is tempting to also attribute the 1.1 eV absorption in lightly...Poly(p-Phenylene Sulfide ) Hexafluoroarsenate: A Novel Conducting Polymer byELEC TE by EET1 T. C. /Clarke, K. K./Kanazawa ,,V. Y. Lee, . J. F., Rabolt... SULFIDE ) HEXAFLUOROARSENATE: A NOVEL CONDUCTING POLYMER T. C. Clarke K. K. Kanazawa V. Y. Lee J. F. Rabolt J. R. Reynolds ’ G. B. Street II Research

  15. Corrosion-protective coatings from electrically conducting polymers

    NASA Technical Reports Server (NTRS)

    Thompson, Karen Gebert; Bryan, Coleman J.; Benicewicz, Brian C.; Wrobleski, Debra A.

    1991-01-01

    In a joint effort between NASA Kennedy and LANL, electrically conductive polymer coatings were developed as corrosion protective coatings for metal surfaces. At NASA Kennedy, the launch environment consist of marine, severe solar, and intermittent high acid and/or elevated temperature conditions. Electrically conductive polymer coatings were developed which impart corrosion resistance to mild steel when exposed to saline and acidic environments. Such coatings also seem to promote corrosion resistance in areas of mild steel where scratches exist in the protective coating. Such coatings appear promising for many commercial applications.

  16. Chemical sensors using peptide-functionalized conducting polymer nanojunction arrays

    NASA Astrophysics Data System (ADS)

    Aguilar, Alvaro Díaz; Forzani, Erica S.; Li, Xiulan; Tao, Nongjian; Nagahara, Larry A.; Amlani, Islamshah; Tsui, Raymond

    2005-11-01

    We demonstrate a heavy metal-ion sensor for drinking water analysis using a conducting polymer nanojunction array. Each nanojunction is formed by bridging a pair of nanoelectrodes separated with a small gap (<60nm) with electrodeposited peptide-modified polyanilines. The signal transduction mechanism of the sensor is based on the change in the nanojunction conductance as a result of polymer conformational changes induced by the metal-ion chelating peptide. The nanojunction sensor allows real-time detection of Cu2+ and Ni2+ at ppt range.

  17. Corrosion-protective coatings from electrically conducting polymers

    SciTech Connect

    Thompson, K.G.; Bryan, C.J.; Benicewicz, B.C.; Wrobleski, D.A.

    1991-12-31

    In a joint research effort involving the Kennedy Space Center and the Los Alamos National Laboratory, electrically conductive polymer coatings have been developed as corrosion-protective coatings for metal surfaces. At the Kennedy Space Center, the launch environment consists of marine, severe solar, and intermittent high acid/elevated temperature conditions. Electrically conductive polymer coatings have been developed which impart corrosion resistance to mild steel when exposed to saline and acidic environments. Such coatings also seem to promote corrosion resistance in areas of mild steel where scratches exist in the protective coating. Such coatings appear promising for many commercial applications.

  18. Bioreceptor-conducting polymer multilayer assemblies for biosensing

    NASA Astrophysics Data System (ADS)

    Samuelson, Lynne A.; Alva, Shridhara; Kumar, Jayant; Kaplan, David L.; Tripathy, Sukant K.

    1998-04-01

    This research focuses on the organized integration of biological receptors and polymers into thin film architectures for biosensing applications. Layer-by-layer electrostatic adsorption was used for the first time to form alternating protein-conducting polymer multilayers. The light-harvesting, phycobiliproteins and the enzyme, alkaline phosphatase were the bioreceptors investigated and sulfonated polystyrene, poly(diallyl dimethyl ammonium chloride) and a new enzymatically polymerized, water soluble, polyaniline were the polymer counterions used for deposition. Spectroscopic characterization was used to determine both multilayer formation and biosensing function of the final bioreceptor-polymer assemblies. These techniques have proven to be simple, chemically mild, and versatile and are expected to find application in the fabrication of ultrathin films for biosensors, opto- electronic devices and biomedical applications.

  19. Thin film conductive polymer for microactuator and micromuscle applications

    SciTech Connect

    Lee, A.P.; Hong, K.; Trevino, J.; Northrup, M.A.

    1994-04-14

    Conductive polymer/polyimide bimorphic microcantilevers have been actuated vertically (out-of-plane) upon the volumetric changes induced by electrochemical doping of the polymer. The microcantilevers that are 200-500 {mu}m in length and 50-100 {mu}m in width can be fully extended from a circularly-curled geometry, and thus generate more than 100 {mu}m displacement. Dynamically the microcantilevers have been driven as fast as 1.2 Hz and the polymer was stable for over a week stored in air and light. Residual stresses in the polymer film is estimated to be as high as 254 MPa, and actuation stresses are as high as 50 MPa.

  20. Photoresponsive Self-Healing Polymer Composite with Photoabsorbing Hybrid Microcapsules.

    PubMed

    Gao, Lei; He, Jinliang; Hu, Jun; Wang, Chao

    2015-11-18

    Microcapsule-based self-healing polymer materials are highly desirable because they can heal large-volume cracks without changing the original chemical structures of polymers. However, they are limited by processing difficulties and inhomogeneous distributions of two components. Herein, we report a one-component photoresponsive self-healing polymer composite with photoabsorbing hybrid microcapsules (PAHM), which gives the microcapsules photoabsorbing properties by introducing nano-TiO2 particles as photoabsorbing and emulsified agents in the poly(urea-formaldehyde)/TiO2 hybrid shells. Upon mechanical damage and then exposure to light, the photoresponsive healing agents in the cracks will be solidified to allow for self-healing, while the healing agents in the unbroken PAHM will be protected and remain unreacted, which endows this photoresponsive microcapsule-based self-healing composite with self-healing properties like those found in the conventional two-component microcapsule-based systems. Given the universality of this hybrid polymerization method, incorporation of the photoabsorbing particles to conventional polymer shells may further broaden the scope of applications of these widely used materials.

  1. A novel synthesis of an Fe(3+)/Fe(2+) layered double hydroxide ('green rust') via controlled electron transfer with a conducting polymer.

    PubMed

    Kim, Min-Sung; Kim, Tae-Hyun; Seo, Young Sun; Oh, Jae-Min; Park, Jin Kuen

    2017-06-28

    This report examines the influence of a conducting polymer on the crystal growth of labile green rust (GR) through hybridization with polypyrrole. All hybrids used in this study were prepared via one-pot co-precipitation at neutral pH, with specific stoichiometric ratios among all chemical species. The role of the conducting polymer and the effective stoichiometric ratio were demonstrated to facilitate the crystal growth of GR.

  2. Polymer degradation rate control of hybrid rocket combustion

    NASA Technical Reports Server (NTRS)

    Stickler, D. B.; Ramohalli, K. N. R.

    1970-01-01

    Polymer degradation to small fragments is treated as a rate controlling step in hybrid rocket combustion. Both numerical and approximate analytical solutions of the complete energy and polymer chain bond conservation equations for the condensed phase are obtained. Comparison with inert atmosphere data is very good. It is found that the intersect of curves of pyrolysis rate versus interface temperature for hybrid combustors, with the thermal degradation theory, falls at a pyrolysis rate very close to that for which a pressure dependence begins to be observable. Since simple thermal degradation cannot give sufficient depolymerization at higher pyrolysis rates, it is suggested that oxidative catalysis of the process occurs at the surface, giving a first order dependence on reactive species concentration at the wall. Estimates of the ratio of this activation energy and interface temperature are in agreement with best fit procedures for hybrid combustion data. Requisite active species concentrations and flux are shown to be compatible with turbulent transport. Pressure dependence of hybrid rocket fuel regression rate is thus shown to be describable in a consistent manner in terms of reactive species catalysis of polymer degradation.

  3. Electronic conduction in polymers, carbon nanotubes and graphene.

    PubMed

    Kaiser, Alan B; Skákalová, Viera

    2011-07-01

    In the years since the discovery of organic polymers that exhibited electrical conductivities comparable to some metals, other novel carbon-based conductors have been developed, including carbon nanotubes and graphene (monolayers of carbon atoms). In this critical review, we discuss the common features and the differences in the conduction mechanisms observed in these carbon-based materials, which range from near ballistic and conventional metallic conduction to fluctuation-assisted tunnelling, variable-range hopping and more exotic mechanisms. For each category of material, we discuss the dependence of conduction on the morphology of the sample. The presence of heterogeneous disorder is often particularly important in determining the overall behaviour, and can lead to surprisingly similar conduction behaviour in polymers, carbon nanotube networks and chemically-derived graphene (122 references).

  4. Silicon-polymer hybrid materials for drug delivery.

    PubMed

    McInnes, Steven J P; Voelcker, Nicolas H

    2009-09-01

    Silicon and its oxides are widely used in biomaterials research, tissue engineering and drug delivery. These materials are highly biocompatible, easily surface functionalized, degrade into nontoxic silicic acid and can be processed into various forms such as micro- and nano-particles, monoliths, membranes and micromachined structures. The large surface area of porous forms of silicon and silica (up to 1200 m2/g) permits high drug loadings. The degradation kinetics of silicon- and silica-based materials can be tailored by coating or grafting with polymers. Incorporation of polymers also improves control over drug-release kinetics. The use of stimuli-responsive polymers has enabled environmental stimuli-triggered drug release. Simultaneously, silicon microfabrication techniques have facilitated the development of sophisticated implantable drug-delivery microdevices. This paper reviews the synthesis, novel properties and biomedical applications of silicon-polymer hybrid materials with particular emphasis on drug delivery. The biocompatible and bioresorptive properties of mesoporous silica and porous silicon make these materials attractive candidates for use in biomedical applications. The combination of polymers with silicon-based materials has generated a large range of novel hybrid materials tailored to applications in localized and systemic drug delivery.

  5. Advanced Proton Conducting Polymer Electrolytes for Electrochemical Capacitors

    NASA Astrophysics Data System (ADS)

    Gao, Han

    Research on solid electrochemical energy storage devices aims to provide high performance, low cost, and safe operation solutions for emerging applications from flexible consumer electronics to microelectronics. Polymer electrolytes, minimizing device sealing and liquid electrolyte leakage, are key enablers for these next-generation technologies. In this thesis, a novel proton-conducing polymer electrolyte system has been developed using heteropolyacids (HPAs) and polyvinyl alcohol for electrochemical capacitors. A thorough understanding of proton conduction mechanisms of HPAs together with the interactions among HPAs, additives, and polymer framework has been developed. Structure and chemical bonding of the electrolytes have been studied extensively to identify and elucidate key attributes affecting the electrolyte properties. Numerical models describing the proton conduction mechanism have been applied to differentiate those attributes. The performance optimization of the polymer electrolytes through additives, polymer structural modifications, and synthesis of alternative HPAs has achieved several important milestones, including: (a) high proton mobility and proton density; (b) good ion accessibility at electrode/electrolyte interface; (c) wide electrochemical stability window; and (d) good environmental stability. Specifically, high proton mobility has been addressed by cross-linking the polymer framework to improve the water storage capability at normal-to-high humidity conditions (e.g. 50-80% RH) as well as by incorporating nano-fillers to enhance the water retention at normal humidity levels (e.g. 30-60% RH). High proton density has been reached by utilizing additional proton donors (i.e. acidic plasticizers) and by developing different HPAs. Good ion accessibility has been achieved through addition of plasticizers. Electrochemical stability window of the electrolyte system has also been investigated and expanded by utilizing HPAs with different heteroatoms

  6. Conducting polymers with immobilised fibrillar collagen for enhanced neural interfacing.

    PubMed

    Liu, Xiao; Yue, Zhilian; Higgins, Michael J; Wallace, Gordon G

    2011-10-01

    Conducting polymers with pendant functionality are advantageous in various bionic and organic bioelectronic applications, as they allow facile incorporation of bio-regulative cues to provide bio-mimicry and conductive environments for cell growth, differentiation and function. In this work, polypyrrole substrates doped with chondroitin sulfate (CS), an extracellular matrix molecule bearing carboxylic acid moieties, were electrochemically synthesized and conjugated with type I collagen. During the coupling process, the conjugated collagen formed a 3-dimensional fibrillar matrix in situ at the conducting polymer interface, as evidenced by atomic force microscopy (AFM) and fluorescence microscopy under aqueous physiological conditions. Cyclic voltammetry (CV) and impedance measurement confirmed no significant reduction in the electroactivity of the fibrillar collagen-modified conducting polymer substrates. Rat pheochromocytoma (nerve) cells showed increased differentiation and neurite outgrowth on the fibrillar collagen, which was further enhanced through electrical stimulation of the underlying conducting polymer substrate. Our study demonstrates that the direct coupling of ECM components such as collagen, followed by their further self-assembly into 3-dimensional matrices, has the potential to improve the neural-electrode interface of implant electrodes by encouraging nerve cell attachment and differentiation.

  7. Tunable Nanopatterning of Conductive Polymers via Electrohydrodynamic Lithography.

    PubMed

    Rickard, Jonathan James Stanley; Farrer, Ian; Oppenheimer, Pola Goldberg

    2016-03-22

    An increasing number of technologies require the fabrication of conductive structures on a broad range of scales and over large areas. Here, we introduce advanced yet simple electrohydrodynamic lithography (EHL) for patterning conductive polymers directly on a substrate with high fidelity. We illustrate the generality of this robust, low-cost method by structuring thin polypyrrole films via electric-field-induced instabilities, yielding well-defined conductive structures with feature sizes ranging from tens of micrometers to hundreds of nanometers. Exploitation of a conductive polymer induces free charge suppression of the field in the polymer film, paving the way for accessing scale sizes in the low submicron range. We show the feasibility of the polypyrrole-based structures for field-effect transistor devices. Controlled EHL pattering of conductive polymer structures at the micro and nano scale demonstrated in this study combined with the possibility of effectively tuning the dimensions of the tailor-made architectures might herald a route toward various submicron device applications in supercapacitors, photovoltaics, sensors, and electronic displays.

  8. Tunable Nanopatterning of Conductive Polymers via Electrohydrodynamic Lithography

    PubMed Central

    2016-01-01

    An increasing number of technologies require the fabrication of conductive structures on a broad range of scales and over large areas. Here, we introduce advanced yet simple electrohydrodynamic lithography (EHL) for patterning conductive polymers directly on a substrate with high fidelity. We illustrate the generality of this robust, low-cost method by structuring thin polypyrrole films via electric-field-induced instabilities, yielding well-defined conductive structures with feature sizes ranging from tens of micrometers to hundreds of nanometers. Exploitation of a conductive polymer induces free charge suppression of the field in the polymer film, paving the way for accessing scale sizes in the low submicron range. We show the feasibility of the polypyrrole-based structures for field-effect transistor devices. Controlled EHL pattering of conductive polymer structures at the micro and nano scale demonstrated in this study combined with the possibility of effectively tuning the dimensions of the tailor-made architectures might herald a route toward various submicron device applications in supercapacitors, photovoltaics, sensors, and electronic displays. PMID:26905779

  9. Nanoparticle Polymer Hybrids for Solar Cells

    NASA Astrophysics Data System (ADS)

    Mackay, Michael

    Polymer-based solar cells are unique since their processing is extremely cost effective compared to silicon-based solar cells. They are also much less energy intensive to manufacture. However, their power conversion efficiency is low. Discussion of what affects this property in the context of the morphology characterized through thermal analysis as well as x-ray and neutron scattering will be given. Support is gratefully acknowledged from the Department of Materials Science and NIST Award 70NANB10H256 through the Center for Neutron Science at the University of Delaware.

  10. Persistence of slow dynamics in Tb(OETAP)2 single molecule magnets embedded in conducting polymers

    NASA Astrophysics Data System (ADS)

    Orlando, T.; Filibian, M.; Sanna, S.; Giménez-Agullo, N.; Sáenz de Pipaón, C.; Ballester, P.; Galán-Mascarós, J. R.; Carretta, P.

    2016-09-01

    The spin dynamics of Tb(OETAP)2 single ion magnets was investigated by means of muon spin relaxation (μSR) both in the bulk material as well as when the molecule is embedded into PEDOT:PSS polymer conductor. The spin fluctuation time is characterized by a high temperature activated trend, with an energy barrier around 320 K, and by a low temperature tunneling regime. When the single ion magnet is embedded into the polymer the energy barrier only slightly decreases and the fluctuation time remains of the same order of magnitude, even at low temperature. This finding shows that these single molecule magnets preserve their characteristics which, if combined with those of the conducting polymer, result in a hybrid material of potential interest for organic spintronics.

  11. Hybrid electrokinetic manipulation in high-conductivity media.

    PubMed

    Gao, Jian; Sin, Mandy L Y; Liu, Tingting; Gau, Vincent; Liao, Joseph C; Wong, Pak Kin

    2011-05-21

    This study reports a hybrid electrokinetic technique for label-free manipulation of pathogenic bacteria in biological samples toward medical diagnostic applications. While most electrokinetic techniques only function in low-conductivity buffers, hybrid electrokinetics enables effective operation in high-conductivity samples, such as physiological fluids (∼1 S m(-1)). The hybrid electrokinetic technique combines short-range electrophoresis and dielectrophoresis, and long-range AC electrothermal flow to improve its effectiveness. The major technical hurdle of electrode instability for manipulating high conductivity samples is tackled by using a Ti-Au-Ti sandwich electrode and a 3-parallel-electrode configuration is designed for continuous isolation of bacteria. The device operates directly with biological samples including urine and buffy coats. We show that pathogenic bacteria and biowarfare agents can be concentrated for over 3 orders of magnitude using hybrid electrokinetics.

  12. Physical properties of Li ion conducting polyphosphazene based polymer electrolytes

    SciTech Connect

    Sanderson, S.; Zawodzinski, T.; Hermes, R.; Davey, J.; Dai, Hongli

    1996-12-31

    We report a systematic study of the transport properties and the underlying physical chemistry of some polyphosphazene (PPhz)-based polymer electrolytes. We synthesized MEEP and variants which employed mixed combinations of different length oxyethylene side-chains. We compare the conductivity and ion-ion interactions in polymer electrolytes obtained with lithium triflate and lithium bis(trifluoromethanesulfonyl)imide (TFSI) salts added to the polymer. The combination of the lithium imide salt and MEEP yields a maximum conductivity of 8 x 10{sup -5} {Omega}{sup -1} cm{sup -1} at room temperature at a salt loading of 8 monomers per lithium. In one of the mixed side-chain variations, a maximum conductivity of 2 x 10{sup -4} {Omega}{sup -1} cm{sup -1} was measured at the same molar ratio. Raman spectral analysis shows some ion aggregation and some polymer - ion interactions in the PPhz-LiTFSI case but much less than observed with Li CF{sub 3}SO{sub 3}. A sharp increase in the Tg as salt is added corresponds to concentrations above which the conductivity significantly decreases and ion associations appear.

  13. Wearable Keyboard Using Conducting Polymer Electrodes on Textiles.

    PubMed

    Takamatsu, Seiichi; Lonjaret, Thomas; Ismailova, Esma; Masuda, Atsuji; Itoh, Toshihiro; Malliaras, George G

    2016-06-01

    A wearable keyboard is demonstrated in which conducting polymer electrodes on a knitted textile sense tactile input as changes in capacitance. The use of a knitted textile as a substrate endows stretchability and compatibility to large-area formats, paving the way for a new type of wearable human-machine interface.

  14. Polymer microfluidic chip for online monitoring of microarray hybridizations.

    PubMed

    Noerholm, Mikkel; Bruus, Henrik; Jakobsen, Mogens H; Telleman, Pieter; Ramsing, Niels B

    2004-02-01

    A disposable single use polymer microfluidics chip has been developed and manufactured by micro injection molding. The chip has the same outer dimensions as a standard microscope slide (25 x 76 x 1.1 mm) and is designed to be compatible with existing microscope slide handling equipment like microarray scanners. The chip contains an inlet, a 10 microL hybridization chamber capable of holding a 1000 spot array, a waste chamber and a vent to allow air to escape when sample is injected. The hybridization chamber ensures highly homogeneous hybridization conditions across the microarray. We describe the use of this chip in a flexible setup with fluorescence based detection, temperature control and liquid handling by computer controlled syringe pumps. The chip and the setup presented in this article provide a powerful tool for highly parallel studies of kinetics and thermodynamics of duplex formation in DNA microarrays. The experimental setup presented in this article enables the on-chip microarray to be hybridized and monitored at several different stringency conditions during a single assay. The performance of the chip and the setup is demonstrated by on-line measurements of a hybridization of a DNA target solution to a microarray. A presented numerical model indicates that the hybridization process in microfluidic hybridization assays is diffusion limited, due to the low values of the diffusion coefficients D of the DNA and RNA molecules involved.

  15. Computational screening of structural and compositional factors for electrically conductive coordination polymers.

    PubMed

    Tiana, Davide; Hendon, Christopher H; Walsh, Aron; Vaid, Thomas P

    2014-07-28

    The combination of organic and inorganic chemical building blocks to form metal-organic frameworks (MOFs) offers opportunities for producing functional materials suitable for energy generation, storage and conversion. However, such applications rely on robust electron transport and the design of conductive hybrid materials is still in its infancy. Here we apply density functional theory to assess the important structural and compositional factors for forming conducting MOFs. We focus on 1D metal-organic polymers as a model system and assess the choice of organic, inorganic and linking units. The results demonstrate that electronic communication is sensitive to the energy and symmetry of the frontier orbitals associated with the organic and inorganic building blocks and offers guidance on how to optimise electrical conduction in hybrid materials.

  16. Structure, morphology and ionic conductivity of solid polymer electrolyte

    SciTech Connect

    Dey, Arup; Karan, S.; Dey, Ashis; De, S.K.

    2011-11-15

    Graphical abstract: Two-dimensional atomic force image of pure polyethylene oxide presents a crystallized network of regular spherulites developing spirals and branches of well distributed surface contours. Highlights: {yields} The incorporation of ceria significantly modifies the morphology of polyethylene oxide (PEO)-KI complex. {yields} The ionic conductivity increases by about two orders of magnitude by the addition of ceria nanoparticles. {yields} Ionic conductivity as a function of ceria concentration reveals two maxima. {yields} Grain boundary effect of nanofiller, strong Lewis acid-base interaction between PEO and nanosized ceria, change of conformation of PEO molecule and epitaxial effect of ceria nanoparticles control the ionic conductivity of composite polymer electrolyte. -- Abstract: Polyethylene oxide (PEO) complexed with potassium iodide (KI) is synthesized to investigate the ionic conductivity of alkaline based polymer electrolytes. The structural and morphological characterizations of the nanocomposite polymer electrolytes are performed by X-ray diffractometry (XRD), atomic force microscopy (AFM), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) measurements. The ionic conductivity increases with the increase of KI concentration up to about 20 wt.%. The effect of nanosized ceria (CeO{sub 2} {approx} 10 nm) fillers on ionic conductivity in PEO-KI polymer electrolyte is also carried out, keeping PEO to KI wt.% ratio 80:20 and 85:15. The result reveals that the addition of ceria nanoparticles enhances the conductivity by two orders of magnitude. The presence of ceria at the highest concentration induces the same molecular environment within PEO chain as that of undoped PEO. Temperature dependence of ionic conductivity follows Arrhenius mechanism.

  17. 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.

  18. Anisotropic Thermal Conduction in Polymers and its Molecular Origins

    NASA Astrophysics Data System (ADS)

    Nieto Simavilla, David; Venerus, David; Schieber, Jay; uCoSm Team

    2014-03-01

    Anisotropy in thermal conductivity has a significant impact on both processing and final properties of materials. Simple molecular arguments suggest that Fourier?s law must be generalized to allow for anisotropic thermal conductivity. We present two complementary experimental methods to obtain quantitative measurements of the thermal diffusivity (conductivity) tensor. We report anisotropic thermal diffusivity and stress in molten, cross-linked and solid polymers under several types of flows. Our results support the validity of a linear relationship between stress and anisotropy in thermal conductivity. When the proportionality constant, the stress-thermal coefficient, is made dimensionless by the plateau modulus of the polymer melt, a universal value of approximately 0.03 is observed for all chemistries. Such a universality is surprising, since phonon transport mechanisms are sensitive to chemical structure. For instance, the analogous stress-optic coefficient depends strongly on chemistry, and can even change sign. Connecting these measurements with current theories for thermal transport in amorphous materials, such as Minimum Thermal Conductivity (MTC) model, is crucial to understand the molecular origins of anisotropic thermal conduction in polymers.

  19. Metallic behaviour of acid doped highly conductive polymers.

    PubMed

    Massonnet, Nicolas; Carella, Alexandre; de Geyer, Arnaud; Faure-Vincent, Jérôme; Simonato, Jean-Pierre

    2015-01-01

    Conductive polymers such as poly(3,4-ethylenedioxythiophene) (PEDOT) are used in a wide range of applications as transparent electrodes, hole injecting layers or thermoelectric materials for room-temperature applications. However, progress is needed to enhance the electrical conductivities of the materials and to provide understanding about their structure-transport relationships. This work presents the synthesis of highly conductive PEDOT-based polymers using iron(iii) trifluoromethanesulfonate as oxidant for the first time. The metallic behaviour of the polymer is revealed by conductivity monitoring from 3 to 300 K. The electrical conductivity is further improved (to 2273 S cm(-1)) using acids, leading to a positive temperature coefficient of resistivity at an unprecedented 45.5% oxidation state. X-ray photoemission spectroscopy (XPS) and time of flight-secondary ion mass spectrometry (ToF-SIMS) analyses demonstrate a complete replacement of the trifluoromethanesulfonate anions by hydrogen sulphate counter ions. This substitution results in an increased concentration of charge carriers (measured in organic electrochemical transistors) along with an enhancement of the mean size of crystalline domains, highlighted by small and wide angle X-ray scattering (SAXS/WAXS), which explains the 80% increase of electrical conductivity.

  20. New secondary batteries utilizing electronically conductive polymer cathodes

    NASA Technical Reports Server (NTRS)

    Martin, Charles R.; White, Ralph E.

    1989-01-01

    The objectives of this project are to characterize the transport properties in electronically conductive polymers and to assess the utility of these films as cathodes in lithium/polymer secondary batteries. During this research period, progress has been made in a literature survey of the historical background, methods of preparation, the physical and chemical properties, and potential technological applications of polythiophene. Progress has also been made in the characterization of polypyrrole flat films and fibrillar films. Cyclic voltammetry and potential step chronocoulometry were used to gain information on peak currents and potentials switching reaction rates, charge capacity, and charge retention. Battery charge/discharge studies were also performed.

  1. Macromolecule-to-amphiphile conversion process of a polyoxometalate-polymer hybrid and assembled hybrid vesicles.

    PubMed

    Xiao, Yu; Han, Yao-Kun; Xia, Nan; Hu, Min-Biao; Zheng, Ping; Wang, Wei

    2012-09-03

    We report our findings on the macromolecule-to-amphiphile conversion process of a polyoxometalate-polymer hybrid and the assembled hybrid vesicles formed by aggregation of the hybrid amphiphile. The polyoxometalate-polymer hybrid is composed of a polyoxometalate (POM) cluster, which is covered by five tetrabutylammonium (Bu(4)N(+)) countercations, and a polystyrene (PS) chain. Through a cation-exchange process the Bu(4)N(+) countercations can be replaced by protons to form a hybrid amphiphile composed of a hydrophilic, protonated POM cluster and a hydrophobic PS chain. By implementing a directed one-dimensional diffusion and analyzing the diffusion data, we confirmed that the diffusion of solvated protons rather than macromolecules or aggregates is the key factor controlling the conversion process. Once the giant hybrid amphiphiles were formed, they immediately assembled into kinetically favored vesicular aggregates. During subsequent annealing these vesicular aggregates were transformed into thermodynamically stable vesicular aggregates with a perfect vesicle structure. The success in the preparation of the POM-containing hybrid vesicles provides us with an opportunity of preparing POM-functionalized vesicles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Conductive polymer-based sensors for biomedical applications.

    PubMed

    Nambiar, Shruti; Yeow, John T W

    2011-01-15

    A class of organic polymers, known as conducting polymers (CPs), has become increasingly popular due to its unique electrical and optical properties. Material characteristics of CPs are similar to those of some metals and inorganic semiconductors, while retaining polymer properties such as flexibility, and ease of processing and synthesis, generally associated with conventional polymers. Owing to these characteristics, research efforts in CPs have gained significant traction to produce several types of CPs since its discovery four decades ago. CPs are often categorised into different types based on the type of electric charges (e.g., delocalized pi electrons, ions, or conductive nanomaterials) responsible for conduction. Several CPs are known to interact with biological samples while maintaining good biocompatibility and hence, they qualify as interesting candidates for use in a numerous biological and medical applications. In this paper, we focus on CP-based sensor elements and the state-of-art of CP-based sensing devices that have potential applications as tools in clinical diagnosis and surgical interventions. Representative applications of CP-based sensors (electrochemical biosensor, tactile sensing 'skins', and thermal sensors) are briefly discussed. Finally, some of the key issues related to CP-based sensors are highlighted.

  3. Optimally conductive networks in randomly dispersed CNT:graphene hybrids

    PubMed Central

    Shim, Wonbo; Kwon, Youbin; Jeon, Seung-Yeol; Yu, Woong-Ryeol

    2015-01-01

    A predictive model is proposed that quantitatively describes the synergistic behavior of the electrical conductivities of CNTs and graphene in CNT:graphene hybrids. The number of CNT-to-CNT, graphene-to-graphene, and graphene-to-CNT contacts is calculated assuming a random distribution of CNTs and graphene particles in the hybrids and using an orientation density function. Calculations reveal that the total number of contacts reaches a maximum at a specific composition and depends on the particle sizes of the graphene and CNTs. The hybrids, prepared using inkjet printing, are distinguished by higher electrical conductivities than that of 100% CNT or graphene at certain composition ratios. These experimental results provide strong evidence that this approach involving constituent element contacts is suitable for investigating the properties of particulate hybrid materials. PMID:26564249

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

    DTIC Science & Technology

    2007-04-18

    DATES COVERED July 10 2003 – January 09 2007 4. TITLE AND SUBTITLE High Temperature Resistant Organic/ Inorganic Hybrid Polymers: An...Supramolecular Chemistry, High Temperature Materials, Organic Inorganic Hybrid Materials, Sensors 15. NUMBER OF PAGES 16...298-102 Enclosure 1 2 High Temperature Resistant Organic/ Inorganic Hybrid Polymers: An Architectural Study DAAD19-03-1-0208 PIs Stuart

  5. Conduction mechanisms in silicon-polymer-metal heterostructures

    SciTech Connect

    Salikhov, R. B. Lachinov, A. N.; Rakhmeev, R. G.

    2007-10-15

    Conduction mechanisms in thin films of wide-gap polymers in silicon-based heterostructures have been experimentally studied. Measuring the temperature dependence of the current-voltage characteristics of samples in the temperature range 80-300 K was used as the basic method. Multilayer Si-SiO{sub 2}-polymer-metal structures were prepared for measurements. Films of poly(diphenylene phthalide), in which a transition from the insulating to a highly conducting state is observed, were used as polymeric layers. The results obtained were used to explain the features of the charge transport in the samples in terms of the hopping conductivity via trap levels, Schottky emission, and field-assisted tunneling emission.

  6. Electropolymerization on wireless electrodes towards conducting polymer microfibre networks

    NASA Astrophysics Data System (ADS)

    Koizumi, Yuki; Shida, Naoki; Ohira, Masato; Nishiyama, Hiroki; Tomita, Ikuyoshi; Inagi, Shinsuke

    2016-01-01

    Conducting polymers can be easily obtained by electrochemical oxidation of aromatic monomers on an electrode surface as a film state. To prepare conducting polymer fibres by electropolymerization, templates such as porous membranes are necessary in the conventional methods. Here we report the electropolymerization of 3,4-ethylenedioxythiophene and its derivatives by alternating current (AC)-bipolar electrolysis. Poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives were found to propagate as a fibre form from the ends of Au wires used as bipolar electrodes (BPEs) parallel to an external electric field, without the use of templates. The effects of applied frequency and of the solvent on the morphology, growth rate and degree of branching of these PEDOT fibres were investigated. In addition, a chain-growth model for the formation of conductive material networks was also demonstrated.

  7. Electropolymerization on wireless electrodes towards conducting polymer microfibre networks

    PubMed Central

    Koizumi, Yuki; Shida, Naoki; Ohira, Masato; Nishiyama, Hiroki; Tomita, Ikuyoshi; Inagi, Shinsuke

    2016-01-01

    Conducting polymers can be easily obtained by electrochemical oxidation of aromatic monomers on an electrode surface as a film state. To prepare conducting polymer fibres by electropolymerization, templates such as porous membranes are necessary in the conventional methods. Here we report the electropolymerization of 3,4-ethylenedioxythiophene and its derivatives by alternating current (AC)-bipolar electrolysis. Poly(3,4-ethylenedioxythiophene) (PEDOT) derivatives were found to propagate as a fibre form from the ends of Au wires used as bipolar electrodes (BPEs) parallel to an external electric field, without the use of templates. The effects of applied frequency and of the solvent on the morphology, growth rate and degree of branching of these PEDOT fibres were investigated. In addition, a chain-growth model for the formation of conductive material networks was also demonstrated. PMID:26804140

  8. Electrically conductive, optically transparent polymer/carbon nanotube composites

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Jr., Joseph G. (Inventor); Harrison, Joycelyn S. (Inventor); Park, Cheol (Inventor); Watson, Kent A. (Inventor); Ounaies, Zoubeida (Inventor)

    2011-01-01

    The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior.

  9. Synthesis of polymer nanostructures with conductance switching properties

    DOEpatents

    Su, Kai; Nuraje, Nurxat; Zhang, Lingzhi; Matsui, Hiroshi; Yang, Nan Loh

    2015-03-03

    The present invention is directed to crystalline organic polymer nanoparticles comprising a conductive organic polymer; wherein the crystalline organic polymer nanoparticles have a size of from 10 nm to 200 nm and exhibits two current-voltage states: (1) a high resistance current-voltage state, and (2) a low resistance current-voltage state, wherein when a first positive threshold voltage (V.sub.th1) or higher positive voltage, or a second negative threshold voltage (V.sub.th2) or higher negative voltage is applied to the nanoparticle, the nanoparticle exhibits the low-resistance current-voltage state, and when a voltage less positive than the first positive threshold voltage or a voltage less negative than the second negative threshold voltage is applied to the nanoparticle, the nanoparticle exhibits the high-resistance current-voltage state. The present invention is also directed methods of manufacturing the nanoparticles using novel interfacial oxidative polymerization techniques.

  10. Conducting Polymer-Based Nanohybrid Transducers: A Potential Route to High Sensitivity and Selectivity Sensors

    PubMed Central

    Park, Seon Joo; Kwon, Oh Seok; Lee, Ji Eun; Jang, Jyongsik; Yoon, Hyeonseok

    2014-01-01

    The development of novel sensing materials provides good opportunities to realize previously unachievable sensor performance. In this review, conducting polymer-based nanohybrids are highlighted as innovative transducers for high-performance chemical and biological sensing devices. Synthetic strategies of the nanohybrids are categorized into four groups: (1) impregnation, followed by reduction; (2) concurrent redox reactions; (3) electrochemical deposition; (4) seeding approach. Nanocale hybridization of conducting polymers with inorganic components can lead to improved sorption, catalytic reaction and/or transport behavior of the material systems. The nanohybrids have thus been used to detect nerve agents, toxic gases, volatile organic compounds, glucose, dopamine, and DNA. Given further advances in nanohybrids synthesis, it is expected that sensor technology will also evolve, especially in terms of sensitivity and selectivity. PMID:24561406

  11. Substrate coating by conductive polymers through spontaneous oxidation and polymerization.

    PubMed

    Kuwabara, Kento; Masaki, Hirotaka; Imai, Hiroaki; Oaki, Yuya

    2017-06-14

    A variety of substrates and substances were coated with conductive polymers at low temperature under ambient pressure. The substrate coating with heteroaromatic polymers proceeded through spontaneous oxidation and polymerization of the monomers, such as pyrrole (Py) and thiophene (Tp) derivatives. The monomer liquid, the solid nitrate oxidant, and the substrate were put in a closed vessel. The vapor of the activated monomer was spontaneously generated on the surface of the solid nitrate oxidant through the diffusion of the monomer vapor. The monomer and its activated species were adsorbed and polymerized on the surface of any substrate in the reaction vessel. The thickness was controlled by the reaction time. The substituents of the monomers had an influence on the coating rate. The morphology of the coated polymers was changed by the substrates with different wettabilities. The thin coating of the heteroaromatic polymer was applied to the preparation of an electrode for charge storage based on the redox reaction. The thin coating on the current collector showed an enhanced high-rate charge-discharge performance. The present synthetic approach can be applied to the coating of polymer materials on a variety of substrates from the monomer vapor under mild conditions.

  12. Laser properties of luminescent conducting polymers in open resonators

    NASA Astrophysics Data System (ADS)

    Eradat Oskouei, Nayer; Gellermann, Werner; Shkunov, Maxim N.; Frolov, Sergey V.; Osaki, M.; Yoshino, Katsumi; Vardeny, Z. Valy

    1997-12-01

    We have investigated the lasing properties of several luminescent conducting polymers, i.e. DOO-PPV and the bi- substituted polyacetylenes PDPA-nBu, and PHxPA, dissolved in various polar and non-polar solvents. PPV polymers emit with high quantum efficiencies in broad emission bands cantered in the orange/red region of the spectrum, depending on the solvent, and the PDPA polymers emit in the blue/green region. Our tested laser resonators include polymer solutions excited with 100 ps pulses from a regeneratively amplified mode-locked Nd:YAG laser. We obtain pulsed, low-threshold laser operation with repetition rate of up to 1 kHz. Resulting mainly from recent reported originally in the literature. The dependencies of threshold pump energy and output versus input power characteristics on material parameters are investigated for a fixed optical gain length. The results are compared with the standard Rhodamine 590 organic dye system used in the same wavelength regions. We have observed that the well know phenomenon of 'concentration quenching' in dye molecules does not happen in polymers. Spectral narrowing in PDPA-nBu solution, emitting near 500 nm, is also obtained for the first time.

  13. Synthesis and characterization of porous polyaniline conductive polymers

    NASA Astrophysics Data System (ADS)

    Price, Aaron D.; Naguib, Hani E.

    2007-04-01

    Polyaniline conductive polymers exhibit great potential for linear actuator applications. Many recent studies report methods to develop polyaniline-based materials with increased mechanical properties, electrical conductivity, and faster response time during actuation. In this study, porous blends of poly(methylmethacrylate) and polyaniline are processed using a two phase batch foaming setup. The effect of materials, processing, and system parameters on the physical properties of the resulting cellular structure are investigated. Hence, the effect of density and cell morphology on the electrical conductivity is elucidated.

  14. Hot pressed K+ ion conducting solid polymer electrolytes: synthesis, ion conduction and polymeric battery fabrication

    NASA Astrophysics Data System (ADS)

    Chandra, Angesh

    2016-07-01

    Synthesis and ion transport studies of hot pressed K+ ion conducting solid polymer electrolytes (SPEs): (1 - x) PEO: x KBr, where 0 < x < 50 in wt%, are reported. The solvent-free/hot-press method is used for synthesis of the present SPEs. The two orders of conductivity enhancement achieved after the polymer-salt complexation in SPE composition: (70:30) with conductivity ( σ) 5.01 × 10-7 S cm-1 from the room temperature conductivity measurements. Materials characterization and polymer-salt complexations of present SPEs have been explained with the help of various techniques viz. X-ray diffraction, Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy technique. To explain the ion conduction in the present SPEs, temperature dependent ionic conductivity ( σ), ionic mobility ( μ), mobile ion concentration ( n), ionic transference number ( t ion ) and ionic drift velocity ( v d ) have been calculated with the help of various experimental techniques. A solid state polymer battery is also fabricated by using the present SPE as an electrolyte and have been calculated their important cell parameters at room temperature.

  15. Conducting polymer nanowire arrays for high performance supercapacitors.

    PubMed

    Wang, Kai; Wu, Haiping; Meng, Yuena; Wei, Zhixiang

    2014-01-15

    This Review provides a brief summary of the most recent research developments in the fabrication and application of one-dimensional ordered conducting polymers nanostructure (especially nanowire arrays) and their composites as electrodes for supercapacitors. By controlling the nucleation and growth process of polymerization, aligned conducting polymer nanowire arrays and their composites with nano-carbon materials can be prepared by employing in situ chemical polymerization or electrochemical polymerization without a template. This kind of nanostructure (such as polypyrrole and polyaniline nanowire arrays) possesses high capacitance, superior rate capability ascribed to large electrochemical surface, and an optimal ion diffusion path in the ordered nanowire structure, which is proved to be an ideal electrode material for high performance supercapacitors. Furthermore, flexible, micro-scale, threadlike, and multifunctional supercapacitors are introduced based on conducting polyaniline nanowire arrays and their composites. These prototypes of supercapacitors utilize the high flexibility, good processability, and large capacitance of conducting polymers, which efficiently extend the usage of supercapacitors in various situations, and even for a complicated integration system of different electronic devices.

  16. Stably Doped Conducting Polymer Nanoshells by Surface Initiated Polymerization.

    PubMed

    Li, Junwei; Yoon, Soon Joon; Hsieh, Bao-Yu; Tai, Wanyi; O'Donnell, Matthew; Gao, Xiaohu

    2015-12-09

    Despite broad applications ranging from electronics to biomedical sensing and imaging, a long-standing problem of conducting polymers is the poor resistance to dedoping, which directly affects their signature electrical and optical properties. This problem is particularly significant for biomedical uses because of fast leaching of dopant ions in physiological environments. Here, we describe a new approach to engineer multimodal core-shell nanoparticles with a stably doped conductive polymer shell in biological environments. It was achieved by making a densely packed polymer brush rather than changing its molecular structure. Polyaniline (PANI) was used as a model compound due to its concentrated near-infrared (NIR) absorption. It was grafted onto a magnetic nanoparticle via a polydopamine intermediate layer. Remarkably, at pH 7 its conductivity is ca. 2000× higher than conventional PANI nanoshells. Similarly, its NIR absorption is enhanced by 2 orders of magnitude, ideal for photothermal imaging and therapy. Another surprising finding is its nonfouling property, even outperforming polyethylene glycol. This platform technology is also expected to open exciting opportunities in engineering stable conductive materials for electronics, imaging, and sensing.

  17. Surface Modification of the Conducting Polymer, Polypyrrole, via Affinity Peptide**

    PubMed Central

    Nickels, Jonathan D.; Schmidt, Christine E.

    2012-01-01

    A novel strategy for affinity-based surface modification of the conducting polymer, polypyrrole, (PPy), has been developed. A 12-amino acid peptide (THRTSTLDYFVI, hereafter denoted T59) was previously identified via the phage display technique. This peptide non-covalently binds to the chlorine-doped conducting polymer polypyrrole (PPyCl). Studies have previously shown that conductive polymers have promising application in neural electrodes, sensors, and for improving regeneration and healing of peripheral nerves and other tissues. Thus, the strong and specific attachment of bio-active molecules to the surface of PPy using the T59 affinity peptide is an exciting new approach to enhance the bioactivity of electrically active materials for various biomedical applications. We demonstrate this by using T59 as a tether to modify PPyCl with the laminin fragment IKVAV to enhance cell interactions, as well as with the so-called stealth molecule poly(ethylene glycol; PEG) to decrease cell interactions. Using these two modification strategies, we were able to control cell attachment and neurite extension on the PPy surface, which is critical for different applications (i.e., the goal for tissue regeneration is to enhance cell interactions, whereas the goal for electrode and sensor applications is to reduce glial cell interactions and thus decrease scarring). Significantly, the conductivity of the PPyCl surface was unaffected by this surface modification technique, which is not the case with other methods that have been explored to surface modify conducting polymers. Finally, using subcutaneous implants, we confirmed that the PPyCl treated with the T59 peptide did not react in vivo differently than untreated PPyCl. PMID:23129217

  18. Surface modification of the conducting polymer, polypyrrole, via affinity peptide.

    PubMed

    Nickels, Jonathan D; Schmidt, Christine E

    2013-05-01

    A novel strategy for affinity-based surface modification of the conducting polymer, polypyrrole, (PPy), has been developed. A 12-amino acid peptide (THRTSTLDYFVI, hereafter denoted T59) was previously identified via the phage display technique. This peptide noncovalently binds to the chlorine-doped conducting polymer polypyrrole (PPyCl). Studies have previously shown that conductive polymers have promising application in neural electrodes, sensors, and for improving regeneration and healing of peripheral nerves and other tissues. Thus, the strong and specific attachment of bioactive molecules to the surface of PPy using the T59 affinity peptide is an exciting new approach to enhance the bioactivity of electrically active materials for various biomedical applications. We demonstrate this by using T59 as a tether to modify PPyCl with the laminin fragment IKVAV to enhance cell interactions, as well as with the so-called stealth molecule poly(ethylene glycol; PEG) to decrease cell interactions. Using these two modification strategies, we were able to control cell attachment and neurite extension on the PPy surface, which is critical for different applications (i.e., the goal for tissue regeneration is to enhance cell interactions, whereas the goal for electrode and sensor applications is to reduce glial cell interactions and thus decrease scarring). Significantly, the conductivity of the PPyCl surface was unaffected by this surface modification technique, which is not the case with other methods that have been explored to surface modify conducting polymers. Finally, using subcutaneous implants, we confirmed that the PPyCl treated with the T59 peptide did not react in vivo differently than untreated PPyCl. Copyright © 2012 Wiley Periodicals, Inc.

  19. Polypyrrole-based conducting polymers and interactions with biological tissues

    PubMed Central

    Ateh, D.D; Navsaria, H.A; Vadgama, P

    2006-01-01

    Polypyrrole (PPy) is a conjugated polymer that displays particular electronic properties including conductivity. In biomedical applications, it is usually electrochemically generated with the incorporation of any anionic species including also negatively charged biological macromolecules such as proteins and polysaccharides to give composite materials. In biomedical research, it has mainly been assessed for its role as a reporting interface in biosensors. However, there is an increasing literature on the application of PPy as a potentially electrically addressable tissue/cell support substrate. Here, we review studies that have considered such PPy based conducting polymers in direct contact with biological tissues and conclude that due to its versatile functional properties, it could contribute to a new generation of biomaterials. PMID:17015302

  20. Conducting Electronic Polymers by Non-Redox Processes

    DTIC Science & Technology

    1988-12-31

    systematic detailed observation of competing crystalline phases in a doped polymer. The multiple structures of the erneraldine form of polyaniline , together...states and other properties has been determined. Class I of the emeraldine form of polyaniline consists of materials prepared in the conducting, doped ...tosylic acid doped polyaniline ad polyethyleneoxide. We found that a 50:50 blend of tosylic acid doped polyaniline:PEO could form a homogeneous film

  1. Microscopic mechanism of reinforcement and conductivity in polymer nanocomposite materials

    NASA Astrophysics Data System (ADS)

    Chang, Tae-Eun

    Modification of polymers by adding various nano-particles is an important method to obtain effective enhancement of materials properties. Within this class of materials, carbon nanotubes (CNT) are among the most studied materials for polymer reinforcement due to their extraordinary mechanical properties, superior thermal and electronic properties, and high aspect ratio. However, to unlock the potential of CNTs for applications, CNTs must be well dispersed in a polymer matrix and the microscopic mechanism of polymer reinforcement by CNTs must be understood. In this study, single-wall carbon nanotube (SWNT) composites with polypropylene (PP)-SWNT and polystyrene (PS)-SWNT were prepared and analyzed. Microscopic study of the mechanism of reinforcement and conductivity by SWNT included Raman spectroscopy, wide-angle X-ray diffraction (WAXD) and dielectric measurement. For PP-SWNT composites, tensile tests show a three times increase in the Young's modulus with addition of only 1 wt% SWNT, and much diminished increase of modulus with further increase in SWNT concentration. For PS-SWNT composites, well-dispersed SWNT/PS composite has been produced, using initial annealing of SWNT and optimum sonication conditions. The studies on the tangential mode in the Raman spectra and TEM indicated well-dispersed SWNTs in a PS matrix. We show that conductivity appears in composites already at very low concentrations, hinting at the formation of a 'percolative' network even below 0.5% of SWNT. The Raman studies for both composites show good transfer of the applied stress from the polymer matrices to SWNTs. However, no significant improvement of mechanical property is observed for PS-SWNT composites. The reason for only a slight increase of mechanical property remains unknown.

  2. High Surface Area Conducting Polymer Composites for Hydrogen Storage

    NASA Astrophysics Data System (ADS)

    Gutowska, Anna; Tarasevich, Barbara; Shin, Yongsoon; Ferris, Kim; Linehan, John; White, James

    2004-03-01

    We are investigating high surface area mesoporous conducting polymer composites as new materials for on-board hydrogen storage. A recent study reported significant levels of hydrogen storage in two conducting polymers, polyaniline (PANI) and polypyrrole (PPy) (8 wtPANI).1 We have used templated synthesis methods to obtain PPy and PANI composites with mesoporous structure. We have designed composites that offer a combination of several desirable properties: - favorable wt. - multiple mechanisms of hydrogen storage (physi-, chemi-sorption, and voids available for gas compression), and high surface area meoporous morphology for enhanced gas-material interactions and greater control of gas transport. Our experimental approaches to materials design were supported by computational methods aimed at developing predictive capabilities for the structure-property relationship (SPR) of electronic structure effects on hydrogen storage capacity in conducting polymers. Computational methods were also used to support design of mesoporous structures for optimized gas-material interactions and effective diffusion control of gas transport. 1. Cho, J. J.; Song, K. S.; Kim, J. W.; Kim, T. H.; Choo, K. Fuel Chemistry Div. Reprints 2002, 47, 790.

  3. Hybrid materials from intermolecular associations between cationic lipid and polymers.

    PubMed

    Pereira, Edla M A; Kosaka, Priscila M; Rosa, Heloísa; Vieira, Débora B; Kawano, Yoshio; Petri, Denise F S; Carmona-Ribeiro, Ana M

    2008-08-07

    Intermolecular associations between a cationic lipid and two model polymers were evaluated from preparation and characterization of hybrid thin films cast on silicon wafers. The novel materials were prepared by spin-coating of a chloroformic solution of lipid and polymer on silicon wafer. Polymers tested for miscibility with the cationic lipid dioctadecyldimethylammonium bromide (DODAB) were polystyrene (PS) and poly(methyl methacrylate) (PMMA). The films thus obtained were characterized by ellipsometry, wettability, optical and atomic force microscopy, Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and activity against Escherichia coli. Whereas intermolecular ion-dipole interactions were available for the PMMA-DODAB interacting pair producing smooth PMMA-DODAB films, the absence of such interactions for PS-DODAB films caused lipid segregation, poor film stability (detachment from the silicon wafer) and large rugosity. In addition, the well-established but still remarkable antimicrobial DODAB properties were transferred to the novel hybrid PMMA/DODAB coating, which is demonstrated to be highly effective against E. coli.

  4. EFFECTS OF TRITIUM GAS EXPOSURE ON ELECTRICALLY CONDUCTING POLYMERS

    SciTech Connect

    Kane, M.; Clark, E.; Lascola, R.

    2009-12-16

    Effects of beta (tritium) and gamma irradiation on the surface electrical conductivity of two types of conducting polymer films are documented to determine their potential use as a sensing and surveillance device for the tritium facility. It was shown that surface conductivity was significantly reduced by irradiation with both gamma and tritium gas. In order to compare the results from the two radiation sources, an approximate dose equivalence was calculated. The materials were also sensitive to small radiation doses (<10{sup 5} rad), showing that there is a measurable response to relatively small total doses of tritium gas. Spectroscopy was also used to confirm the mechanism by which this sensing device would operate in order to calibrate this sensor for potential use. It was determined that one material (polyaniline) was very sensitive to oxidation while the other material (PEDOT-PSS) was not. However, polyaniline provided the best response as a sensing material, and it is suggested that an oxygen-impermeable, radiation-transparent coating be applied to this material for future device prototype fabrication. A great deal of interest has developed in recent years in the area of conducting polymers due to the high levels of conductivity that can be achieved, some comparable to that of metals [Gerard 2002]. Additionally, the desirable physical and chemical properties of a polymer are retained and can be exploited for various applications, including light emitting diodes (LED), anti-static packaging, electronic coatings, and sensors. The electron transfer mechanism is generally accepted as one of electron 'hopping' through delocalized electrons in the conjugated backbone, although other mechanisms have been proposed based on the type of polymer and dopant [Inzelt 2000, Gerard 2002]. The conducting polymer polyaniline (PANi) is of particular interest because there are extensive studies on the modulation of the conductivity by changing either the oxidation state of the

  5. Electrochemical synthesis of Sm2O3 nanoparticles: Application in conductive polymer composite films for supercapacitors.

    PubMed

    Mohammad Shiri, Hamid; Ehsani, Ali; Jalali Khales, Mina

    2017-11-01

    A novel electrosynthetic method was introduced to synthesize of Sm2O3 nanoparticles and furthermore, for improving the electrochemical performance of conductive polymer, hybrid POAP/Sm2O3 films have then been fabricated by POAP electropolymerization in the presence of Sm2O3 nanoparticles as active electrodes for electrochemical supercapacitors. The structure, morphology, chemical composition of Sm2O3 nanoparticles was examined. Surface and electrochemical analyses have been used for characterization of Sm2O3 and POAP/Sm2O3 composite films. Different electrochemical methods including galvanostatic charge discharge experiments, cyclic voltammetry and electrochemical impedance spectroscopy have been applied to study the system performance. The supercapacity behavior of the composite film was attributed to the (i) high active surface area of the composite, (ii) charge transfer along the polymer chain due to the conjugation form of the polymer and finally (iii) synergism effect between conductive polymer and Sm2O3 nanoparticles. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Biomimetic sensing layer based on electrospun conductive polymer webs.

    PubMed

    Zampetti, E; Pantalei, S; Scalese, S; Bearzotti, A; De Cesare, F; Spinella, C; Macagnano, A

    2011-01-15

    The aim of the present study is to combine a bio-inspired nanofibrous artificial epithelium to the electronic nose (e-nose) principles. The sensing device set up was an electronic nose consisting of an array of 9 micro-chemoresistors (Cr-Au, 3×3) coated with electrospun nanofibrous structures. These were comprised of doped polyemeraldine base blended with 3 different polymers: polyethylene oxide, polyvinilpyrrolidone and polystyrene, which acted as carriers for the conducting polymer and were the major responsible of the features of each fibrous overlay (electrical parameters, selectivity and sensitivity ranges). The two sensing strategies here adopted and compared consisted in the use of 2 different textural coatings: a single- and a double-overlay, where the double-overlay resulting from overdeposition of 2 different polymer blends. Such e-nose included a plurality of nanofibres whose electrical parameters were at the same time depending on each polymer exposure to analytes (NO(2), NH(3)) and on the spatial distribution of the interlacing fibres. The morphology of the coating arrangements of this novel e-nose was investigated by scanning electron microscopy (SEM) and its sensor responses were processed by multicomponent data analyses (PCA and PLS) reporting encouraging results for detection and recognition of analytes at ppb levels.

  7. Electronically conductive polymer binder for lithium-ion battery electrode

    DOEpatents

    Liu, Gao; Xun, Shidi; Battaglia, Vincent S; Zheng, Honghe

    2014-10-07

    A family of carboxylic acid group containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  8. Functional Conducting Polymers via Thiol-ene Chemistry

    PubMed Central

    Feldman, Kathleen E.; Martin, David C.

    2012-01-01

    We demonstrate here that thiol-ene chemistry can be used to provide side-chain functionalized monomers based on 3,4-propylenedioxythiophene (ProDOT) containing ionic, neutral, hydrophobic, and hydrophilic side chains. All reactions gave high yields and purification could generally be accomplished through precipitation. These monomers were polymerized either chemically or electro-chemically to give soluble materials or conductive films, respectively. This strategy provides for facile tuning of the solubility, film surface chemistry, and film morphology of this class of conducting polymers. PMID:25585932

  9. Optical Studies of the Metallic State in Conducting Polymers

    NASA Astrophysics Data System (ADS)

    Kohlman, Randolph Scott

    A systematic charge transport study was performed at direct current, optical (10-55,000 cm^ {-1}, and microwave (6.5 GHz) frequencies to probe the insulator-metal (IM) transition which occurs as a function of sample processing in conducting polymers, notably Polyaniline (PAN) and Polypyrrole (PPy). These measurements demonstrate the universality of the inhomogeneous metallic state in conducting polymers. Optical and microwave measurements of the dielectric function (varepsilon( omega)] demonstrate a crossover from positive to large negative values for samples processed to lie near the IM transition. The negative dielectric response is attributed to a small fraction of the conduction electron gas which demonstrates Drude dispersion. The majority of the conduction electrons remain localized. In contrast, samples far from the IM transition on the insulating side demonstrate localized hopping behavior with positive varepsilon(omega) at low frequency. Detailed studies of the transport properties of PAN samples approaching the IM transition reveal that, though the localization is controlled by structural disorder, the transition is not a conventional Anderson transition such as has been applied to doped semiconductors. This is asserted because (1) samples with conductivity ( sigma_{DC}) higher than the minimum metallic conductivity (sigma_{min}) become insulating at low temperature; (2) millikelvin sigma _{DC} for selected insulating samples is not consistent with hopping transport; (3) the density of free electrons present in a sample scales with sigma_{DC}(T) so that a sample which demonstrates metallic behavior at low temperature may have a smaller density of free electrons at room temperature than a sample which demonstrates insulating behavior at low temperature; (4) varepsilon( omega) and the optical conductivity ( sigma(omega)] for metallic samples are consistent with macroscopically inhomogeneous models but not Anderson localization models; and (5) the polymers

  10. Electronically conductive polymer binder for lithium-ion battery electrode

    DOEpatents

    Liu, Gao; Xun, Shidi; Battaglia, Vincent S.; Zheng, Honghe

    2017-05-16

    A family of carboxylic acid group containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  11. Ab-initio study of napthelene based conducting polymer

    SciTech Connect

    Ruhela, Ankur; Kanchan, Reena; Srivastava, Anurag; Sinha, O. P.

    2014-04-24

    In this paper, we have identified structural and electronic properties of conducting polymers by using DFT based ATK-VNL ab-initio tool. Naphthalene derivative structures were stabilized by varying the bond length between two atoms of the molecule C-N and C-C. We have also studied the molecular energy spectrum of naphthalene derivatives and found the HOMOLUMO for the same. A comparison of structural and electronic properties of naphthalene derivatives by attaching the functional group of amine, have been performed and found that they show good semi conducting properties.

  12. Hybrid tandem photovoltaic devices with a transparent conductive interconnecting recombination layer

    SciTech Connect

    Kim, Taehee; Choi, Jin Young; Jeon, Jun Hong; Kim, Youn-Su; Kim, Bong-Soo; Lee, Doh-Kwon; Kim, Honggon; Han, Seunghee; Kim, Kyungkon

    2012-10-15

    Highlights: ► This work enhanced power conversion efficiency of the hybrid tandem solar cell from 1.0% to 2.6%. ► The interfacial series resistance of the tandem solar cell was eliminated by inserting ITO layer. ► This work shows the feasibility of the highly efficient hybrid tandem solar cells. -- Abstract: We demonstrate hybrid tandem photovoltaic devices with a transparent conductive interconnecting recombination layer. The series-connected hybrid tandem photovoltaic devices were developed by combining hydrogenated amorphous silicon (a-Si:H) and polymer-based organic photovoltaics (OPVs). In order to enhance the interfacial connection between the subcells, we employed highly transparent and conductive indium tin oxide (ITO) thin layer. By using the ITO interconnecting layer, the power conversion efficiency of the hybrid tandem solar cell was enhanced from 1.0% (V{sub OC} = 1.041 V, J{sub SC} = 2.97 mA/cm{sup 2}, FF = 32.3%) to 2.6% (V{sub OC} = 1.336 V, J{sub SC} = 4.65 mA/cm{sup 2}, FF = 41.98%) due to the eliminated interfacial series resistance.

  13. Conductive hydrophobic hybrid textiles modified with carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Kowalczyk, D.; Brzeziński, S.; Makowski, T.; Fortuniak, W.

    2015-12-01

    The paper presents the results of modifying and testing modern hybrid polyester-cotton woven fabrics with deposited multi-wall carbon nanotubes and imparted hydrophobicity. The effect of the carbon nanotubes deposited on these fabrics on their conductive properties and hydrophobicity has been assessed. The electro-conductive and hydrophobic composite fabrics obtained in this way, being light, elastic and resistant to mechanical effects, make it possible to be widely used in various industrial fields.

  14. Highly Conductive Solid-State Hybrid Electrolytes Operating at Subzero Temperatures.

    PubMed

    Kwon, Taeyoung; Choi, Ilyoung; Park, Moon Jeong

    2017-07-19

    We report a unique, highly conductive, dendrite-inhibited, solid-state polymer electrolyte platform that demonstrates excellent battery performance at subzero temperatures. A design based on functionalized inorganic nanoparticles with interconnected mesopores that contain surface nitrile groups is the key to this development. Solid-state hybrid polymer electrolytes based on succinonitrile (SN) electrolytes and porous nanoparticles were fabricated via a simple UV-curing process. SN electrolytes were effectively confined within the mesopores. This stimulated favorable interactions with lithium ions, reduced leakage of SN electrolytes over time, and improved mechanical strength of membranes. Inhibition of lithium dendrite growth and improved electrochemical stability up to 5.2 V were also demonstrated. The hybrid electrolytes exhibited high ionic conductivities of 2 × 10(-3) S cm(-1) at room temperature and >10(-4) S cm(-1) at subzero temperatures, leading to stable and improved battery performance at subzero temperatures. Li cells made with lithium titanate anodes exhibited stable discharge capacities of 151 mAh g(-1) at temperatures below -10 °C. This corresponds to 92% of the capacity achieved at room temperature (164 mAh g(-1)). Our work represents a significant advance in solid-state polymer electrolyte technology and far exceeds the performance available with conventional polymeric battery separators.

  15. Better Proton-Conducting Polymers for Fuel-Cell Membranes

    NASA Technical Reports Server (NTRS)

    Narayan, Sri; Reddy, Prakash

    2012-01-01

    Polyoxyphenylene triazole sulfonic acid has been proposed as a basis for development of improved proton-conducting polymeric materials for solid-electrolyte membranes in hydrogen/air fuel cells. Heretofore, the proton-conducting membrane materials of choice have been exemplified by a family of perfluorosulfonic acid-based polymers (Nafion7 or equivalent). These materials are suitable for operation in the temperature of 75 to 85 C, but in order to reduce the sizes and/or increase the energy-conversion efficiencies of fuel-cell systems, it would be desirable to increase temperatures to as high as 120 C for transportation applications, and to as high as 180 C for stationary applications. However, at 120 C and at relative humidity values below 50 percent, the loss of water from perfluorosulfonic acid-based polymer membranes results in fuel-cell power densities too low to be of practical value. Therefore, membrane electrolyte materials that have usefully high proton conductivity in the temperature range of 180 C at low relative humidity and that do not rely on water for proton conduction at 180 C would be desirable. The proposed polyoxyphenylene triazole sulfonic acid-based materials have been conjectured to have these desirable properties. These materials would be free of volatile or mobile acid constituents. The generic molecular structure of these materials is intended to exploit the fact, demonstrated in previous research, that materials that contain ionizable acid and base groups covalently attached to thermally stable polymer backbones exhibit proton conduction even in the anhydrous state.

  16. Hybrid energy harvesting systems, using piezoelectric elements and dielectric polymers

    NASA Astrophysics Data System (ADS)

    Cornogolub, Alexandru; Cottinet, Pierre-Jean; Petit, Lionel

    2016-09-01

    Interest in energy harvesting applications has increased a lot during recent years. This is especially true for systems using electroactive materials like dielectric polymers or piezoelectric materials. Unfortunately, these materials despite multiple advantages, present some important drawbacks. For example, many dielectric polymers demonstrated high energy densities; they are cheap, easy to process and can be easily integrated in many different structures. But at the same time, dielectric polymer generators require an external energy supply which could greatly compromise their autonomy. Piezoelectric systems, on the other hand, are completely autonomous and can be easily miniaturized. However, most common piezoelectric materials present a high rigidity and are brittle by nature and therefore their integration could be difficult. This paper investigates the possibility of using hybrid systems combining piezoelectric elements and dielectric polymers for mechanical energy harvesting applications and it is focused mainly on the problem of electrical energy transfer. Our objective is to show that such systems can be interesting and that it is possible to benefit from the advantages of both materials. For this, different configurations were considered and the problem of their optimization was addressed. The experimental work enabled us to prove the concept and identify the main practical limitations.

  17. Aqueous-Processed Insulating Polymer/Nanocrystal Hybrid Solar Cells.

    PubMed

    Jin, Gan; Chen, Zhaolai; Dong, Chunwei; Cheng, Zhongkai; Du, Xiaohang; Zeng, Qingsen; Liu, Fangyuan; Sun, Haizhu; Zhang, Hao; Yang, Bai

    2016-03-23

    A novel kind of hybrid solar cell (HSC) was developed by introducing water-soluble insulating polymer poly(vinyl alcohol) (PVA) into nanocrystals (NCs), which revealed that the most frequently used conjugated polymer could be replaced by an insulating one. It was realized by strategically taking advantage of the characteristic of decomposition for the polymer at annealing temperature, and it was interesting to discover that partial decomposition of PVA left behind plenty of pits on the surfaces of CdTe NC films, enlarging surface contact area between CdTe NCs and subsequently evaporated MoO3. Moreover, the residual annealed PVA filled in the voids among spherical CdTe NCs, which led to the decrease of leakage current. An improved shunt resistance (increased by ∼80%) was achieved, indicating the charge-carrier recombination was effectively overcome. As a result, the new HSCs were endowed with increased Voc, fill factor, and power conversion efficiency compared with the pure NC device. This approach can be applied to other insulating polymers (e.g., PVP) with advantages in synthesis, type, economy, stability, and so on, providing a novel universal cost-effective way to achieve higher photovoltaic performance.

  18. Improved Lithium Ionic Conductivity in Composite Polymer Electrolytes with Oxide-Ion Conducting Nanowires.

    PubMed

    Liu, Wei; Lin, Dingchang; Sun, Jie; Zhou, Guangmin; Cui, Yi

    2016-12-27

    Solid Li-ion electrolytes used in all-solid-state lithium-ion batteries (LIBs) are being considered to replace conventional liquid electrolytes that have leakage, flammability, and poor chemical stability issues, which represents one major challenge and opportunity for next-generation high-energy-density batteries. However, the low mobility of lithium ions in solid electrolytes limits their practical applications. Here, we report a solid composite polymer electrolyte with Y2O3-doped ZrO2 (YSZ) nanowires that are enriched with positive-charged oxygen vacancies. The morphologies and ionic conductivities have been studied systemically according to concentration of Y2O3 dopant in the nanowires. In comparison to the conventional filler-free electrolyte with a conductivity of 3.62 × 10(-7) S cm(-1), the composite polymer electrolytes with the YSZ nanowires show much higher ionic conductivity. It indicates that incorporation of 7 mol % of Y2O3-doped ZrO2 nanowires results in the highest ionic conductivity of 1.07 × 10(-5) S cm(-1) at 30 °C. This conductivity enhancement originates from the positive-charged oxygen vacancies on the surfaces of the nanowires that could associate with anions and then release more Li ions. Our work demonstrates a composite polymer electrolyte with oxygen-ion conductive nanowires that could address the challenges of all-solid-state LIBs.

  19. Conductivity of oriented bis-azo polymer films.

    PubMed

    Apitz, Dirk; Bertram, Ralph Peter; Benter, Nils; Sommer-Larsen, Peter; Johansen, Per Michael; Buse, Karsten

    2006-02-13

    The conductivity properties of electro-optic, photoaddressable, dense bis-azo chromophore polymer films are investigated by using samples corona poled at various temperatures. A dielectric spectrometer is applied to measure the frequency dependence of the conductivity at different temperatures before and after heating the material to above the glass transition temperature. The results show that the orientation of the chromophores changes the charge-carrier mobility. Ionic conductivity dominates in a more disordered configuration of the material, while the competing process of hole hopping takes over as a transition to a liquid-crystalline phase occurs when the material is heated to much higher than the glass transition temperature. Such microcrystallization strongly enhances the conductivity.

  20. Applications of conducting polymers and their issues in biomedical engineering.

    PubMed

    Ravichandran, Rajeswari; Sundarrajan, Subramanian; Venugopal, Jayarama Reddy; Mukherjee, Shayanti; Ramakrishna, Seeram

    2010-10-06

    Conducting polymers (CPs) have attracted much interest as suitable matrices of biomolecules and have been used to enhance the stability, speed and sensitivity of various biomedical devices. Moreover, CPs are inexpensive, easy to synthesize and versatile because their properties can be readily modulated by (i) surface functionalization techniques and (ii) the use of a wide range of molecules that can be entrapped or used as dopants. This paper discusses the various surface modifications of the CP that can be employed in order to impart physico-chemical and biological guidance cues that promote cell adhesion/proliferation at the polymer-tissue interface. This ability of the CP to induce various cellular mechanisms widens its applications in medical fields and bioengineering.

  1. Multifunctional and biomimicking electrochemical properties of conducting polymers

    NASA Astrophysics Data System (ADS)

    Otero, Toribio

    2005-06-01

    Electrochemical oxidation and reduction taking place in films of a conducting polymer involve: generation and annihilation of positive charges on the polymeric chains, conformational changes along the polymeric chains, coulombic repulsions and generation of free volume with interchange of ions and water molecules between the polymer and the solution. So, electric pulses, conformational changes, ionic and aqueous interchanges are involved, as it occurs during most of the biological functions. Those changes induce, simultaneously, different electrochemical properties: electrochemomechanical by swelling and shrinking processes, electrochromic by change of the molecular orbitals, charge storage by accumulation of positive or negative charges, electron-ion transduction between an electronic conductor and an electrolyte. All those properties mimic biological functions: muscles, mimicking skins, electric organs or nervous pulses. Some of the developed devices as sensing actuators (muscles), or smart membranes are presented.

  2. Molecular design of conducting polymer for electrochromic applications

    NASA Astrophysics Data System (ADS)

    Yang, Sze C.; Clark, R. L.; Liao, H.; Sun, L.

    1995-09-01

    The electrochromism of polyaniline in the near infrared spectral range is studied. Spectroelectrochemical data are used to construct optically monitored cyclic voltamograms (o- CV). Details of the electrochromic effects are clarified by comparing o-CV with the ordinary current monitored cyclic voltamograms (i-CV). Components of Faradaic currents to the cyclic voltamogram can be resolved by comparing o-CV with i-CV. We discuss molecular designs for modifying the properties of polyaniline. By a template-guided polymerization scheme, we synthesize the double strand polymeric complex of polyaniline. The first strand is a conducting polymer and the second strand is a polyelectrolyte. This molecular complex has the advantage of being more stable, more processable than the conventional polyaniline. The double strand molecular complex offers increased flexibility in molecular design of electrochromic and electroactive polymers.

  3. Multidimensional conducting polymer nanotubes for ultrasensitive chemical nerve agent sensing.

    PubMed

    Kwon, Oh Seok; Park, Seon Joo; Lee, Jun Seop; Park, Eunyu; Kim, Taejoon; Park, Hyun-Woo; You, Sun Ah; Yoon, Hyeonseok; Jang, Jyongsik

    2012-06-13

    Tailoring the morphology of materials in the nanometer regime is vital to realizing enhanced device performance. Here, we demonstrate flexible nerve agent sensors, based on hydroxylated poly(3,4-ethylenedioxythiophene) (PEDOT) nanotubes (HPNTs) with surface substructures such as nanonodules (NNs) and nanorods (NRs). The surface substructures can be grown on a nanofiber surface by controlling critical synthetic conditions during vapor deposition polymerization (VDP) on the polymer nanotemplate, leading to the formation of multidimensional conducting polymer nanostructures. Hydroxyl groups are found to interact with the nerve agents. Representatively, the sensing response of dimethyl methylphosphonate (DMMP) as a simulant for sarin is highly sensitive and reversible from the aligned nanotubes. The minimum detection limit is as low as 10 ppt. Additionally, the sensor had excellent mechanical bendability and durability.

  4. Dynamic modulation of detection window in conducting polymer based biosensors.

    PubMed

    Choong, Chwee-Lin; Milne, William I

    2010-06-15

    Here we demonstrate a novel application that employs the ion exchange properties of conducting polymers (CP) to modulate the detection window of a CP based biosensor under electrical stimuli. The detection window can be modulated by electrochemically controlling the degree of swelling of the CP associated with ion transport in and out of the polymer. We show that the modulation in the detection window of a caffeine imprinted polypyrrole biosensor, and by extension other CP based biosensors, can be achieved with this mechanism. Such dynamic modulation in the detection window has great potential for the development of smart biosensors, where the sensitivity of the sensor can be dynamically optimized for a specific test solution. Copyright 2010 Elsevier B.V. All rights reserved.

  5. Chemiresistors based on conducting polymers: a review on measurement techniques.

    PubMed

    Lange, Ulrich; Mirsky, Vladimir M

    2011-02-21

    This review covers the development of measurement configurations for chemiresistors based on conducting polymers. The simplest chemiresistors are based on application of a two-electrode technique. Artifacts caused by contact resistance can be overcome by application of a four-electrode technique. Simultaneous application of the two- and four-electrode measurement configurations provides an internal control of sensor integrity. An incorporation of two additional electrodes controlling the redox state of chemosensitive polymers and connecting to the measurement electrodes through liquid or (quasi)solid electrolyte results in a six-electrode technique; an electrically driven regeneration of such sensors allows one to perform fast and completely reversible measurements. Copyright © 2010 Elsevier B.V. All rights reserved.

  6. Transport mechanisms in conducting polymers: do general behaviours exis

    NASA Astrophysics Data System (ADS)

    Travers, J. P.

    1998-06-01

    We review several studies of transport properties of conducting polymers (CP) as a function of a parameter related to their structure or microstructure. We show that in strongly disordered CP, electron transport is dominated by hopping between conducting grains separated by insulating barriers. Although the nature of the metal-insulator transition is still a controversial topic in weakly disordered CP, several results indicate that heterogeneities play an important role. Thus heterogeneous disorder seems to control the conductivity of a large majority of CP. Plusieurs études sur la conductivité des polymères conducteurs (PC) en relation avec la microstructure sont rassemblées. Dans les PC très désordonnés, les sauts entre grains conducteurs séparés par des barrières isolantes dominent la conduction. Bien que la situation soit moins claire dans les PC peu désordonnés, des résultats indiquent que les hétérogénéités y jouent un rôle important. Ainsi, le désordre de nature hétérogène semble contrôler la conductivité de la grande majorité des PC.

  7. Water-processable polymer-nanocrystal hybrids for thermoelectrics.

    PubMed

    See, Kevin C; Feser, Joseph P; Chen, Cynthia E; Majumdar, Arun; Urban, Jeffrey J; Segalman, Rachel A

    2010-11-10

    We report the synthesis and thermoelectric characterization of composite nanocrystals composed of a tellurium core functionalized with the conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Solution processed nanocrystal films electronically out perform both PEDOT:PSS and unfunctionalized Te nanorods while retaining a polymeric thermal conductivity, resulting in a room temperature ZT ∼ 0.1. This combination of electronic and thermal transport indicates the potential for tailored transport in nanoscale organic/inorganic heterostructures.

  8. Conducting polymer actuators: From basic concepts to proprioceptive systems

    NASA Astrophysics Data System (ADS)

    Martinez Gil, Jose Gabriel

    Designers and engineers have been dreaming for decades of motors sensing, by themselves, working and surrounding conditions, as biological muscles do originating proprioception. Here bilayer full polymeric artificial muscles were checked up to very high cathodic potential limits (-2.5 V) in aqueous solution by cyclic voltammetry. The electrochemical driven exchange of ions from the conducting polymer film, and the concomitant Faradaic bending movement of the muscle, takes place in the full studied potential range. The presence of trapped counterion after deep reduction was corroborated by EDX determinations giving quite high electronic conductivity to the device. The large bending movement was used as a tool to quantify the amount of water exchanged per reaction unit (exchanged electron or ion). The potential evolutions of self-supported films of conducting polymers or conducting polymers (polypyrrole, polyaniline) coating different microfibers, during its oxidation/reduction senses working mechanical, thermal, chemical or electrical variables. The evolution of the muscle potential from electrochemical artificial muscles based on electroactive materials such as intrinsically conducting polymers and driven by constant currents senses, while working, any variation of the mechanical (trailed mass, obstacles, pressure, strain or stress), thermal or chemical conditions of work. One physically uniform artificial muscle includes one electrochemical motor and several sensors working simultaneously under the same driving reaction. Actuating (current and charge) and sensing (potential and energy) magnitudes are present, simultaneously, in the only two connecting wires and can be read by the computer at any time. From basic polymeric, mechanical and electrochemical principles a physicochemical equation describing artificial proprioception has been developed. It includes and describes, simultaneously, the evolution of the muscle potential during actuation as a function of the

  9. Crystal-surface-induced simultaneous synthesis and hierarchical morphogenesis of conductive polymers.

    PubMed

    Kuwabara, Kento; Oaki, Yuya; Muramatsu, Ryo; Imai, Hiroaki

    2015-06-14

    The surface of oxidant crystals facilitates the simultaneous synthesis and morphogenesis of conductive polymer materials. Oxidant crystals as a condensed phase of the oxidative agent induce the formation of the conductive polymer nanoparticles and their accumulated films.

  10. Computational analysis of electrical conduction in hybrid nanomaterials with embedded non-penetrating conductive particles

    NASA Astrophysics Data System (ADS)

    Cai, Jizhe; Naraghi, Mohammad

    2016-08-01

    In this work, a comprehensive multi-resolution two-dimensional (2D) resistor network model is proposed to analyze the electrical conductivity of hybrid nanomaterials made of insulating matrix with conductive particles such as CNT reinforced nanocomposites and thick film resistors. Unlike existing approaches, our model takes into account the impenetrability of the particles and their random placement within the matrix. Moreover, our model presents a detailed description of intra-particle conductivity via finite element analysis, which to the authors’ best knowledge has not been addressed before. The inter-particle conductivity is assumed to be primarily due to electron tunneling. The model is then used to predict the electrical conductivity of electrospun carbon nanofibers as a function of microstructural parameters such as turbostratic domain alignment and aspect ratio. To simulate the microstructure of single CNF, randomly positioned nucleation sites were seeded and grown as turbostratic particles with anisotropic growth rates. Particle growth was in steps and growth of each particle in each direction was stopped upon contact with other particles. The study points to the significant contribution of both intra-particle and inter-particle conductivity to the overall conductivity of hybrid composites. Influence of particle alignment and anisotropic growth rate ratio on electrical conductivity is also discussed. The results show that partial alignment in contrast to complete alignment can result in maximum electrical conductivity of whole CNF. High degrees of alignment can adversely affect conductivity by lowering the probability of the formation of a conductive path. The results demonstrate approaches to enhance electrical conductivity of hybrid materials through controlling their microstructure which is applicable not only to carbon nanofibers, but also many other types of hybrid composites such as thick film resistors.

  11. 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.

  12. Electrosynthetically patterned conducting polymer films for investigation of neural signaling

    NASA Astrophysics Data System (ADS)

    Simon, Daniel T.; Carter, Sue A.

    2006-05-01

    The ion-mediated conduction and versatility of device fabrication of conducting polymers provide a route to the study of neural signaling. Patterned junctions of conducting polypyrrole have been electropolymerized on commercially available microelectrode arrays, with typical dimensions 200μm between electrodes, each electrode being 30μm in diameter. Tetrabutylammonium perchlorate or sodium p-toluenesulfonate were used as electrolyte/counterion in the organic solvent. Individual polypyrrole junctions, when synthesized and connected in a three-electrode configuration, exhibit current-switching behavior analogous to neural weighting. Junctions copolymerized with thiophene exhibit current rectification and the nonlinear current-voltage behavior requisite for complex neural systems (i.e., the activation function).

  13. Shear induced electrical behaviour of conductive polymer composites

    NASA Astrophysics Data System (ADS)

    Starý, Zdeněk; Krückel, Johannes; Schubert, Dirk W.

    2013-04-01

    The time-dependent electrical resistance of polymethylmethacrylate containing carbon black was measured under oscillatory shear in the molten state. The electrical signal was oscillating exactly at the doubled frequency of the oscillatory shear deformation. Moreover, the experimental results gave a hint to the development of conductive structures in polymer melts under shear deformation. It was shown that the flow induced destruction of conductive paths dominates over the flow induced build-up in the beginning of the shear deformations. However, for longer times both competitive effects reach a dynamic equilibrium and only the thermally induced build-up of pathways influences the changes in the composite resistance during the shear. Furthermore, the oscillating electrical response depends clearly on the deformation amplitude applied. A simple physical model describing the behaviour of conductive pathways under shear deformation was derived and utilized for the description of the experimental data.

  14. Thermal conductivity of polymer composite pigmented with titanium dioxide

    NASA Astrophysics Data System (ADS)

    Ghebrid, N.; Guellal, M.; Rouabah, F.

    2017-04-01

    The aim of this work is to provide a numerical modeling of thermal conductivity of a polymer matrix polystyrene composite filled with titanium dioxide spheres, and to compare the obtained results with theoretical prediction models and the experimental data as a function of the quenching temperature. For this purpose, a numerical study was conducted using the finite element method to predict the effective thermal conductivity of the composite. In addition, a comparison with the results from the analytical models showed that the proposed numerical model is in good agreement with the analytical models of Hatta-Taya and Hashin-Shtrikman. Finally, the comparison of the numerical model to experimental results based on the quenching temperature shows that the best quenching temperature that agrees well with the theoretical model Hashin-Shtrikman is 20 °C.

  15. Conducting polymer-based multilayer films for instructive biomaterial coatings

    PubMed Central

    Hardy, John G; Li, Hetian; Chow, Jacqueline K; Geissler, Sydney A; McElroy, Austin B; Nguy, Lindsey; Hernandez, Derek S; Schmidt, Christine E

    2015-01-01

    Aim: To demonstrate the design, fabrication and testing of conformable conducting biomaterials that encourage cell alignment. Materials & methods: Thin conducting composite biomaterials based on multilayer films of poly(3.4-ethylenedioxythiophene) derivatives, chitosan and gelatin were prepared in a layer-by-layer fashion. Fibroblasts were observed with fluorescence microscopy and their alignment (relative to the dipping direction and direction of electrical current passed through the films) was determined using ImageJ. Results: Fibroblasts adhered to and proliferated on the films. Fibroblasts aligned with the dipping direction used during film preparation and this was enhanced by a DC current. Conclusion: We report the preparation of conducting polymer-based films that enhance the alignment of fibroblasts on their surface which is an important feature of a variety of tissues. PMID:28031928

  16. Intrinsic electrical conductivity of nanostructured metal-organic polymer chains

    PubMed Central

    Hermosa, Cristina; Vicente Álvarez, Jose; Azani, Mohammad-Reza; Gómez-García, Carlos J.; Fritz, Michelle; Soler, Jose M.; Gómez-Herrero, Julio; Gómez-Navarro, Cristina; Zamora, Félix

    2013-01-01

    One-dimensional conductive polymers are attractive materials because of their potential in flexible and transparent electronics. Despite years of research, on the macro- and nano-scale, structural disorder represents the major hurdle in achieving high conductivities. Here we report measurements of highly ordered metal-organic nanoribbons, whose intrinsic (defect-free) conductivity is found to be 104 S m−1, three orders of magnitude higher than that of our macroscopic crystals. This magnitude is preserved for distances as large as 300 nm. Above this length, the presence of structural defects (~ 0.5%) gives rise to an inter-fibre-mediated charge transport similar to that of macroscopic crystals. We provide the first direct experimental evidence of the gapless electronic structure predicted for these compounds. Our results postulate metal-organic molecular wires as good metallic interconnectors in nanodevices. PMID:23591876

  17. Preparation and characterization of conducting polymer/silver hexacyanoferrate nanocomposite

    NASA Astrophysics Data System (ADS)

    de Azevedo, W. M.; de Mattos, I. L.; Navarro, M.; da Silva, E. F., Jr.

    2008-11-01

    In this work, we present an alternative route to prepare silver hexacyanoferrate(II)/polyaniline (PANI) composite thin films. Differently from the electrochemical method, used to synthesize the conducting polymer film on a electrode surface, this new chemical route makes use of dialysis membrane as a solid support to synthesize the silver hexacyanoferrate(III) compound, and subsequently uses this composite membrane as oxidizing agent to polymerize the aniline monomer. The spectroscopic (UV-vis and IR region) and electrochemical characterization (cyclic voltammetry) indicates that the polymeric composite remains optically active and conductive. The X-ray analysis shows that the composite membrane/Ag 3[Fe III(CN) 6] has an crystalline structure that can be assigned to the Ag 3[Fe III(CN) 6] structure, and after reaction with aniline solution it became less crystalline. Additionally the SEM measurements shown that the reaction of silver ions with hexacyanoferrate(III) across the membrane results in a well defined and aliened Ag 3[Fe III(CN) 6] crystals and when this crystalline compound reacts with aniline monomer silver wire of 100 nm of diameter by 6 μm longer are formed together with the conducting polymer polyaniline/Ag x[Fe II(CN) 6] composite.

  18. Hierarchical nanostructured conducting polymer hydrogel with high electrochemical activity

    PubMed Central

    Pan, Lijia; Yu, Guihua; Zhai, Dongyuan; Lee, Hye Ryoung; Zhao, Wenting; Liu, Nian; Wang, Huiliang; Tee, Benjamin C.-K.; Shi, Yi; Cui, Yi; Bao, Zhenan

    2012-01-01

    Conducting polymer hydrogels represent a unique class of materials that synergizes the advantageous features of hydrogels and organic conductors and have been used in many applications such as bioelectronics and energy storage devices. They are often synthesized by polymerizing conductive polymer monomer within a nonconducting hydrogel matrix, resulting in deterioration of their electrical properties. Here, we report a scalable and versatile synthesis of multifunctional polyaniline (PAni) hydrogel with excellent electronic conductivity and electrochemical properties. With high surface area and three-dimensional porous nanostructures, the PAni hydrogels demonstrated potential as high-performance supercapacitor electrodes with high specific capacitance (∼480 F·g-1), unprecedented rate capability, and cycling stability (∼83% capacitance retention after 10,000 cycles). The PAni hydrogels can also function as the active component of glucose oxidase sensors with fast response time (∼0.3 s) and superior sensitivity (∼16.7 μA·mM-1). The scalable synthesis and excellent electrode performance of the PAni hydrogel make it an attractive candidate for bioelectronics and future-generation energy storage electrodes. PMID:22645374

  19. Conducting-polymer-driven actively shaped propellers and screws

    NASA Astrophysics Data System (ADS)

    Madden, John D.; Schmid, Bryan; Lafontaine, Serge R.; Madden, Peter G. A.; Hover, Franz S.; McLetchie, Karl; Hunter, Ian W.

    2003-07-01

    Conducting polymer actuators are employed to create actively shaped hydrodynamic foils. The active foils are designed to allow control over camber, much like the ailerons of an airplane wing. Control of camber promises to enable variable thrust in propellers and screws, increased maneuverability, and improved stealth. The design and fabrication of the active foils are presented, the forces are measured and operation is demonstrated both in still air and water. The foils have a "wing" span of 240 mm, and an average chord length (width) of 70 mm. The trailing 30 mm of the foil is composed of a thin polypyrrole actuator that curls chordwise to achieve variable camber. The actuator consists of two 30 μm thick sheets of hexafluorophosphate doped polypyrrole separated from each other by a gel electrolyte. A polymer layer encapsulates the entire structure. Potentials are applied between the polymer layers to induce reversible bending by approximately 35 degrees, and generating forces of 0.15 N. These forces and displacements are expected to enable operation in water at flow rates of > 1 m/s and ~ 30 m/s in air.

  20. All-solid-state reference electrodes based on conducting polymers.

    PubMed

    Kisiel, Anna; Marcisz, Honorata; Michalska, Agata; Maksymiuk, Krzysztof

    2005-12-01

    A novel construction of solution free (pseudo)reference electrodes, compatible with all-solid-state potentiometric indicator electrodes, has been proposed. These electrodes use conducting polymers (CP): polypyrrole (PPy) or poly(3,4-ethylenedioxythiophene) (PEDOT). Two different arrangements have been tested: solely based on CP and those where the CP phase is covered with a poly(vinyl chloride) based outer membrane of tailored composition. The former arrangement was designed to suppress or compensate cation- and anion-exchange, using mobile perchlorate ions and poly(4-styrenesulfonate) or dodecylbenzenesulfonate anions as immobilized dopants. The following systems were used: (i) polypyrrole layers doped simultaneously by two kinds of anions, both mobile and immobilized in the polymer layer; (ii) bilayers of polypyrrole with anion exchanging inner layer and cation-exchanging outer layer; (iii) polypyrrole doped by surfactant dodecylbenzenesulfonate ions, which inhibit ion exchange on the polymer/solution interface. For the above systems, recorded potentials have been found to be practically independent of electrolyte concentration. The best results, profound stability of potentials, have been obtained for poly(3,4-ethylenedioxythiophene) or polypyrrole doped by poly(4-styrenesulfonate) anions covered by a poly(vinyl chloride) based membrane, containing both anion- and cation-exchangers as well as solid potassium chloride and silver chloride with metallic silver. Differently to the cases (i)-(iii) these electrodes are much less sensitive to the influence of redox and pH interferences. This arrangement has been also characterized using electrochemical impedance spectroscopy and chronopotentiometry.

  1. 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

  2. Lifetime of biomolecules in polymer-based hybrid nanodevices

    NASA Astrophysics Data System (ADS)

    Brunner, Christian; Ernst, Karl-Heinz; Hess, Henry; Vogel, Viola

    2004-10-01

    Prolonging the lifetime of biomolecules in their functional states is critical for many applications where biomolecules are integrated into synthetic materials or devices. A simplified molecular shuttle system, which consists of fluorescently labelled microtubules propelled by kinesin motor proteins bound to the surface of a flowcell, served here as a model system to probe the lifetime of a hybrid device. In this system, the functional decay can easily be assayed by utilizing optical microscopy to detect motility and disintegration of microtubules. We found that the lifetimes of these hybrid systems were mainly limited by the stability of microtubules (MTs), rather than of kinesin. To determine the biocompatibility of polymers widely used in microfabrication, we assembled flowcells with glass bottom surfaces and covers fabricated from glass, poly(urethane) (PU), poly(methyl-methacrylate) (PMMA), poly(dimethylsiloxane) (PDMS) and ethylene-vinyl alcohol copolymer (EVOH). Without illumination, only PU had a substantial negative impact on MT stability, while PMMA, PDMS and EVOH showed stabilities comparable to glass. Under the influence of light, however, the MTs degraded rapidly in the presence of PDMS or PMMA, even in the presence of oxygen scavengers. A similar effect was observed on glass if oxygen scavengers were not added to the medium. Strong bleaching of the fluorophores was again only found on the polymer substrates and photobleaching coincided with an accelerated depolymerization of the MTs.

  3. Perspective: Outstanding theoretical questions in polymer-nanoparticle hybrids

    NASA Astrophysics Data System (ADS)

    Kumar, Sanat K.; Ganesan, Venkat; Riggleman, Robert A.

    2017-07-01

    This topical review discusses the theoretical progress made in the field of polymer nanocomposites, i.e., hybrid materials created by mixing (typically inorganic) nanoparticles (NPs) with organic polymers. It primarily focuses on the outstanding issues in this field and is structured around five separate topics: (i) the synthesis of functionalized nanoparticles; (ii) their phase behavior when mixed with a homopolymer matrix and their assembly into well-defined superstructures; (iii) the role of processing on the structures realized by these hybrid materials and the role of the mobilities of the different constituents; (iv) the role of external fields (electric, magnetic) in the active assembly of the NPs; and (v) the engineering properties that result and the factors that control them. While the most is known about topic (ii), we believe that significant progress needs to be made in the other four topics before the practical promise offered by these materials can be realized. This review delineates the most pressing issues on these topics and poses specific questions that we believe need to be addressed in the immediate future.

  4. Synthesis and applications of electrically conducting polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Ku, Bon-Cheol

    This research focuses on the synthesis and applications of electrically conducting polymer nanocomposites through molecular self-assembly. Two different classes of polymers, polyaniline (PANI) and polyacetylenes have been synthesized by biomimetic catalysis and spontaneous polymerization method. For gas barrier materials, commercially available polymers, poly(allylamine hydrochloride) (PAH) and poly (acrylic acid) (PAA), have also been used and thermally cross-linked. The morphological, optical and electrical properties of amphiphilic polyacetylenes have been studied. Furthermore, barrier properties, permselectivity, pervaporation properties of polyacetylenes/aluminosilicate nanocomposites have been investigated. For processability and electrical properties of carbon nanotube and conducting polymers, substituted ionic polyacetylenes (SIPA) have been covalently incorporated onto single-walled carbon nanotubes (SWNT) using the "grafting-from" technique. In the first study, a nanocomposite film catalyst has been prepared by electrostatic layer-by-layer (ELBL) self-assembly of a polyelectrolyte and a biomimetic catalyst for synthesis of polyaniline. Poly(dimethyl diallylammonium chloride) (PDAC) and hematin have been used as polycation and counter anions, respectively. The absorption spectra by UV-vis-NIR spectroscopy showed that conductive form polyaniline was formed not only as a coating on the surface of the ELBL composites but was also formed in solution. Furthermore, it was found that the reaction rate was affected by pH and concentration of hematin in the multilayers. The feasibility of controlled desorption of hematin molecules from the LBL assembly was explored and demonstrated by changing the pH and hematin concentration. The polymerization rate of aniline in solution was enhanced with decreasing pH of the solutions due to increased desorption of hematin nanoparticles from the multilayers. These ELBL hematin assemblies demonstrated both a way to functionalize

  5. Conducting polymer transistors making use of activated carbon gate electrodes.

    PubMed

    Tang, Hao; Kumar, Prajwal; Zhang, Shiming; Yi, Zhihui; Crescenzo, Gregory De; Santato, Clara; Soavi, Francesca; Cicoira, Fabio

    2015-01-14

    The characteristics of the gate electrode have significant effects on the behavior of organic electrochemical transistors (OECTs), which are intensively investigated for applications in the booming field of organic bioelectronics. In this work, high specific surface area activated carbon (AC) was used as gate electrode material in OECTs based on the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) doped with poly(styrenesulfonate) (PSS). We found that the high specific capacitance of the AC gate electrodes leads to high drain-source current modulation in OECTs, while their intrinsic quasi-reference characteristics make unnecessary the presence of an additional reference electrode to monitor the OECT channel potential.

  6. Conductive polymer sensor arrays for smart orthopaedic implants

    NASA Astrophysics Data System (ADS)

    Micolini, Carolina; Holness, F. B.; Johnson, James A.; Price, Aaron D.

    2017-04-01

    This study proposes and demonstrates the design, implementation, and characterization of a 3D-printed smartpolymer sensor array using conductive polyaniline (PANI) structures embedded in a polymeric substrate. The piezoresistive characteristics of PANI were studied to evaluate the efficacy of the manufacturing of an embedded pressure sensor. PANI's stability throughout loading and unloading cycles together with the response to incremental loading cycles was investigated. It is demonstrated that this specially developed multi-material additive manufacturing process for polyaniline is a good candidate for the manufacture of implant components with smart-polymer sensors embedded for the analysis of joint loads in orthopaedic implants.

  7. Fabrication and characterization of solid-state, conducting polymer actuators

    SciTech Connect

    Xie, J.; Sansinena, J. M.; Gao, J.; Wang, H. L.

    2004-01-01

    We report here the fabrication and characterization of solid-state, conducting polymer actuators. The electrochemical activity of polyaniline (PANI) thin film coated with solid-state polyelectrolyte is very similar to the polyaniline thin film in an aqueous solution. The solid-state actuator is adhere to a lever arm of an force transducer and the force generation is measured in real time. The force generated by the actuator is found to be length dependent. However, the overall torques generated by the actuators with different lengths remains essentially the same. The effect of stimulation signals such as voltage, current, on the bending angle and displacement is also studied using square wave potential.

  8. Two-dimensional transition metal dichalcogenide/conducting polymer composites: synthesis and applications.

    PubMed

    Sajedi-Moghaddam, Ali; Saievar-Iranizad, Esmaiel; Pumera, Martin

    2017-06-22

    The exploration of hybridizing transition metal dichalcogenide (TMD) nanosheets with other materials as a unique approach for engineering their properties has attracted considerable attention from the scientific community for both basic studies and numerous potential applications. Among the various kinds of functional materials in hand, the utilization of intrinsically conducting polymers (CPs) in the construction of advanced hybrid composites with TMD nanosheets is considered as a fascinating approach. In this review, we aim at providing a survey of the literature on recent progress in composites based on 2D TMD and CPs. In this regard, we first discuss the different synthetic strategies used for the fabrication of two-dimensional transition metal dichalcogenide/conducting polymer (2D TMD/CP) composites in detail. Subsequently, we demonstrate the state-of-the-art advances in the utilization of these novel composites in promising applications such as energy storage, sensing devices, hydrogen production and so on. Finally, we also highlight some perspectives on the major challenges and future directions in this field of research.

  9. Development of novel multifunctional biobased polymer composites with tailored conductive network of micro-and-nano-fillers

    NASA Astrophysics Data System (ADS)

    Leung, Siu N.; Ghaffari, Shahriar; Naguib, Hani E.

    2013-04-01

    Biobased/green polymers and nanotechnology warrant a multidisciplinary approach to promote the development of the next generation of materials, products, and processes that are environmentally sustainable. The scientific challenge is to find the suitable applications, and thereby to create the demand for large scale production of biobased/green polymers that would foster sustainable development of these eco-friendly materials in contrast to their petroleum/fossil fuel derived counterparts. In this context, this research aims to investigate the synergistic effect of green materials and nanotechnology to develop a new family of multifunctional biobased polymer composites with promoted thermal conductivity. For instance, such composite can be used as a heat management material in the electronics industry. A series of parametric studies were conducted to elucidate the science behind materials behavior and their structure-toproperty relationships. Using biobased polymers (e.g., polylactic acid (PLA)) as the matrix, heat transfer networks were developed and structured by embedding hexagonal boron nitride (hBN) and graphene nanoplatelets (GNP) in the PLA matrix. The use of hybrid filler system, with optimized material formulation, was found to promote the composite's effective thermal conductivity by 10-folded over neat PLA. This was achieved by promoting the development of an interconnected thermally conductive network through structuring hybrid fillers. The thermally conductive composite is expected to afford unique opportunities to injection mold three-dimensional, net-shape, lightweight, and eco-friendly microelectronic enclosures with superior heat dissipation performance.

  10. Enhancement in ionic conductivity on solid polymer electrolytes containing large conducting species

    SciTech Connect

    Praveen, D.; Damle, Ramakrishna

    2016-05-23

    Solid Polymer Electrolytes (SPEs) lack better conducting properties at ambient temperatures. Various methods to enhance their ionic conductivity like irradiation with swift heavy ions, γ-rays, swift electrons and quenching at low temperature etc., have been explored in the literature. Among these, one of the oldest methods is incorporation of different conducting species into the polymer matrix and/or addition of nano-sized inert particles into SPEs. Various new salts like LiBr, Mg(ClO{sub 4}){sub 2}, NH{sub 4}I etc., have already been tried in the past with some success. Also various nanoparticles like Al{sub 2}O{sub 3}, TiO{sub 2} etc., have been tried in the past. In this article, we have investigated an SPE containing Rubidium as a conducting species. Rubidium has a larger ionic size compared to lithium and sodium ions which have been investigated in the recent past. In the present article, we have investigated the conductivity of large sized conducting species and shown the enhancement in the ionic conductivity by addition of nano-sized inert particles.

  11. High Efficiency Hybrid Silicon Nanopillar-Polymer Solar Cells

    PubMed Central

    Pudasaini, Pushpa Raj; Ruiz-Zepeda, Francisco; Sharma, Manisha; Elam, David; Ponce, Arturo; Ayon, Arturo A

    2014-01-01

    Recently, inorganic/organic hybrid solar cells have been considered as a viable alternative for low-cost photovoltaic devices because the Schottky junction between inorganic and organic materials can be formed employing low temperature processing methods. We present an efficient hybrid solar cell based on highly ordered silicon nanopillars (SiNPs) and poly (3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS). The proposed device is formed by spin coating the organic polymer PEDOT:PSS on a SiNP array fabricated using metal assisted electroless chemical etching process. The characteristics of the hybrid solar cells are investigated as a function of SiNP height. A maximum power conversion efficiency (PCE) of 9.65% has been achieved for an optimized SiNP array hybrid solar cell with nanopillar height of 400 nm, despite the absence of a back surface field enhancement. The effect of an ultrathin atomic layer deposition (ALD), grown aluminum oxide (Al2O3), as a passivation layer (recombination barrier) has also been studied for the enhanced electrical performance of the device. With the inclusion of the ultrathin ALD deposited Al2O3 between the SiNP array textured surface and the PEDOT:PSS layer, the PCE of the fabricated device was observed to increase to 10.56%, which is ~10% greater than the corresponding device without the Al2O3 layer. The device described herein is considered to be promising toward the realization of a low-cost, high-efficiency inorganic/organic hybrid solar cell. PMID:24032746

  12. High efficiency hybrid silicon nanopillar-polymer solar cells.

    PubMed

    Pudasaini, Pushpa Raj; Ruiz-Zepeda, Francisco; Sharma, Manisha; Elam, David; Ponce, Arturo; Ayon, Arturo A

    2013-10-09

    Recently, inorganic/organic hybrid solar cells have been considered as a viable alternative for low-cost photovoltaic devices because the Schottky junction between inorganic and organic materials can be formed employing low temperature processing methods. We present an efficient hybrid solar cell based on highly ordered silicon nanopillars (SiNPs) and poly(3,4-ethylene-dioxythiophene):polystyrenesulfonate (PEDOT:PSS). The proposed device is formed by spin coating the organic polymer PEDOT:PSS on a SiNP array fabricated using metal assisted electroless chemical etching process. The characteristics of the hybrid solar cells are investigated as a function of SiNP height. A maximum power conversion efficiency (PCE) of 9.65% has been achieved for an optimized SiNP array hybrid solar cell with nanopillar height of 400 nm, despite the absence of a back surface field enhancement. The effect of an ultrathin atomic layer deposition (ALD), grown aluminum oxide (Al2O3), as a passivation layer (recombination barrier) has also been studied for the enhanced electrical performance of the device. With the inclusion of the ultrathin ALD deposited Al2O3 between the SiNP array textured surface and the PEDOT:PSS layer, the PCE of the fabricated device was observed to increase to 10.56%, which is ∼10% greater than the corresponding device without the Al2O3 layer. The device described herein is considered to be promising toward the realization of a low-cost, high-efficiency inorganic/organic hybrid solar cell.

  13. Absorption modulation of FSS-polymer nanocomposites through incorporation of conductive nanofillers

    NASA Astrophysics Data System (ADS)

    Jaiswar, Rajkumar; Danlée, Yann; Mesfin, Henok; Delcorte, Arnaud; Hermans, Sophie; Bailly, Christian; Raskin, Jean-Pierre; Huynen, Isabelle

    2017-03-01

    The hybrid concept of utilizing frequency selective surface (FSS) and polymer nanocomposite (PNC) for absorption modulation is presented in 8-18 GHz frequency band. The extruded PNCs are fabricated by incorporating different weight% fraction of conductive fillers, namely carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs), in high, low and mixed nano-filler concentration in a polycarbonate matrix. The FSS metallic resonator is patterned over a dielectric substrate which lies on grounded PNCs. It was found that absorption depends on wt% fraction of conductive inclusions in polycarbonate matrix, i.e., variation in conductivity of grounded PNCs due to varying concentration of conductive fillers results in modulation of absorption. Peaks of nearly 100% magnitude of absorption and modulated absorption band are observed at 8.2 GHz, and between 12 and 18 GHz frequency bands, respectively, by varying conductivity of polymer composite. We demonstrate here that the bandwidth and magnitude of absorption can be fixed by the combination of SSRs (for limits of the band) and concentrations in nanofillers (for intensity of absorption).

  14. Conductivity in organic semiconductors hybridized with the vacuum field

    NASA Astrophysics Data System (ADS)

    Orgiu, E.; George, J.; Hutchison, J. A.; Devaux, E.; Dayen, J. F.; Doudin, B.; Stellacci, F.; Genet, C.; Schachenmayer, J.; Genes, C.; Pupillo, G.; Samorì, P.; Ebbesen, T. W.

    2015-11-01

    Much effort over the past decades has been focused on improving carrier mobility in organic thin-film transistors by optimizing the organization of the material or the device architecture. Here we take a different path to solving this problem, by injecting carriers into states that are hybridized to the vacuum electromagnetic field. To test this idea, organic semiconductors were strongly coupled to plasmonic modes to form coherent states that can extend over as many as 105 molecules and should thereby favour conductivity. Experiments show that indeed the current does increase by an order of magnitude at resonance in the coupled state, reflecting mostly a change in field-effect mobility. A theoretical quantum model confirms the delocalization of the wavefunctions of the hybridized states and its effect on the conductivity. Our findings illustrate the potential of engineering the vacuum electromagnetic environment to modify and to improve properties of materials.

  15. Coating of zinc ferrite particles with a conducting polymer, polyaniline.

    PubMed

    Stejskal, Jaroslav; Trchová, Miroslava; Brodinová, Jitka; Kalenda, Petr; Fedorova, Svetlana V; Prokes, Jan; Zemek, Josef

    2006-06-01

    Particles of zinc ferrite, ZnOFe2O3, were coated with polyaniline (PANI) phosphate during the in situ polymerization of aniline in an aqueous solution of phosphoric acid. The PANI-ferrite composites were characterized by FTIR spectroscopy. X-ray photoelectron spectroscopy was used to determine the degree of coating with a conducting polymer. Even a low content of PANI, 1.4 wt%, resulted in the 45% coating of the particles' surface. On the other hand, even at high PANI content, the coating of ferrite surface did not exceeded 90%. This is explained by the clustering of hydrophobic aniline oligomers at the hydrophilic ferrite surface and the consequent irregular PANI coating. The conductivity increased from 2 x 10(-9) to 6.5 S cm(-1) with increasing fraction of PANI phosphate in the composite. The percolation threshold was located at 3-4 vol% of the conducting component. In the absence of any acid, a conducting product, 1.4 x 10(-2) Scm(-1), was also obtained. As the concentration of phosphoric acid increased to 3 M, the conductivity of the composites reached 1.8 S cm(-1) at 10-14 wt% of PANI. The ferrite alone can act as an oxidant for aniline; a product having a conductivity 0.11 S cm(-1) was obtained after a one-month immersion of ferrite in an acidic solution of aniline.

  16. Electrical Conductivity in Polymer Blends/ Multiwall Carbon Nanotubes

    SciTech Connect

    Kulkarni, Ajit R.; Bose, Suryasarathi; Bhattacharyya, Arup R.

    2008-10-23

    Carbon nanotubes (CNT) based polymer composites have emerged as the future multifunctional materials in view of its exceptional mechanical, thermal and electrical properties. One of the major interests is to develop conductive polymer composites preferably at low concentration of CNT utilizing their high aspect ratio (L/D) for numerous applications, which include antistatic devices, capacitors and materials for EMI shielding. In this context, polymer blends have emerged as a potential candidate in lowering the percolation thresholds further by the utilization of 'double-percolation' which arises from the synergistic improvements in blend properties associated with the co-continuous morphology. Due to strong inter-tube van der Waals' forces, they often tend to aggregate and uniform dispersion remains a challenge. To overcome this challenge, we exploited sodium salt of 6-aminohexanoic acid (Na-AHA) which was able to assist in debundlling the multiwall carbon nanotubes (MWNT) through 'cation-{pi}' interactions during melt-mixing leading to percolative 'network-like' structure of MWNT within polyamide6 (PA6) phase in co-continuous PA6/acrylonitrile butadiene styrene (ABS) blends. The composite exhibited low electrical percolation thresholds of 0.25 wt% of MWNT, the lowest reported value in this system so far. Retention of 'network-like structure' in the solid state with significant refinement was observed even at lower MWNT concentration in presence Na-AHA, which was assessed through AC electrical conductivity measurements. Reactive coupling was found to be a dominant factor besides 'cation-{pi}' interactions in achieving low electrical percolation in PA6/ABS+MWNT composites.

  17. Nanocomposites of iridium oxide and conducting polymers as electroactive phases in biological media.

    PubMed

    Moral-Vico, J; Sánchez-Redondo, S; Lichtenstein, M P; Suñol, C; Casañ-Pastor, N

    2014-05-01

    Much effort is currently devoted to implementing new materials in electrodes that will be used in the central nervous system, either for functional electrostimulation or for tests on nerve regeneration. Their main aim is to improve the charge capacity of the electrodes, while preventing damaging secondary reactions, such as peroxide formation, occurring while applying the electric field. Thus, hybrids may represent a new generation of materials. Two novel hybrid materials are synthesized using three known biocompatible materials tested in the neural system: polypyrrole (PPy), poly(3,4-ethylenedioxythiophene) (PEDOT) and iridium oxide (IrO2). In particular, PPy-IrO2 and PEDOT-IrO2 hybrid nanocomposite materials are prepared by chemical polymerization in hydrothermal conditions, using IrO2 as oxidizing agent. The reaction yields a significant ordered new hybrid where the conducting polymer is formed around the IrO2 nanoparticles, encapsulating them. Scanning electron microscopy and backscattering techniques show the extent of the encapsulation. Both X-ray photoelectron and Fourier transform infrared spectroscopies identify the components of the phases, as well as the absence of impurities. Electrochemical properties of the final phases in powder and pellet form are evaluated by cyclic voltammetry. Biocompatibility is tested with MTT toxicity tests using primary cultures of cortical neurons grown in vitro for 6 and 9days. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  18. A novel 3D sandwich structure of hybrid graphite nanosheets and silver nanowires as fillers for improved thermal conductivity

    NASA Astrophysics Data System (ADS)

    Zhuang, Xiao; Zhou, Yongcun; Liu, Feng

    2017-01-01

    We explored a novel 3D sandwich structure of fillers in the polymer matrix to enhance thermal conductivity. A variety of fillers in the polymer matrix play a significant role in the physical properties of the composite. Fillers containing particle and line structures are popular, and enhance the thermal and electrical conductivities. Therefore, filler-based matrix network improves conductivity. We propose a sandwich structure consisting of hybrid graphite nanosheets (two dimensions), and silver nanowires (AgNWs) (one dimension), to create a 3D sandwich structure of polyimide matrix with improved thermal conductivity. Surface treatment of graphite and silver nanowires were conducted to reduce the dielectric constant of the composite. We designed the filler of 20 wt% resulting in a high thermal conductivity of 3.21 W m-1 K-1 with 15% C@SiO2 and 5% AgNWs@SiO2 filler loading. The novel combination and structure markedly enhanced the thermal conductivity of the composite.

  19. 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.

  20. Hybrid Thin Films Based Upon Polyoxometalates-Polymer Assembly

    NASA Astrophysics Data System (ADS)

    Qi, Na; Jing, Benxin; Zhu, Yingxi

    2014-03-01

    Block copolymers (BCPs) and polyoxometalates (POMs) have been used individually as building blocks for design and synthesis of novel functional materials. POM nanoclusters, the assemblies of transition metal oxides with well-defined atomic coordination structure, have been recently explored as novel nanomaterials... for catalysis, semiconductors, and even anti-cancer treatment due to their unique chemical, optical and electrical characteristics. We have explored the blending of inorganic POM nanocluster with BCPs into hierarchaically structured inorganic-organic hybrid nanocomposites. Using polystyrene-b-poly(ethylene oxide) (PS-b-PEO) thin films as the template, we have observed that the spatial organization of BCP thin films is modified by molybdenum based POM nanocluster to form 2D in-plane hexagonal ordered or 3D ordered network of POM-BCP assemblies, depending on the concentration ratio of POM to PS-b-PEO. The dielectric properties of such hybrid thin films can be enhanced by embedded POMs but show a strong dependence on the supramolecular structures of POM-polymer complexes. The assembly of nanoclusters in BCP-templated thin films could pave a new path to design new hybrid nanocomposites with uniquely combined functionality and material properties.

  1. Rechargeable aluminum batteries with conducting polymers as positive electrodes.

    SciTech Connect

    Hudak, Nicholas S.

    2013-12-01

    This report is a summary of research results from an Early Career LDRD project con-ducted from January 2012 to December 2013 at Sandia National Laboratories. Demonstrated here is the use of conducting polymers as active materials in the posi-tive electrodes of rechargeable aluminum-based batteries operating at room tempera-ture. The battery chemistry is based on chloroaluminate ionic liquid electrolytes, which allow reversible stripping and plating of aluminum metal at the negative elec-trode. Characterization of electrochemically synthesized polypyrrole films revealed doping of the polymers with chloroaluminate anions, which is a quasi-reversible reac-tion that facilitates battery cycling. Stable galvanostatic cycling of polypyrrole and polythiophene cells was demonstrated, with capacities at near-theoretical levels (30-100 mAh g-1) and coulombic efficiencies approaching 100%. The energy density of a sealed sandwich-type cell with polythiophene at the positive electrode was estimated as 44 Wh kg-1, which is competitive with state-of-the-art battery chemistries for grid-scale energy storage.

  2. Tetraarylborate polymer networks as single-ion conducting solid electrolytes

    SciTech Connect

    Van Humbeck, Jeffrey F.; Aubrey, Michael L.; Alsbaiee, Alaaeddin; Ameloot, Rob; Coates, Geoffrey W.; Dichtel, William R.; Long, Jeffrey R.

    2015-06-23

    A new family of solid polymer electrolytes based upon anionic tetrakis(phenyl)borate tetrahedral nodes and linear bis-alkyne linkers is reported. Sonogashira polymerizations using tetrakis(4-iodophenyl)borate, tetrakis(4-iodo-2,3,5,6-tetrafluorophenyl)borate and tetrakis(4-bromo-2,3,5,6-tetrafluorophenyl)borate delivered highly cross-linked polymer networks with both 1,4-diethynylbeznene and a tri(ethylene glycol) substituted derivative. Promising initial conductivity metrics have been observed, including high room temperature conductivities (up to 2.7 × 10-4 S cm-1), moderate activation energies (0.25–0.28 eV), and high lithium ion transport numbers (up to tLi+ = 0.93). Initial investigations into the effects of important materials parameters such as bulk morphology, porosity, fluorination, and other chemical modification, provide starting design parameters for further development of this new class of solid electrolytes.

  3. Nanostructured conducting polymers for stiffness controlled cell adhesion

    NASA Astrophysics Data System (ADS)

    Moyen, Eric; Hama, Adel; Ismailova, Esma; Assaud, Loic; Malliaras, George; Hanbücken, Margrit; Owens, Roisin M.

    2016-02-01

    We propose a facile and reproducible method, based on ultra thin porous alumina membranes, to produce cm2 ordered arrays of nano-pores and nano-pillars on any kind of substrates. In particular our method enables the fabrication of conducting polymers nano-structures, such as poly[3,4-ethylenedioxythiophene]:poly[styrene sulfonate] (PEDOT:PSS). Here, we demonstrate the potential interest of those templates with controlled cell adhesion studies. The triggering of the eventual fate of the cell (proliferation, death, differentiation or migration) is mediated through chemical cues from the adsorbed proteins and physical cues such as surface energy, stiffness and topography. Interestingly, as well as through material properties, stiffness modifications can be induced by nano-topography, the ability of nano-pillars to bend defining an effective stiffness. By controlling the diameter, length, depth and material of the nano-structures, one can possibly tune the effective stiffness of a (nano) structured substrate. First results indicate a possible change in the fate of living cells on such nano-patterned devices, whether they are made of conducting polymer (soft material) or silicon (hard material).

  4. An amperometric acetylcholine biosensor based on a conducting polymer.

    PubMed

    Kanik, Fulya Ekiz; Kolb, Marit; Timur, Suna; Bahadir, Müfit; Toppare, Levent

    2013-08-01

    An amperometric acetylcholine biosensor was prepared by the generation of the conducting polymer poly(4-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)benzenamine) (poly(SNS-NH2)) on graphite electrodes. For pesticide detection, the enzymes acetylcholinesterase (AChE) and choline oxidase (ChO) were co-immobilized onto the conducting polymer poly(SNS-NH2) films using covalent binding technique. Electrochemical polymerization was carried out using a three-electrode cell configuration via cyclic voltammetry. Characterization of resulting acetylcholine biosensor was done in terms of optimum pH, enzyme loading, range of linear response and shelf-life. Linear range was 0.12-10mM and shelf-life 4 weeks. Sensitivity was calculated as 2.19μAmM(-1)cm(-2). The designed biosensor was tested for the determination of paraoxon-ethyl in spiked tap water samples. The results were compared with a conventional quantification method using HPLC-DAD. Linear correlation of the quantification results with both methods (R(2)=0.998) was obtained. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Tetraarylborate polymer networks as single-ion conducting solid electrolytes

    DOE PAGES

    Van Humbeck, Jeffrey F.; Aubrey, Michael L.; Alsbaiee, Alaaeddin; ...

    2015-06-23

    A new family of solid polymer electrolytes based upon anionic tetrakis(phenyl)borate tetrahedral nodes and linear bis-alkyne linkers is reported. Sonogashira polymerizations using tetrakis(4-iodophenyl)borate, tetrakis(4-iodo-2,3,5,6-tetrafluorophenyl)borate and tetrakis(4-bromo-2,3,5,6-tetrafluorophenyl)borate delivered highly cross-linked polymer networks with both 1,4-diethynylbeznene and a tri(ethylene glycol) substituted derivative. Promising initial conductivity metrics have been observed, including high room temperature conductivities (up to 2.7 × 10-4 S cm-1), moderate activation energies (0.25–0.28 eV), and high lithium ion transport numbers (up to tLi+ = 0.93). Initial investigations into the effects of important materials parameters such as bulk morphology, porosity, fluorination, and other chemical modification, provide starting design parameters for furthermore » development of this new class of solid electrolytes.« less

  6. Voltage-induced electroluminescence characteristics of hybrid light-emitting diodes with CdSe/Cd/ZnS core-shell nanoparticles embedded in a conducting polymer on plastic substrates

    SciTech Connect

    Kwak, Kiyeol; Cho, Kyoungah E-mail: sangsig@korea.ac.kr; Kim, Sangsig E-mail: sangsig@korea.ac.kr

    2014-03-10

    We investigate the electroluminescence (EL) characteristics of a hybrid light-emitting diode (HyLED) with an emissive layer comprised of CdSe/Cd/ZnS core-shell nanoparticles (NPs) embedded in poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PFO) on a plastic substrate. The EL characteristics change dramatically with increasing of the biased voltage. At low voltages, recombination of electrons and holes occurs only in the PFO film because of poor charge transfer in the PFO-CdSe/Cd/ZnS NPs composite film, while the color of the light-emitting from the HyLED changes from blue to red as the biased voltage increases from 7.5 to 17.5 V. We examine and discuss the mechanism of this color tunability.

  7. Electronically conductive polymer binder for lithium-ion battery electrode

    DOEpatents

    Liu, Gao; Battaglia, Vincent S.; Park, Sang -Jae

    2015-10-06

    A family of carboxylic acid groups containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. Triethyleneoxide side chains provide improved adhesion to materials such as, graphite, silicon, silicon alloy, tin, tin alloy. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  8. Electronically conductive polymer binder for lithium-ion battery electrode

    DOEpatents

    Liu, Gao; Xun, Shidi; Battaglia, Vincent S.; Zheng, Honghe; Wu, Mingyan

    2015-07-07

    A family of carboxylic acid groups containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. Triethyleneoxide side chains provide improved adhesion to materials such as, graphite, silicon, silicon alloy, tin, tin alloy. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  9. Multiscale Modeling of Thermal Conductivity of Polymer/Carbon Nanocomposites

    NASA Technical Reports Server (NTRS)

    Clancy, Thomas C.; Frankland, Sarah-Jane V.; Hinkley, Jeffrey A.; Gates, Thomas S.

    2010-01-01

    Molecular dynamics simulation was used to estimate the interfacial thermal (Kapitza) resistance between nanoparticles and amorphous and crystalline polymer matrices. Bulk thermal conductivities of the nanocomposites were then estimated using an established effective medium approach. To study functionalization, oligomeric ethylene-vinyl alcohol copolymers were chemically bonded to a single wall carbon nanotube. The results, in a poly(ethylene-vinyl acetate) matrix, are similar to those obtained previously for grafted linear hydrocarbon chains. To study the effect of noncovalent functionalization, two types of polyethylene matrices. -- aligned (extended-chain crystalline) vs. amorphous (random coils) were modeled. Both matrices produced the same interfacial thermal resistance values. Finally, functionalization of edges and faces of plate-like graphite nanoparticles was found to be only modestly effective in reducing the interfacial thermal resistance and improving the composite thermal conductivity

  10. Electronically conductive polymer binder for lithium-ion battery electrode

    DOEpatents

    Liu, Gao; Xun, Shidi; Battaglia, Vincent S.; Zheng, Honghe; Wu, Mingyan

    2017-08-01

    A family of carboxylic acid groups containing fluorene/fluorenon copolymers is disclosed as binders of silicon particles in the fabrication of negative electrodes for use with lithium ion batteries. Triethyleneoxide side chains provide improved adhesion to materials such as, graphite, silicon, silicon alloy, tin, tin alloy. These binders enable the use of silicon as an electrode material as they significantly improve the cycle-ability of silicon by preventing electrode degradation over time. In particular, these polymers, which become conductive on first charge, bind to the silicon particles of the electrode, are flexible so as to better accommodate the expansion and contraction of the electrode during charge/discharge, and being conductive promote the flow battery current.

  11. Metalated hybrid polymers as catalytic reagents for phosphate ester hydrolysis and plasmid modification.

    PubMed

    Chandrasekhar, Vadapalli; Deria, Pravas; Krishnan, Venkatasubbaiah; Athimoolam, Arunachalampillai; Singh, Sanjay; Madhavaiah, C; Srivatsan, S G; Verma, Sandeep

    2004-03-22

    Pendant pyrazolylcyclophosphazene containing hybrid cross-linked polymer (CPPL) has been utilized for binding Zn(II). The metalated polymer (CPPL-Zn) has been found to be very effective catalyst for the hydrolysis of a RNA model phosphodiester substrate [2-(hydroxypropyl)-p-nitrophenyl phosphate, hNPP]. In addition, CPPL-Zn also cleaved supercoiled plasmid DNA pBR322 thus providing a novel structural motif of inorganic-organic hybrid polymers as synthetic nucleases.

  12. Hybrid integrated photonic components based on a polymer platform

    NASA Astrophysics Data System (ADS)

    Eldada, Louay A.

    2003-06-01

    We report on a polymer-on-silicon optical bench platform that enables the hybrid integration of elemental passive and active optical functions. Planar polymer circuits are produced photolithographically, and slots are formed in them for the insertion of chips and films of a variety of materials. The polymer circuits provide interconnects, static routing elements such as couplers, taps, and multi/demultiplexers, as well as thermo-optically dynamic elements such as switches, variable optical attenuators, and tunable notch filters. Crystal-ion-sliced thin films of lithium niobate are inserted in the polymer circuit for polarization control or for electro-optic modulation. Films of yttrium iron garnet and neodymium iron boron magnets are inserted in order to magneto-optically achieve non-reciprocal operation for isolation and circulation. Indium phosphide and gallium arsenide chips are inserted for light generation, amplification, and detection, as well as wavelength conversion. The functions enabled by this multi-material platform span the range of the building blocks needed in optical circuits, while using the highest-performance material system for each function. We demonstrated complex-functionality photonic components based on this technology, including a metro ring node module and a tunable optical transmitter. The metro ring node chip includes switches, variable optical attenuators, taps, and detectors; it enables optical add/drop multiplexing, power monitoring, and automatic load balancing, and it supports shared and dedicated protection protocols in two-fiber metro ring optical networks. The tunable optical transmitter chip includes a tunable external cavity laser, an isolator, and a high-speed modulator.

  13. Formation of conductive polymers using nitrosyl ion as an oxidizing agent

    SciTech Connect

    Choi, Kyoung-Shin; Jung, Yongju; Singh, Nikhilendra

    2016-06-07

    A method of forming a conductive polymer deposit on a substrate is disclosed. The method may include the steps of preparing a composition comprising monomers of the conductive polymer and a nitrosyl precursor, contacting the substrate with the composition so as to allow formation of nitrosyl ion on the exterior surface of the substrate, and allowing the monomer to polymerize into the conductive polymer, wherein the polymerization is initiated by the nitrosyl ion and the conductive polymer is deposited on the exterior surface of the substrate. The conductive polymer may be polypyrrole.

  14. Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications.

    PubMed

    Kádár, Roland; Abbasi, Mahdi; Figuli, Roxana; Rigdahl, Mikael; Wilhelm, Manfred

    2017-01-24

    The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate) (EBA) nanocomposite hybrids containing graphite nanoplatelets (GnP) and carbon black (CB). The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests.

  15. Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

    PubMed Central

    Kádár, Roland; Abbasi, Mahdi; Figuli, Roxana; Rigdahl, Mikael; Wilhelm, Manfred

    2017-01-01

    The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate) (EBA) nanocomposite hybrids containing graphite nanoplatelets (GnP) and carbon black (CB). The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests. PMID:28336857

  16. Controlling the electrical conductive network formation of polymer nanocomposites via polymer functionalization.

    PubMed

    Gao, Yangyang; Wu, Youping; Liu, Jun; Zhang, Liqun

    2016-12-06

    By adopting coarse-grained molecular dynamics simulations, the effect of polymer functionalization on the relationship between the microstructure and the electric percolation probability of nanorod filled polymer nanocomposites has been investigated. At a low chain functionalization degree, the nanorods in the polymer matrix form isolated aggregates with a local order structure. At a moderate chain functionalization degree, the local order structure of the nanorod aggregate is gradually broken up. Meanwhile, excessive functionalization chain beads can connect the isolated aggregates together, which leads to the maximum size of nanorod aggregation. At a high chain functionalization degree, it forms a single nanorod structure in the matrix. As a result, the highest percolation probability of the materials appears at the moderate chain functionalization degree, which is attributed to the formation of the tightly connected nanorod network by analyzing the main cluster. In addition, this optimum chain functionalization degree exists at two chain functionalization modes (random and diblock). Lastly, under the tensile field, even though the contact distance between nanorods nearly remains unchanged, the topological structure of the percolation network is broken down. While under the shear field, the contact distance between nanorods increases and the topological structure of the percolation network is broken down, which leads to a decrease in the percolation probability. In total, the topological structure of the percolation network dominates the percolation probability, which is not a necessary connection with the contact distance between nanorods. In summary, this work presents further understanding of the electric conductive properties of nanorod-filled nanocomposites with functionalized polymers.

  17. Conducting polymers on non-conducting substrates: Chemical coating processes and applications

    NASA Astrophysics Data System (ADS)

    Geniès, Eugène M.

    1996-01-01

    The presentation will be as follows: —Historical background —Oxidizing polymerization mechanism of heterocycles and aromatic compounds: the cases of pyrrole and anilin —The processes: solute, gas phase and from conducting polymer solutions —The substrates: glass, polymers, inorganic materials, textiles, powders. —Properties of coatings: —Chemical properties: redox, acid-base —Properties resulting from the polymer doping counter-ion —Physical properties: : optical, magnetic, conducting, microwave absorption —Stability —Applications: optics, microelectronics, sensors, electrochrome glasses, electromagnetic and antistatic shielding, military applications, packaging for electronic components, biocompat- ibility, plasturgy. —Commercial applications throughout the world. How to obtain these materials —Conclusions The examples will be taken from the results of our laboratory, those of CEA-Direction des Technologies Avancées—Centre d'Etudes et de Recherche sur les Matériaux—Centre d'Etudes Nucléaires de Grenoble (Mssrs R. Jolly and J. C. Thiéblemont), from the Milliken Research Corp. (Dr. H. H. Kuhn), from the Zipperlin Kessler company (Dr. B. Wessling), from the Americhem company and from I.B.M. (Dr. M. Angelopoulos).

  18. Conducting polymers on non-conducting substrates: Chemical coating processes and applications

    SciTech Connect

    Genies, E.M.

    1996-01-01

    The presentation will be as follows: {emdash}Historical background {emdash}Oxidizing polymerization mechanism of heterocycles and aromatic compounds: the cases of pyrrole and anilin {emdash}The processes: solute, gas phase and from conducting polymer solutions {emdash}The substrates: glass, polymers, inorganic materials, textiles, powders. {emdash}Properties of coatings: {emdash}Chemical properties: redox, acid-base {emdash}Properties resulting from the polymer doping counter-ion {emdash}Physical properties: : optical, magnetic, conducting, microwave absorption {emdash}Stability {emdash}Applications: optics, microelectronics, sensors, electrochrome glasses, electromagnetic and antistatic shielding, military applications, packaging for electronic components, biocompat- ibility, plasturgy. {emdash}Commercial applications throughout the world. How to obtain these materials {emdash}Conclusions The examples will be taken from the results of our laboratory, those of CEA-Direction des Technologies Avanc{acute e}es{emdash}Centre d{close_quote}Etudes et de Recherche sur les Mat{acute e}riaux{emdash}Centre d{close_quote}Etudes Nucl{acute e}aires de Grenoble (Mssrs R. Jolly and J. C. Thi{acute e}blemont), from the Milliken Research Corp. (Dr. H. H. Kuhn), from the Zipperlin Kessler company (Dr. B. Wessling), from the Americhem company and from I.B.M. (Dr. M. Angelopoulos). {copyright} {ital 1996 American Institute of Physics.}

  19. Conductive polymer combined silk fiber bundle for bioelectrical signal recording.

    PubMed

    Tsukada, Shingo; Nakashima, Hiroshi; Torimitsu, Keiichi

    2012-01-01

    Electrode materials for recording biomedical signals, such as electrocardiography (ECG), electroencephalography (EEG) and evoked potentials data, are expected to be soft, hydrophilic and electroconductive to minimize the stress imposed on living tissue, especially during long-term monitoring. We have developed and characterized string-shaped electrodes made from conductive polymer with silk fiber bundles (thread), which offer a new biocompatible stress free interface with living tissue in both wet and dry conditions.An electroconductive polyelectrolyte, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) was electrochemically combined with silk thread made from natural Bombyx mori. The polymer composite 280 µm thread exhibited a conductivity of 0.00117 S/cm (which corresponds to a DC resistance of 2.62 Mohm/cm). The addition of glycerol to the PEDOT-PSS silk thread improved the conductivity to 0.102 S/cm (20.6 kohm/cm). The wettability of PEDOT-PSS was controlled with glycerol, which improved its durability in water and washing cycles. The glycerol treated PEDOT-PSS silk thread showed a tensile strength of 1000 cN in both wet and dry states. Without using any electrolytes, pastes or solutions, the thread directly collects electrical signals from living tissue and transmits them through metal cables. ECG, EEG, and sensory evoked potential (SEP) signals were recorded from experimental animals by using this thread placed on the skin. PEDOT-PSS silk glycerol composite thread offers a new class of biocompatible electrodes in the field of biomedical and health promotion that does not induce stress in the subjects.

  20. Conductive Polymer Combined Silk Fiber Bundle for Bioelectrical Signal Recording

    PubMed Central

    Tsukada, Shingo; Nakashima, Hiroshi; Torimitsu, Keiichi

    2012-01-01

    Electrode materials for recording biomedical signals, such as electrocardiography (ECG), electroencephalography (EEG) and evoked potentials data, are expected to be soft, hydrophilic and electroconductive to minimize the stress imposed on living tissue, especially during long-term monitoring. We have developed and characterized string-shaped electrodes made from conductive polymer with silk fiber bundles (thread), which offer a new biocompatible stress free interface with living tissue in both wet and dry conditions. An electroconductive polyelectrolyte, poly(3,4-ethylenedioxythiophene) -poly(styrenesulfonate) (PEDOT-PSS) was electrochemically combined with silk thread made from natural Bombyx mori. The polymer composite 280 µm thread exhibited a conductivity of 0.00117 S/cm (which corresponds to a DC resistance of 2.62 Mohm/cm). The addition of glycerol to the PEDOT-PSS silk thread improved the conductivity to 0.102 S/cm (20.6 kohm/cm). The wettability of PEDOT-PSS was controlled with glycerol, which improved its durability in water and washing cycles. The glycerol treated PEDOT-PSS silk thread showed a tensile strength of 1000 cN in both wet and dry states. Without using any electrolytes, pastes or solutions, the thread directly collects electrical signals from living tissue and transmits them through metal cables. ECG, EEG, and sensory evoked potential (SEP) signals were recorded from experimental animals by using this thread placed on the skin. PEDOT-PSS silk glycerol composite thread offers a new class of biocompatible electrodes in the field of biomedical and health promotion that does not induce stress in the subjects. PMID:22493670

  1. Applications of multifunctional polymer-matrix composites in hybrid heat sinks

    NASA Astrophysics Data System (ADS)

    Leung, Siu N.; Khan, Omer M.; Naguib, Hani E.; Dawson, Francis; Adinkrah, Vincent

    2012-04-01

    Designers of electronic devices and telecommunications equipment have used three-dimensional chip architecture, comprised of a vertically integrated stack of chips, to increase the number of transistors on integrated circuits. These latest chips generate excessive amount of heat, and thus can reach unacceptably high temperatures. In this context, this research aims to develop thermally conductive liquid crystal polymer (LCP)/hexagonal boron nitride (hBN) composite films to replace the traditionally-used Kapton films that satisfy the electrical insulation requirements for the attachment of heat sinks to the chips without compromising the heat dissipation performance. Parametric study was conducted to elucidate the effects of hBN contents on the heat dissipation ability of the composite. The performance of the hybrid heat sinks were experimentally simulated by measuring the temperature distribution of the hybrid heat sinks attached to a 10 W square-faced (i.e., 10 cm by 10 cm) heater. Experimental simulation show that the maximum temperature of the heater mounted with a hybrid heat sink reduced with increased hBN content. It is believed the fibrillation of LCP matrix leads to highly ordered structure, promoting heat dissipation ability of the electrically insulating pad of the hybrid heat sink.

  2. Submicron magnetic core conducting polypyrrole polymer shell: Preparation and characterization.

    PubMed

    Tenório-Neto, Ernandes Taveira; Baraket, Abdoullatif; Kabbaj, Dounia; Zine, Nadia; Errachid, Abdelhamid; Fessi, Hatem; Kunita, Marcos Hiroiuqui; Elaissari, Abdelhamid

    2016-04-01

    Magnetic particles are of great interest in various biomedical applications, such as, sample preparation, in vitro biomedical diagnosis, and both in vivo diagnosis and therapy. For in vitro applications and especially in labs-on-a-chip, microfluidics, microsystems, or biosensors, the needed magnetic dispersion should answer various criteria, for instance, submicron size in order to avoid a rapid sedimentation rate, fast separations under an applied magnetic field, and appreciable colloidal stability (stable dispersion under shearing process). Then, the aim of this work was to prepare highly magnetic particles with a magnetic core and conducting polymer shell particles in order to be used not only as a carrier, but also for the in vitro detection step. The prepared magnetic seed dispersions were functionalized using pyrrole and pyrrole-2-carboxylic acid. The obtained core-shell particles were characterized in terms of particle size, size distribution, magnetization properties, FTIR analysis, surface morphology, chemical composition, and finally, the conducting property of those particles were evaluated by cyclic voltammetry. The obtained functional submicron highly magnetic particles are found to be conducting material bearing function carboxylic group on the surface. These promising conducting magnetic particles can be used for both transport and lab-on-a-chip detection.

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

    SciTech Connect

    Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan; Lantz, Kevin R.

    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 work 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.

  4. Inkjet printed organic electrochemical transistors with highly conducting polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Afonso, Mónica; Morgado, Jorge; Alcácer, Luís

    2016-10-01

    Organic Electrochemical Transistors (OECTs) were fabricated with two kinds of highly conducting polymer electrolytes, one with cations of small dimensions (Li+) and the other with cations of large dimensions (1-ethyl-3-methylimidazolium, EMI+). All OECTs exhibit transconductance values in the millisiemens range. Those with the larger EMI+ cations reach higher transconductance values and the saturated region of their I(V) characteristics extends to drain negative voltages of the order of -2 V without breakdown. These OECTs aim at potential applications for which it is relevant to use a solid polymer electrolyte instead of an aqueous electrolyte, namely, for integration in complex devices or in sensors and transducers where the electrolyte film may act as a membrane to prevent direct contact of the active material (PEDOT:PSS) with the biological media. The choice of electrolytes with cations of disparate sizes aims at assessing the nature (Faradaic or capacitive) of the processes occurring at the electrolyte/channel interface. The results obtained are consistent with a Faradaic-based operation mechanism.

  5. High rechargeable sodium metal-conducting polymer batteries

    NASA Astrophysics Data System (ADS)

    Guerfi, A.; Trottier, J.; Gagnon, C.; Barray, F.; Zaghib, K.

    2016-12-01

    Rechargeable lithium batteries accelerated the wireless revolution over the last two decades, and they are now a mature technology for transportation applications in electric vehicles (EV). However, numerous studies have concluded that the proven lithium reserves can hardly absorb the growth in demand. Therefore, sustainable sodium batteries are being considered to overcome the lithium resource shortages that may arise from large-scale application in EVs and stationary energy storage. It is difficult to find a suitable host material for reversible Na-ion storage due to the size of the Na+ ion (0.102 nm) compared to the Li+ ion (0.076 nm). Here we report a low cost and simple sodium technology that is based on a metal-free cathode material. Sodium metal was used as the anode with a conducting polymer cathode and electrochemically tested in a liquid electrolyte. With this technology, a host material for Na intercalation is not required, and because a polymer conductor is used, the size of the Na ion is not an issue.

  6. Amine-functionalized polypyrrole: Inherently cell adhesive conducting polymer.

    PubMed

    Lee, Jae Y; Schmidt, Christine E

    2015-06-01

    Electrically conducting polymers (CPs) have been recognized as novel biomaterials that can electrically communicate with biological systems. For their tissue engineering applications, CPs have been modified to promote cell adhesion for improved interactions between biomaterials and cells/tissues. Conventional approaches to improve cell adhesion involve the surface modification of CPs with biomolecules, such as physical adsorption of cell adhesive proteins and polycationic polymers, or their chemical immobilization; however, these approaches require additional multiple modification steps with expensive biomolecules. In this study, as a simple and effective alternative to such additional biomolecule treatment, we synthesized amine-functionalized polypyrrole (APPy) that inherently presents cell adhesion-supporting positive charges under physiological conditions. The synthesized APPy provides electrical activity in a moderate range and a hydrophilic surface compared to regular polypyrrole (PPy) homopolymers. Under both serum and serum-free conditions, APPy exhibited superior attachment of human dermal fibroblasts and Schwann cells compared to PPy homopolymer controls. Moreover, Schwann cell adhesion onto the APPy copolymer was at least similar to that on poly-l-lysine treated PPy controls. Our results indicate that amine-functionalized CP substrates will be useful to achieve good cell adhesion and potentially electrically stimulate various cells. In addition, amine functionality present on CPs can further serve as a novel and flexible platform to chemically tether various bioactive molecules, such as growth factors, antibodies, and chemical drugs. © 2014 Wiley Periodicals, Inc.

  7. 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.

  8. Reciprocated suppression of polymer crystallization toward improved solid polymer electrolytes: Higher ion conductivity and tunable mechanical properties

    SciTech Connect

    Bi, Sheng; Sun, Che-Nan; Zawodzinski, Thomas A.; Ren, Fei; Keum, Jong Kahk; Ahn, Suk-Kyun; Li, Dawen; Chen, Jihua

    2015-08-06

    Solid polymer electrolytes based on lithium bis(trifluoromethanesulfonyl) imide and polymer matrix were extensively studied in the past due to their excellent potential in a broad range of energy related applications. Poly(vinylidene fluoride) (PVDF) and polyethylene oxide (PEO) are among the most examined polymer candidates as solid polymer electrolyte matrix. In this paper, we study the effect of reciprocated suppression of polymer crystallization in PVDF/PEO binary matrix on ion transport and mechanical properties of the resultant solid polymer electrolytes. With electron and X-ray diffractions as well as energy filtered transmission electron microscopy, we identify and examine the appropriate blending composition that is responsible for the diminishment of both PVDF and PEO crystallites. Laslty, a three-fold conductivity enhancement is achieved along with a highly tunable elastic modulus ranging from 20 to 200 MPa, which is expected to contribute toward future designs of solid polymer electrolytes with high room-temperature ion conductivities and mechanical flexibility.

  9. Enhanced thermal-mechanical properties of polymer composites with hybrid boron nitride nanofillers

    NASA Astrophysics Data System (ADS)

    Yan, Haiyan; Tang, Yanxia; Su, Juling; Yang, Xiaoyan

    2014-02-01

    The present work focuses on the investigation of the thermal-mechanical properties of the epoxy composites with hybrid boron nitride nanotubes (BNNTs) and boron nitride nanosheets (BNNSs). The stable dispersions of BNNTs-BNNSs were achieved by a noncovalent functionalization with pyrene carboxylic acid. The resulting epoxy/BNNTs-BNNSs composites exhibited homogeneously dispersed BNNTs-BNNSs and a strong filler-matrix interface interaction. The composites showed a 95 % increase in thermal conductivity and a 57 % improvement in Young's modulus by addition of only 1 vol. % BNNTs-BNNSs. Meanwhile, the composites also retained a high electrical resistance of pure epoxy. Our study thus shows the potential for hybrid BNNTs-BNNSs to be successfully used as the nanofillers of polymer composites for applications in electrically insulating thermal interface materials.

  10. Fabrication and characterization of solid state conducting polymer actuators

    NASA Astrophysics Data System (ADS)

    Xie, Jian; Sansinena, Jose-Maria; Gao, Junbo; Wang, Hsing-Lin

    2004-07-01

    We report here the fabrication and characterization of solid-state conducting polymer actuators. The electrochemical activity of polyaniline (PANI) thin film coated with solid-state polyelectrolyte is very similar to the polyaniline thin film in an aqueous solution. The solid-state actuator is adhered to a lever arm of a force transducer and the force generation is measured in real time. The force generated by the actuator is found to be length dependent. However, the overall torque generated by the actuators with different lengths remains essentially the same. The effect of stimulation signals such as voltage, and current, on the bending angle and displacement is also studied using square wave potential.

  11. Conductive polymer-based microextraction methods: a review.

    PubMed

    Bagheri, Habib; Ayazi, Zahra; Naderi, Mehrnoush

    2013-03-12

    Conductive polymers (CPs) are classified as materials which exhibit highly reversible redox behavior and the unusual combined properties of metal and plastics. CPs, due to their multifunctionality, ease of synthesis and their stability, have attracted more attentions in different fields of research, including sample preparation. CPs along with several commercial hydrophilic sorbents, are alternative to the commercially available hydrophobic sorbents which despite their high specific surface areas, have poor interactions and retentions in the extraction of polar compounds. This review covers a general overview regarding the recent progress and new applications of CPs toward their synthesis and use in novel extraction and microextraction techniques including solid phase microextraction (SPME), electrochemically controlled solid-phase microextraction (EC-SPME) and other relevant techniques. Furthermore the contribution of nano-structured CPs in these methodologies is also reviewed.

  12. Porous palladium coated conducting polymer nanoparticles for ultrasensitive hydrogen sensors.

    PubMed

    Lee, Jun Seop; Kim, Sung Gun; Cho, Sunghun; Jang, Jyongsik

    2015-12-28

    Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl(2)) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm) and stability toward hydrogen gas at room temperature due to the palladium sensing layer.

  13. Applications of conducting polymers and their issues in biomedical engineering

    PubMed Central

    Ravichandran, Rajeswari; Sundarrajan, Subramanian; Venugopal, Jayarama Reddy; Mukherjee, Shayanti; Ramakrishna, Seeram

    2010-01-01

    Conducting polymers (CPs) have attracted much interest as suitable matrices of biomolecules and have been used to enhance the stability, speed and sensitivity of various biomedical devices. Moreover, CPs are inexpensive, easy to synthesize and versatile because their properties can be readily modulated by (i) surface functionalization techniques and (ii) the use of a wide range of molecules that can be entrapped or used as dopants. This paper discusses the various surface modifications of the CP that can be employed in order to impart physico-chemical and biological guidance cues that promote cell adhesion/proliferation at the polymer–tissue interface. This ability of the CP to induce various cellular mechanisms widens its applications in medical fields and bioengineering. PMID:20610422

  14. Conducting Polymers for Neural Prosthetic and Neural Interface Applications

    PubMed Central

    2015-01-01

    Neural interfacing devices are an artificial mechanism for restoring or supplementing the function of the nervous system lost as a result of injury or disease. Conducting polymers (CPs) are gaining significant attention due to their capacity to meet the performance criteria of a number of neuronal therapies including recording and stimulating neural activity, the regeneration of neural tissue and the delivery of bioactive molecules for mediating device-tissue interactions. CPs form a flexible platform technology that enables the development of tailored materials for a range of neuronal diagnostic and treatment therapies. In this review the application of CPs for neural prostheses and other neural interfacing devices are discussed, with a specific focus on neural recording, neural stimulation, neural regeneration, and therapeutic drug delivery. PMID:26414302

  15. Development of bioactive conducting polymers for neural interfaces.

    PubMed

    Poole-Warren, Laura; Lovell, Nigel; Baek, Sungchul; Green, Rylie

    2010-01-01

    Bioelectrodes for neural recording and neurostimulation are an integral component of a number of neuroprosthetic devices, including the commercially available cochlear implant, and developmental devices, such as the bionic eye and brain-machine interfaces. Current electrode designs limit the application of such devices owing to suboptimal material properties that lead to minimal interaction with the target neural tissue and the formation of fibrotic capsules. In designing an ideal bioelectrode, a number of design criteria must be considered with respect to physical, mechanical, electrical and biological properties. Conducting polymers have the potential to address the synergistic interaction of these properties and show promise as superior coatings for next-generation electrodes in implant devices.

  16. Conductive Polymer Porous Film with Tunable Wettability and Adhesion

    PubMed Central

    Teng, Yuqi; Zhang, Yuqi; Heng, Liping; Meng, Xiangfu; Yang, Qiaowen; Jiang, Lei

    2015-01-01

    A conductive polymer porous film with tunable wettability and adhesion was fabricated by the chloroform solution of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyricacid-methyl-ester (PCBM) via the freeze drying method. The porous film could be obtained from the solution of 0.8 wt%, whose pore diameters ranged from 50 nm to 500 nm. The hydrophobic porous surface with a water contact angle (CA) of 144.7° could be transferred into a hydrophilic surface with CA of 25° by applying a voltage. The water adhesive force on the porous film increased with the increase of the external voltage. The electro-controllable wettability and adhesion of the porous film have potential application in manipulating liquid collection and transportation. PMID:28788033

  17. Conducting Polymers for Neural Prosthetic and Neural Interface Applications.

    PubMed

    Green, Rylie; Abidian, Mohammad Reza

    2015-12-09

    Neural-interfacing devices are an artificial mechanism for restoring or supplementing the function of the nervous system, lost as a result of injury or disease. Conducting polymers (CPs) are gaining significant attention due to their capacity to meet the performance criteria of a number of neuronal therapies including recording and stimulating neural activity, the regeneration of neural tissue and the delivery of bioactive molecules for mediating device-tissue interactions. CPs form a flexible platform technology that enables the development of tailored materials for a range of neuronal diagnostic and treatment therapies. In this review, the application of CPs for neural prostheses and other neural interfacing devices is discussed, with a specific focus on neural recording, neural stimulation, neural regeneration, and therapeutic drug delivery.

  18. Controlled synthesis of transition metal/conducting polymer nanocomposites.

    PubMed

    Liu, Zhen; Liu, Yang; Zhang, Lin; Poyraz, Selcuk; Lu, Ning; Kim, Moon; Smith, James; Wang, Xiaolong; Yu, Yajiao; Zhang, Xinyu

    2012-08-24

    A novel displacement reaction has been observed to occur between conducting polymers (CP) and metal salts which can be used to fabricate nanostructured CP-metal composites in a one-pot manner. Vanadium pentoxide (V(2)O(5)) nanofiber is used during the synthesis as the reactive seeds to induce the nanofibril CP-metal network formation. The CP-metal nanocomposites exhibit excellent sensory properties for hydrogen peroxide (H(2)O(2)) detection, where both high sensitivity and a low detection limit can be obtained. The sensory performance of the CP-metal composite can be further enhanced by a facile microwave treatment. It is believed that the CP-metal nanofibril network can be converted to a carbon-metal network by a microwave-induced carbonization process and result in the sensory enhancement.

  19. Controlled synthesis of transition metal/conducting polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Liu, Zhen; Liu, Yang; Zhang, Lin; Poyraz, Selcuk; Lu, Ning; Kim, Moon; Smith, James; Wang, Xiaolong; Yu, Yajiao; Zhang, Xinyu

    2012-08-01

    A novel displacement reaction has been observed to occur between conducting polymers (CP) and metal salts which can be used to fabricate nanostructured CP-metal composites in a one-pot manner. Vanadium pentoxide (V 2O5) nanofiber is used during the synthesis as the reactive seeds to induce the nanofibril CP-metal network formation. The CP-metal nanocomposites exhibit excellent sensory properties for hydrogen peroxide (H2O2) detection, where both high sensitivity and a low detection limit can be obtained. The sensory performance of the CP-metal composite can be further enhanced by a facile microwave treatment. It is believed that the CP-metal nanofibril network can be converted to a carbon-metal network by a microwave-induced carbonization process and result in the sensory enhancement.

  20. Moving beyond mass-based parameters for conductivity analysis of sulfonated polymers

    SciTech Connect

    Kim, Yu Seung; Pivovar, Bryan

    2009-01-01

    Proton conductivity of polymer electrolytes is critical for fuel cells and has therefore been studied in significant detail. The conductivity of sulfonated polymers has been linked to material characteristics in order to elucidate trends. Mass based measurements based on water uptake and ion exchange capacity are two of the most common material characteristics used to make comparisons between polymer electrolytes, but have significant limitations when correlated to proton conductivity. These limitations arise in part because different polymers can have significantly different densities and conduction happens over length scales more appropriately represented by volume measurements rather than mass. Herein, we establish and review volume related parameters that can be used to compare proton conductivity of different polymer electrolytes. Morphological effects on proton conductivity are also considered. Finally, the impact of these phenomena on designing next generation sulfonated polymers for polymer electrolyte membrane fuel cells is discussed.

  1. Conductive paper from lignocellulose wood microfibers coated with a nanocomposite of carbon nanotubes and conductive polymers

    NASA Astrophysics Data System (ADS)

    Agarwal, Mangilal; Xing, Qi; Shim, Bong Sup; Kotov, Nicholas; Varahramyan, Kody; Lvov, Yuri

    2009-05-01

    Composite nanocoating of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) and aqueous dispersion of carbon nanotubes (CNT-PSS) on lignocellulose wood microfibers has been developed to make conductive microfibers and paper sheets. To construct the multilayers on wood microfibers, cationic poly(ethyleneimine) (PEI) has been used in alternate deposition with anionic conductive PEDOT-PSS and solubilized CNT-PSS. Using a Keithley microprobe measurement system, current-voltage measurements have been carried out on single composite microfibers after deposition of each layer to optimize the electrical properties of the coated microfibers. The conductivity of the resultant wood microfibers was in the range of 10-2-2 S cm-1 depending on the architecture of the coated layer. Further, the conductivity of the coated wood microfibers increased up to 20 S cm-1 by sandwiching multilayers of conductive co-polymer PEDOT-PSS with CNT-PSS through a polycation (PEI) interlayer. Moreover, paper hand sheets were manufactured from these coated wood microfibers with conductivity ranging from 1 to 20 S cm-1. A paper composite structure consisting of conductive/dielectric/conductive layers that acts as a capacitor has also been fabricated and is reported.

  2. DC-conductivity and magnetoresistance of inherently conducting polymers. Polyacetylene and poly(3-alkylthiophenes)

    NASA Astrophysics Data System (ADS)

    Vaekiparta, K.

    Inherently conducting polymers with optimal charge transport properties lie in the vicinity of the M-I transition. The most powerful demonstration of this is potassium-doped highly conducting polyacetylene (room temperature dc-conductivity 3000-4000 S/cm), the dc-conductivity of which shows a temperature dependence (power law) in perfect accordance with the theory for a material in the critical intermediate regime of the M-I transition. As suggested by earlier research, iodine doped polyacetylene (doped to the maximum of room temperature conductivity, 1 to 100,000 S/cm) is on the metallic side of the M-I transition. Based on de-conductivity and magnetoresistance measurements, this work confirms the dominating role of weak localization effects on the charge transport in the temperature regime 2-60 K, and suggest that electron-electron interactions play an important role below 2 K. Ferric chloride doped poly(3-alkylthiophenes) (P3OT and P3HT, with room temperature conductivities 30-160 S/cm) show a temperature behavior of dc-conductivity due to localized charge carriers and are therefore on the insulating side of the M-I transition.

  3. Conductive paper from lignocellulose wood microfibers coated with a nanocomposite of carbon nanotubes and conductive polymers.

    PubMed

    Agarwal, Mangilal; Xing, Qi; Shim, Bong Sup; Kotov, Nicholas; Varahramyan, Kody; Lvov, Yuri

    2009-05-27

    Composite nanocoating of poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT-PSS) and aqueous dispersion of carbon nanotubes (CNT-PSS) on lignocellulose wood microfibers has been developed to make conductive microfibers and paper sheets. To construct the multilayers on wood microfibers, cationic poly(ethyleneimine) (PEI) has been used in alternate deposition with anionic conductive PEDOT-PSS and solubilized CNT-PSS. Using a Keithley microprobe measurement system, current-voltage measurements have been carried out on single composite microfibers after deposition of each layer to optimize the electrical properties of the coated microfibers. The conductivity of the resultant wood microfibers was in the range of 10(-2)-2 S cm(-1) depending on the architecture of the coated layer. Further, the conductivity of the coated wood microfibers increased up to 20 S cm(-1) by sandwiching multilayers of conductive co-polymer PEDOT-PSS with CNT-PSS through a polycation (PEI) interlayer. Moreover, paper hand sheets were manufactured from these coated wood microfibers with conductivity ranging from 1 to 20 S cm(-1). A paper composite structure consisting of conductive/dielectric/conductive layers that acts as a capacitor has also been fabricated and is reported.

  4. 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

  5. Modular and orthogonal synthesis of hybrid polymers and networks.

    PubMed

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

    2015-03-28

    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.

  6. Enhancing the Thermal Conductance of Polymer and Sapphire Interface via Self-Assembled Monolayer.

    PubMed

    Zheng, Kun; Sun, Fangyuan; Zhu, Jie; Ma, Yongmei; Li, Xiaobo; Tang, Dawei; Wang, Fosong; Wang, Xiaojia

    2016-08-23

    Interfacial thermal conductance (ITC) receives enormous consideration because of its significance in determining thermal performance of hybrid materials, such as polymer based nanocomposites. In this study, the ITC between sapphire and polystyrene (PS) was systematically investigated by time domain thermoreflectance (TDTR) method. Silane based self-assembled monolayers (SAMs) with varying end groups, -NH2, -Cl, -SH and -H, were introduced into sapphire/PS interface, and their effects on ITC were investigated. The ITC was found to be enhanced up by a factor of 7 through functionalizing the sapphire surface with SAM, which ends with a chloride group (-Cl). The results show that the enhancement of the thermal transport across the SAM-functionalized interface comes from both strong covalent bonding between sapphire and silane-based SAM, and the high compatibility between the SAM and PS. Among the SAMs studied in this work, we found that the ITC almost linearly depends on solubility parameters, which could be the dominant factor influencing on the ITC compared with wettability and adhesion. The SAMs serve as an intermediate layer that bridges the sapphire and PS. Such a feature can be applied to ceramic-polymer immiscible interfaces by functionalizing the ceramic surface with molecules that are miscible with the polymer materials. This research provides guidance on the design of critical-heat transfer materials such as composites and nanofluids for thermal management.

  7. Studies on the defluoridation of water using conducting polymer/montmorillonite composites.

    PubMed

    Karthikeyan, M; Kumar, K K Satheesh; Elango, K P

    2012-01-01

    Conducting polymer/inorganic hybrid composites have large surface areas, which makes the adsorbent properties of the polymer composites as good the constituents. Polyaniline/montmorilonite (PANi-MMT) and polypyrrole/montmorillonite (PPy-MMT) composites were prepared, characterized (Fourier transform infrared, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction patterns) and were employed as adsorbents for the removal of fluoride ions from aqueous solution by the batch sorption method. The spectral studies of the adsorbents before and after the adsorption are recorded to get better insight into the mechanism of the adsorption process. The results indicated that the removal of fluoride ions from water by these composites occurs via the combined effect of both the constituents, that is, through a physico-chemical mechanism. The amount of fluoride ion adsorbed by PANi-MMT and PPy-MMT at 30 degrees C is observed to be 2.3 and 5.1 mg g(-1), respectively, when compared to 0.77 and 2.66 mg g(-1), respectively, for the polymers alone. The Langmuir, Freundlich and Dubinin-Radushkevich isotherms were used to describe the adsorption equilibrium.

  8. PATTERN RECOGNITION STUDIES OF HALOGENATED ORGANIC COMPOUNDS USING CONDUCTING POLYMER SENSOR ARRAYS. (R825323)

    EPA Science Inventory

    Direct measurement of volatile and semivolatile halogenated organic compounds of environmental interest was carried out using arrays of conducting polymer sensors. Mathematical expressions of the sensor arrays using microscopic polymer network model is described. A classical, non...

  9. Intrinsically Conductive Polymer Fibers from Thermoplastic trans-1,4-Polyisoprene.

    PubMed

    Han, Peng; Zhang, Xiaohong; Qiao, Jinliang

    2016-05-17

    Herein, we report a new strategy to prepare conductive polymer fibers to overcome the insurmountable weakness of current conductive polymer fibers. First, special thermoplastic polymers are processed into polymer fibers using a conventional melt-spinning process, and then the nonconductive polymer fibers are converted into intrinsically conductive polymer fibers. Using this new strategy, intrinsically conductive polymer fibers have been prepared by melt spinning low-cost thermoplastic trans-1,4-polyisoprene and doping with iodine, which can be as fine as 0.01 mm, and the resistivity can be as low as 10(-2) Ω m. Moreover, it has been found that drawing can improve the orientation of trans-1,4-polyisoprene crystals in the fibers and, thus, the conductivity of the conductive polymer fibers. Therefore, conductive fibers with excellent conductivities can be prepared by large drawing ratios before doping. Such conductive polymer fibers with low cost could be used in textile, clothing, packing, and other fields, which would benefit both industry and daily life. The newly developed method also allows one to produce conductive polymers of any shape besides fibers for antistatic or conductive applications.

  10. Impedance characterization of epoxy composite containing conductive hybrid carbon fillers

    NASA Astrophysics Data System (ADS)

    Othman, Raja Nor; Tawil, Siti Nooraya; Zailan, Suhaila

    2017-08-01

    Epoxy composites containg carbon fillers are prepared in this work with an intention to characterise their electrical properties. The performance of electrical conductivity of epoxy composites is assessed by adding various loadings of conductive carbon fillers into the neat epoxy. First, Carbon Black (CB) was incorporated within epoxy matrix at several loadings. The increase in the specific conductivity of more than five orders of magnitude was observed between 3 wt. % and 4 wt.% CB loading, recorded at 10 kHz frequency. As such, the critical percolation loading, pc was recorded in between 3 wt.% and 4 wt.%. For the samples containing CB at loading 4 wt.% and above, the conductivity remains independent of the frequency, indicating a purely ohmic behaviour. It is also observed that the specific conductivity values can be altered by increasing the hardener stirring time up to 15 minutes, where the pc was successfully lowered down to < 3 wt. % It was further intended to study the hybrid effects by adding CNT to the composites. The conductivity data showed that the composite becomes frequency independent, even at 2 wt. % carbon loading (1 wt. % CB + 1 wt. % CNT), demonstrating the roles contributed by high aspect ratio conductive CNT in enhancing the formation of percolated path at much lower loading.

  11. Strain sensing conductive polymer composites: Sensitivity and stability

    NASA Astrophysics Data System (ADS)

    Deng, Hua; Du, Rongni; Duan, Linyan; Fu, Qiang

    2016-03-01

    The effect of conductive network morphology and interfacial interaction on the strain sensing capability of conductive polymer composites (CPCs) is thought as crucial. Nevertheless, the stability in strain sensing behavior has barely been investigated. Herein, the resistivity-strain behavior in terms of stability and sensitivity of CPCs based on poly(styrene-butadiene-styrene) (SBS) containing multiwalled carbon nanotubes (MWCNTs) are studied. It is shown that the preparation method has an important influence on the resistivity-strain behavior of these CPCs. The sensitivity increases with decreasing filler content for both composites under linear uniaxial strain, showing higher strain sensitivity near the percolation threshold. A higher and wider range of sensitivities is obtained for melt mixed SBS/MWCNT. Meanwhile, resistivity downward drifting and shoulder peaks are shown for composites from melt mixing under dynamic strain. Interestingly, linear relationships and reversible resistivity in every cycle are observed for composites from solution mixing, showing good electromechanical consistency, stability and durability. From the TEM, rheology, SEM, SAXS, Raman microscopy and analytical modeling studies, the difference in morphology is thought to be responsible for such resistivity-strain behavior. As more disordered and less densely packed conductive networks in melt mixed CPCs are more easily destroyed under strain, evenly distributed and densely packed networks in solution mixed CPCs are more stable during cyclic stretching. Finally, different human motions have been detected using these CPCs, demonstrating the potential application of these CPCs as movement sensors.

  12. Conductivity in zeolite-polymer composite membranes for PEMFCs

    NASA Astrophysics Data System (ADS)

    Sancho, T.; Soler, J.; Pina, M. P.

    Structured materials, such as zeolites can be candidates to be used as electrolytes in proton exchange membrane fuel cells (PEMFC) to substitute polymeric membranes, taking advantage of their higher chemical and thermal stability and their specific adsorption properties. The possibility to work at temperatures of nearly 150 °C would make easy the selection of the fuel, decreasing the influence of CO in the catalyst poisoning, and it would also improve the kinetics of the electrochemical reactions involved. In this work, four zeolites and related materials have been studied: mordenite, NaA zeolite, umbite and ETS-10. In special, the influence of relative humidity and temperature have been carefully explored. A conductivity cell was designed and built to measure in cross direction, by using the electrochemical impedance spectroscopy. The experimental system was validated using Nafion ® as a reference material by comparing the results with bibliography data. Samples were prepared by pressing the zeolite powders, with size of 1 μm on average, using polymer PVDF (10 wt.%) as a binder. The results here obtained, in spite of not reaching the absolute values of the Nafion ® ones, show a lower effect of the dehydration phenomenon on the conduction performance in the temperature range studied (from room temperature to 150 °C). This increase of the operation temperature range would give important advantages to the PEMFC. ETS-10 sample shows the best behaviour with respect to conductivity exhibiting an activation energy value comparable with reported for Nafion ® membrane.

  13. Ag-graphene hybrid conductive ink for writing electronics.

    PubMed

    Xu, L Y; Yang, G Y; Jing, H Y; Wei, J; Han, Y D

    2014-02-07

    With the aim of preparing a method for the writing of electronics on paper by the use of common commercial rollerball pens loaded with conductive ink, hybrid conductive ink composed of Ag nanoparticles (15 wt%) and graphene-Ag composite nanosheets (0.15 wt%) formed by depositing Ag nanoparticles (∼10 nm) onto graphene sheets was prepared for the first time. Owing to the electrical pathway effect of graphene and the decreased contact resistance of graphene junctions by depositing Ag nanoparticles (NPs) onto graphene sheets, the concentration of Ag NPs was significantly reduced while maintaining high conductivity at a curing temperature of 100 ° C. A typical resistivity value measured was 1.9 × 10(-7) Ω m, which is 12 times the value for bulk silver. Even over thousands of bending cycles or rolling, the resistance values of writing tracks only increase slightly. The stability and flexibility of the writing circuits are good, demonstrating the promising future of this hybrid ink and direct writing method.

  14. Ag-graphene hybrid conductive ink for writing electronics

    NASA Astrophysics Data System (ADS)

    Xu, L. Y.; Yang, G. Y.; Jing, H. Y.; Wei, J.; Han, Y. D.

    2014-02-01

    With the aim of preparing a method for the writing of electronics on paper by the use of common commercial rollerball pens loaded with conductive ink, hybrid conductive ink composed of Ag nanoparticles (15 wt%) and graphene-Ag composite nanosheets (0.15 wt%) formed by depositing Ag nanoparticles (˜10 nm) onto graphene sheets was prepared for the first time. Owing to the electrical pathway effect of graphene and the decreased contact resistance of graphene junctions by depositing Ag nanoparticles (NPs) onto graphene sheets, the concentration of Ag NPs was significantly reduced while maintaining high conductivity at a curing temperature of 100 ° C. A typical resistivity value measured was 1.9 × 10-7 Ω m, which is 12 times the value for bulk silver. Even over thousands of bending cycles or rolling, the resistance values of writing tracks only increase slightly. The stability and flexibility of the writing circuits are good, demonstrating the promising future of this hybrid ink and direct writing method.

  15. Magnetism in (Semi)Conducting Macrocycles of pi conjugated Polymers

    DTIC Science & Technology

    2016-12-09

    the investigation of potential magnetic properties of macrocycles of pi-conjugated polymers. This research was initially motivated by the observation ...the subsequently observed ferromagnetic hysteretic behavior at low temperature (T < 20k) in these polymers. Concomitantly nanoscopic doughnut...structures ( ~12 nm) in spincoated thin films of these polymers were observed by AFM. Interestingly the magnetic properties and doughnut structures are

  16. Understanding hopping transport and thermoelectric properties of conducting polymers

    NASA Astrophysics Data System (ADS)

    Ihnatsenka, S.; Crispin, X.; Zozoulenko, I. V.

    2015-07-01

    We calculate the conductivity σ and the Seebeck coefficient S for the phonon-assisted hopping transport in conducting polymers poly(3,4-ethylenedioxythiophene) or PEDOT, experimentally studied by Bubnova et al. [J. Am. Chem. Soc. 134, 16456 (2012)], 10.1021/ja305188r. We use the Monte Carlo technique as well as the semianalytical approach based on the transport energy concept. We demonstrate that both approaches show a good qualitative agreement for the concentration dependence of σ and S . At the same time, we find that the semianalytical approach is not in a position to describe the temperature dependence of the conductivity. We find that both Gaussian and exponential density of states (DOS) reproduce rather well the experimental data for the concentration dependence of σ and S giving similar fitting parameters of the theory. The obtained parameters correspond to a hopping model of localized quasiparticles extending over 2-3 monomer units with typical jumps over a distance of 3-4 units. The energetic disorder (broadening of the DOS) is estimated to be 0.1 eV. Using the Monte Carlo calculation we reproduce the activation behavior of the conductivity with the calculated activation energy close to the experimentally observed one. We find that for a low carrier concentration a number of free carriers contributing to the transport deviates strongly from the measured oxidation level. Possible reasons for this behavior are discussed. We also study the effect of the dimensionality on the charge transport by calculating the Seebeck coefficient and the conductivity for the cases of three-, two-, and one-dimensional motion.

  17. Complex impedance and conductivity of agar-based ion-conducting polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Nwanya, A. C.; Amaechi, C. I.; Udounwa, A. E.; Osuji, R. U.; Maaza, M.; Ezema, F. I.

    2015-04-01

    Agar-based electrolyte standing films with different salts and weak acids as ion and proton conductors were prepared and characterized by X-ray diffraction, UV-visible spectrophotometry, photoluminescence emission spectroscopy and electrochemical impedance spectroscopy. The salts used are lithium perchlorate (LiClO4) and potassium perchlorate (KClO4), while the weak acids used are acetic acid (CH3COOH) and lactic acid (C3H6O3). The values of the ion conductivity obtained for the agar-based polymer films are 6.54 × 10-8, 9.12 × 10-8, 3.53 × 10-8, 2.24 × 10-8 S/cm for the agar/acetic acid, agar/lactic acid, agar/LiClO4 and agar/KClO4 polymer films, respectively. As a function of temperature, the ion conductivity exhibits an Arrhenius behavior and the estimated activation energy is ≈0.1 eV for all the samples. The samples depicted high values of dielectric permittivity toward low frequencies which is due mostly to electrode polarization effect. The samples showed very high transparency (85-98 %) in the visible region, and this high transparency is one of the major requirements for application in electrochromic devices (ECD). The values of conductivity and activation energy obtained indicate that the electrolytes are good materials for application in ECD.

  18. Improved performance of Li hybrid solid polymer electrolyte cells

    NASA Astrophysics Data System (ADS)

    Nagasubramanian, G.; Bronstein, Lyudmila; Carini, John

    The seminal research by Wright et al. on polyethylene oxide (PEO) solid polymer electrolyte (SPE) generated intense interest in all solid-state rechargeable lithium batteries. Following this a number of researchers have studied the physical, electrical and transport properties of thin film PEO electrolyte containing Li salt. These studies have clearly identified the limitations of the PEO electrolyte. Chief among the limitations are a low cation transport number (t +), high crystallinity and segmental motion of the polymer chain, which carries the cation through the bulk electrolyte. While low t + leads to cell polarization and increase in cell resistance high T g reduces conductivity at and around room temperatures. For example, the conductivity of PEO electrolyte containing lithium salt is <10 -7 S cm -1 at room temperature. Although modified PEO electrolytes with lower T g exhibited higher conductivity (∼10 -5 S cm -1 at RT) the t + is still very low ∼0.25 for lithium ion. Numerous other attempts to improving t + have met with limited success. The latest approach involves integrating nano domains of inorganic moieties, such as silcate, alumosilicate, etc. within the polymer component. This approach yields an inorganic-organic component (OIC) based polymer electrolyte with higher conductivity and t + for Li + . This paper describes the improved electrical and electrochemical properties of OIC-based polymer electrolyte and cells containing Li anode with either a TiS 2 cathode or Mag-10 carbon electrode. Several solid polymer electrolytes derived from silicate OIC and salt-in-polymer constituent based on Li triflate (LiTf) and PEO are studied. A typical composition of the SPE investigated in this work consists of 600 kDa PEO, lithium triflate (LiTf, LiSO 3CF 3) and 55% of silicate based on (3-glycidoxypropyl)trimethoxysilane and tetramethoxysilane at molar ratio 4:1 and 0.65 mol% of aluminum(tri- sec-butoxide) (GTMOS-Al1-900k-55%). Several pouch cells

  19. Polymerization of the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT) around living neural cells

    PubMed Central

    Richardson-Burns, Sarah M.; Hendricks, Jeffrey L.; Foster, Brian; Povlich, Laura K.; Kim, Dong-Hwan; Martin, David C.

    2007-01-01

    In this paper we describe interactions between neural cells and the conducting polymer poly(3,4-ethylenedioxythiophene (PEDOT) toward development of electrically conductive biomaterials intended for direct, functional contact with electrically-active tissues such as the nervous system, heart, and skeletal muscle. We introduce a process for polymerizing PEDOT around living cells and describe a neural cell-templated conducting polymer coating for microelectrodes and a hybrid conducting polymer-live neural cell electrode. We found that neural cells could be exposed to working concentrations (0.01 M) of the EDOT monomer for as long as 72 hours while maintaining 80% cell viability. PEDOT could be electrochemically deposited around neurons cultured on electrodes using 0.5-1 μA/mm2 galvanostatic current. PEDOT polymerized on the electrode and surrounded the cells, covering cell processes. The polymerization was impeded in regions where cells were well-adhered to the substrate. The cells could be removed from the PEDOT matrix to generate a neural cell-templated biomimetic conductive substrate with cell-shaped features that were cell-attracting. Live cells embedded within the conductive polymer matrix remained viable for at least 120 hours following polymerization. Dying cells primarily underwent apoptotic cell death. PEDOT, PEDOT+live neurons, and neuron-templated PEDOT coatings on electrodes significantly enhanced the electrical properties as compared to the bare electrode as indicated by decreased electrical impedance of 1-1.5 orders of magnitude at 0.01-1 kHz and significantly increased charge transfer capacity. PEDOT coatings showed a decrease of the phase angle of the impedance from roughly 80 degrees for the bare electrode to 5-35 degrees at frequencies >0.1 kHz. Equivalent circuit modeling indicated that PEDOT-coated electrodes were best described by R(C(RT)) circuit. We found that an RC parallel circuit must be added to the model for PEDOT+live neuron and neuron

  20. Development of multilayer conducting polymer actuator for power application

    NASA Astrophysics Data System (ADS)

    Ikushima, Kimiya; Kudoh, Yuji; Hiraoka, Maki; Yokoyama, Kazuo; Nagamitsu, Sachio

    2009-03-01

    In late years many kinds of home-use robot have been developed to assist elderly care and housework. Most of these robots are designed with conventional electromagnetic motors. For safety it is desirable to replace these electromagnetic motors with artificial muscle. However, an actuator for such a robot is required to have simple structure, low driving voltage, high stress generation, high durability, and operability in the air. No polymer actuator satisfying all these requirements has been realized yet. To meet these we took following two approaches focusing on conducting polymer actuators which can output high power in the air. (Approach 1) We have newly developed an actuator by multiply laminating ionic liquid infiltrated separators and polypyrrole films. Compared with conventional actuator that is driven in a bath of ionic liquid, the new actuator can greatly increase generated stress since the total sectional area is tremendously small. In our experiment, the new actuator consists of minimum unit with thickness of 128um and has work/weight ratio of 0.92J/kg by laminating 9 units in 0.5Hz driving condition. In addition, the driving experiment has shown a stable driving characteristic even for 10,000 cycles durability test. Furthermore, from our design consideration, it has been found that the work/weight ratio can be improved up to 8J/kg (1/8 of mammalian muscle of 64J/kg) in 0.1Hz by reducing the thickness of each unit to 30um. (Approach 2) In order to realize a simplified actuator structure in the air without sealing, we propose the use of ionic liquid gel. The actuation characteristic of suggested multilayered actuator using ionic liquid gel is simulated by computer. The result shows that performance degradation due to the use of ionic liquid gel is negligible small when ionic liquid gel with the elasticity of 3kPa or less is used. From above two results it is concluded that the proposed multilayerd actuator is promising for the future robotic applications

  1. Understanding correlation effects for ion conduction in polymer electrolytes.

    PubMed

    Maitra, Arijit; Heuer, Andreas

    2008-08-14

    Polymer electrolytes typically exhibit diminished ionic conductivity due to the presence of correlation effects between the cations and anions. Microscopically, transient ionic aggregates, e.g., ion-pairs, ion-triplets, or higher order ionic clusters, engender ionic correlations. Employing all-atom simulation of a model polymer electrolyte comprising of poly(ethylene oxide) and lithium iodide, the ionic correlations are explored through construction of elementary functions between pairs of the ionic species that qualitatively explains the spatio-temporal nature of these correlations. Furthermore, commencing from the exact Einstein-like equation describing the collective diffusivity of the ions in terms of the average diffusivity of the ions (i.e., the self-terms) and the correlations from distinct pairs of ions, several phenomenological parameters are introduced to keep track of the simplification procedure that finally boils down to the recently proposed phenomenological model by Stolwijk and Obeidi (SO) [Stolwijk, N. A.; Obeidi, S. Phys. Rev. Lett. 2004, 93, 125901]. The approximation parameters, which can be retrieved from simulations, point to the necessity of additional information in order to fully describe the correlation effects apart from the mere fraction of ion-pairs that apparently accounts for the correlations originating from only the nearest neighbor structural correlations. These parameters are close to, but are not exactly unity, as assumed in the SO model. Finally, as an application of the extended SO model, one is able to estimate the dynamics of the free and non-free ions as well as their fractions from the knowledge of the single particle diffusivities and the collective diffusivity of the ions.

  2. Stimulation of Neurite Outgrowth Using an Electrically Conducting Polymer

    NASA Astrophysics Data System (ADS)

    Schmidt, Christine E.; Shastri, Venkatram R.; Vacanti, Joseph P.; Langer, Robert

    1997-08-01

    Damage to peripheral nerves often cannot be repaired by the juxtaposition of the severed nerve ends. Surgeons have typically used autologous nerve grafts, which have several drawbacks including the need for multiple surgical procedures and loss of function at the donor site. As an alternative, the use of nerve guidance channels to bridge the gap between severed nerve ends is being explored. In this paper, the electrically conductive polymer--oxidized polypyrrole (PP)--has been evaluated for use as a substrate to enhance nerve cell interactions in culture as a first step toward potentially using such polymers to stimulate in vivo nerve regeneration. Image analysis demonstrates that PC-12 cells and primary chicken sciatic nerve explants attached and extended neurites equally well on both PP films and tissue culture polystyrene in the absence of electrical stimulation. In contrast, PC-12 cells interacted poorly with indium tin oxide (ITO), poly(L-lactic acid) (PLA), and poly(lactic acid-coglycolic acid) surfaces. However, PC-12 cells cultured on PP films and subjected to an electrical stimulus through the film showed a significant increase in neurite lengths compared with ones that were not subjected to electrical stimulation through the film and tissue culture polystyrene controls. The median neurite length for PC-12 cells grown on PP and subjected to an electrical stimulus was 18.14 μ m (n = 5643) compared with 9.5 μ m (n = 4440) for controls. Furthermore, animal implantation studies reveal that PP invokes little adverse tissue response compared with poly(lactic acid-coglycolic acid).

  3. Conducting polymer composite materials for smart microwave windows

    NASA Astrophysics Data System (ADS)

    Barnes, Alan; Lees, K.; Wright, Peter V.; Chambers, Barry

    1999-07-01

    Samples of poly(aniline)-silver-polymer electrolyte particulate composites have been characterized at microwave frequencies when small d.c. electric fields are applied across them in both coaxial line and waveguide measurement test sets. The experimental data shows that the initial conductivity of the materials is dependent on the concentration of sliver metal and suggest that changes in resistance due to chemical switching take place, at least in part, in the manufacture of the composites. When silver is used as the electrodes, the experimental data show that changes in the slope of the cyclic voltammograms coincide with large changes in microwave reflectivity or transmission consistent with increasing conductivity of the composites when fields are applied. The reverse change occurs when the fields are removed. Measurements have shown that the composites are able to switch between the two impedance stats in times of less than one second for well over a million cycles with no apparent depreciation in material properties. Large area films have also been prepared and studied using the 'free space' technique.

  4. Highly Conductive, Stretchable, and Transparent Solid Polymer Electrolyte Membrane

    NASA Astrophysics Data System (ADS)

    He, Ruixuan; Echeverri, Mauricio; Kyu, Thein

    2014-03-01

    With the guidance of ternary phase diagrams, completely amorphous polymer electrolyte membranes (PEM) were successfully prepared by melt processing for lithium-ion battery. The PEM under consideration consisted of poly (ethylene glycol diacrylate) (PEGDA), succinonitrile (SCN) and Lithium bis(trifluoro-methane)sulfonamide (LiTFSI). After UV-crosslinking, the PEM is transparent and light-weight. Addition of SCN plastic crystal affords not only dissociation of the lithium salt, but also plasticization to the crosslinked PEGDA network. Of particular importance is the achievement of room-temperature ionic conductivity of ~10-3 S/cm, which is comparable to that of commercial liquid electrolyte. Higher ionic conductivities were achieved at elevated temperatures or with use of a moderately higher molecular weight of PEGDA. In terms of electrochemical and chemical stability, the PEM exhibited oxidative stability up to 5 V against lithium reference electrode. Stable interface behavior between the PEM and lithium electrode is also seen with ageing time. In the tensile tests, samples containing low molecular weight PEGDA are stiffer, whereas the high molecular weight PEGDA is stretchable up to 80% elongation. Supported by NSF-DMR 1161070.

  5. Soft capacitor fibers using conductive polymers for electronic textiles

    NASA Astrophysics Data System (ADS)

    Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

    2010-11-01

    A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60-100 nF m-1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L-1, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage.

  6. Conductivity and Stability of Photopolymerized Polymer Electrolyte Network

    NASA Astrophysics Data System (ADS)

    Kyu, Thein; He, Ruixuan; Chen, Yu-Ming; Mao, Jialin; Zhu, Yu; Kyu'S Group, , Dr.; Zhu'S Group Collaboration, , Dr.

    2014-03-01

    A melt-processing window has been identified within the wide isotropic region of the phase diagram of ternary blends consisting of poly (ethylene glycol diacrylate) (PEGDA), tetraethylene glycol dimethyl ether (TEGDME) and lithium bis(trifluoromethane) sulfonamide (LiTFSI). Upon UV-crosslinking of PEGDA in the isotropic window, the polymer electrolyte membrane (PEM) network thus formed is completely transparent and remains in the single phase without undergoing polymerization-induced phase separation or polymerization-induced crystallization. These PEM networks are solid albeit flexible and light-weight with safety and space saving attributes. The ionic conductivity as determined by AC impedance spectroscopy exhibited very high room-temperature ionic conductivity on the order of ~10-3 S/cm in several compositions, viz., 10/45/45, 20/40/40 and 30/35/35 PEGDA/TEGDME/LiTFSI networks. Cyclic voltammetry measurement of these solid-state PEM networks revealed excellent electrochemical stability against lithium reference electrode. The above study has been extended to the anode (graphite) and cathode (LiFePO4) half-cell configurations with lithium as counter electrode. Charge/discharge cycling behavior of these half cells will be discussed. Supported by NSF-DMR 1161070 and University of Akron.

  7. 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.

  8. Novel negatively charged hybrids. 3. Removal of Pb2+ from aqueous solution using zwitterionic hybrid polymers as adsorbent.

    PubMed

    Liu, Junsheng; Ma, Yue; Zhang, Yaping; Shao, Guoquan

    2010-01-15

    Using zwitterionic hybrid polymers as adsorbent, the adsorption kinetics and isotherm, thermodynamic parameters of Delta G, Delta H and DeltaS for the removal of Pb(2+) from aqueous solution were investigated. It is indicated that the adsorption of Pb(2+) ions on these zwitterionic hybrid polymers followed the Lagergren second-order kinetic model and Freundlich isotherm model, demonstrating that the adsorption process might be Langmuir monolayer adsorption. The negative values of Delta G and the positive values of Delta H evidence that Pb(2+) adsorption on these zwitterionic hybrid polymers is spontaneous and endothermic process in nature. Moreover, the zwitterionic hybrid polymers produced reveal relatively higher desorption efficiency in 2 mol dm(-3) aqueous HNO(3) solution, indicating that they can be recycled in industrial processes. These findings suggest that these zwitterionic hybrid polymers are the promising adsorbents for Pb(2+) removal and can be potentially applied in the separation and recovery of Pb(2+) ions from the waste chemicals and contaminated water of lead-acid rechargeable battery.

  9. Single lithium-ion conducting solid polymer electrolytes: advances and perspectives.

    PubMed

    Zhang, Heng; Li, Chunmei; Piszcz, Michal; Coya, Estibaliz; Rojo, Teofilo; Rodriguez-Martinez, Lide M; Armand, Michel; Zhou, Zhibin

    2017-02-06

    Electrochemical energy storage is one of the main societal challenges to humankind in this century. The performances of classical Li-ion batteries (LIBs) with non-aqueous liquid electrolytes have made great advances in the past two decades, but the intrinsic instability of liquid electrolytes results in safety issues, and the energy density of the state-of-the-art LIBs cannot satisfy the practical requirement. Therefore, rechargeable lithium metal batteries (LMBs) have been intensively investigated considering the high theoretical capacity of lithium metal and its low negative potential. However, the progress in the field of non-aqueous liquid electrolytes for LMBs has been sluggish, with several seemingly insurmountable barriers, including dendritic Li growth and rapid capacity fading. Solid polymer electrolytes (SPEs) offer a perfect solution to these safety concerns and to the enhancement of energy density. Traditional SPEs are dual-ion conductors, in which both cations and anions are mobile and will cause a concentration polarization thus leading to poor performances of both LIBs and LMBs. Single lithium-ion (Li-ion) conducting solid polymer electrolytes (SLIC-SPEs), which have anions covalently bonded to the polymer, inorganic backbone, or immobilized by anion acceptors, are generally accepted to have advantages over conventional dual-ion conducting SPEs for application in LMBs. A high Li-ion transference number (LTN), the absence of the detrimental effect of anion polarization, and the low rate of Li dendrite growth are examples of benefits of SLIC-SPEs. To date, many types of SLIC-SPEs have been reported, including those based on organic polymers, organic-inorganic hybrid polymers and anion acceptors. In this review, a brief overview of synthetic strategies on how to realize SLIC-SPEs is given. The fundamental physical and electrochemical properties of SLIC-SPEs prepared by different methods are discussed in detail. In particular, special attention is paid

  10. Biocompatible polymer/quantum dots hybrid materials: current status and future developments.

    PubMed

    Shen, Lei

    2011-12-02

    Quantum dots (QDs) are nanometer-sized semiconductor particles with tunable fluorescent optical property that can be adjusted by their chemical composition, size, or shape. In the past 10 years, they have been demonstrated as a powerful fluorescence tool for biological and biomedical applications, such as diagnostics, biosensing and biolabeling. QDs with high fluorescence quantum yield and optical stability are usually synthesized in organic solvents. In aqueous solution, however, their metallic toxicity, non-dissolubility and photo-luminescence instability prevent the direct utility of QDs in biological media. Polymers are widely used to cover and coat QDs for fabricating biocompatible QDs. Such hybrid materials can provide solubility and robust colloidal and optical stability in water. At the same time, polymers can carry ionic or reactive functional groups for incorporation into the end-use application of QDs, such as receptor targeting and cell attachment. This review provides an overview of the recent development of methods for generating biocompatible polymer/QDs hybrid materials with desirable properties. Polymers with different architectures, such as homo- and co-polymer, hyperbranched polymer, and polymeric nanogel, have been used to anchor and protect QDs. The resulted biocompatible polymer/QDs hybrid materials show successful applications in the fields of bioimaging and biosensing. While considerable progress has been made in the design of biocompatible polymer/QDs materials, the research challenges and future developments in this area should affect the technologies of biomaterials and biosensors and result in even better biocompatible polymer/QDs hybrid materials.

  11. Biocompatible Polymer/Quantum Dots Hybrid Materials: Current Status and Future Developments

    PubMed Central

    Shen, Lei

    2011-01-01

    Quantum dots (QDs) are nanometer-sized semiconductor particles with tunable fluorescent optical property that can be adjusted by their chemical composition, size, or shape. In the past 10 years, they have been demonstrated as a powerful fluorescence tool for biological and biomedical applications, such as diagnostics, biosensing and biolabeling. QDs with high fluorescence quantum yield and optical stability are usually synthesized in organic solvents. In aqueous solution, however, their metallic toxicity, non-dissolubility and photo-luminescence instability prevent the direct utility of QDs in biological media. Polymers are widely used to cover and coat QDs for fabricating biocompatible QDs. Such hybrid materials can provide solubility and robust colloidal and optical stability in water. At the same time, polymers can carry ionic or reactive functional groups for incorporation into the end-use application of QDs, such as receptor targeting and cell attachment. This review provides an overview of the recent development of methods for generating biocompatible polymer/QDs hybrid materials with desirable properties. Polymers with different architectures, such as homo- and co-polymer, hyperbranched polymer, and polymeric nanogel, have been used to anchor and protect QDs. The resulted biocompatible polymer/QDs hybrid materials show successful applications in the fields of bioimaging and biosensing. While considerable progress has been made in the design of biocompatible polymer/QDs materials, the research challenges and future developments in this area should affect the technologies of biomaterials and biosensors and result in even better biocompatible polymer/QDs hybrid materials. PMID:24956449

  12. Synthesis of Conductive Nanofillers/Nanofibers and Electrical Properties of their Conductive Polymer Composites

    NASA Astrophysics Data System (ADS)

    Sarvi, Ali

    Thanks to their corrosion resistance, light weight, low cost, and ease of processing, electrically conducting polymer composites (CPCs) have received significant attention for the replacement of metals and inorganic materials for sensors, actuators, supercapacitors, and electromagnetic interference (EMI) shields. In this PhD thesis, high aspect ratio conductive nanofillers namely copper nanowires (CuNWs) and multiwall carbon nanotubes (MWCNTs) were coated with polyaniline (PANi) using solution mixing and in-situ polymerization method, respectively. Transmission electron microscopy (TEM) showed a smooth polyaniline nano-coating between 5--18 nm in thickness on the nanofillers' surface. The coating thickness and; consequently, electrical conductivity was controlled and tuned by polyaniline/aniline concentration in solution. Composites with tunable conductivity may be used as chemisensors, electronic pressure sensors and switches. Coated nanofillers demonstrated better dispersion in polystyrene (PS) and provided lower electrical percolation threshold. Dispersion of nanofillers in PS was investigated using rheological measurements and confirmed with electron micrographs and nano-scale images of CPCs. Polyaniline (PANi), when used as a coating layer, was able to attenuate electromagnetic (EM) waves via absorption and store electrical charges though pseudocapacitance mechanism. The dielectric measurements of MWCNT-PANi/PS composites showed one order of magnitude increase in real electrical permittivity compared to that of MWCNT/PS composites making them suitable for charge storage purposes. Incorporation of PANi also brought a new insight into conductive network formation mechanism in electrospun mats where the orientation of conductive high aspect ratio nanofillers is a major problem. Conductive nanofibers of poly(vinylidene fluoride) (PVDF) filled with coated multiwall carbon nanotubes (MWCNTs) were fabricated using electrospinning. These highly oriented PVDF

  13. Porous palladium coated conducting polymer nanoparticles for ultrasensitive hydrogen sensors

    NASA Astrophysics Data System (ADS)

    Lee, Jun Seop; Kim, Sung Gun; Cho, Sunghun; Jang, Jyongsik

    2015-12-01

    Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm) and stability toward hydrogen gas at room temperature due to the palladium sensing layer.Hydrogen, a clean-burning fuel, is of key importance to various industrial applications, including fuel cells and in the aerospace and automotive industries. However, hydrogen gas is odorless, colorless, and highly flammable; thus appropriate safety protocol implementation and monitoring are essential. Highly sensitive hydrogen leak detection and surveillance sensor systems are needed; additionally, the ability to maintain uniformity through repetitive hydrogen sensing is becoming increasingly important. In this report, we detail the fabrication of porous palladium coated conducting polymer (3-carboxylate polypyrrole) nanoparticles (Pd@CPPys) to detect hydrogen gas. The Pd@CPPys are produced by means of facile alkyl functionalization and chemical reduction of a pristine 3-carboxylate polypyrrole nanoparticle-contained palladium precursor (PdCl2) solution. The resulting Pd@CPPy-based sensor electrode exhibits ultrahigh sensitivity (0.1 ppm

  14. [Research progresses on electroactive and electrically conductive polymers for tissue engineering scaffolds].

    PubMed

    Li, Meng-yan; Bidez, Paul; Guterman-Tretter, Elizabeth; Guo, Yi; MacDiarmid, Alan G; Lelkes, Peter I; Yuan, Xu-bo; Yuan, Xiao-yan; Sheng, Jing; Li, Hua; Song, Cun-xian; Yen, Wei

    2006-12-01

    Electroactive and/or electrically conductive polymers have shown potential applications in the culture of excitable cells and as the electroactive scaffolds for neuronal or cardiac tissue engineering. The biocompatibility of the conductive polymer can be improved by covalently grafting or blending with oligo- or polypeptides. The new progresses in this area on two types of conductive polymers, polypyrrole and polyaniline (PANi) are reviewed in this paper. The studies of oligopeptide-modified PANi and electrospun PANi/gelatin nanofibers are highlighted.

  15. 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.

  16. Investigation of Carrier Collection Capability in Organic Heterostructure with Conductive Polymer Nanofiber

    NASA Astrophysics Data System (ADS)

    Yamashita, Kenichi; Maeda, Tatsuya; Kusakabe, Youhei; Kotaki, Masaya

    2011-08-01

    The capability of carrier collection was investigated for an organic heterointerface with conductive polymer nanofibers and a fullerene derivative. The electrospinning method was employed for fabricating conductive polymer nanofibers. In a photovoltaic device with this heterointerface, a rather large photocurrent was obtained in spite of the fact that the polymer nanofibers were large at submicrometer diameter. It was considered that conductive polymer nanofibers can serve as a conduction path for photoinduced carriers and might be helpful for the marked improvement in power conversion efficiency of organic thin film solar cell.

  17. 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.

  18. Hybrid polymer fabrication process for electro-enzymatic glucose sensor

    NASA Astrophysics Data System (ADS)

    Patel, Jasbir N.; Kaminska, Bozena; Gray, Bonnie L.; Gates, Byron D.

    2008-02-01

    We present a novel self-aligned and hybrid polymer fabrication process for an electro-enzymatic glucose sensor. The self-aligned fabrication process is performed using polydimethylsiloxane (PDMS) as a process substrate material, SU-8 as a sensor structural material, and gold as an electrode material. PDMS has many advantages as a process substrate over conventional substrates such as bare silicon or glass. During the fabrication process, SU-8 has good adhesion to the PDMS. However, after completion of all fabrication steps, the SU-8 based sensors can be easily peeled-off from the PDMS. The PDMS is prepared on a glass handle wafer, and is reusable for many process cycles. Such an SU-8 release technique from a PDMS substrate has never been proposed before. The novel process is employed to realize a glucose sensor with active and reference gold electrodes that are sandwiched between two SU-8 layers with contact pad openings and the active area opening to the top SU-8 layer. The enzyme glucose oxidase is immobilized within the confined active area opening to provide an active electrode sensing surface. After successful fabrication using the hybrid process, the overall thickness of the sensors is measured between 166.15 μm and 210.15 μm. The sensor area and the electrode area are 2mm x 3mm and 2mm x 2mm respectively. The resulting glucose sensors are mechanically flexible. A linear response is observed for the glucose sensors, typically between 50mg/dl and 600mg/dl glucose concentrations.

  19. Substrate dependent stability of conducting polymer coatings on medical electrodes.

    PubMed

    Green, Rylie A; Hassarati, Rachelle T; Bouchinet, Lucie; Lee, Chaekyung S; Cheong, Gin L M; Yu, Jin F; Dodds, Christopher W; Suaning, Gregg J; Poole-Warren, Laura A; Lovell, Nigel H

    2012-09-01

    Conducting polymer (CP) coatings on medical electrodes have the potential to provide superior performance when compared to conventional metallic electrodes, but their stability is strongly dependant on the substrate properties. The aim of this study was to examine the effect of laser roughening of underlying platinum (Pt) electrode surfaces on the mechanical, electrical and biological performance of CP coatings. In addition, the impact of dopant type on electrical performance and stability was assessed. The CP poly(ethylene dioxythiophene) (PEDOT) was coated on Pt microelectrode arrays, with three conventional dopant ions. The in vitro electrical characteristics were assessed by cyclic voltammetry and biphasic stimulation. Results showed that laser roughening of the underlying substrate did not affect the charge injection limit of the coated material, but significantly improved the passive stability and chronic stimulation lifetime without failure of the coating. Accelerated material ageing and long-term biphasic stimulus studies determined that some PEDOT variants experienced delamination within as little as 10 days when the underlying Pt was smooth, but laser roughening to produce a surface index of 2.5 improved stability, such that more than 1.3 billion stimulation cycles could be applied without evidence of failure. PEDOT doped with paratoluene sulfonate (PEDOT/pTS) was found to be the most stable CP on roughened Pt, and presented a surface topography which encouraged neural cell attachment.

  20. Biocompatible silk-conducting polymer composite trilayer actuators

    NASA Astrophysics Data System (ADS)

    Fengel, Carly V.; Bradshaw, Nathan P.; Severt, Sean Y.; Murphy, Amanda R.; Leger, Janelle M.

    2017-05-01

    Biocompatible materials capable of controlled actuation are in high demand for use in biomedical applications such as dynamic tissue scaffolding, valves, and steerable surgical tools. Conducting polymer actuators are of interest because they operate in aqueous electrolytes at low voltages and can generate stresses similar to natural muscle. Recently, our group has demonstrated a composite material of silk and poly(pyrrole) (PPy) that is mechanically robust, made from biocompatible materials, and bends under an applied voltage when incorporated into a simple bilayer device architecture and actuated using a biologically relevant electrolyte. Here we present trilayer devices composed of two silk-PPy composite layers separated by an insulating silk layer. The trilayer architecture allows one side to expand while the other contracts, resulting in improved performance over bilayer devices. Specifically, this configuration shows a larger angle of deflection per volt applied than the analogous bilayer system, while maintaining a consistent current response throughout cycling. In addition, the overall motion of the trilayer devices is more symmetric than that of the bilayer analogs, allowing for fully reversible operation.

  1. Carbon nanotubes filled polymer composites: A comprehensive study on improving dispersion, network formation and electrical conductivity

    NASA Astrophysics Data System (ADS)

    Chakravarthi, Divya Kannan

    In this dissertation, we determine how the dispersion, network formation and alignment of carbon nanotubes in polymer nanocomposites affect the electrical properties of two different polymer composite systems: high temperature bismaleimide (BMI) and polyethylene. The knowledge gained from this study will facilitate optimization of the above mentioned parameters, which would further enhance the electrical properties of polymer nanocomposites. BMI carbon fiber composites filled with nickel-coated single walled carbon nanotubes (Ni-SWNTs) were processed using high temperature vacuum assisted resin transfer molding (VARTM) to study the effect of lightning strike mitigation. Coating the SWNTs with nickel resulted in enhanced dispersions confirmed by atomic force microscopy (AFM) and dynamic light scattering (DLS). An improved interface between the carbon fiber and Ni-SWNTs resulted in better surface coverage on the carbon plies. These hybrid composites were tested for Zone 2A lightning strike mitigation. The electrical resistivity of the composite system was reduced by ten orders of magnitude with the addition of 4 weight percent Ni-SWNTs (calculated with respect to the weight of a single carbon ply). The Ni-SWNTs - filled composites showed a reduced amount of damage to simulated lightning strike compared to their unfilled counterparts indicated by the minimal carbon fiber pull out. Methods to reduce the electrical resistivity of 10 weight percent SWNTs --- medium density polyethylene (MDPE) composites were studied. The composites processed by hot coagulation method were subjected to low DC electric fields (10 V) at polymer melt temperatures to study the effect of viscosity, nanotube welding, dispersion and, resultant changes in electrical resistivity. The electrical resistivity of the composites was reduced by two orders of magnitude compared to 10 wt% CNT-MDPE baseline. For effective alignment of SWNTs, a new process called Electric field Vacuum Spray was devised to

  2. Real-Time Control of Biological Motor Activity using Graphene-polymer Hybrid Bioenergy Storage Device

    NASA Astrophysics Data System (ADS)

    Lee, Dong; Byun, Kyung-Eun; Choi, Dong; Kim, Eunji; Kim, Daesan; Seo, David; Yang, Heejun; Seo, Sunae; Hong, Seunghun; Hybrid Nanodevice Lab Team; Samsung Research Park Team

    2013-03-01

    Biological motors have been drawing an attention as a key component for highly efficient nanomechanical systems. For such applications, many researchers have tried to control the activity of motor proteins through various methods such as microfluidics or UV-active compounds. However, these methods have some limitations such as the incapability of controlling local biomotor activity and a slow response rate. Herein, we developed a graphene-polymer hybrid nanostructure-based bioenergy storage device which enables the real-time control of biomotor activity. In this strategy, graphene layers functionalized with amine groups were utilized as a transparent electrode supporting the motility of biomotors. And conducting polymer patterns doped with adenosine triphosphate (ATP) were electrically deposited on the graphene and utilized for the fast release of ATP by electrical stimuli through the graphene. Such controlled release of ATP allowed us to control the motility of actin filaments propelled by myosin biomotors in real time. This strategy should enable integrated nanodevices for the real-time control of biological motors to the nanodevices, which can be a significant stepping stone toward hybrid nanomechanical systems based on motor proteins.

  3. Conductive polymer and Si nanoparticles composite secondary particles and structured current collectors for high loading lithium ion negative electrode application

    DOEpatents

    Liu, Gao

    2017-07-11

    Embodiments of the present invention disclose a composition of matter comprising a silicon (Si) nanoparticle coated with a conductive polymer. Another embodiment discloses a method for preparing a composition of matter comprising a plurality of silicon (Si) nanoparticles coated with a conductive polymer comprising providing Si nanoparticles, providing a conductive polymer, preparing a Si nanoparticle, conductive polymer, and solvent slurry, spraying the slurry into a liquid medium that is a non-solvent of the conductive polymer, and precipitating the silicon (Si) nanoparticles coated with the conductive polymer. Another embodiment discloses an anode comprising a current collector, and a composition of matter comprising a silicon (Si) nanoparticle coated with a conductive polymer.

  4. Highly Electrically Conducting Glass-Graphene Nanoplatelets Hybrid Coatings.

    PubMed

    Garcia, E; Nistal, A; Khalifa, A; Essa, Y; Martín de la Escalera, F; Osendi, M I; Miranzo, P

    2015-08-19

    Hybrid coatings consisting of a heat resistant Y2O3-Al2O3-SiO2 (YAS) glass containing 2.3 wt % of graphene nanoplatelets (GNPs) were developed by flame spraying homogeneous ceramic powders-GNP granules. Around 40% of the GNPs survived the high spraying temperatures and were distributed along the splat-interfaces, forming a percolated network. These YAS-GNP coatings are potentially interesting in thermal protection systems and electromagnetic interference shields for aerospace applications; therefore silicon carbide (SiC) materials at the forefront of those applications were employed as substrates. Whereas the YAS coatings are nonconductive, the YAS-GNP coatings showed in-plane electrical conductivity (∼10(2) S·m(-1)) for which a low percolation limit (below 3.6 vol %) is inferred. Indentation tests revealed the formation of a highly damaged indentation zone showing multiple shear displacements between adjacent splats probably favored by the graphene sheets location. The indentation radial cracks typically found in brittle glass coatings are not detected in the hybrid coatings that are also more compliant.

  5. Conductivity study and fourier transform infrared (FTIR) characterization of methyl cellulose solid polymer electrolyte with sodium iodide conducting ion

    SciTech Connect

    Abiddin, Jamal Farghali Bin Zainal; Ahmad, Azizah Hanom

    2015-08-28

    Sodium ion (Na{sup +}) based solid polymer electrolyte (SPE) has been prepared using solution cast technique with distilled water as solvent and Methylcellulose (MC) as a polymer host. Methylcellulose polymer was chosen as the polymer host due to the abundance of lone pair electrons in the carbonyl and C-O-C constituents, which in turn provide multiple hopping sites for the Na{sup +} conducting ions. Variable compositions of sodium iodide (NaI) salt were prepared to investigate the optimum MC-NaI weight ratio. Results from Electrical Impedance Spectroscopy (EIS) technique show that pure methylcellulose has a low conductivity of 3.61 × 10{sup −11} S/cm.The conductivity increases as NaI content increases up to optimum NaIcomposition of 40 wt%, which yields an average conductivity of 2.70 × 10{sup −5} S/cm.

  6. New Secondary Batteries Using Electronically Conductive Polymer Cathodes

    NASA Technical Reports Server (NTRS)

    Martin, Charles R.; White, Ralph E.

    1991-01-01

    A Li/Polypyrrole secondary battery was designed and built, and the effect of controlling the morphology of the polymer on enhancement of counterion diffusion in the polymer phase was explored. The experimental work was done at Colorado State University, while the mathematical modeling of the battery was done at Texas A and M University. Manuscripts and publications resulting from the project are listed.

  7. Grafting of Conductive Polymers onto the Functionalized Carbon Nanotubes

    DTIC Science & Technology

    2010-08-23

    2,5- benzimidazole )/carbon nanotube composite film” Journal of Polymer Science, Part A: Polymer Chemistry 2010, 48, 1067. 3. Han, S.-W.; Oh, S.-J...34Synthesis and Characterization of poly(2,5- benzimidazole ) (ABPBI) Grafted CArbon Nanotubes." MRS. 2009 fall meeting, Prepr. Boston, MA, November 30

  8. One-pot synthesis of conducting graphene-polymer composites and their strain sensing application.

    PubMed

    Eswaraiah, Varrla; Balasubramaniam, Krishnan; Ramaprabhu, Sundara

    2012-02-21

    In situ reduction of graphite oxide in polymer powder has been implemented using focused solar electromagnetic radiation. The simultaneous reduction of graphite oxide, melting of the polymer and embedding of reduced graphite oxide nanoflakes in polymer offer a new way of synthesizing conducting graphene/polymer composites. An electromechanical application of the present reduced graphite oxide-PVDF nanocomposite has been proposed with a gauge factor of 12.1. This journal is © The Royal Society of Chemistry 2012

  9. Biofunctionalized conductive polymers enable efficient CO2 electroreduction

    PubMed Central

    Coskun, Halime; Aljabour, Abdalaziz; De Luna, Phil; Farka, Dominik; Greunz, Theresia; Stifter, David; Kus, Mahmut; Zheng, Xueli; Liu, Min; Hassel, Achim W.; Schöfberger, Wolfgang; Sargent, Edward H.; Sariciftci, Niyazi Serdar; Stadler, Philipp

    2017-01-01

    Selective electrocatalysts are urgently needed for carbon dioxide (CO2) reduction to replace fossil fuels with renewable fuels, thereby closing the carbon cycle. To date, noble metals have achieved the best performance in energy yield and faradaic efficiency and have recently reached impressive electrical-to-chemical power conversion efficiencies. However, the scarcity of precious metals makes the search for scalable, metal-free, CO2 reduction reaction (CO2RR) catalysts all the more important. We report an all-organic, that is, metal-free, electrocatalyst that achieves impressive performance comparable to that of best-in-class Ag electrocatalysts. We hypothesized that polydopamine—a conjugated polymer whose structure incorporates hydrogen-bonded motifs found in enzymes—could offer the combination of efficient electrical conduction, together with rendered active catalytic sites, and potentially thereby enable CO2RR. Only by developing a vapor-phase polymerization of polydopamine were we able to combine the needed excellent conductivity with thin film–based processing. We achieve catalytic performance with geometric current densities of 18 mA cm−2 at 0.21 V overpotential (−0.86 V versus normal hydrogen electrode) for the electrosynthesis of C1 species (carbon monoxide and formate) with continuous 16-hour operation at >80% faradaic efficiency. Our catalyst exhibits lower overpotentials than state-of-the-art formate-selective metal electrocatalysts (for example, 0.5 V for Ag at 18 mA cm−1). The results confirm the value of exploiting hydrogen-bonded sequences as effective catalytic centers for renewable and cost-efficient industrial CO2RR applications. PMID:28798958

  10. Biofunctionalized conductive polymers enable efficient CO2 electroreduction.

    PubMed

    Coskun, Halime; Aljabour, Abdalaziz; De Luna, Phil; Farka, Dominik; Greunz, Theresia; Stifter, David; Kus, Mahmut; Zheng, Xueli; Liu, Min; Hassel, Achim W; Schöfberger, Wolfgang; Sargent, Edward H; Sariciftci, Niyazi Serdar; Stadler, Philipp

    2017-08-01

    Selective electrocatalysts are urgently needed for carbon dioxide (CO2) reduction to replace fossil fuels with renewable fuels, thereby closing the carbon cycle. To date, noble metals have achieved the best performance in energy yield and faradaic efficiency and have recently reached impressive electrical-to-chemical power conversion efficiencies. However, the scarcity of precious metals makes the search for scalable, metal-free, CO2 reduction reaction (CO2RR) catalysts all the more important. We report an all-organic, that is, metal-free, electrocatalyst that achieves impressive performance comparable to that of best-in-class Ag electrocatalysts. We hypothesized that polydopamine-a conjugated polymer whose structure incorporates hydrogen-bonded motifs found in enzymes-could offer the combination of efficient electrical conduction, together with rendered active catalytic sites, and potentially thereby enable CO2RR. Only by developing a vapor-phase polymerization of polydopamine were we able to combine the needed excellent conductivity with thin film-based processing. We achieve catalytic performance with geometric current densities of 18 mA cm(-2) at 0.21 V overpotential (-0.86 V versus normal hydrogen electrode) for the electrosynthesis of C1 species (carbon monoxide and formate) with continuous 16-hour operation at >80% faradaic efficiency. Our catalyst exhibits lower overpotentials than state-of-the-art formate-selective metal electrocatalysts (for example, 0.5 V for Ag at 18 mA cm(-1)). The results confirm the value of exploiting hydrogen-bonded sequences as effective catalytic centers for renewable and cost-efficient industrial CO2RR applications.

  11. Electroanalytical measurements without electrolytes: conducting polymers as probes for redox titration in non-conductive organic media.

    PubMed

    Lange, Ulrich; Mirsky, Vladimir M

    2012-09-26

    Electroanalytical methods have been applied only in conducting media. An application of conducting polymers allows to overcome this limitation. If such material is in electrochemical equilibrium with dissolved redox active species, its electrical conductivity depends on the redox potential of these species. Therefore, conductometric measurements with conducting polymers can provide about the same information as classical redox electrodes. The approach was applied for redox titration. Equivalent points obtained by this titration in aqueous and organic electrolytes were identical. Then the approach was applied for determination of bromine number by redox titration in non-conducting organic phase. Copyright © 2012 Elsevier B.V. All rights reserved.

  12. Design of hybrid conjugated polymer materials: 1) Novel inorganic/organic hybrid semiconductors and 2) Surface modification via grafting approaches

    NASA Astrophysics Data System (ADS)

    Peterson, Joseph J.

    The research presented in this dissertation focuses on the design and synthesis of novel hybrid conjugated polymer materials using two different approaches: (1) inorganic/organic hybrid semiconductors through the incorporation of carboranes into the polymer structure and (2) the modification of surfaces with conjugated polymers via grafting approaches. Hybrid conjugated polymeric materials, which are materials or systems in which conjugated polymers are chemically integrated with non-traditional structures or surfaces, have the potential to harness useful properties from both components of the material to help overcome hurdles in their practical realization in polymer-based devices. This work is centered around the synthetic challenges of creating new hybrid conjugated systems and their potential for advancing the field of polymer-based electronics through both greater understanding of the behavior of hybrid systems, and access to improved performance and new applications. Chapter 1 highlights the potential applications and advantages for these hybrid systems, and provides some historical perspective, along with relevant background materials, to illustrate the rationale behind this work. Chapter 2 explores the synthesis of poly(fluorene)s with pendant carborane cages. The Ni(0) dehalogenative polymerization of a dibromofluorene with pendant carborane cages tethered to the bridging 9-position produced hybrid polymers produced polymers which combined the useful emissive characteristics of poly(fluorene) with the thermal and chemical stability of carborane cages. The materials were found to display increased glass transition temperatures and showed improved emission color stability after annealing at high temperatures relative to the non-hybrid polymer. The design and synthesis of a poly(fluorene)-based hybrid material with carborane cages in the backbone, rather than as pendant groups, begins in chapter 3. Poly(fluorene) with p-carborane in the backbone is

  13. Fabrication of multilayered conductive polymer structures via selective visible light photopolymerization

    NASA Astrophysics Data System (ADS)

    Cullen, Andrew T.; Price, Aaron D.

    2017-04-01

    Electropolymerization of pyrrole is commonly employed to fabricate intrinsically conductive polymer films that exhibit desirable electromechanical properties. Due to their monolithic nature, electroactive polypyrrole films produced via this process are typically limited to simple linear or bending actuation modes, which has hindered their application in complex actuation tasks. This initiative aims to develop the specialized fabrication methods and polymer formulations required to realize three-dimensional conductive polymer structures capable of more elaborate actuation modes. Our group has previously reported the application of the digital light processing additive manufacturing process for the fabrication of three-dimensional conductive polymer structures using ultraviolet radiation. In this investigation, we further expand upon this initial work and present an improved polymer formulation designed for digital light processing additive manufacturing using visible light. This technology enables the design of novel electroactive polymer sensors and actuators with enhanced capabilities and brings us one step closer to realizing more advanced electroactive polymer enabled devices.

  14. Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

    NASA Astrophysics Data System (ADS)

    Jarad, Amer N.; Ibrahim, Kamarulazizi; Ahmed, Nasser M.

    2016-07-01

    In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10-5 (Ω.cm)-1, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

  15. Synthesis and characterization thin films of conductive polymer (PANI) for optoelectronic device application

    SciTech Connect

    Jarad, Amer N. Ibrahim, Kamarulazizi Ahmed, Nasser M.

    2016-07-06

    In this work we report preparation and investigation of structural and optical properties of polyaniline conducting polymer. By using sol-gel in spin coating technique to synthesize thin films of conducting polymer polyaniline (PANI). Conducting polymer polyaniline was synthesized by the chemical oxidative polymerization of aniline monomers. The thin films were characterized by technique: Hall effect, High Resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FTIR) spectroscopy, Field emission scanning electron microscopy (FE-SEM), and UV-vis spectroscopy. Polyaniline conductive polymer exhibit amorphous nature as confirmed by HR-XRD. The presence of characteristic bonds of polyaniline was observed from FTIR spectroscopy technique. Electrical and optical properties revealed that (p-type) conductivity PANI with room temperature, the conductivity was 6.289×10{sup −5} (Ω.cm){sup −1}, with tow of absorption peak at 426,805 nm has been attributed due to quantized size of polyaniline conducting polymer.

  16. Liquid/Liquid interfacial polymerization to grow single crystalline nanoneedles of various conducting polymers.

    PubMed

    Nuraje, Nurxat; Su, Kai; Yang, Nan-Loh; Matsui, Hiroshi

    2008-03-01

    Single crystalline nanoneedles of polyaniline (PANI) and polypyrrole (PPY) were synthesized using an interfacial polymerization for the first time. The interfacial crystallization of conductive polymers at the liquid/liquid interface allowed PANI and PPY polymers to form single crystalline nanocrystals in a rice-like shape in the dimensions of 63 nm x 12 nm for PANI and 70 nm x 20 nm for PPY. Those crystalline nanoneedles displayed a fast conductance switching in the time scale of milliseconds. An important growth condition necessary to yield highly crystalline conductive polymers was the extended crystallization time at the liquid/liquid interfaces to increase the degree of crystallization. As compared to other interfacial polymerization methods, lower concentrations of monomer and oxidant solutions were employed to further extend the crystallization time. While other interfacial growth of conducting polymers yielded noncrystalline polymer fibers, our interfacial method produced single crystalline nanocrystals of conductive polymers. We recently reported the liquid/liquid interfacial synthesis of conducting PEDOT nanocrystals; however, this liquid/liquid interfacial method needs to be extended to other conductive polymer nanocrystal syntheses in order to demonstrate that our technique could be applied as the general fabrication procedure for the single crystalline conducting polymer growth. In this report, we showed that the liquid/liquid interfacial crystallization could yield PANI nanocrystals and PPY nanocrystals, other important conductive polymers, in addition to PEDOT nanocrystals. The resulting crystalline polymers have a fast conductance switching time between the insulating and conducting states on the order of milliseconds. This technique will be useful to synthesize conducting polymers via oxidative coupling processes in a single crystal state, which is extremely difficult to achieve by other synthetic methods.

  17. Hybrid 1x2 WDM components based on polymer mountings

    NASA Astrophysics Data System (ADS)

    Klotzbuecher, Thomas; Sprzagala, M.; Koch, Anne; Teubner, Ulrich

    2004-08-01

    In future airplanes optical data networks are expected to be state of the art. The advantages of optical technology compared to wire-based systems are higher data rates, smaller sensitivity against electromagnetic interference (EMI) and less weight. Today avionics full duplex switched ethernet (AFDX) is realised on duplex copper wires connecting two switches. An optical version of AFDX could be realised on a simplex fibre, using a two-wavelength transmission over one fibre. This would require a wavelength selective coupler, allowing a bi-directional data transmission with two wavelengths. In this work a simple WDM module is introduced, based on the principle of a micro-optical bench made of a polymer with hybrid integration of lenses and filters and allowing both multiplexing as well as de-multiplexing of wavelengths 850 nm and 1310 nm. Two different designs have been realised, one with ball lenses and one with GRIN lenses, both using edge filters for wavelength separation. The fabrication and optical performance of such couplers is described and discussed.

  18. 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.

  19. Enhanced thermal conductivity of novel multifunctional polyphenylene sulfide composites embedded with heat transfer networks of hybrid fillers

    NASA Astrophysics Data System (ADS)

    Leung, Siu N.; Khan, Omer M.; Chan, Ellen; Naguib, Hani E.; Dawson, Francis; Adinkrah, Vincent; Lakatos-Hayward, Laszlo

    2011-04-01

    Today's smaller, more powerful electronic devices, communications equipment, and lighting apparatus required optimum heat dissipation solutions. Traditionally, metals are widely known for their superior thermal conductivity; however, their good electrical conductivity has limited their applications in heat management components for microelectronic applications. This prompts the requirement to develop novel plastic composites that satisfy multifunctional requirements thermally, electrically, and mechanically. Furthermore, the moldability of polymer composites would make them ideal for manufacturing three-dimensional, net-shape enclosures and/or heat management assembly. Using polyphenylene sulfide (PPS) as the matrix, heat transfer networks were developed and structured by embedding hexagonal boron nitride (BN) alone, blending BN fillers of different shapes and sizes, as well as hybridizing BN fillers with carbonaceous nano- and micro-fillers. Parametric studies were conducted to elucidate the effects of types, shapes, sizes, and hybridization of fillers on the composite's thermal and electrical properties. The use of hybrid fillers, with optimized material formulations, was found to effectively promote a composite's thermal conductivity. This was achieved by optimizing the development of an interconnected thermal conductive network through structuring hybrid fillers with appropriate shapes and sizes. The thermal conductive composite affords unique opportunities to injection mold three-dimensional, net-shape microelectronic enclosures with superior heat dissipation performance.

  20. Application of nano-structured conducting polymers to humidity sensing

    NASA Astrophysics Data System (ADS)

    Park, Pilyeon

    Nanostructures, such as nanowires, nanocolumns, and nanotubes, have attracted a lot of attention because of their huge potential impact on a variety of applications. For sensor applications, nanostructures provide high surface area to volume ratios. The high surface area to volume ratio allows more reaction areas between target species and detection materials and also improves the detection sensitivity and response time. The main goal of this research was to exploit the advantages and develop innovative methods to accomplish the synthesis of nanowires and nano-coulmn conducting polymers used in humidity detection. To accomplish this, two fabrication methods are used. The first one utilizes the geometric confinement effect of a temporary nanochannel template to orient, precisely position, and assemble Polyaniline (PANI) nanowires as they are synthesized. The other approach is to simply spin-coat a polymer onto a substrate, and then oxygen plasma etch to generate a nano-columned Polyethylenedioxythiophene (PEDOT) thin film. 200 nm silicon oxide coated wafers with embedded platinum electrodes are used as a substrate for both fabrication methods. The biggest advantage of this first method is that it is simple, requires a single-step, i.e., synthesizing and positioning procedures are carried out simultaneously. The second method is potentially manufacturable and economic yet environmentally safe. These two methods do not produce extra nano-building materials to discard or create a health hazard. Both PANI nanowires and nano-columned PEDOT films have been tested for humidity detection using a system designed and built for this research to monitor response (current changes) to moisture, To explain the surface to volume ratio effect, 200 nm PANI nanowires and 10 microm PANI wires were directly compared for detecting moisture, and it was shown that the PANI nanowire had a better sensitivity. It was found difficult to monitor the behaviors of the PEDOT reaction to varying

  1. Anisotropic Thermal Conduction in a Polymer Liquid Subjected to Shear Flow

    NASA Astrophysics Data System (ADS)

    Venerus, David C.; Schieber, Jay D.; Balasubramanian, Venkat; Bush, Kendall; Smoukov, Stoyan

    2004-08-01

    Flow-induced anisotropic thermal conduction in a polymer liquid is studied using force Rayleigh scattering. Time-dependent measurements of the complete thermal diffusivity tensor, which includes one off-diagonal and three diagonal components, are reported on an entangled polymer melt subjected to a uniform shear deformation. These data, in conjunction with mechanical measurements of the stress, provide the first direct evidence that the thermal conductivity tensor and the stress tensor are linearly related in a deformed polymer liquid.

  2. Performance of conducting polymer electrodes for stimulating neuroprosthetics

    NASA Astrophysics Data System (ADS)

    Green, R. A.; Matteucci, P. B.; Hassarati, R. T.; Giraud, B.; Dodds, C. W. D.; Chen, S.; Byrnes-Preston, P. J.; Suaning, G. J.; Poole-Warren, L. A.; Lovell, N. H.

    2013-02-01

    Objective. Recent interest in the use of conducting polymers (CPs) for neural stimulation electrodes has been growing; however, concerns remain regarding the stability of coatings under stimulation conditions. These studies examine the factors of the CP and implant environment that affect coating stability. The CP poly(ethylene dioxythiophene) (PEDOT) is examined in comparison to platinum (Pt), to demonstrate the potential performance of these coatings in neuroprosthetic applications. Approach. PEDOT is coated on Pt microelectrode arrays and assessed in vitro for charge injection limit and long-term stability under stimulation in biologically relevant electrolytes. Physical and electrical stability of coatings following ethylene oxide (ETO) sterilization is established and efficacy of PEDOT as a visual prosthesis bioelectrode is assessed in the feline model. Main results. It was demonstrated that PEDOT reduced the potential excursion at a Pt electrode interface by 72% in biologically relevant solutions. The charge injection limit of PEDOT for material stability was found to be on average 30× larger than Pt when tested in physiological saline and 20× larger than Pt when tested in protein supplemented media. Additionally stability of the coating was confirmed electrically and morphologically following ETO processing. It was demonstrated that PEDOT-coated electrodes had lower potential excursions in vivo and electrically evoked potentials (EEPs) could be detected within the visual cortex. Significance. These studies demonstrate that PEDOT can be produced as a stable electrode coating which can be sterilized and perform effectively and safely in neuroprosthetic applications. Furthermore these findings address the necessity for characterizing in vitro properties of electrodes in biologically relevant milieu which mimic the in vivo environment more closely.

  3. Conducting polymer nanostructures for photocatalysis under visible light

    NASA Astrophysics Data System (ADS)

    Ghosh, Srabanti; Kouamé, Natalie A.; Ramos, Laurence; Remita, Samy; Dazzi, Alexandre; Deniset-Besseau, Ariane; Beaunier, Patricia; Goubard, Fabrice; Aubert, Pierre-Henri; Remita, Hynd

    2015-05-01

    Visible-light-responsive photocatalysts can directly harvest energy from solar light, offering a desirable way to solve energy and environment issues. Here, we show that one-dimensional poly(diphenylbutadiyne) nanostructures synthesized by photopolymerization using a soft templating approach have high photocatalytic activity under visible light without the assistance of sacrificial reagents or precious metal co-catalysts. These polymer nanostructures are very stable even after repeated cycling. Transmission electron microscopy and nanoscale infrared characterizations reveal that the morphology and structure of the polymer nanostructures remain unchanged after many photocatalytic cycles. These stable and cheap polymer nanofibres are easy to process and can be reused without appreciable loss of activity. Our findings may help the development of semiconducting-based polymers for applications in self-cleaning surfaces, hydrogen generation and photovoltaics.

  4. Sensing and actuating capabilities of a shape memory polymer composite integrated with hybrid filler

    NASA Astrophysics Data System (ADS)

    Lu, Haibao; Yu, Kai; Liu, Yanju; Leng, Jinsong

    2010-06-01

    In this paper, hybrid fillers, including carbon black (CB) and chopped short carbon fibers (SCF), are integrated into a styrene-based shape memory polymer (SMP) with sensing and actuating capabilities. The hybrid filler is expected to transform insulating SMP into conducting. Static mechanical properties of the SMP composites containing various filler concentrations of hybrid filler reinforcement are studied first, and it is theoretically and experimentally confirmed that the mechanical properties are significantly improved by a factor of filler content of SCF. The excellent electrical properties of this novel type of SMP composite are determined by a four-point-probe method. As a consequence, the sensing properties of SMP composite filled with 5 wt% CB and 2 wt% SCF are characterized by functions of temperature and strain. These two experimental results both aid the use of SMP composites as sensors that respond to changes in temperature or mechanical loads. On the other hand, the actuating capability of SMP composites is also validated and demonstrated. The dynamic mechanical analysis result reveals that the output strength of SMP composites is improved with an increase in filler content of SCF. The actuating capability of SMP composites is subsequently demonstrated in a series of photographs.

  5. Highly Conducting, Iodine-Doped Fluoroaluminum and Fluorogallium Naphthalocyanine Polymers.

    DTIC Science & Technology

    1982-10-20

    manium (8), alumif (10), and gallium (10) polymers are stable at high tea "Orattes under vacuum and that the silicon polymer is inert to concen...but this did not interfere.) Properties and Structures of Fluoroaluminum and Fluorogallium 2,3-Naphthalo- cyanine The two fluorides are dark green when...Can " ONR Pasadena Detachment Attn: Dr. A# B. Amster, Attn: Dr. R. J. Marcus Chemistry Division 1030 East Green Street China. Lake, California 93555

  6. Development of Soldier Conformable Antennae Using Conducting Polymers

    DTIC Science & Technology

    2010-12-01

    flexible. Wires synthesized from these materials have a wide range of applications that can include smart textiles (Carpi and Rossi, 2005; Spinks et...have its first resonant frequency at 200 MHz. The resulting laminate was then sewn into a camouflage material. The polymer was then connected to a...2005: Electroactive Polymer- Based Devices for e- Textiles in Biomedicine. IEEE Trans.Inf.Technol.Biomed., 9, 295-318. Carswell, A., E. O’Rear, and B

  7. 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

  8. Thermo-reversible morphology and conductivity of a conjugated polymer network embedded in polymeric self-assembly

    NASA Astrophysics Data System (ADS)

    Han, Youngkyu; Carrillo, Jan-Michael Y.; Zhang, Zhe; Li, Yunchao; Hong, Kunlun; Sumpter, Bobby G.; Ohl, Michael; Paranthaman, Mariappan Parans; Smith, Gregory S.; Do, Changwoo

    Self-assembly of block copolymers provides opportunities to create nano hybrid materials, utilizing self-assembled micro-domains with a variety of morphology and periodic architectures as templates for functional nano-fillers. Here we report new progress towards the fabrication of a thermally responsive conducting polymer self-assembly made from a water-soluble poly(thiophene) derivative with short PEO side chains and Pluronic L62 solution in water. The structural and electrical properties of conjugated polymer-embedded nanostructures were investigated by combining SANS, SAXS, CGMD simulations, and impedance spectroscopy. The L62 solution template organizes the conjugated polymers by stably incorporating them into the hydrophilic domains thus inhibiting aggregation. The changing morphology of L62 during the micellar-to-lamellar phase transition defines the embedded conjugated polymer network. The conductivity is strongly coupled to the structural change of the templating L62 phase and exhibits thermally reversible behavior with no signs of quenching of the conductivity at high temperature. The research was sponsored by the Scientific User Facilities Division, Office of BES, U.S. DOE and Laboratory Directed Research and Development Program of ORNL, managed by UT-Battelle, LLC.

  9. Screen printable flexible conductive nanocomposite polymer with applications to wearable sensors

    NASA Astrophysics Data System (ADS)

    Chung, D.; Khosla, A.; Gray, B. L.

    2014-04-01

    We have developed a conductive nanocomposite polymer that possesses both good conductivity and flexibility, and screen printed it onto fabric to realize wearable flexible electrodes and electronic routing. The conductive polymer consists of dispersed silver nanoparticles (90~210nm) in a screen printable plastisol polymer. The conductive polymer is conductive for weight-percentages above approximately 61 wt-% of Ag nanoparticles, and has a resistivity of 2.12×10-6 ohm·m at 70 wt-% of Ag nanoparticles. To test the screen printed conductive polymer's flexibility and its effect on conductivity, we measured the resistivity of the Ag-doped composite polymer at different bending angles (-90˚ ~ 90˚) with a 10° step angle at different wt-% of silver particles, and compared the results. We also tested washability of the screen printed conductive polymer as applied to fabric for long-term use in wearable sensors systems. We also used the screen printed Ag composite polymer to realize an example wearable system. Flexible wearable dry electrocardiogram (ECG) electrodes were developed and ECG signal was measured via the electrodes. The sensing ECG electrodes (3mm diameter circle) were chloridized to form Ag/AgCl electrodes. We measured an ECG signal using a simple right-leg driven ECG circuit and observed normal ECG signals even without application of electrolyte gel.

  10. Hybrid nanostructures using pi-conjugated polymers and nanoscale metals: synthesis, characteristics, and optoelectronic applications.

    PubMed

    Park, Dong Hyuk; Kim, Mi Suk; Joo, Jinsoo

    2010-07-01

    Pi-conjugated organic systems have been used as optoelectronic and sensing materials due to their characteristics of efficient light emission or absorption, and p-type charge transport. The hybrid nanostructures of pi-conjugated organic systems with nanoscale metals offer surface plasmon (SP)-enhanced luminescence, which can be applied to organic-based optoelectronics, photonics, and sensing. Various hybrid nanostructures using light-emitting polymers with nanoscale metals have been fabricated and have shown considerable enhancement of photoluminescence efficiency due to energy and charge transfer effects in SP resonance coupling. In this tutorial review, recent conceptual and technological achievements in light-emitting polymers-based hybrid nanostructures are described.

  11. Directly patternable, highly conducting polymers for broad applications in organic electronics.

    PubMed

    Yoo, Joung Eun; Lee, Kwang Seok; Garcia, Andres; Tarver, Jacob; Gomez, Enrique D; Baldwin, Kimberly; Sun, Yangming; Meng, Hong; Nguyen, Thuc-Quyen; Loo, Yueh-Lin

    2010-03-30

    Postdeposition solvent annealing of water-dispersible conducting polymers induces dramatic structural rearrangement and improves electrical conductivities by more than two orders of magnitude. We attain electrical conductivities in excess of 50 S/cm when polyaniline films are exposed to dichloroacetic acid. Subjecting commercially available poly(ethylene dioxythiophene) to the same treatment yields a conductivity as high as 250 S/cm. This process has enabled the wide incorporation of conducting polymers in organic electronics; conducting polymers that are not typically processable can now be deposited from solution and their conductivities subsequently enhanced to practical levels via a simple and straightforward solvent annealing process. The treated conducting polymers are thus promising alternatives for metals as source and drain electrodes in organic thin-film transistors as well as for transparent metal oxide conductors as anodes in organic solar cells and light-emitting diodes.

  12. Continuous cellularization of calcium phosphate hybrid scaffolds induced by plasma polymer activation.

    PubMed

    Bergemann, Claudia; Cornelsen, Matthias; Quade, Antje; Laube, Thorsten; Schnabelrauch, Matthias; Rebl, Henrike; Weißmann, Volker; Seitz, Hermann; Nebe, Barbara

    2016-02-01

    The generation of hybrid materials based on β-tricalcium phosphate (TCP) and various biodegradable polymers like poly(l-lactide-co-d,l-lactide) (PLA) represents a common approach to overcoming the disadvantages of pure TCP devices. These disadvantages lie in TCP's mechanical properties, such as brittleness. The positive characteristic of PLA - improvement of compressive strength of calcium phosphate scaffolds - is diametrically opposed to its cell attractiveness. Therefore, the objective of this work was to optimize osteoblast migration and cellularization inside a three-dimensionally (3D) printed, PLA polymer stabilized TCP hybrid scaffold by a plasma polymer process depositing amino groups via allylamine. MG-63 osteoblastic cells inside the 10mm hybrid scaffold were dynamically cultivated for 14days in a 3D model system integrated in a perfusion reactor. The whole TCP/PLA hybrid scaffold was continuously colonized due to plasma polymerized allylamine activation inducing the migration potential of osteoblasts.

  13. A review of properties and potential aerospace applications of electrically conducting polymers

    NASA Technical Reports Server (NTRS)

    Meador, Mary Ann B.; Gaier, James R.; Good, Brian S.; Sharp, G. Richard; Meador, Michael A.

    1990-01-01

    An overview of current research in conducting polymers is presented. Emphasis is placed on development of materials useful for aeronautic and space applications. Research on organic conducting polymers began in the early 1970s with the discovery of polyacetylene. Since then, many polymers which share structural characteristics with polyacetylene have been prepared which conduct electricity, especially when they are doped with suitable agents. Problems with environmental instability, difficult processing, poor mechanical properties and high cost have slowed the development of conducting polymers. However, practical use of these materials is imminent, based on recent refinements in understanding how polymers conduct, more systematic approaches to the development of new materials, and significant improvements in both the processing and properties.

  14. Proton Conducting Polymer Membrane Using The Ionic Liquid 2-Hydroxyethylammonium Lactate For Ethanol Fuel Cells

    NASA Astrophysics Data System (ADS)

    Oliveira, L.; José, N. M.; Boaventura, J.; Iglesias, M.; Mattedi, S.

    2011-12-01

    In this work, there were developed a proton conducting polymer membrane using an ammonium based protic ionic liquid: 2-hydroxyethylamominum lactate for use in proton exchange fuel cells (PEMFC). This kind of ionic liquid has been proven to be biodegradable and they have potentially low toxicity besides low cost of preparation, simple synthesis and purification. The prepared membranes are hybrid organic-inorganic materials. The polymeric matrix is prepared with polydimethylsiloxane (PDMS) mixed with tetraethoxysilane (TEOS) in a ratio of 70/30% in weight. Then, the eletrolytical mixture containing sodium monododecylsulfate (SDS) and the ionic liquid was introduced in the lattice near the gel point, there were used different proportions of the eletrolyte from 5 to 30% in weight. The prepared membranes were characterized using infrared spectroscopy (FTIR), X-ray diffraction (DRX), termogravimetric analysis (TGA), scanning electronic microscopy (SEM) and conductivity and impedance measurements. The prepared materials are flexible, with good thermal and mechanical stability and with a great potential to be used as conducting membranes of fuel cells. The used mixture minimizes the lixiviation lost of the ionic liquid from the polymeric membrane and enhances the cell efficiency if compared with traditional synthetic membranes.

  15. Organic thin film transistor by using polymer electrolyte to modulate the conductivity of conjugated polymer

    NASA Astrophysics Data System (ADS)

    Lin, Yu-Ju; Li, Yu-Chang; Yeh, Chih-Chieh; Chung, Sheng-Feng; Huang, Li-Ming; Wen, Ten-Chin; Wang, Yeong-Her

    2006-11-01

    This work presents an organic thin film transistor using double polymer layers, polymer electrolyte/conjugated polymer, i.e., poly(diallyldimethylammonium chloride) (PDDA)/poly(diphenylamine) (PDPA) structure. The single mobile anions (Cl-) pending on the PDDA are stuffed into the conjugated polymer to dope the nitrogen atoms (imine) by applying the gate bias, resulting a higher drain current under the same source-drain voltage. The PDDA/PDPA polymer structure working in the enhancement mode which operates under atmospheric conditions as a typical p-channel transistor is demonstrated.

  16. Hybrid electro-optic polymer modulator compatible to silicon photonic waveguide (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Yokoyama, Shiyoshi

    2016-09-01

    Electro-optic (EO) polymers are the promising material of choice for the waveguide modulation application due to their high EO coefficient, optical transparency, low dielectric loss, and compatibility with many materials and substrates. This widespread compatibility enables the construction of the unique hybrid polymer device to the silicon waveguide. One of the successful demonstrations in recent progress is the hybrid silicon modulator to the EO polymer. The hybrid silicon and polymer modulators have already demonstrated a very low half-wave voltage and multi-GHz bandwidth response. While, the fabrication is quite elaborate, involving the high-resolution lithography, controlled etching, and ion implantation process. In order to simplify the hybrid silicon and EO polymer modulator, we apply the conventional photolithography technique. The waveguide consists of silicon core with a thickness of 30 nm and a width of 2 μm, and the cladding is the polymer. In such a thin silicon core, the side-wall scattering can be significantly reduced, thus the measured propagation loss of the waveguide is 1.5 dB/cm. The optical mode calculation reveals that 55% of the optical field extends into the polymer cladding. The hybrid phase modulator waveguide performed the half-wave voltage of the modulator to be 4.6 V at 1550 nm and excellent temperature stability at 85C for longer than 500 hours. We also investigate a mode converter which can couple the light from the hybrid polymer waveguide to the silicon strip waveguide. The coupling loss between two devices is measured to be 0.5 dB.

  17. Hybrid carbon nanotube-polymer scaffolds for cardiac tissue regeneration

    NASA Astrophysics Data System (ADS)

    Ahadian, Samad; Davenport-Huyer, Locke; Smith, Nathaniel; Radisic, Milica

    2017-02-01

    Due to insufficient supply of heart transplants and limited regenerative ability of heart tissues, cardiac tissue engineering has emerged to restore or regenerate the structure and function of native cardiac tissues. Scaffolds play a major role in fabrication of functional cardiac tissues, providing structural support, biodegradation, and cell affinity. However, currently used scaffolds in cardiac tissue regeneration tend to lack adequate electrical conductivity and favorable mechanical properties. In response to these concerns, carbon nanotubes (CNTs) have been used to enhance electrical and mechanical properties of scaffolds in cardiac tissue engineering. Here, we review different hybrid CNT-biomaterial scaffolds, both natural and synthetic, in cardiac tissue regeneration and their fabrication methods. Furthermore, CNT toxicity is also discussed. We further outline future trends in this research area toward using CNTs as a functional nanomaterial in cardiac tissue engineering.

  18. Redox-active charge carriers of conducting polymers as a tuner of conductivity and its potential window

    PubMed Central

    Park, Han-Saem; Ko, Seo-Jin; Park, Jeong-Seok; Kim, Jin Young; Song, Hyun-Kon

    2013-01-01

    Electric conductivity of conducting polymers has been steadily enhanced towards a level worthy of being called its alias, “synthetic metal”. PEDOT:PSS (poly(3,4-ethylenedioxythiophene) doped with poly(styrene sulfonate)), as a representative conducting polymer, recently reached around 3,000 S cm−1, the value to open the possibility to replace transparent conductive oxides. The leading strategy to drive the conductivity increase is solvent annealing in which aqueous solution of PEDOT:PSS is treated with an assistant solvent such as DMSO (dimethyl sulfoxide). In addition to the conductivity enhancement, we found that the potential range in which PEDOT:PSS is conductive is tuned wider into a negative potential direction by the DMSO-annealing. Also, the increase in a redox-active fraction of charge carriers is proposed to be responsible for the enhancement of conductivity in the solvent annealing process. PMID:23949091

  19. 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.

  20. Biodegradable inorganic-organic hybrids of methacrylate star polymers for bone regeneration.

    PubMed

    Chung, Justin J; Fujita, Yuki; Li, Siwei; Stevens, Molly M; Kasuga, Toshihiro; Georgiou, Theoni K; Jones, Julian R

    2017-03-08

    Hybrids that are molecular scale co-networks of organic and inorganic components are promising biomaterials, improving the brittleness of bioactive glass and the strength of polymers. Methacrylate polymers have high potential as the organic source for hybrids since they can be produced, through controlled polymerization, with sophisticated polymer architectures that can bond to silicate networks. Previous studies showed the mechanical properties of hybrids can be modified by polymer architecture and molar mass (MM). However, biodegradability is critical if hybrids are to be used as tissue engineering scaffolds, since the templates must be remodelled by host tissue. Degradation by-products have to either completely biodegrade or be excreted by the kidneys. Enzyme, or bio-degradation is preferred to hydrolysis by water uptake as it is expected to give a more controlled degradation rate. Here, branched and star shaped poly(methyl methacrylate-co-3-(trimethoxysilyl)propyl methacrylate) (poly(MMA-co-TMSPMA)) were synthesized with disulphide based dimethacrylate (DSDMA) as a biodegradable branching agent. Biodegradability was confirmed by exposing the copolymers to glutathione, a tripeptide which is known to cleave disulphide bonds. Cleaved parts of the star polymer from the hybrid system were detected after 2weeks of immersion in glutathione solution, and MM was under threshold of kidney filtration. The presence of the branching agent did not reduce the mechanical properties of the hybrids and bone progenitor cells attached on the hybrids in vitro. Incorporation of the DSDMA branching agent has opened more possibilities to design biodegradable methacrylate polymer based hybrids for regenerative medicine.

  1. Rheology, structure, and properties of new phosphate glass/polymer hybrids

    NASA Astrophysics Data System (ADS)

    Urman, Kevin Leonard

    Physical modification of structure and properties via polymer blending and reinforcement is a common practice in the plastics industry and has a large economic advantage over synthesizing new polymeric materials to fulfill new material needs. Despite the large amount of interest in polymer blends and composites, the currently available commercial materials cannot satisfy the growing need for new advanced materials. This need is being addressed in part by inorganic/organic hybrid materials. By blending low-TG phosphate glasses with polymeric materials, a new class of inorganic/organic hybrids can be created. These hybrids can be processed conventionally with glass loadings of up to 60% by volume or 90% by weight, making it possible to obtain significant improvements in properties that are impossible to achieve from classical polymer blends and composites. This class of inorganic/organic hybrids containing both the inorganic low-TG phosphate glass (Pglass) and the organic polymer are very unique materials because both hybrid components are fluid during processing. Thereby, providing the ability to tailor both the hybrid morphology and properties in unprecedented ways through carefully controlled processing. This dissertation discusses the continuing research into low-Tg tin fluorophosphate glass blended with commodity resins. The specific resins of interest are low density polyethylene (LDPE), polyamide 12, and polyamide 6. The shear rheology and the extensional flow characteristics of LDPE hybrids were studied to understand hybrid behavior under flow characteristics typical of many polymer processing techniques. The elongational flow was also utilized to generate unique morphologies, enhance crystallinity, and to alter polymer chain orientation. The extension of this field into interacting commodity resins like polyamide 12 and polyamide 6 yielded new hybrids with unprecedented properties. Polyamide 12 hybrids were used to build the first processing

  2. Electrical conducting behavior of hybrid nanocomposites containing polyaniline, carbon nanotube, and carbon black

    NASA Astrophysics Data System (ADS)

    Veena, M. G.; Renukappa, N. M.; Siddaramaiah, M.; Sudhakersamuel, R. D.

    2008-12-01

    Nanocomposites of high density polyethylene (HDPE) reinforced with hybrid fillers of polyaniline coated multiwalled carbon nanotube (MWNT), and carbon black (CB) were developed aiming at enhancing the electrical conductivity of the composites. The electrical properties such as volume resistivity, impedance, and conductance have been measured as a function of filler volume concentration (%), frequency and voltage. The electrical property such as volume resistivity depends on the concentration of fillers. This is due to the formation of a continuous conducting network throughout the polymer matrix with increase in the conducting filler. This kind of variation is referred as Maxwell-Wagner effect. The resistance of the prepared PANI/c-MWNT/CB/HDPE nanocomposites is found to be ohmic. It was shown that adding CB in PANI/c-MWCNTs composites can enhance the electrical properties of the nanocomposites: a low percolation threshold was achieved with 0.25 wt% CNTs and 20 wt% of CB/HDPE. CB enhanced the ductility of the nanocomposites, confirming the synergic effect of CB as effective multi-functional filler.

  3. Methods of enhancing conductivity of a polymer-ceramic composite electrolyte

    NASA Technical Reports Server (NTRS)

    Kumar, Binod (Inventor)

    2003-01-01

    Methods for enhancing conductivity of polymer-ceramic composite electrolytes are provided which include forming a polymer-ceramic composite electrolyte film by a melt casting technique and uniaxially stretching the film from about 5 to 15% in length. The polymer-ceramic composite electrolyte is also preferably annealed after stretching such that it has a room temperature conductivity of from 10.sup.-4 S cm.sup.-1 to 10.sup.-3 S cm.sup.-1. The polymer-ceramic composite electrolyte formed by the methods of the present invention may be used in lithium rechargeable batteries.

  4. Methods of enhancing conductivity of a polymer-ceramic composite electrolyte

    DOEpatents

    Kumar, Binod

    2003-12-02

    Methods for enhancing conductivity of polymer-ceramic composite electrolytes are provided which include forming a polymer-ceramic composite electrolyte film by a melt casting technique and uniaxially stretching the film from about 5 to 15% in length. The polymer-ceramic composite electrolyte is also preferably annealed after stretching such that it has a room temperature conductivity of from 10.sup.-4 S cm.sup.-1 to 10.sup.-3 S cm.sup.-1. The polymer-ceramic composite electrolyte formed by the methods of the present invention may be used in lithium rechargeable batteries.

  5. Carbon paste electrode modified with duplex molecularly imprinted polymer hybrid film for metronidazole detection.

    PubMed

    Xiao, Ni; Deng, Jian; Cheng, Jianlin; Ju, Saiqin; Zhao, Haiqing; Xie, Jin; Qian, Duo; He, Jun

    2016-07-15

    A novel electrochemical sensor based on duplex molecularly imprinted polymer (DMIP) hybrid film modified carbon paste electrode (CPE) has been developed for highly sensitive and selective determination of metronidazole (MNZ). A conductive poly(anilinomethyltriethoxysilane) film is firstly electrodeposited on the surface of a CPE, and then a molecularly imprinted polysiloxane (MIPS) membrane is covalently covered on the film via sol-gel process. The as-constructed DMIP hybrid film, combining the advantages of MIPS and conducting MIP, can make feasible the direct and efficient signal transformation between the target analyte and the transducer, as well as enhance the imprinting recognition capability, mass transfer efficiency and the detection sensitivity. Under optimized conditions, the reduction peak currents of MNZ are linear to MNZ concentrations in the range from 4.0×10(-7) to 2.0×10(-4) molL(-1) with a detection limit of 9.1×10(-8)molL(-1). The RSD values vary from 2.9% to 4.7% for intra-day and from 3.4% to 4.2% for inter-day precision. The DMIP-based sensor has been successfully applied for the determination of MNZ in biological and pharmaceutical samples. The accuracy and reliability of the method is further confirmed by high performance liquid chromatography. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Synthesis of functionalized asymmetric star polymers containing conductive polyacetylene segments by living anionic polymerization.

    PubMed

    Zhao, Youliang; Higashihara, Tomoya; Sugiyama, Kenji; Hirao, Akira

    2005-10-19

    Novel 3-arm ABC, 4-arm ABCD, and 5-arm ABCDE asymmetric star polymers comprising the conductive polyacetylene precursor, poly(4-methylphenyl vinyl sulfoxide) (PMePVSO), and other segments, such as polystyrene, poly(alpha-methylstyrene), poly(4-methoxystyrene), poly(4-trimethylsilylstyrene), and poly(4-methylstyrene), were synthesized by the methodology based on living anionic polymerization using DPE-functionalized polymers. This methodology involves the addition reaction of a DPE-functionalized polymer to a living anionic polymer followed by the living anionic polymerization of MePVSO initiated from the in situ formed polymer anion with two, three, or four polymer segments. The resultant asymmetric star polymers possessed predetermined molecular weights, narrow molecular weight distributions (Mw/Mn < 1.03), and desired compositions as confirmed by SEC, 1H NMR, SLS, and elemental analysis. After thermal treatment, the PMePVSO segment in the star polymer could be completely converted into a conductive polyacetylene segment, evident from TGA and elemental analysis. These asymmetric star polymers are expected to exhibit interesting solution properties and unique microphase-separated morphological suprastructures with potential applications in nanoscopic conductive materials. Moreover, this methodology can afford the target asymmetric star polymers with arm segments varying in a wide range and enables the synthesis of more complex macromolecular architectures.

  7. Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

    PubMed Central

    Collman, James P.; McDevitt, John T.; Yee, Gordon T.; Leidner, Charles R.; McCullough, Laughlin G.; Little, William A.; Torrance, Jerry B.

    1986-01-01

    The synthesis and characterization of pyrazine-bridged polymers of iron(II/III), ruthenium(II/III), and osmium(II/III) octaethylporphyrin (dubbed “shish-kebab” polymers) are presented. Optical and dc conductivity measurements reveal that the ruthenium and osmium polymers, when partially oxidized, are highly conductive. Electrochemical and ESR results are presented that indicate the existence of an interesting metal-centered conduction pathway. Unlike most of the previously reported porphyrinic molecular metals in which the conduction electrons are macrocyclic-based, electron transport in these materials proceeds exclusively along the metal-pyrazine backbone. PMID:16593717

  8. 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.

  9. 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

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

    SciTech Connect

    Gupta, Sanju 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 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, 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 determine

  11. Characterization of proton conducting blend polymer electrolyte using PVA-PAN doped with NH4SCN

    NASA Astrophysics Data System (ADS)

    Premalatha, M.; Mathavan, T.; Selvasekarapandian, S.; Genova, F. Kingslin Mary; Umamaheswari, R.

    2016-05-01

    Polymer electrolytes with proton conductivity based on blend polymer using polyvinyl alcohol (PVA) and poly acrylo nitrile (PAN) doped with ammonium thiocyanate have been prepared by solution casting method using DMF as solvent. The complex formation between the blend polymer and the salt has been confirmed by FTIR Spectroscopy. The amorphous nature of the blend polymer electrolytes have been confirmed by XRD analysis. The highest conductivity at 303 K has been found to be 3.25 × 10-3 S cm-1 for 20 mol % NH4SCN doped 92.5PVA:7.5PAN system. The increase in conductivity of the doped blend polymer electrolytes with increasing temperature suggests the Arrhenius type thermally activated process. The activation energy is found to be low (0.066 eV) for the highest conductivity sample.

  12. Studies on Proton Conducting Polymer Electrolytes Based on Pvdf-Pva with NH4NO3

    NASA Astrophysics Data System (ADS)

    Muthuvinayagam, M.; Gopinathan, C.; Rajeswari, N.; Selvasekarapandian, S.; Sanjeeviraja, C.

    2013-07-01

    PVDF-PVA polymer electrolytes with various blend ratios are prepared by solution casting technique with DMF (Merck) as solvent to optimize the blend ratio on the basis of high ionic conductivity. Then, different concentrations of NH4NO3 are doped with the optimized PVDF-PVA blend ratio and polymer blend electrolytes are prepared. The complex formation has been confirmed by XRD and FTIR analysis. The ac impedance studies are performed to evaluate the ionic conductivity of the polymer electrolyte membranes in the range 303-323K and it is found that the temperature dependence of ionic conductivity of the polymer blend electrolytes obey the Arrhenius relation. The maximum ionic conductivity is found to be 5.99×10-4 S/cm with activation energy Ea=0.21 eV for PVDF-PVA-NH4NO3 (80:20:0.4MWt%) polymer electrolyte.

  13. Spray-coated carbon nanotube carpets for creeping reduction of conducting polymer based artificial muscles

    NASA Astrophysics Data System (ADS)

    Simaite, Aiva; Delagarde, Aude; Tondu, Bertrand; Souères, Philippe; Flahaut, Emmanuel; Bergaud, Christian

    2017-01-01

    During cyclic actuation, conducting polymer based artificial muscles are often creeping from the initial movement range. One of the likely reasons of such behaviour is unbalanced charging during conducting polymer oxidation and reduction. To improve the actuation reversibility and subsequently the long time performance of ionic actuators, we suggest using spray-coated carbon nanotube (CNT) carpets on the surface of the conducting polymer electrodes. We show that carbon nanotubes facilitate a conducting polymer redox reaction and improve its reversibility. Consequently, in the long term, charge accumulation in the polymer film is avoided leading to a significantly improved lifetime performance during cycling actuation. To our knowledge, it is the first time a simple solution to an actuator creeping problem has been suggested.

  14. Spray-coated carbon nanotube carpets for creeping reduction of conducting polymer based artificial muscles.

    PubMed

    Simaite, Aiva; Delagarde, Aude; Tondu, Bertrand; Souères, Philippe; Flahaut, Emmanuel; Bergaud, Christian

    2017-01-13

    During cyclic actuation, conducting polymer based artificial muscles are often creeping from the initial movement range. One of the likely reasons of such behaviour is unbalanced charging during conducting polymer oxidation and reduction. To improve the actuation reversibility and subsequently the long time performance of ionic actuators, we suggest using spray-coated carbon nanotube (CNT) carpets on the surface of the conducting polymer electrodes. We show that carbon nanotubes facilitate a conducting polymer redox reaction and improve its reversibility. Consequently, in the long term, charge accumulation in the polymer film is avoided leading to a significantly improved lifetime performance during cycling actuation. To our knowledge, it is the first time a simple solution to an actuator creeping problem has been suggested.

  15. The influence of interfaces on the dielectric properties of MnZn-based hybrid polymer composites

    NASA Astrophysics Data System (ADS)

    Moučka, R.; Vilčáková, J.; Kazantseva, N. E.; Lopatin, A. V.; Sáha, P.

    2008-11-01

    In the present paper we report on the specific features of the dielectric properties of a MnZn ferrite/Al based composite. Previously, it has been shown that high-frequency magnetic losses in such hybrid composites (HCs) can be enhanced due to the formation of a core-shell-like structure of a composite, in which ferrite particles are immersed into a conducting medium formed by a continuous network of conducting particles that spans throughout the polymer matrix. Simultaneously, one can vary the dielectric properties of HCs by changing the type and the concentration of conducting particles. Dielectric constant and ac conductivity measurements of MnZn-based composites have been made over the frequency range of 10 Hz-100 kHz in temperature interval from -30 to 100 °C and at ambient temperature up to 3 GHz. The results obtained show that addition of aluminum into the MnZn ferrite/polyurethane composite leads to a decrease in the dc conductivity due to the insulating barrier of Al-Al2O3. On the other hand, ac conductivity of MnZn ferrite and aluminum/polyurethane composite is greater than that of a two-component system due to the occurrence of Maxwell-Wagner-Sillars relaxation processes with a rather low value of activation energy and significantly higher relaxation time. Thus, on one side, aluminum provides sufficient conductivity of the "shell" and thus leads to the enhancement of effective permeability, but, on other side, it does not significantly contribute to the total conductivity (effective permittivity) of HCs. The analysis of the efficiency of HCs with different types of conducting filler as electromagnetic wave absorbers (EWAs) has shown that the matching frequency of EWAs can be effectively controlled in the radio-frequency range through an appropriate choice of the type of conducting filler.

  16. Reciprocated suppression of polymer crystallization toward improved solid polymer electrolytes: Higher ion conductivity and tunable mechanical properties

    DOE PAGES

    Bi, Sheng; Sun, Che-Nan; Zawodzinski, Thomas A.; ...

    2015-08-06

    Solid polymer electrolytes based on lithium bis(trifluoromethanesulfonyl) imide and polymer matrix were extensively studied in the past due to their excellent potential in a broad range of energy related applications. Poly(vinylidene fluoride) (PVDF) and polyethylene oxide (PEO) are among the most examined polymer candidates as solid polymer electrolyte matrix. In this paper, we study the effect of reciprocated suppression of polymer crystallization in PVDF/PEO binary matrix on ion transport and mechanical properties of the resultant solid polymer electrolytes. With electron and X-ray diffractions as well as energy filtered transmission electron microscopy, we identify and examine the appropriate blending composition thatmore » is responsible for the diminishment of both PVDF and PEO crystallites. Laslty, a three-fold conductivity enhancement is achieved along with a highly tunable elastic modulus ranging from 20 to 200 MPa, which is expected to contribute toward future designs of solid polymer electrolytes with high room-temperature ion conductivities and mechanical flexibility.« less

  17. Conducting polymer based DNA biosensor for the detection of the Bacillus cereus group species

    NASA Astrophysics Data System (ADS)

    Velusamy, Vijayalakshmi; Arshak, Khalil; Korostynska, Olga; Oliwa, Kamila; Adley, Catherine

    2009-05-01

    Biosensor designs are emerging at a significant rate and play an increasingly important role in foodborne pathogen detection. Conducting polymers are excellent tools for the fabrication of biosensors and polypyrrole has been used in the detection of biomolecules due to its unique properties. The prime intention of this paper was to pioneer the design and fabrication of a single-strand (ss) DNA biosensor for the detection of the Bacillus cereus (B.cereus) group species. Growth of B. cereus, results in production of several highly active toxins. Therefore, consumption of food containing >106 bacteria/gm may results in emetic and diarrhoeal syndromes. The most common source of this bacterium is found in liquid food products, milk powder, mixed food products and is of particular concern in the baby formula industry. The electrochemical deposition technique, such as cyclic voltammetry, was used to develop and test a model DNA-based biosensor on a gold electrode electropolymerized with polypyrrole. The electrically conducting polymer, polypyrrole is used as a platform for immobilizing DNA (1μg) on the gold electrode surface, since it can be more easily deposited from neutral pH aqueous solutions of pyrrolemonomers. The average current peak during the electrodeposition event is 288μA. There is a clear change in the current after hybridization of the complementary oligonucleotide (6.35μA) and for the noncomplementary oligonucleotide (5.77μA). The drop in current after each event was clearly noticeable and it proved to be effective.

  18. Bioinspired Routes to Lithium-Ion Conducting Polymers and Nanomembranes

    DTIC Science & Technology

    2008-05-21

    is then catalyzed by a copper complex in the presence of methyl methacrylate , glycidyl methacrylate , and ethyleneglycol dimethacrylate as monomers ... methyl methacrylate , glycidyl methacrylate , phenyl methacrylate , ethylene glycol dimetharylate, styrene, and acrylonitrile were all successful preformed...For the methyl methacrylate polymerization the time and conversion dependant polymer characteristics where studied using GPC and refractive index

  19. Novel, Solvent-Free, Single Ion-Conductive Polymer Electrolytes

    DTIC Science & Technology

    2008-02-01

    SUBJECT TERMS EOARD, Power, Electrochemistry, Batteries 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT UL 18, NUMBER OF PAGES...the diffraction patterns of the LiBOB-PEO with the LiTf and LiBF4 -based polymer electrolyte. As can be seen from the Figures, the XRD lines

  20. Proton Conductive Nanosheets Formed by Alignment of Metallo-Supramolecular Polymers.

    PubMed

    Pandey, Rakesh K; Rana, Utpal; Chakraborty, Chanchal; Moriyama, Satoshi; Higuchi, Masayoshi

    2016-06-01

    Linear Fe(II)-based metallo-supramolecular polymer chains were precisely aligned by the simple replacement of the counteranion with an N,N'-bis(4-benzosulfonic acid)perylene-3,4,9,10-tetracarboxylbisimide (PSA) dianion, which linked the polymer chains strongly. A parallel alignment of the polymer chains promoted by the PSA dianions yielded nanosheets formation. The nanosheets' structure was analyzed with FESEM, HRTEM, UV-vis, and XRD in detail. The nanosheets showed more than 5 times higher proton conductivity than the original polymer due to the smooth ionic conduction through the aligned polymer chains. The complex impedance plot with two semicircles also suggested the presence of grain boundaries in the polymer nanosheets.