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Sample records for polyethylene oxide polyethylene

  1. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Oxidized polyethylene. 172.260 Section 172.260... CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may... polyethylene is the basic resin produced by the mild air oxidation of polyethylene. The polyethylene used...

  2. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Oxidized polyethylene. 172.260 Section 172.260... CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may... polyethylene is the basic resin produced by the mild air oxidation of polyethylene. The polyethylene used...

  3. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Oxidized polyethylene. 172.260 Section 172.260... CONSUMPTION Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may... polyethylene is the basic resin produced by the mild air oxidation of polyethylene. The polyethylene used...

  4. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Oxidized polyethylene. 172.260 Section 172.260... § 172.260 Oxidized polyethylene. Oxidized polyethylene may be safely used as a component of food, subject to the following restrictions: (a) Oxidized polyethylene is the basic resin produced by the...

  5. 21 CFR 177.1620 - Polyethylene, oxidized.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene, oxidized. 177.1620 Section 177.1620... Contact Surfaces § 177.1620 Polyethylene, oxidized. Oxidized polyethylene identified in paragraph (a) of... following prescribed conditions: (a) Oxidized polyethylene is the basic resin produced by the mild...

  6. 21 CFR 172.260 - Oxidized polyethylene.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Oxidized polyethylene. 172.260 Section 172.260 Food... Coatings, Films and Related Substances § 172.260 Oxidized polyethylene. Oxidized polyethylene may be safely used as a component of food, subject to the following restrictions: (a) Oxidized polyethylene is...

  7. 21 CFR 177.1620 - Polyethylene, oxidized.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene, oxidized. 177.1620 Section 177.1620... Components of Single and Repeated Use Food Contact Surfaces § 177.1620 Polyethylene, oxidized. Oxidized polyethylene identified in paragraph (a) of this section may be safely used as a component of...

  8. 21 CFR 177.1620 - Polyethylene, oxidized.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene, oxidized. 177.1620 Section 177.1620... Components of Single and Repeated Use Food Contact Surfaces § 177.1620 Polyethylene, oxidized. Oxidized polyethylene identified in paragraph (a) of this section may be safely used as a component of...

  9. 21 CFR 177.1620 - Polyethylene, oxidized.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene, oxidized. 177.1620 Section 177.1620... Components of Single and Repeated Use Food Contact Surfaces § 177.1620 Polyethylene, oxidized. Oxidized polyethylene identified in paragraph (a) of this section may be safely used as a component of...

  10. 21 CFR 177.1620 - Polyethylene, oxidized.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene, oxidized. 177.1620 Section 177.1620... Components of Single and Repeated Use Food Contact Surfaces § 177.1620 Polyethylene, oxidized. Oxidized polyethylene identified in paragraph (a) of this section may be safely used as a component of...

  11. Poly(ethylene oxide) functionalization

    DOEpatents

    Pratt, Russell Clayton

    2014-04-08

    A simple procedure is provided by which the hydroxyl termini of poly(ethylene oxide) can be appended with functional groups to a useful extent by reaction and precipitation. The polymer is dissolved in warmed toluene, treated with an excess of organic base and somewhat less of an excess of a reactive acylating reagent, reacted for several hours, then precipitated in isopropanol so that the product can be isolated as a solid, and salt byproducts are washed away. This procedure enables functionalization of the polymer while not requiring laborious purification steps such as solvent-solvent extraction or dialysis to remove undesirable side products.

  12. Self-Healing of Polyethylene Oxide

    NASA Astrophysics Data System (ADS)

    Chipara, Dorina Magdalena; Flores, Maritza; Puente, Nancy; Lozano, Karen

    2011-03-01

    Autonomic self-healing is expected to enhance the lifetime of polymeric materials, resins, and composites subjected to long term mechanical stresses. The self-healing process is initiated by the rupture of some polyurea-formaldehyde microcapsules filled with monomer. The self-healing polymer is actually a compound containing microcapsules filled with monomer and catalyst particles. The monomer released from these broken microcapsules is diffusing within the polymer, reacting with the catalyst and starting a polymerization reaction. This new polymer, growing within the propagating crack, stops the mechanical failure. While the process is pretty slow (timescale of the order of 10 to 100 s), there are many important technological applications that would benefit from the availability of self-healing polymers. We report about the addition of self-healing capabilities to polyethylene oxide by using polyurea formaldehyde microcapsules filled with dicyclopentadiene and first generation Grubbs catalysts. Details regarding the physical and chemical steps used to add self-healing capabilities to polyethylene oxide will be presented. Self-healing efficiency was assessed by fatigues tests.

  13. Polyethylene oxide hydration in grafted layers

    NASA Astrophysics Data System (ADS)

    Dormidontova, Elena; Wang, Zilu

    Hydration of water soluble polymers is one of the key-factors defining their conformation and properties, similar to biopolymers. Polyethylene oxide (PEO) is one of the most important biomedical-applications polymers and is known for its reverse temperature solubility due to hydrogen bonding with water. As in many practical applications PEO chains are grafted to surfaces, e.g. of nanoparticles or planar surfaces, it is important to understand PEO hydration in such grafted layers. Using atomistic molecular dynamic simulations we investigate the details of molecular conformation and hydration of PEO end-grafted to gold surfaces. We analyze polymer and water density distribution as a function of distance from the surface for different grafting densities. Based on a detailed analysis of hydrogen bonding between polymer and water in grafted PEO layers, we will discuss the extent of PEO hydration and its implication for polymer conformation, mobility and layer properties. This research is supported by NSF (DMR-1410928).

  14. Anomalous diffusion of poly(ethylene oxide) in agarose gels.

    PubMed

    Brenner, Tom; Matsukawa, Shingo

    2016-11-01

    We report on the effect of probe size and diffusion time of poly(ethylene) oxide in agarose gels. Time-dependence of the diffusion coefficient, reflecting anomalous diffusion, was observed for poly(ethylene) oxide chains with hydrodynamic radii exceeding about 20nm at an agarose concentration of 2%. The main conclusion is that the pore distribution includes pores that are only several nm across, in agreement with scattering reports in the literature. Interpretation of the diffusion coefficient dependence on the probe size based on a model of entangled rigid rods yielded a rod length of 72nm.

  15. Polyethylene Oxidation in Total Hip Arthroplasty: Evolution and New Advances

    PubMed Central

    Gómez-Barrena, Enrique; Medel, Francisco; Puértolas, José Antonio

    2009-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) remains the gold standard acetabular bearing material for hip arthroplasty. Its successful performance has shown consistent results and survivorship in total hip replacement (THR) above 85% after 15 years, with different patients, surgeons, or designs. As THR results have been challenged by wear, oxidation, and liner fracture, relevant research on the material properties in the past decade has led to the development and clinical introduction of highly crosslinked polyethylenes (HXLPE). More stress on the bearing (more active, overweighted, younger patients), and more variability in the implantation technique in different small and large Hospitals may further compromise the clinical performance for many patients. The long-term in vivo performance of these materials remains to be proven. Clinical and retrieval studies after more than 5 years of in vivo use with HXLPE in THR are reviewed and consistently show a substantial decrease in wear rate. Moreover, a second generation of improved polyethylenes is backed by in vitro data and awaits more clinical experience to confirm the experimental improvements. Also, new antioxidant, free radical scavengers, candidates and the reinforcement of polyethylene through composites are currently under basic research. Oxidation of polyethylene is today significantly reduced by present formulations, and this forgiving, affordable, and wellknown material is still reliable to meet today’s higher requirements in total hip replacement. PMID:20111694

  16. Influence of different factors on the destruction of films based on polylactic acid and oxidized polyethylene

    NASA Astrophysics Data System (ADS)

    Podzorova, M. V.; Tertyshnaya, Yu. V.; Pantyukhov, P. V.; Shibryaeva, L. S.; Popov, A. A.; Nikolaeva, S.

    2016-11-01

    Influence of different environmental factors on the degradation of film samples based on polylactic acid and low density polyethylene with the addition of oxidized polyethylene was studied in this work. Different methods were used to find the relationship between degradation and ultraviolet, moisture, oxygen. It was found that the addition of oxidized polyethylene, used as a model of recycled polyethylene, promotes the degradation of blends.

  17. Wear Analysis in THA Utilizing Oxidized Zirconium and Crosslinked Polyethylene

    PubMed Central

    Garvin, Kevin L.; Mangla, Jimmi; Murdoch, Nathan; Martell, John M.

    2008-01-01

    Oxidized zirconium, a material with a ceramic surface on a metal substrate, and highly cross-linked polyethylene are two materials developed to reduce wear. We measured in vivo femoral head penetration in patients with these advanced bearings. We hypothesized the linear wear rates would be lower than those published for cobalt-chrome and standard polyethylene. We retrospectively reviewed a select series of 56 THAs in a relatively young, active patient population utilizing oxidized zirconium femoral heads and highly cross-linked polyethylene acetabular liners. Femoral head penetration was determined using the Martell computerized edge-detection method. All patients were available for 2-year clinical and radiographic followup. True linear wear was 4 μm/year (95% confidence intervals, ± 59 μm/year). The early wear rates in this cohort of relatively young, active patients were low and we believe justify the continued study of these alternative bearing surfaces. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18946711

  18. Polyethylene Glycol 3350

    MedlinePlus

    Polyethylene glycol 3350 is used to treat occasional constipation. Polyethylene glycol 3350 is in a class of medications ... Polyethylene glycol 3350 comes as a powder to be mixed with a liquid and taken by mouth. ...

  19. Electrospun Polyaniline/Polyethylene Oxide Nanofiber Field Effect Transistor

    NASA Technical Reports Server (NTRS)

    Pinto, N. J.; Johnson, A. T.; MacDiarmid, A. G.; Mueller, C. H.; Theofylaktos, N.; Robinson, D. C.; Miranda, F. A.

    2003-01-01

    We report on the observation of field effect transistor (FET) behavior in electrospun camphorsulfonic acid doped polyaniline(PANi)/polyethylene oxide(PE0) nanofibers. Saturation channel currents are observed at surprisingly low source/drain voltages. The hole mobility in the depletion regime is 1.4 x 10(exp -4) sq cm/V s while the 1-D charge density (at zero gate bias) is calculated to be approximately 1 hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (approx. 10(exp -3) S/cm). Reducing or eliminating the PEO content in the fiber is expected to enhance device parameters. Electrospinning is thus proposed as a simple method of fabricating 1-D polymer FET's.

  20. Stability of β-carotene in polyethylene oxide electrospun nanofibers

    NASA Astrophysics Data System (ADS)

    Peinado, I.; Mason, M.; Romano, A.; Biasioli, F.; Scampicchio, M.

    2016-05-01

    β-carotene (βc) was successfully incorporated into electrospun nanofibers of poly-(ethylene oxide) (PEO) with the aim of prolonging its shelf life and thermal stability. The physical and thermal properties of the βc-PEO-nanofibers were determined by scanning electron microscopy (SEM), color analysis, and differential scanning calorimetry (DSC). The nanofibers of PEO and βc-PEO exhibited average fiber diameters of 320 ± 46 and 230 ± 21 nm, with colorimetric coordinates L* = 95.7 ± 2.4 and 89.4 ± 4.6 and b* = -0.5 ± 0.1 and 6.2 ± 3.0 respectively. Thermogravimetric analysis coupled with Proton Transfer-Mass Spectroscopy (TGA/PTR-ms) demonstrated that coated βc inside PEO nanofibers increased thermal stability when compared to standard βc in powder form. In addition, β-carotene in the membranes showed higher stability during storage when compared with β-carotene in solution with a decrease in concentration of 57 ± 4% and 70 ± 2% respectively, thus should extend the shelf life of this compound. Also, TGA coupled with PTR-MS resulted in a promising technique to online-monitoring thermal degradation.

  1. Various-sourced pectin and polyethylene oxide electrospun fibers.

    PubMed

    Rockwell, Pamela L; Kiechel, Marjorie A; Atchison, Jennifer S; Toth, Laura J; Schauer, Caroline L

    2014-07-17

    Pectin, a naturally occurring and biorenewable polysaccharide, is derived from plant cell wall tissue and used in applications ranging from food processing to biomedical engineering. Due to extraction methods and source variation, there is currently no consensus in literature as to the exact structure of pectin. Here, we have studied key material properties of electrospun pectin blends with polyethylene oxide (PEO) (1:1, v/v) in order to demonstrate the fabrication of a fibrous and less toxic material system, as well as to understand the effects of source variability on the resulting fibrous mats. The bulk pectin degree of esterification (DE) estimated using FTIR (bulk apple pomace (AP)=28%, bulk citrus peel (CP)=86% and bulk sugar beet pulp (SBP)=91%) was shown to inversely correlate with electrospun fiber crystallinity determined using XRD (PEO-AP=37%, PEO-CP=28% and PEO-SBP=23%). This in turn affected the trend observed for the mean fiber diameter (n=50) (PEO-AP=124 ± 26 nm, PEO-CP=493 ± 254 nm and PEO-SBP=581 ± 178 nm) and elastic tensile moduli (1.6 ± 0.2 MPa, 4.37 ± 0.64 MPa and 2.49 ± 1.46 MPa, respectively) of the fibrous mats. Electrospun fibers containing bulk AP had the lowest DE, highest crystallinity, smallest mean fiber diameter, and lowest tensile modulus compared to either the bulk CP or bulk SBP. Bound water in PEO-CP fiber and bulk pectin impurities in PEO-SPB were observed to influence fiber branching and mean diameter distributions, which in turn influenced the fiber tensile properties. These results indicate that pectin, when blended with PEO in water, produces submicron fibrous mats with pectin influencing the blend fiber properties. Moreover, the source of pectin is an important variable in creating electrospun blend fibrous mats with desired material properties.

  2. Effect of ultraviolet radiation in the photo-oxidation of High Density Polyethylene and Biodegradable Polyethylene films

    NASA Astrophysics Data System (ADS)

    Martínez-Romo, A.; González Mota, R.; Bernal, J. J. Soto; Frausto Reyes, C.; Rosales Candelas, I.

    2015-01-01

    One of the most widely used plastics in the world is the High density polyethylene (HDPE), it is a stable material due to its carbon-carbon bonds, causing their slow degradation; which is why we are looking for alternative ways to accelerate the degradation process of this polymer. An alternative is the addition of oxidized groups in its molecular structure, which results in the development of polymers susceptible to biodegradation (PE-BIO). In this paper, HDPE and PE-BIO films were exposed to UV-B radiation (320-280 nm) at different exposure times, 0-60 days. The effects of UV radiation in samples of HDPE and PE-BIO were characterized using infrared spectroscopy with attenuated total reflectance (ATR). The results show that the exposed materials undergo changes in their molecular structure, due to the infrared bands formed which corresponds to the photo-oxidation of HDPE and PE films when submitted to UV-B radiation.

  3. FETs Based on Doped Polyaniline/Polyethylene Oxide Fibers

    NASA Technical Reports Server (NTRS)

    Theofylaktos, Noulie; Robinson, Daryl; Miranda, Felix; Pinto, Nicholas; Johnson, Alan, Jr.; MacDiarmid, Alan; Mueller, Carl

    2006-01-01

    A family of experimental highly miniaturized field-effect transistors (FETs) is based on exploitation of the electrical properties of nanofibers of polyaniline/ polyethylene oxide (PANi/PEO) doped with camphorsulfonic acid. These polymer-based FETs have the potential for becoming building blocks of relatively inexpensive, low-voltage, highspeed logic circuits that could supplant complementary metal oxide/semiconductor (CMOS) logic circuits. The development of these polymerbased FETs offers advantages over the competing development of FETs based on carbon nanotubes. Whereas it is difficult to control the molecular structures and, hence, the electrical properties of carbon nanotubes, it is easy to tailor the electrical properties of these polymerbased FETs, throughout the range from insulating through semiconducting to metallic, through choices of doping levels and chemical manipulation of polymer side chains. A further advantage of doped PANi/PEO nanofibers is that they can be made to draw very small currents and operate at low voltage levels, and thus are promising for applications in which there are requirements to use many FETs to obtain large computational capabilities while minimizing power demands. Fabrication of an experimental FET in this family begins with the preparation of a substrate as follows: A layer of silicon dioxide between 50 and 200 nm thick is deposited on a highly doped (resistivity 0.01 W.cm) silicon substrate, then gold electrodes/contact stripes are deposited on the oxide. Next, one or more fibers of camphorsulphonic acid-doped PANi/PEO having diameters of the order of 100 nm are electrospun onto the substrate so as to span the gap between the gold electrodes (see Figure 1). Figure 2 depicts measured current-versus-voltage characteristics of the device of Figure 1, showing that saturation channel currents occur at source-todrain potentials that are surprisingly low, relative to those of CMOS FETs. The hole mobility in the depletion regime in

  4. Extrusion of polysaccharide nanocrystal reinforced polymer nanocomposites through compatibilization with poly(ethylene oxide).

    PubMed

    Pereda, Mariana; El Kissi, Nadia; Dufresne, Alain

    2014-06-25

    Polysaccharide nanocrystals with a rodlike shape but with different dimensions and specific surface area were prepared from cotton and capim dourado cellulose, and with a plateletlike morphology from waxy maize starch granules. The rheological behavior of aqueous solutions of poly(ethylene oxide) (PEO) with different molecular weights when adding these nanoparticles was investigated evidencing specific interactions between PEO chains and nanocrystals. Because PEO also bears hydrophobic moieties, it was employed as a compatibilizing agent for the melt processing of polymer nanocomposites. The freeze-dried mixtures were used to prepare nanocomposite materials with a low density polyethylene matrix by extrusion. The thermal and mechanical behavior of ensuing nanocomposites was studied.

  5. [Biodegradation of polyethylene].

    PubMed

    Yang, Jun; Song, Yi-ling; Qin, Xiao-yan

    2007-05-01

    Plastic material is one of the most serious solid wastes pollution. More than 40 million tons of plastics produced each year are discarded into environment. Plastics accumulated in the environment is highly resistant to biodegradation and not be able to take part in substance recycle. To increase the biodegradation efficiency of plastics by different means is the main research direction. This article reviewed the recent research works of polyethylene biodegradation that included the modification and pretreatment of polyethylene, biodegradation pathway, the relevant microbes and enzymes and the changes of physical, chemical and biological properties after biodegradation. The study directions of exploiting the kinds of life-forms of biodegradation polyethylene except the microorganisms, isolating and cloning the key enzymes and gene that could produce active groups, and enhancing the study on polyethylene biodegradation without additive were proposed.

  6. Oxidation in ultrahigh molecular weight polyethylene and cross-linked polyethylene acetabular cups tested against roughened femoral heads in a hip joint simulator.

    PubMed

    Taddei, Paola; Affatato, Saverio; Fagnano, Concezio; Toni, Aldo

    2006-06-01

    This study was aimed at comparing the oxidative degradation of commercial acetabular cups made of cross-linked polyethylene (XLPE) and conventional ultrahigh molecular weight polyethylene (UHMWPE). After testing against deliberately scratched CoCrMo femoral heads in a hip joint simulator, the cups, microtomed parallel to the articulating surface, were analyzed by IR spectroscopy. Due to the potential for artifacts caused by absorbed contaminants, the IR spectra were compared only after hexane extraction; actually, XLPE was found to absorb more serum than UHMWPE. The two sets of unworn acetabular cups showed different oxidation patterns with consequently different distributions of carbonyl species; unworn XLPE was characterized by lower contents of carbonyl species and hydrogen-bonded alcohols and higher contents of trans-vinylene species than unworn UHMWPE. Upon simulator testing, UHMWPE showed more significant changes in oxidation indexes and distribution of carbonyl compounds than XLPE, confirming a better wear behavior for XLPE under the adopted testing conditions.

  7. Anisotropic charge transport in ion-conductive photoresponsive polyethylene oxide-based mesomorphic materials

    NASA Astrophysics Data System (ADS)

    Binet, Corinne; Allart, Alexandre; Judeinstein, Patrick; Roussel, Frédérick

    2017-01-01

    The mechanism of charge motion in conductive and photosensitive mesogenic block copolymers containing polyethylene oxide (PEO) segments is investigated over a wide frequency and temperature range with the broadband dielectric spectroscopy technique. It is found that the ultraviolet (UV) irradiation, the UV intensity, and the anchoring conditions of mesogenic unit in the cells produce changes in conductivity properties and in the molecular arrangement. The anisotropic nature of the conductivity is established.

  8. Anisotropic charge transport in ion-conductive photoresponsive polyethylene oxide-based mesomorphic materials.

    PubMed

    Binet, Corinne; Allart, Alexandre; Judeinstein, Patrick; Roussel, Frédérick

    2017-01-01

    The mechanism of charge motion in conductive and photosensitive mesogenic block copolymers containing polyethylene oxide (PEO) segments is investigated over a wide frequency and temperature range with the broadband dielectric spectroscopy technique. It is found that the ultraviolet (UV) irradiation, the UV intensity, and the anchoring conditions of mesogenic unit in the cells produce changes in conductivity properties and in the molecular arrangement. The anisotropic nature of the conductivity is established.

  9. Degradable polyethylene: fantasy or reality.

    PubMed

    Roy, Prasun K; Hakkarainen, Minna; Varma, Indra K; Albertsson, Ann-Christine

    2011-05-15

    Plastic waste disposal is one of the serious environmental issues being tackled by our society today. Polyethylene, particularly in packaging films, has received criticism as it tends to accumulate over a period of time, leaving behind an undesirable visual footprint. Degradable polyethylene, which would enter the eco-cycle harmlessly through biodegradation would be a desirable solution to this problem. However, the "degradable polyethylene" which is presently being promoted as an environmentally friendly alternative to the nondegradable counterpart, does not seem to meet this criterion. This article reviews the state of the art on the aspect of degradability of polyethylene containing pro-oxidants, and more importantly the effect these polymers could have on the environment in the long run. On exposure to heat, light, and oxygen, these polymers disintegrate into small fragments, thereby reducing or increasing the visual presence. However, these fragments can remain in the environment for prolonged time periods. This article also outlines important questions, particularly in terms of time scale of complete degradation, environmental fate of the polymer residues, and possible accumulation of toxins, the answers to which need to be established prior to accepting these polymers as environmentally benign alternatives to their nondegradable equivalents. It appears from the existing literature that our search for biodegradable polyethylene has not yet been realized.

  10. Antibacterial wound dressing from chitosan/polyethylene oxide nanofibers mats embedded with silver nanoparticles.

    PubMed

    Wang, Xiaoli; Cheng, Feng; Gao, Jing; Wang, Lu

    2015-03-01

    Novel antibacterial nanomaterials have been developed for biomedical applications. The present study involves the preparation and properties of antibacterial nanofibers from chitosan/polyethylene oxide electrospun nanofibers incorporated with silver nanoparticles. Silver nanoparticles were efficiently synthesized in situ after ultra violet (UV) with AgNO3 as precursor and chitosan/polyethylene oxide as reducing agent and protecting agent, respectively. Then the resultant solutions were electrospun into nanofibers. The formation of silver nanoparticles was confirmed with ultraviolet visible (UV-vis) and transmission electron microscopy (TEM), and the electrospun nanofibers were characterized by scanning electron microscopy and energy dispersive X-ray. The resultant fibers exhibited uniform morphology with silver nanoparticles distributed throughout the fiber. Also, the fibers showed certain tensile strength and excellent antibacterial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. Sustained release of silver nanoparticles from fibers could last for over 72 h. The silver-containing chitosan/polyethylene oxide nanofibers showed excellent cytocompatibility.

  11. The stimulation of postdermabrasion wound healing with stabilized aloe vera gel-polyethylene oxide dressing.

    PubMed

    Fulton, J E

    1990-05-01

    Full-face dermabrasion provided an ideal opportunity to document the effects of dressings on wound healing management. Following the procedure, the abraded face was divided in half. One side was treated with the standard polyethylene oxide gel wound dressings. The other side was treated with a polyethylene oxide gel dressing saturated with stabilized aloe vera. The polyethylene oxide dressing provided an excellent matrix for the release of aloe vera gel during the initial 5 days of wound healing. By 24-48 hours there was dramatic vasoconstriction and accompanying reduction in edema on the aloe-treated side. By the third to fourth day there was less exudate and crusting at the aloe site, and by the fifth to sixth day the reepithelialization at the aloe site was complete. Overall, wound healing was approximately 72 hours faster at the aloe site. This acceleration in wound healing is important to reduce bacterial contamination, subsequent keloid formation, and/or pigmentary changes. The exact mechanism of acceleration of wound healing by aloe vera is unknown.

  12. Polyethylene encapsulation of molten salt oxidation mixed low-level radioactive salt residues

    SciTech Connect

    Lageraaen, P.R.; Kalb, P.D.; Grimmett, D.L.; Gay, R.L.; Newman, C.D.

    1995-10-01

    A limited scope treatability study was conducted for polyethylene encapsulation of salt residues generated by a Molten Salt Oxidation (MSO) technology demonstration at the Energy Technology Engineering Center (ETEC), operated by Rockwell International for the US Department of Energy (DOE). During 1992 and 1993, ETEC performed a demonstration with a prototype MSO unit and treated approximately 50 gallons of mixed waste comprised of radioactively contaminated oils produced by hot cell operations. A sample of the mixed waste contaminated spent salt was used during the BNL polyethylene encapsulation treatability study. A nominal waste loading of 50 wt % was successfully processed and waste form test specimens were made for Toxicity Characteristic Leaching Procedure (TCLP) testing. The encapsulated product was compared with base-line TCLP results for total chromium and was found to be well within allowable EPA guidelines.

  13. Method for casting polyethylene pipe

    NASA Technical Reports Server (NTRS)

    Elam, R. M., Jr.

    1973-01-01

    Short lengths of 7-cm ID polyethylene pipe are cast in a mold which has a core made of room-temperature-vulcanizable (RTV) silicone. Core expands during casting and shrinks on cooling to allow for contraction of the polyethylene.

  14. Synthesis of cobalt stearate as oxidant additive for oxo-biodegradable polyethylene

    SciTech Connect

    Asriza, Ristika O.; Arcana, I Made

    2015-09-30

    Cobalt stearate is an oxidant additives that can initiate a process of degradation in high density polyethylene (HDPE). To determine the effect of cobalt stearate in HDPE, oxo-biodegradable polyethylene film was given an irradiation with UV light or heating at various temperature. After given a heating, the FTIR spectra showed a new absorption peak at wave number 1712 cm{sup −1} indicating the presence of carbonyl groups in polymers, whereas after irradiation with UV light is not visible the presence of this absorption peak. The increase concentration of cobalt stearate added in HDPE and the higher heating temperature, the intensity of the absorption peak of the carbonyl group increased. The increasing intensity of the carbonyl group absorption is caused the presence of damage in the film surface after heating, and this result is supported by analysis the surface properties of the film with using SEM. Biodegradation tests were performed on oxo-biodegradable polyethylene film which has been given heating or UV light with using activated sludge under optimal conditions the growth of microorganisms. After biodegradation, the maximum weight decreased by 23% in the oxo-biodegradable polyethylene film with a cobalt stearate concentration of 0.2% and after heating at a temperature of 75 °C for 10 days, and only 0.69% in the same film after irradiation UV light for 10 days. Based on the results above, cobalt stearate additive is more effective to initiate the oxidative degradation of HDPE when it is initiated by heating compared to irradiation with UV light.

  15. ZPPR-20 phase D : a cylindrical assembly of polyethylene moderated U metal reflected by beryllium oxide and polyethylene.

    SciTech Connect

    Lell, R.; Grimm, K.; McKnight, R.; Shaefer, R.; Nuclear Engineering Division; INL

    2006-09-30

    The Zero Power Physics Reactor (ZPPR) fast critical facility was built at the Argonne National Laboratory-West (ANL-W) site in Idaho in 1969 to obtain neutron physics information necessary for the design of fast breeder reactors. The ZPPR-20D Benchmark Assembly was part of a series of cores built in Assembly 20 (References 1 through 3) of the ZPPR facility to provide data for developing a nuclear power source for space applications (SP-100). The assemblies were beryllium oxide reflected and had core fuel compositions containing enriched uranium fuel, niobium and rhenium. ZPPR-20 Phase C (HEU-MET-FAST-075) was built as the reference flight configuration. Two other configurations, Phases D and E, simulated accident scenarios. Phase D modeled the water immersion scenario during a launch accident, and Phase E (SUB-HEU-MET-FAST-001) modeled the earth burial scenario during a launch accident. Two configurations were recorded for the simulated water immersion accident scenario (Phase D); the critical configuration, documented here, and the subcritical configuration (SUB-HEU-MET-MIXED-001). Experiments in Assembly 20 Phases 20A through 20F were performed in 1988. The reference water immersion configuration for the ZPPR-20D assembly was obtained as reactor loading 129 on October 7, 1988 with a fissile mass of 167.477 kg and a reactivity of -4.626 {+-} 0.044{cents} (k {approx} 0.9997). The SP-100 core was to be constructed of highly enriched uranium nitride, niobium, rhenium and depleted lithium. The core design called for two enrichment zones with niobium-1% zirconium alloy fuel cladding and core structure. Rhenium was to be used as a fuel pin liner to provide shut down in the event of water immersion and flooding. The core coolant was to be depleted lithium metal ({sup 7}Li). The core was to be surrounded radially with a niobium reactor vessel and bypass which would carry the lithium coolant to the forward inlet plenum. Immediately inside the reactor vessel was a rhenium

  16. Method for shaping polyethylene tubing

    NASA Technical Reports Server (NTRS)

    Kramer, R. C.

    1981-01-01

    Method forms polyethylene plastic tubing into configurations previously only possible with metal tubing. By using polyethylene in place of copper or stain less steel tubing inlow pressure systems, fabrication costs are significantly reduced. Polyethylene tubing can be used whenever low pressure tubing is needed in oil operations, aircraft and space applications, powerplants, and testing laboratories.

  17. Microviscosity in Pluronic and Tetronic poly(ethylene oxide)-poly(propylene oxide) block copolymer micelles

    SciTech Connect

    Nivaggioli, T.; Tsao, B.; Alexandridis, P.; Hatton, T.A. )

    1995-01-01

    The micellar microviscosity afforded by Pluronic and Tetronic poly(ethylene oxide)-poly(propylene oxide) block copolymer aqueous solutions has been investigated by fluorescence and NMR spectroscopy. Comparison is made with bulk poly(propylene oxide) (PPO) samples of different molecular weights. The microviscosity in Pluronic PEO-PPO-PEO copolymer micelles is much larger than that observed in conventional surfactant micelles and depends strongly on the size of the hydrophobic PPO block: the larger this block, the higher the viscosity. Above the critical micellar temperature (CMT), as temperature increases, the microviscosity decreases. However, this decrease is not as important as that observed in bulk PPO. Hence, the relative microviscosity, defined as the ratio of the two observed phenomena, increases. This suggests structural transformation of the micelles resulting in a core becoming more and more compact as temperature increases. Such results have been confirmed by NMR studies that showed broadening of the PPO peak and relatively constant spin-lattice relaxation time, T[sub i], with increasing temperature while the PEO signal remained relatively sharp with an exponential increase in T[sub 1]. 30 refs., 9 figs., 1 tab.

  18. Field Effect Transistor Behavior in Electrospun Polyaniline/Polyethylene Oxide Nanofibers

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; Theofylaktos, Noulle; Robinson, Daryl C.; Mueller, Carl H.; Pinto, Nicholas J.

    2004-01-01

    Novel translators and logic devices based on nanotechnology concepts are under intense development. The potential for ultra-low power circuitry makes nanotechnology attractive for applications such as digital electronics and sensors. Furthermore, the ability to form devices on flexible substrates expands the range of applications where electronic circuitry can be introduced. For NASA, nonotechndogy offers opportunities for increased onboard data processing and thus autonomous decision-making ability, ad novel sensors that detect and respond to external stimuli with few oversight requirements. The goat of this work is to demonstrate transistor behavior in polyaniline/ polyethylene oxide nanofibers, thus creating a foundation for future logic devices.

  19. Chitin-incorporated poly(ethylene oxide)-based nanocomposite electrolytes for lithium batteries.

    PubMed

    Stephan, A Manuel; Kumar, T Prem; Kulandainathan, M Anbu; Lakshmi, N Angu

    2009-02-19

    Nanocomposite polymer electrolytes (NCPE), with different proportions of poly(ethylene oxide)/LiClO(4)/chitin were prepared by a hot press method. Nanochitin, a biopolymer, poly(beta-(1-->4)-N acetyl-d-glucosamine) was incorporated as a filler in poly(ethylene oxide) (PEO). The ionic conductivity of the composite polymer electrolytes was enhanced by one order upon addition of nanochitin. The lithium transference number, t(Li)(+), was increased from 0.24 to 0.51 upon chitin addition. The membranes were subjected to scanning electron microscopy, thermogravimetric-differential thermal analysis, differential scanning calorimetry, ionic conductivity, and Fourier transform infrared (FTIR) spectroscopy analysis. The free volume V(f) was probed by positron annihilation lifetime spectroscopy studies at 30 degrees C. Li/NCPE/Li symmetric cells were assembled, and the thickness of the solid electrolyte interface as a function of time was analyzed. This paper also describes FTIR spectroscopic studies of the interface between lithium metal and NCPE, which suggests that the surface chemistry of lithium electrodes in contact with NCPE is dominated by compounds with C-N-Li and C-O-Li bonding.

  20. Local Structure and Ion Transport in Glassy Poly(ethylene oxide styrene) Copolymers

    NASA Astrophysics Data System (ADS)

    Yang, Han-Chang; Mays, Jimmy; Sokolov, Alexei P.; Winey, Karen I.

    2014-03-01

    Polymer electrolytes have attracted attention for a wide variety of applications in energy production such as lithium-ion batteries and fuel cells. The concept of free volume provides important information about ion mobility and chain dynamics in the polymer matrix. Researchers have recently demonstrated that ion transport in glassy polymer can be improved by designing a system with high free volume. We have studied the effect of temperature and humidity on the intermolecular correlations of poly(ethylene oxide styrene-block-styrene) (PEOSt- b-St) block copolymer and poly(ethylene oxide styrene) (PEOSt) homopolymer using in situ multi-angle x-ray scattering across a wide range of scattering angles (q = 0.007-1.5 Å-1) . An increase in backbone-to-backbone distance is observed, indicating an increase in free volume between different polymer main chains. Structural characterization of the polymer segments will be discussed together with conductivity and dielectric results to better understand the ion transport mechanism in the local environment of the polymer system. Department of Chemistry, University of Tennessee.

  1. Stability of polyethylene oxide in matrix tablets prepared by hot-melt extrusion.

    PubMed

    Crowley, Michael M; Zhang, Feng; Koleng, John J; McGinity, James W

    2002-11-01

    The thermal stability of polyethylene oxide (PEO) in sustained release tablets prepared by hot-melt extrusion was investigated. The weight average molecular weight of the polymer was studied using gel permeation chromatography. The chemical stability of PEO was found to be dependent on both the storage and processing temperature, and the molecular weight of the polymer. Storage of the polymer above its melting point significantly increased polymer degradation, and the degradation process was accelerated as the molecular weight was reduced. The thermal stability of PEO MW = 1,000,000 (PEO 1 M) in sustained release chlropheniramine maleate (CPM) tablets prepared by hot-melt extrusion was found to depend on the processing temperature and screw speed. Lower molecular weight PEO MW = 100,000 (PEO 100 K) was demonstrated to be a suitable processing aid for PEO 1 M. Incorporation of PEO 100 K reduced degradation of PEO 1 M and did not alter the release rate of CPM. Vitamin E, Vitamin E Succinate and Vitamin E TPGS were found to be suitable stabilizers for PEO, however, ascorbic acid was shown to degrade the polymer in solution. Thermal analysis demonstrated that Vitamin E Succinate and Vitamin E TPGS were dispersed at the molecular level in hot-melt extruded tablets. Solubilized Vitamin E Succinate and Vitamin E TPGS suppressed the melting point of the polyethylene oxide. Drug release rates from hot-melt extruded tablets stabilized with antioxidants were found to be dependent on the hydrophilic nature of the antioxidant.

  2. Polyethylene oxide-polytetrahydrofurane-PEDOT conducting interpenetrating polymer networks for high speed actuators

    NASA Astrophysics Data System (ADS)

    Plesse, C.; Khaldi, A.; Wang, Q.; Cattan, E.; Teyssié, D.; Chevrot, C.; Vidal, F.

    2011-12-01

    In recent years, numerous studies on electro-active polymer (EAP) actuators have been reported. One promising technology is the elaboration of electronic conducting polymer-based actuators with interpenetrating polymer network (IPNs) architecture. In this study, the synthesis and characterisation of conducting IPNs for actuator applications is described. The IPNs are synthesised from polyethylene oxide (PEO) and polytetrahydrofurane (PTHF) networks in which the conducting polymer (poly(3,4-ethylenedioxythiophene)) is incorporated. In a first step, PEO/PTHF IPNs were prepared via an 'in situ' process using poly(ethylene glycol) methacrylate and dimethacrylate and hydroxytelechelic PTHF as starting materials. The IPN mechanical properties were examined by DMA and tensile strength tests. N-ethylmethylimidazolium bis(trifluoromethanesulfonyl)imide (EMITFSI) swollen PEO/PTHF IPNs show ionic conductivities up to 10-3 S cm-1 at 30 °C. In a second step, the conducting IPN actuators were prepared by oxidative polymerisation of 3,4-ethylenedioxithiophene (EDOT) using FeCl3 as an oxidising agent within the PEO/PTHF IPN host matrix. The frequency response performance of the bending conducting IPN actuator was then evaluated. The resulting actuator exhibits a mechanical resonance frequency of up to 125 Hz with 0.75% strain for an applied potential of ± 5 V.

  3. Atomistic simulation of CO2 solubility in poly(ethylene oxide) oligomers

    NASA Astrophysics Data System (ADS)

    Hong, Bingbing; Panagiotopoulos, Athanassios Z.

    2014-06-01

    We have performed atomistic molecular dynamics simulations coupled with thermodynamic integration to obtain the excess chemical potential and pressure-composition phase diagrams for CO2 in poly(ethylene oxide) oligomers. Poly(ethylene oxide) dimethyl ether, CH3O(CH2CH2O)nCH3 (PEO for short) is a widely applied physical solvent that forms the major organic constituent of a class of novel nanoparticle-based absorbents. Good predictions were obtained for pressure-composition-density relations for CO2 + PEO oligomers (2 ≤ n ≤ 12), using the Potoff force field for PEO [J. Chem. Phys. 136, 044514 (2012)] together with the TraPPE model for CO2 [AIChE J. 47, 1676 (2001)]. Water effects on Henry's constant of CO2 in PEO have also been investigated. Addition of modest amounts of water in PEO produces a relatively small increase in Henry's constant. Dependence of the calculated Henry's constant on the weight percentage of water falls on a temperature-dependent master curve, irrespective of PEO chain length.

  4. A study on optical absorption and constants of doped poly(ethylene oxide)

    NASA Astrophysics Data System (ADS)

    Al-Faleh, R. S.; Zihlif, A. M.

    2011-05-01

    Thin films of polymer electrolyte based on poly(ethylene oxide) doped with sodium iodide (NaI) were prepared using the solution cast method. The films obtained have average thickness of 70 μm and different NaI concentrations. Absorption and reflectance spectra of UV-radiation were studied in the wavelength range 300-800 nm. The optical results were analyzed in terms of absorption formula for non-crystalline materials. The optical energy gap and the basic optical constants, refractive index, and dielectric constants of the prepared films have been investigated and showed a clear dependence on the NaI concentration. The interpreted absorption mechanism is a direct electron transition. The observed optical energy gap for neat poly(ethylene oxide) is about 2.6 eV, and decreases to a value 2.36 eV for the film of 15 wt% NaI content. It was found that the calculated refractive index and the dielectric constants of the polymer electrolyte thin films increase with NaI content. Models were used to describe the dependences of the dielectric constant on the NaI concentration, and the refractive index on the incident photon energy.

  5. Effect of Oxidation on Localized Heat Generation and Dielectric Breakdown of Low-Density Polyethylene Film

    NASA Astrophysics Data System (ADS)

    Tsurimoto, Takao; Nagao, Masayuki; Kosaki, Masamitsu

    1995-12-01

    The effect of oxidation on localized heat generation and dielectric breakdown in low-density polyethylene (LDPE) film was studied by thermography. In the non-McKeown-type epoxy-free electrode system, localized heat generation of LDPE film leading to dielectric breakdown increased and breakdown strength decreased upon oxidation. In the McKeown-type specimen, however, the breakdown strength of oxidized LDPE film is higher than that of an unoxidized one. It is considered that enhancement of the thermal process is a major factor of breakdown in the epoxy-free electrode system and that homo-space charge and/or electron scattering effect is dominant in the McKeown type specimen.

  6. Effect of cosolvents on the self-assembly of a non-ionic polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer in the protic ionic liquid ethylammonium nitrate.

    PubMed

    Chen, Zhengfei; Greaves, Tamar L; Caruso, Rachel A; Drummond, Calum J

    2015-03-01

    The effect of water and methanol on the self-assembled structures formed by the polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer Pluronic P123 in ethylammonium nitrate was investigated by small angle X-ray scattering (SAXS). Two ternary phase diagrams were established. The addition of water had only a minor effect on the liquid crystal structures, however methanol had a significant effect, which was attributed to methanol being a good solvent for both the PEO and PPO blocks of the polymer. No lyotropic liquid crystal phases were retained when methanol reached 25 wt%. The phase behaviour did not change significantly over the temperature range from 25 to 45°C.

  7. Fabrication and anti-fouling properties of photochemically and thermally immobilized poly(ethylene oxide) and low molecular weight poly(ethylene glycol) thin films.

    PubMed

    Wang, Hui; Ren, Jin; Hlaing, Aye; Yan, Mingdi

    2011-02-01

    Poly(ethylene oxide) (PEO) and low molecular weight poly(ethylene glycol) (PEG) were covalently immobilized on silicon wafers and gold films by way of the CH insertion reaction of perfluorophenyl azides (PFPAs) by either photolysis or thermolysis. The immobilization does not require chemical derivatization of PEO or PEG, and polymers of different molecular weights were successfully attached to the substrate to give uniform films. Microarrays were also generated by printing polymer solutions on PFPA-functionalized wafer or Au slides followed by light activation. For low molecular weight PEG, the immobilization was highly dependent on the quality of the film deposited on the substrate. While the spin-coated and printed PEG showed poor immobilization efficiency, thermal treatment of the PEG melt on PFPA-functionalized surfaces resulted in excellent film quality, giving, for example, a grafting density of 9.2×10(-4)Å(-2) and an average distance between grafted chains of 33Å for PEG 20,000. The anti-fouling property of the films was evaluated by fluorescence microscopy and surface plasmon resonance imaging (SPRi). Low protein adsorption was observed on thermally-immobilized PEG whereas the photoimmobilized PEG showed increased protein adsorption. In addition, protein arrays were created using polystyrene (PS) and PEG based on the differential protein adsorption of the two polymers.

  8. Polyethylene Glycol Propionaldehydes

    NASA Technical Reports Server (NTRS)

    Harris, Joe M.; Sedaghat-Herati, Mohammad R.; Karr, Laurel J.

    1992-01-01

    New class of compounds derived from polyethylene glycol (PEG's) namely, PEG-propionaldehydes, offers two important advantages over other classes of PEG aldehyde derivatives: compounds exhibit selective chemical reactivity toward amino groups and are stable in aqueous environment. PEG's and derivatives used to couple variety of other molecules, such as, to tether protein molecules to surfaces. Biotechnical and biomedical applications include partitioning of two phases in aqueous media; immobilization of such proteins as enzymes, antibodies, and antigens; modification of drugs; and preparation of protein-rejecting surfaces. In addition, surfaces coated with PEG's and derivatives used to control wetting and electroosmosis. Another potential application, coupling to aminated surfaces.

  9. Lithium-Salt-Containing High-Molecular-Weight Polystyrene-block-Polyethylene Oxide Block Copolymer Films.

    PubMed

    Metwalli, Ezzeldin; Rasool, Majid; Brunner, Simon; Müller-Buschbaum, Peter

    2015-08-10

    Ionic conductivity in relation to the morphology of lithium-doped high-molecular-weight polystyrene-block-polyethylene oxide (PS-b-PEO) diblock copolymer films was investigated as solid-state membranes for lithium-ion batteries. The tendency of the polyethylene (PEO) block to crystallize was highly suppressed by increasing both the salt-doping level and the temperature. The PEO crystallites completely vanished at a salt-doping ratio of Li/EO>0.08, at which the PEO segments were hindered from entering the crystalline unit of the PEO chain. A kinetically trapped lamella morphology of PS-b-PEO was observed, due to PEO crystallization. The increase in the lamella spacing with increasing salt concentration was attributed to the conformation of the PEO chain rather than the volume contribution of the salt or the previously reported increase in the effective interaction parameter. Upon loading the salt, the PEO chains changed from a compact/highly folded conformation to an amorphous/expanded-like conformation. The ionic conductivity was enhanced by amorphization of PEO and thereby the mobility of the PEO blocks increased upon increasing the salt-doping level.

  10. Electrical Characterization of Polyaniline/polyethylene Oxide Nanofibers for Field Effect Transistors

    NASA Technical Reports Server (NTRS)

    Mueller, Carl H.; Theofylaktos, Noulie; Pinto, Nicholas J.; Robinson, Daryl C.; Miranda, Felix A.

    2002-01-01

    Nanofibers comprised of polyaniline/polyethylene oxide (PANI/PEO) are being developed for novel logic devices. We report the electrical conductivity of PANI/PEO nanofibers with diameters in the 100 to 200 nm range. We measured conductivity values of approx. 0.3 to 1.0 S/cm, which is higher than the values reported for thicker nanofibers, but less than the bulk value of PANI. The electrical measurements were performed by depositing the fibers on pre-electroded, oxidized silicon (Si) substrates. The excellent adherence of the nanofibers to the SiO2 as well as the gold (Au) electrodes may be useful in the design of future devices.

  11. Raman spectroscopy of biomedical polyethylenes.

    PubMed

    Pezzotti, Giuseppe

    2017-03-27

    With the development of three-dimensional Raman algorithms for local mapping of oxidation and plastic strain, and the ability to resolve molecular orientation patterns with microscopic spatial resolution, there is an opportunity to re-examine many of the foundations on which our understanding of biomedical grade ultra-high molecular weight polyethylenes (UHMWPEs) are based. By implementing polarized Raman spectroscopy into an automatized tool with an improved precision in non-destructively resolving Euler angles, oxidation levels, and microscopic strain, we become capable to make accurate and traceable measurements of the in vitro and in vivo tribological responses of a variety of commercially available UHMWPE bearings for artificial hip and knee joints. In this paper, we first review the foundations and the main algorithms for Raman analyses of oxidation and strain of biomedical polyethylene. Then, we critically re-examine a large body of Raman data previously collected on different polyethylene joint components after in vitro testing or in vivo service, in order to shed new light on an area of particular importance to joint orthopedics: the microscopic nature of UHMWPE surface degradation in the human body. A complex scenario of physical chemistry appears from the Raman analyses, which highlights the importance of molecular-scale phenomena besides mere microstructural changes. The availability of the Raman microscopic probe for visualizing oxidation patterns unveiled striking findings related to the chemical contribution to wear degradation: chain-breaking and subsequent formation of carboxylic acid sites preferentially occur in correspondence of third-phase regions, and they are triggered by emission of dehydroxylated oxygen from ceramic oxide counterparts. These findings profoundly differ from more popular (and simplistic) notions of mechanistic tribology adopted in analyzing joint simulator data.

  12. Janus-Type Dendrimer-like Poly(ethylene oxide)s

    PubMed Central

    Feng, Xiaoshuang; Taton, Daniel; Ibarboure, Emmanuel; Chaikof, Elliot L.; Gnanou, Yves

    2009-01-01

    A straightforward and original methodology allowing the synthesis of Janus-type dendrimer-like poly(ethylene oxide)s (PEOs) carrying orthogonal functional groups on their surface is described. The use of 3-allyloxy-1,2-propanediol (1) as a latent AB2-type heterofunctional initiator of anionic ring-opening polymerization (AROP) of ethylene oxide (EO) and of selective branching agents of PEO chain ends served to construct the two dendrons of these dendrimer-like PEOs, following a divergent pathway. Thus, the first PEO generation of the first dendron was grown by AROP from 1 followed by the reaction of the corresponding α-allyl,ω,ω′-bishydroxy- heterofunctional PEO derivative with 2-(3′-chloromethybenzyloxymethyl)-2-methyl-5,5-dimethyl-1,3-dioxane (2) used as a branching agent. This afforded the dendron A with four latent peripheral hydroxyls protected in the form of two ketal rings. The remaining α-allylic double bond of the PEO thus prepared was transformed into two hydroxyl groups using OsO4 in order to create the first PEO generation of the dendron B by AROP of EO. Allyl chloride (3) was then used as another (latent) branching agent to react with the terminal hydroxyl of the corresponding PEO chains. Deprotection under acidic conditions of the ketal groups of dendron A, followed by AROP of EO, afforded the second PEO generation on this face. This alternate and divergent procedure, combining AROP of EO and selective branching of PEO branches, could be readily iterated, one dendron after the other up to the generation six, leading to a Janus-type dendrimer-like PEO exhibiting a total mass of around 300 kg/mol and possessing 64 peripheral groups on each face. The possibility of orthogonal functionalization of the surfaces of such Janus-type dendritic PEOs was exploited. Indeed, a dendron of generation 4 was functionalized with hydroxyl functions at its periphery, whereas the other was end-capped with either tertiary amino or disulfide groups. In a variant of

  13. Accumulation of magnetic iron oxide nanoparticles coated with variably sized polyethylene glycol in murine tumors.

    PubMed

    Larsen, Esben Kjær Unmack; Nielsen, Thomas; Wittenborn, Thomas; Rydtoft, Louise Munk; Lokanathan, Arcot R; Hansen, Line; Østergaard, Leif; Kingshott, Peter; Howard, Kenneth A; Besenbacher, Flemming; Nielsen, Niels Chr; Kjems, Jørgen

    2012-04-07

    Iron oxide nanoparticles have found widespread applications in different areas including cell separation, drug delivery and as contrast agents. Due to water insolubility and stability issues, nanoparticles utilized for biological applications require coatings such as the commonly employed polyethylene glycol (PEG). Despite its frequent use, the influence of PEG coatings on the physicochemical and biological properties of iron nanoparticles has hitherto not been studied in detail. To address this, we studied the effect of 333-20,000 Da PEG coatings that resulted in larger hydrodynamic size, lower surface charge, longer circulation half-life, and lower uptake in macrophage cells when the particles were coated with high molecular weight (M(w)) PEG molecules. By use of magnetic resonance imaging, we show coating-dependent in vivo uptake in murine tumors with an optimal coating M(w) of 10,000 Da.

  14. Friction and wear of polyethylene oxide polymer having a range of molecular weights

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1978-01-01

    Sliding friction and wear experiments were conducted at light loads (25 to 250 g) with various molecular weights of the polyethylene oxide polymer sliding on itself and iron. Results of the experimental investigation indicate that: (1) the coefficient of friction for the polymer decreases with increasing molecular weight; (2) friction coefficient is higher for the polymer sliding on itself than it is for the polymer sliding on iron; (3) at sufficiently high loads localized surface melting occurs and the friction coefficient is the same for the polymer sliding on itself and iron; (4) fracture cracks develop in the sliding wear track at higher but not lower sliding velocities, reflecting a strain rate sensitivity to crack initiation, and (5) the friction coefficient for the polymer sliding on iron increases with the formation of a polymer film on the iron surface.

  15. Field Effect Transistor Behavior in Electrospun Polyaniline/Polyethylene Oxide Nanofibers

    NASA Technical Reports Server (NTRS)

    Miranda, Felix A.; Theofylaktos, Noulie; Mueller, Carl H.; Pinto, Nicholas J.

    2004-01-01

    Novel transistors and logic devices based on nanotechnology concepts are under intense development. The potential for ultra-low-power circuitry makes nanotechnology attractive for applications such as digital electronics and sensors. For NASA applications, nanotechnology offers tremendous opportunities for increased onboard data processing, and thus autonomous decision-making ability, and novel sensors that detect and respond to environmental stimuli with little oversight requirements. Polyaniline (PANi) is an intriguing material because its electrical conductivity can be changed from insulating to metallic by varying the doping levels and conformations of the polymer chain, and when combined with polyethylene oxide (PEO), can be formed into nanofibers with diameters ranging from approximately 50 to 500 nm (depending on the deposition conditions). The initial goal of this work was to demonstrate transistor behavior in these nanofibers, thus creating a foundation for future logic devices.

  16. Conformation and hydration of surface grafted and free polyethylene oxide chains in solutions

    NASA Astrophysics Data System (ADS)

    Dahal, Udaya; Wang, Zilu; Dormidontova, Elena

    Due to the wide application of polyethylene oxide (PEO), ranging from biomedicine to fuel cells, it is one of the most studied polymers in the scientific world. In order to elucidate detailed molecular-level insights on the impact of surface grafting on PEO conformation, we performed atomistic molecular dynamics simulations of PEO chains in solution and grafted to a flat gold surface in different solvents. We examined the hydration as well as conformation of the free chain compared to the grafted polymer in pure water and mixed solvents. We find that grafted chains are stiffer and have a stronger tendency to form helical structures in isobutyric acid or mixture of isobutyric acid and water solution than the free chains in corresponding solutions. For grafted chains exposed to pure water the random coil conformation is retained at low grafting density, but becomes stretched and more dehydrated as the grafting density or temperature increases. This research is supported by NSF (DMR-1410928).

  17. Gelation, swelling and water vapor permeability behavior of radiation synthesized poly(ethylene oxide) hydrogels

    NASA Astrophysics Data System (ADS)

    Savaş, Hülya; Güven, Olgun

    2002-04-01

    In this study, gamma ray induced gelation of aqueous solutions of poly(ethylene oxide), (PEO) with 73.300 Da average molecular weight has been studied. Percent of conversion of polymer into gel as well as swelling behavior were investigated gravimetrically. The effect of the dose rate on these properties was studied. Within the dose rate range studied, it is observed that low dose rate irradiation favors chain scission and although the dominant effect is still crosslinking, %gelation at a given dose decreases. Water vapor permeability (Wvp) of PEO hydrogels has been studied with regard to crosslink density changes and temperature. The water vapor permeability of hydrogels obtained at high dose rate was found to be lower than those obtained at low dose rate which was related to higher crosslink density achieved under higher dose rate irradiations.

  18. In situ preparation of poly(ethylene oxide)-SiO 2 composite polymer electrolytes

    NASA Astrophysics Data System (ADS)

    Liu, Y.; Lee, J. Y.; Hong, L.

    Amorphous poly(ethylene oxide) (PEO)-SiO 2 composites are prepared by in situ reactions that involve the simultaneous formation of the polymer network and inorganic nanoparticles. The polymer matrix is formed by ultraviolet irradiation of a PEO macromer, and silica is produced in situ by the sol-gel method. The PEO-SiO 2 composite mixed with LiBF 4 is used as a lithium-ion conducting solid electrolyte and electrochemical transport properties such as ionic conductivity and Li + transference number are measured. A significant increase in the Li + transference number, up to 0.56, is found together with a slight decrease in the ionic conductivity. The results are interpreted in terms of interactions between the surface OH groups of the inorganic particles, the cations, the anions, and the ether oxygen atoms on the PEO backbone.

  19. Collective motion in Poly(ethylene oxide)/poly(methylmethacrylate) blends

    SciTech Connect

    Farago, Bela; Chen Chunxia; Maranas, Janna K.; Kamath, Sudesh; Colby, Ralph H.; Pasquale, Anthony J.; Long, Timothy E.

    2005-09-01

    We present neutron spin echo and structural measurements on a perdeutereted miscible polymer blend: poly(ethylene oxide)[PEO]/poly(methyl methacrylate)[PMMA], characterized by a large difference in component glass transition temperatures and minimal interactions. The measurements cover the q range 0.35 to 1.66 A{sup -1} and the temperature range T{sub g}-75 to T{sub g}+89 K, where T{sub g} is the blend glass transition. The spectra, obtained directly in the time domain, are very broad with stretching parameters {beta}{approx}0.30. The relaxation times vary considerably over the spatial range considered however at none of the q values do we see two distinct relaxation times. At small spatial scales relaxations are still detectable at temperatures far below T{sub g}. The temperature dependence of these relaxation times strongly resembles the {beta}-relaxation process observed in pure PMMA.

  20. Poly(ethylene oxide) star polymer adsorption at the silica/aqueous interface and displacement by linear poly(ethylene oxide).

    PubMed

    Saigal, Trishna; Riley, John K; Golas, Patricia Lynn; Bodvik, Rasmus; Claesson, Per M; Matyjaszewski, Krzysztof; Tilton, Robert D

    2013-03-26

    Multiarm star copolymers with approximately 460 poly(ethylene oxide) (PEO) arms that have a degree of polymerization N = 45 were synthesized via atom transfer radical polymerization (ATRP) of PEO-methacrylate macromonomers in the presence of divinyl benzene cross-linkers. These are an example of molecular or nanoparticulate brushes that are of interest as steric stabilizers or boundary lubrication agents when adsorbed from solution to a solid/aqueous interface. We use ellipsometry to measure adsorption isotherms at the silica/aqueous interface for PEO star polymers and linear PEO chains having molecular weights comparable either to the star polymer or to the individual arms. The compactness of the PEO star polymers (molecular weight 1.2 × 10(6)) yields a saturation surface excess concentration that is approximately 3.5 times greater than that of the high molecular weight (1 × 10(6)) linear PEO. Adsorption of low molecular weight (6000) linear PEO was below the detection limit. Competitive adsorption experiments were conducted with ellipsometry, complemented by independent quartz crystal microbalance with dissipation (QCM-D) measurements. Linear PEO (high molecular weight) displaced preadsorbed PEO star polymers over the course of approximately 1.5 h, to form a mixed adsorbed layer having not only a significantly lower overall polymer surface excess concentration, but also a significantly greater amount of hydrodynamically entrapped water. Challenging a preadsorbed linear PEO (high molecular weight) layer with PEO star polymers produced no measurable change in the overall polymer surface excess concentration, but changes in the QCM-D energy dissipation and resonance frequency suggested that the introduction of PEO star polymers caused a slight swelling of the layer with a correspondingly small increase in entrapped water content.

  1. Complement activation on poly(ethylene oxide)-like RFGD-deposited surfaces

    PubMed Central

    Szott, Luisa Mayorga; Stein, M. Jeanette; Ratner, Buddy D.; Horbett, Thomas A.

    2010-01-01

    Non-specific protein adsorption, particularly fibrinogen (Fg), is thought to be an initiating step in the foreign body response (FBR) to biomaterials by promoting phagocyte attachment. In previous studies, we therefore prepared radio frequency glow discharge (RFGD) polyethylene oxide (PEO)-like tetraglyme coatings (CH3O(CH2CH2O)4CH3) adsorbing less than 10 ng/cm2 Fg and showed that they had the expected low monocyte adhesion in vitro. However, when these were implanted in vivo, many adherent inflammatory cells and a fibrous capsule were found, suggesting the role of alternative proteins, such as activated complement proteins, in the FBR to these materials. We therefore investigated complement interactions with the tetraglyme surfaces. First, because of its well known role in complement C3 activation, we measured the hydroxyl group (-OH) content of tetraglyme, but found it to be very low. Second, we measured C3 adsorption to tetraglyme from plasma. Low amounts of C3 adsorbed on tetraglyme, though it displayed higher binding strength than the control surfaces. Finally, complement activation was determined by measuring C3a and SC5b-9 levels in serum after incubating with tetraglyme, as well as other surfaces that served as positive and negative controls, namely poly(vinyl alcohol) hydrogels, Silastic sheeting, and poly(ethylene glycol) self-assembled monolayers with different end groups. Despite displaying low hydroxyl group concentration, relatively high C3a and SC5b-9 levels were found in serum exposed to tetraglyme, similar to the values due to our positive control, PVA. Our results support the conclusion that complement activation by tetraglyme is a possible mechanism involved in the FBR to these biomaterials. PMID:21105163

  2. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene, fluorinated. 177.1615 Section 177... Contact Surfaces § 177.1615 Polyethylene, fluorinated. Fluorinated polyethylene, identified in paragraph... prescribed conditions: (a) Fluorinated polyethylene food-contact articles are produced by modifying...

  3. Radiation resistivity of polyacenaphthylene-grafted polyethylene

    NASA Astrophysics Data System (ADS)

    Hayakawa, Kiyoshi; Kawase, Kaoru; Yamakita, Hiromi

    Thin poly (ethylene-g-acenaphthylene) films prepared by the vapor-phase grafting method were subjected to the γ-irradiation in air, and various changes in tensile and structural properties of the film were investigated by comparing with those of the untreated or crosslinked polyethylene film. Polyethylene got to lose its inherent necking property by oxidative degradation and to be brittle-fractured by the irradiation dose less than 100 Mrad in air. The polyacenaphthylene-grafted polyethylenes (extent of grafting, ˜ 54 by {100( P-P°) }/{P°}), however, kept their ductility up to 200 Mrad or more, and the rate of increase in elastic modulus as well as yield strength with the increasing irradiation dose was considerably lower than that of untreated or crosslinked polyethylene. The effect of the grafting extent, and that of the irradiation dose-rate on the fracture energy were also examined. The weight increase of polyethylene due to the oxygen consumption and the resulting formation of carbonyl group which proceeded proportionally with the irradiation dose were remarkably suppressed by the grafting, whereas the double bond formation seemed to be unaffected by it. The grafted film held the original content of gel fraction unchanged during the irradiation in air, but the average molecular weight of the sol fraction decreased gradually. Meanwhile, the gel fraction of the crosslinked polyethylene was degenerated by a small dose of irradiation. The analysis of gaseous products revealed the formation of water, methanol, acetaldehyde and so forth from the irradiated grafted film. The grafting procedure and the subsequent irradiation of the grafted film did not affect the degree of crystallinity of the backbone polyethylene. The role played by the grafted polyacenaphthylene for endowing the radiation resistivity to polyethylene and its inherent limitation in effect were discussed from the structural point of view of the grafted film.

  4. Surface activity of poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) copolymers

    SciTech Connect

    Alexandridis, P.; Athanassiou, V.; Fukuda, Shinya; Hatton, T.A. )

    1994-08-01

    The surface tension of aqueous solutions of seven poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (PEO-PPO-PEO) Pluronic copolymers, covering a wide range of molecular weights (3400-14600) and PPO/PEO ratios (0.19-1.79), was determined over the 10[sup [minus]5]-10% w/v concentration range, at two temperatures (25 and 35[degree]C). Two breaks (changes in slope) were observed in the surface tension vs log concentration curve for most of the copolymers. The low-concentration break, occurring at bulk copolymer concentrations of approximately 10[sup [minus]3]%, is believed to originate from rearrangement of the copolymer molecules on the surface at complete coverage of the air/water interface. The breaks at the high-concentration part of the surface tension curve occurred at concentrations that correspond to the critical micellization concentration values as determined by a dye solubilization technique. The surface area per copolymer molecule, A, increased as a function of the number of EO segments, N[sub EO], obeying a scaling law (A [approx] N[sub EO][sup 1/2]) similar to that of lower molecular weight C[sub i]E[sub j] nonionic surfactants. 56 refs., 6 figs., 2 tabs.

  5. Confinement effects on the crystallization of poly(ethylene oxide) nanotubes.

    PubMed

    Maiz, Jon; Martin, Jaime; Mijangos, Carmen

    2012-08-21

    In this work, we show the effects of nanoconfinement on the crystallization of poly(ethylene oxide) (PEO) nanotubes embedded in anodized aluminum oxide (AAO) templates. The morphological characteristics of the hollow 1D PEO nanostructures were evaluated by scanning electron microscopy (SEM). The crystallization of the PEO nanostructures and bulk was studied with differential scanning calorimetry (DSC) and wide-angle X-ray diffraction (WAXD). The crystallization of PEO nanotubes studied by DSC is strongly influenced by the confinement showing a strong reduction in the crystallization temperature of the polymer. X-ray diffraction (XRD) experiments confirmed the isothermal crystallization results obtained by DSC, and studies carried out at low temperatures showed the absence of crystallites oriented with the extended chains perpendicular to the pore wall within the PEO nanotubes, which has been shown to be the typical crystal orientation for one-dimensional polymer nanostructures. In contrast, only planes oriented 33, 45, and 90° with respect to the plane (120) are arranged parallel to the pore's main axis, indicating preferential crystal growth in the direction of the radial component. Calculations based on classical nucleation theory suggest that heterogeneous nucleation prevails in the bulk PEO whereas for the PEO nanotubes a surface nucleation mechanism is more consistent with the obtained results.

  6. Electrochemical oxidation of polyethylene glycol in electroplating solution using paraffin composite copper hexacyanoferrate modified (PCCHM) anode.

    PubMed

    Bejankiwar, Rajesh S; Basu, Abir; Cementi, Max

    2004-01-01

    Electrochemical oxidation of polyethylene glycol (PEG) in an acidic (pH 0.18 to 0.42) and high ionic strength electroplating solution was investigated. The electroplating solution is a major source of wastewater in the printing wiring board industry. A paraffin composite copper hexacyanoferrate modified (PCCHM) electrode was used as the anode and a bare graphite electrode was used as the cathode. The changes in PEG and total organic carbon (TOC) concentrations during the course of the reaction were monitored. The efficiency of the PCCHM anode was compared with bare graphite anode and it was found that the former showed significant electrocatalytic property for PEG and TOC removal. Chlorides present in the solution were found to contribute significantly in the overall organic removal process. Short chain organic compounds like acetic acid, oxalic acid, formic acid and ethylene glycol formed during electrolysis were identified by HPLC method. Anode surface area and applied current density were found to influence the electro-oxidation process, in which the former was found to be dominating. Investigations of the kinetics for the present electrochemical reaction suggested that the two stage first-order kinetic model provides a much better representation of the overall mechanism of the process if compared to the generalized kinetic model.

  7. Steric stabilization of microspheres with grafted polyethylene oxide reduces phagocytosis by rat Kupffer cells in vitro.

    PubMed

    Harper, G R; Davies, M C; Davis, S S; Tadros, T F; Taylor, D C; Irving, M P; Waters, J A

    1991-09-01

    Sterically stabilized polyethylene oxide-polystyrene copolymer microspheres, (PS-PEO) and charge stabilized polystyrene (PS) microspheres of similar size (1 micron) were prepared in order to compare their uptake by cultured rat Kupffer cells isolated by centrifugal elutriation. The uptake of the sterically stabilized particles was found to be much less than that for the charge stabilized control. The uptake of microspheres stabilized with covalently grafted PEO was lower or equivalent to that of control microspheres stabilized by the adsorption of the non-ionic PEO-polypropylene oxide (PPO-PEO) surfactant Poloxamer 238 or Methoxy-PEO. Phagocytic uptake by Kupffer cells at low and body temperature (8 degrees C and 37 degrees C) demonstrated that PS-PEO particles showed both low adherence and low metabolic uptake. The adsorption of PEO, as Poloxamer 238, to particles with covalently attached or grafted PEO resulted in a synergistic reduction in uptake that was greater than the individual effects of grafting and adsorption alone (P less than or equal to 0.001). It is suggested that this combination produces a more effective steric barrier on the particle surface with the Poloxamer adsorbing to the surface between the grafted PEO chains. The relevance to drug targeting/carrier systems is discussed.

  8. Low-cost flexible supercapacitors based on laser reduced graphene oxide supported on polyethylene terephthalate substrate

    NASA Astrophysics Data System (ADS)

    Ghoniem, Engy; Mori, Shinsuke; Abdel-Moniem, Ahmed

    2016-08-01

    A controlled high powered CO2 laser system is used to reduce and pattern graphene oxide (GO) film supported onto a flexible polyethylene terephthalate (PET) substrate. The laser reduced graphene oxide (rGO) film is characterized and evaluated electrochemically in the absence and presence of an overlying anodicaly deposited thin film of pseuodcapactive MnO2 as electrodes for supercapacitor applications using aqueous electrolyte. The laser treatment of the GO film leads to an overlapped structure of defective multi-layer rGO sheets with an electrical conductivity of 273 S m-1. The rGO and MnO2/rGO electrodes exhibit specific capacitance in the range of 82-107 and 172-368 Fg-1 at applied current range of 0.1-1.0 mA cm-2 and retain 98 and 95% of their initial capacitances after 2000 cycles at a current density of 1.0 mA cm-2, respectively. Also, the rGO is assigned as an electrode material for flexible conventionally stacked and interdigitated in-plane supercapacitor structures using gel electrolyte. Three electrode architectures of 2, 4, and 6 sub-electrodes are studied for the interdigital in-plane design. The device with interdigital 6 sub-electrodes architecture I-PS(6) delivers power density of 537.1 Wcm-3 and an energy density of 0.45 mWh cm-3.

  9. Isothermal Crystallization of Poly(ethylene oxide) / Single Walled Carbon Nanotube Nanocomposites

    NASA Astrophysics Data System (ADS)

    Lorenzo, Arnaldo; Chatterjee, Tirtha; Krishnamoorti, Ramanan

    2011-03-01

    The isothermal crystallization behavior of poly(ethylene oxide)/single walled carbon nanotubes (PEO/SWNT) nanocomposites were studied with a focus on the overall crystallization kinetics and the morphological evolution of PEO using differential scanning calorimetry and in-situ small angle x-ray scattering measurements, respectively. The overall crystallization process of the PEO was strongly affected by lithium dodecyl sulfate (LDS) stabilized carbon nanotubes. Further, analysis of the overall crystallization kinetics showed that the PEO chains were topologically constrained by the presence of LDS with an increased energy barrier associated with nucleation and crystal growth, and the nanotubes further act as a barrier to chain transport or enhance the LDS action on the PEO chains. The energy penalty and diffusional barrier to chain transport in the nanocomposites disrupt the PEO crystal helical conformation. This destabilization leads to formation of thinner crystal lamellae and suggests that the crystallization kinetics is primarily controlled by the growth process. This study is particularly interesting considering the suppression of the PEO crystallinity in presence of small amounts of Lithium ion based surfactant and carbon nanotubes.

  10. Flocculation with poly(ethylene oxide)/tyrosine-rich polypeptide complexes.

    PubMed

    Lu, Chen; Pelton, Robert

    2005-04-26

    New insights into the mechanism for the flocculation of aqueous colloids by the sequential addition of a water-borne phenolic polymer, called cofactor, followed by very high molecular poly(ethylene oxide) (PEO) are presented. It is proposed that PEO/cofactor complexes form in the aqueous phase and adsorb onto the surfaces of the target colloidal particles. Flocculation will occur if PEO/cofactor complex on one particle will bind to adsorbed complex on a second particle; i.e., if the complexes are sticky. The proposed mechanism was illustrated by flocculation experiments with precipitated calcium carbonate, very high molecular weight PEO, and a polypeptide cofactor called PEY1 which was a 1:1 random copolymer of l-glycine and l-tyrosine. Independent measurements of the PEO/PEY1 complex properties, in the absence of calcium carbonate, were used to support the mechanism. In order for PEO/PEY1 complexes to be sticky, they must simultaneously have unbound PEY1 and polymer segments. With time the complexes deactivate (i.e., lose their stickiness) by a reconfiguration process which results in elimination of either unbound PEY1 or PEO segments.

  11. AC and DC electrospinning of hydroxypropylmethylcellulose with polyethylene oxides as secondary polymer for improved drug dissolution.

    PubMed

    Balogh, Attila; Farkas, Balázs; Verreck, Geert; Mensch, Jürgen; Borbás, Enikő; Nagy, Brigitta; Marosi, György; Nagy, Zsombor Kristóf

    2016-05-30

    Alternating current electrospinning (ACES) capable to reach multiple times higher specific productivities than widely used direct current electrospinning (DCES) was investigated and compared with DCES to prepare drug-loaded formulations based on one of the most widespread polymeric matrix used for commercialized pharmaceutical solid dispersions, hydroxypropylmethylcellulose 2910 (HPMC). In order to improve the insufficient spinnability of HPMC (both with ACES and DCES) polyethylene oxide (PEO) as secondary polymer with intense ACES activity was introduced into the electrospinning solution. Different grades of this polymer used at as low concentrations in the fibers as 0.1% or less enabled the production of high quality HPMC-based fibrous mats without altering its physicochemical properties remarkably. Increasing concentrations of higher molecular weight PEOs led to the thickening of fibers from submicronic diameters to several microns of thickness. ACES fibers loaded with the poorly water-soluble model drug spironolactone were several times thinner than drug-loaded fibers prepared with DCES in spite of the higher feeding rates applied. The amorphous HPMC-based fibers with large surface area enhanced the dissolution of spironolactone significantly, the presence of small amounts of PEO did not affect the dissolution rate. The presented results confirm the diverse applicability of ACES, a novel technique to prepare fibrous drug delivery systems.

  12. Effects of ionic liquids on cation dynamics in amorphous polyethylene oxide electrolytes

    SciTech Connect

    Chattoraj, Joyjit Diddens, Diddo; Heuer, Andreas

    2014-01-14

    We perform extensive molecular dynamics simulations of a poly(ethylene oxide)-based polymer electrolyte material containing lithium bis(trifluoromethanesulfonyl)imide salt for a wide temperature regime above and below the experimental crystallization temperature with and without N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid (IL). The impact of the IL-concentration on the cation dynamics is studied. The increase of the cation mobility upon addition of IL is significant but temperature-independent. This can be related to distinct variations of the underlying transport properties as expressed within the previously introduced transport model of polymer electrolytes. Even for the largest IL concentration the transport model perfectly predicts the non-trivial time-dependence of the cationic mean square displacement for all temperatures. Finally, we compare our numerical and theoretical findings with the results of recent nuclear magnetic resonance experiments. In this way we can exclusively relate the strong experimentally observed dependence of the low-temperature Li-diffusivity on the IL concentration to the impact of IL on crystallization.

  13. Dynamics of Water Associated with Lithium Ions Distributed in Polyethylene Oxide

    SciTech Connect

    Zhang, Zhe; Ohl, Michael; Diallo, Souleymane O.; Jalarvo, Niina H.; Hong, Kunlun; Han, Youngkyu; Smith, Gregory S.; Do, Changwoo

    2015-11-03

    We studied the dynamics of water in polyethylene oxide (PEO)/LiCl solution with quasielastic neutron scattering experiments and molecular dynamics (MD) simulations. Two different time scales of water diffusion representing interfacial water and bulk water dynamics have been identified. Furthermore, the measured diffusion coefficient of interfacial water remained 5–10 times smaller than that of bulk water, but both were slowed by approximately 50% in the presence of Li+. Detailed analysis of MD trajectories suggests that Li+ is favorably found at the surface of the hydration layer, and the probability to find the caged Li+ configuration formed by the PEO is lower than for the noncaged Li+-PEO configuration. In both configurations, however, the slowing down of water molecules is driven by reorienting water molecules and creating water-Li+ hydration complexes. Moreover, performing the MD simulation with different ions (Na+ and K+) revealed that smaller ionic radius of the ions is a key factor in disrupting the formation of PEO cages by allowing spaces for water molecules to come in between the ion and PEO.

  14. In Situ Study of Strain-Dependent Ion Conductivity of Stretchable Polyethylene Oxide Electrolyte

    PubMed Central

    Kelly, Taylor; Ghadi, Bahar Moradi; Berg, Sean; Ardebili, Haleh

    2016-01-01

    There is a strong need in developing stretchable batteries that can accommodate stretchable or irregularly shaped applications including medical implants, wearable devices and stretchable electronics. Stretchable solid polymer electrolytes are ideal candidates for creating fully stretchable lithium ion batteries mainly due to their mechanical and electrochemical stability, thin-film manufacturability and enhanced safety. However, the characteristics of ion conductivity of polymer electrolytes during tensile deformation are not well understood. Here, we investigate the effects of tensile strain on the ion conductivity of thin-film polyethylene oxide (PEO) through an in situ study. The results of this investigation demonstrate that both in-plane and through-plane ion conductivities of PEO undergo steady and linear growths with respect to the tensile strain. The coefficients of strain-dependent ion conductivity enhancement (CSDICE) for in-plane and through-plane conduction were found to be 28.5 and 27.2, respectively. Tensile stress-strain curves and polarization light microscopy (PLM) of the polymer electrolyte film reveal critical insights on the microstructural transformation of stretched PEO and the potential consequences on ionic conductivity. PMID:26831948

  15. Photopolymerization-induced crystallization and phase separation in poly(ethylene oxide)/triacrylate blends

    SciTech Connect

    Park, Soo Jeoung; Kyu, Thein

    2008-12-28

    The present article describes experimental and theoretical investigations of miscibility and crystallization behavior of blends of poly(ethylene oxide) (PEO) and triacrylate monomer (TA) using differential scanning calorimetry and optical microscopy. The PEO/TA blends manifested a single T{sub g} varying systematically with composition suggestive of a miscible character in their amorphous states. Moreover, there occurs melting point depression of PEO crystals with increasing TA. A phase diagram was subsequently established that exhibited a solid+liquid coexistence region bound by the liquidus and solidus lines, followed by an upper critical solution temperature (UCST) at a lower temperature. The emerging phase morphology was investigated to verify the coexistence regions. Upon photopolymerization in the isotropic melt above the melting point depression curve, both the UCST and the melting temperatures move upward and eventually surpass the reaction temperature, resulting in phase separation as well as crystallization of PEO driven by the changing supercooling, i.e., the thermodynamic driving force. Of particular interest is the interplay between photopolymerization-induced phase separation and crystallization, which eventually determines the final phase morphology of the PEO/TA blend such as crystalline lamellae, sheaf, or spherulites in isotropic liquid, phase separated domains, and viscous fingering liquids.

  16. Photopolymerization-induced crystallization and phase separation in poly(ethylene oxide)/triacrylate blends.

    PubMed

    Park, Soo Jeoung; Kyu, Thein

    2008-12-28

    The present article describes experimental and theoretical investigations of miscibility and crystallization behavior of blends of poly(ethylene oxide) (PEO) and triacrylate monomer (TA) using differential scanning calorimetry and optical microscopy. The PEO/TA blends manifested a single T(g) varying systematically with composition suggestive of a miscible character in their amorphous states. Moreover, there occurs melting point depression of PEO crystals with increasing TA. A phase diagram was subsequently established that exhibited a solid+liquid coexistence region bound by the liquidus and solidus lines, followed by an upper critical solution temperature (UCST) at a lower temperature. The emerging phase morphology was investigated to verify the coexistence regions. Upon photopolymerization in the isotropic melt above the melting point depression curve, both the UCST and the melting temperatures move upward and eventually surpass the reaction temperature, resulting in phase separation as well as crystallization of PEO driven by the changing supercooling, i.e., the thermodynamic driving force. Of particular interest is the interplay between photopolymerization-induced phase separation and crystallization, which eventually determines the final phase morphology of the PEO/TA blend such as crystalline lamellae, sheaf, or spherulites in isotropic liquid, phase separated domains, and viscous fingering liquids.

  17. Metal adsorption of gamma-irradiated carboxymethyl cellulose/polyethylene oxide blend films

    NASA Astrophysics Data System (ADS)

    El-Naggar, Amal A.; Magida, M. M.; Ibrahim, Sayeda M.

    2016-03-01

    Blend films of different ratios of carboxymethyl cellulose (CMC)/polyethylene oxide (PEO) were prepared by the solution casting method. To investigate the effect of irradiation on all properties of prepared blend, it was exposed to different gamma irradiation doses (10, 20, and 30 kGy). Physical properties such as gel fraction (GF) (%) and swelling (SW) (%) were investigated. It was found that the GF (%) increases with increasing irradiation dose up to 20 kGy, while SW (%) decreases with an increase in the irradiation doses for all blend compositions. Moreover, the structural and mechanical properties of the prepared films were studied. The results of the mechanical properties obtained showed that there is an improvement in these properties with an increase in both CMC and irradiation dose up to 20 kGy. The efficiency of metal ions uptake was measured using a UV spectrophotometer. The prepared films showed good tendency to absorb and release metal ions from aqueous media. Thus, the CMC/PEO film can be used in agricultural domain.

  18. In Situ Study of Strain-Dependent Ion Conductivity of Stretchable Polyethylene Oxide Electrolyte

    NASA Astrophysics Data System (ADS)

    Kelly, Taylor; Ghadi, Bahar Moradi; Berg, Sean; Ardebili, Haleh

    2016-02-01

    There is a strong need in developing stretchable batteries that can accommodate stretchable or irregularly shaped applications including medical implants, wearable devices and stretchable electronics. Stretchable solid polymer electrolytes are ideal candidates for creating fully stretchable lithium ion batteries mainly due to their mechanical and electrochemical stability, thin-film manufacturability and enhanced safety. However, the characteristics of ion conductivity of polymer electrolytes during tensile deformation are not well understood. Here, we investigate the effects of tensile strain on the ion conductivity of thin-film polyethylene oxide (PEO) through an in situ study. The results of this investigation demonstrate that both in-plane and through-plane ion conductivities of PEO undergo steady and linear growths with respect to the tensile strain. The coefficients of strain-dependent ion conductivity enhancement (CSDICE) for in-plane and through-plane conduction were found to be 28.5 and 27.2, respectively. Tensile stress-strain curves and polarization light microscopy (PLM) of the polymer electrolyte film reveal critical insights on the microstructural transformation of stretched PEO and the potential consequences on ionic conductivity.

  19. Poly(propylene fumarate)/Polyethylene Glycol-Modified Graphene Oxide Nanocomposites for Tissue Engineering.

    PubMed

    Díez-Pascual, Ana M; Díez-Vicente, Angel L

    2016-07-20

    Poly(propylene fumarate) (PPF)-based nanocomposites incorporating different amounts of polyethylene glycol-functionalized graphene oxide (PEG-GO) have been prepared via sonication and thermal curing, and their surface morphology, structure, thermal stability, hydrophilicity, water absorption, biodegradation, cytotoxicity, mechanical, viscoelastic and antibacterial properties have been investigated. SEM and TEM images corroborated that the noncovalent functionalization with PEG caused the exfoliation of GO into thinner flakes. IR spectra suggested the presence of strong hydrogen-bonding interactions between the nanocomposite components. A gradual rise in the level of hydrophilicity, water uptake, biodegradation rate, surface roughness, protein absorption capability and thermal stability was found upon increasing GO concentration in the composites. Tensile tests revealed improved stiffness, strength and toughness for the composites compared to unfilled PPF, ascribed to a homogeneous GO dispersion within the matrix along with a strong PPF/PEG-GO interfacial adhesion via polar and hydrogen bonding interactions. Further, the nanocomposites retained enough stiffness and strength under a biological state to provide effective support for bone tissue formation. The antibacterial activity was investigated against Gram-positive Staphylococcus aureus and Staphylococcus epidermidis as well as Gram-negative Pseudomonas aeruginosa and Escherichia coli microorganisms, and it rose sharply upon increasing GO concentration; systematically, the biocide effect was stronger versus Gram-positive bacteria. Cell viability data demonstrated that PPF/PEG-GO composites do not induce toxicity over human dermal fibroblasts. These novel materials show great potential to be applied in the bone tissue engineering field.

  20. Polyethylene oxide (PEO)-hyaluronic acid (HA) nanofibers with kanamycin inhibits the growth of Listeria monocytogenes.

    PubMed

    Ahire, J J; Robertson, D D; van Reenen, A J; Dicks, L M T

    2017-02-01

    Listeria monocytogenes is well known to cause prosthetic joint infections in immunocompromised patients. In this study, polyethylene oxide (PEO) nanofibers, containing kanamycin and hyaluronic acid (HA), were prepared by electrospinning at a constant electric field of 10kV. PEO nanofibers spun with 0.2% (w/v) HA and 1% (w/v) kanamycin had a smooth, bead-free structure at 30-35% relative humidity. The average diameter of the nanofibers was 83±20nm. Attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy indicated that kanamycin was successfully incorporated into PEO/HA matrix. The presence of kanamycin affects the thermal properties of PEO/HA nanofibers, as shown by differential scanning calorimetry (DSC) and thermogravimetric analyses (TGA). The kanamycin-PEO-HA nanofibers (1mg; 47±3μg kanamycin) inhibited the growth of L. monocytogenes EDGe by 62%, as compared with PEO-HA nanofibers, suggesting that it may be used to coat prosthetic implants to prevent secondary infections.

  1. Lithium Ion Pathway within Li7 La3 Zr2 O12 -Polyethylene Oxide Composite Electrolytes.

    PubMed

    Zheng, Jin; Tang, Mingxue; Hu, Yan-Yan

    2016-09-26

    Polymer-ceramic composite electrolytes are emerging as a promising solution to deliver high ionic conductivity, optimal mechanical properties, and good safety for developing high-performance all-solid-state rechargeable batteries. Composite electrolytes have been prepared with cubic-phase Li7 La3 Zr2 O12 (LLZO) garnet and polyethylene oxide (PEO) and employed in symmetric lithium battery cells. By combining selective isotope labeling and high-resolution solid-state Li NMR, we are able to track Li ion pathways within LLZO-PEO composite electrolytes by monitoring the replacement of (7) Li in the composite electrolyte by (6) Li from the (6) Li metal electrodes during battery cycling. We have provided the first experimental evidence to show that Li ions favor the pathway through the LLZO ceramic phase instead of the PEO-LLZO interface or PEO. This approach can be widely applied to study ion pathways in ionic conductors and to provide useful insights for developing composite materials for energy storage and harvesting.

  2. Encapsulation of T4 bacteriophage in electrospun poly(ethylene oxide)/cellulose diacetate fibers.

    PubMed

    Korehei, Reza; Kadla, John F

    2014-01-16

    Phage therapy is a potentially beneficial approach to food preservation and storage. Sustained delivery of bacteriophage can prevent bacterial growth on contaminated food surfaces. Using coaxial electrospinning bacteriophage can be encapsulated in electrospun fibers with high viability. The resulting bio-based electrospun fibers may have potential as a food packaging material. In the present work, T4 bacteriophage (T4 phage) was incorporated into core/shell electrospun fibers made from poly(ethylene oxide) (PEO), cellulose diacetate (CDA), and their blends. Fibers prepared using PEO as the shell polymer showed an immediate burst release of T4 phage upon submersion in buffer. The blending of CDA with PEO significantly decreased the rate of phage release, with no released T4 phage being detected from the solely CDA fibers. Increasing the PEO molecular weight increased the electrospun fiber diameter and viscosity of the releasing medium, which resulted in a relatively slower T4 phage release profile. SEM analyses of the electrospun fiber morphologies were in good agreement with the T4 phage release profiles. Depending on the PEO/CDA ratio, the post-release electrospun fiber morphologies varied from discontinuous fibers to minimally swollen fibers. From these results it is suggested that the T4 phage release mechanism is through solvent activation/polymer dissolution in the case of the PEO fibers and/or by diffusion control from the PEO/CDA blend fibers.

  3. Effects of ionic liquids on cation dynamics in amorphous polyethylene oxide electrolytes.

    PubMed

    Chattoraj, Joyjit; Diddens, Diddo; Heuer, Andreas

    2014-01-14

    We perform extensive molecular dynamics simulations of a poly(ethylene oxide)-based polymer electrolyte material containing lithium bis(trifluoromethanesulfonyl)imide salt for a wide temperature regime above and below the experimental crystallization temperature with and without N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid (IL). The impact of the IL-concentration on the cation dynamics is studied. The increase of the cation mobility upon addition of IL is significant but temperature-independent. This can be related to distinct variations of the underlying transport properties as expressed within the previously introduced transport model of polymer electrolytes. Even for the largest IL concentration the transport model perfectly predicts the non-trivial time-dependence of the cationic mean square displacement for all temperatures. Finally, we compare our numerical and theoretical findings with the results of recent nuclear magnetic resonance experiments. In this way we can exclusively relate the strong experimentally observed dependence of the low-temperature Li-diffusivity on the IL concentration to the impact of IL on crystallization.

  4. Effects of ionic liquids on cation dynamics in amorphous polyethylene oxide electrolytes

    NASA Astrophysics Data System (ADS)

    Chattoraj, Joyjit; Diddens, Diddo; Heuer, Andreas

    2014-01-01

    We perform extensive molecular dynamics simulations of a poly(ethylene oxide)-based polymer electrolyte material containing lithium bis(trifluoromethanesulfonyl)imide salt for a wide temperature regime above and below the experimental crystallization temperature with and without N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulfonyl)imide ionic liquid (IL). The impact of the IL-concentration on the cation dynamics is studied. The increase of the cation mobility upon addition of IL is significant but temperature-independent. This can be related to distinct variations of the underlying transport properties as expressed within the previously introduced transport model of polymer electrolytes. Even for the largest IL concentration the transport model perfectly predicts the non-trivial time-dependence of the cationic mean square displacement for all temperatures. Finally, we compare our numerical and theoretical findings with the results of recent nuclear magnetic resonance experiments. In this way we can exclusively relate the strong experimentally observed dependence of the low-temperature Li-diffusivity on the IL concentration to the impact of IL on crystallization.

  5. Shape and Mechanical Control of Poly(ethylene oxide) Based Polymersome with Polyoxometalates via Hydrogen Bond.

    PubMed

    Jing, Benxin; Wang, Xiaofeng; Wang, Haitao; Qiu, Jie; Shi, Yi; Gao, Haifeng; Zhu, Yingxi

    2017-02-23

    Polymersomes are self-assembled vesicles of amphiphilic block copolymers and have been explored for wide applications from drug delivery to micro/nanoreactors. As polymersomes are soft and highly deformable, their shape instability due to osmolarity difference across polymer membranes and low elasticity could conversely limit their practical use. Instead of selecting particular polymer chemical reactions to enhance the mechanical properties, we have employed inorganic polyoxometalate (POM) clusters as simple physical cross-linkers to control the shape and mechanical stability of polymersomes in aqueous suspensions. Robust spherical shape with enhanced elastic and bending moduli of POM-dressed poly(ethylene oxide) (PEO) based polymersomes is achieved. We have accounted for the hydrogen bonding between POM and PEO blocks for the adsorption and stabilization of POMS on polymersomes, whose interaction strength could also be tuned by mixing solvents of hydrogen bond donors or receptors with water. The stimuli-responsive properties of POMs are introduced in POM-dressed polymersomes upon the interaction of POMs with PEO blocks in aqueous media. As POM can be used as nanomedicines, catalysts, and other functional nanomaterials, POM-dressed polymersomes with significant shape and mechanical reinforcement could broaden the applications of PEO-based polymersomes and other PEO-tethered nanocolloids.

  6. The diffusion and conduction of lithium in poly(ethylene oxide)-based sulfonate ionomers

    NASA Astrophysics Data System (ADS)

    LaFemina, Nikki H.; Chen, Quan; Colby, Ralph H.; Mueller, Karl T.

    2016-09-01

    Pulsed field gradient nuclear magnetic resonance spectroscopy and dielectric relaxation spectroscopy have been utilized to investigate lithium dynamics within poly(ethylene oxide) (PEO)-based lithium sulfonate ionomers of varying ion content. The ion content is set by the fraction of sulfonated phthalates and the molecular weight of the PEO spacer, both of which can be varied independently. The molecular level dynamics of the ionomers are dominated by either Vogel-Fulcher-Tammann or Arrhenius behavior depending on ion content, spacer length, temperature, and degree of ionic aggregation. In these ionomers the main determinants of the self-diffusion of lithium and the observed conductivities are the ion content and ionic states of the lithium ion, which are profoundly affected by the interactions of the lithium ions with the ether oxygens of the polymer. Since many lithium ions move by segmental polymer motion in the ion pair state, their diffusion is significantly larger than that estimated from conductivity using the Nernst-Einstein equation.

  7. High efficiency solid state dye sensitized solar cells with graphene-polyethylene oxide composite electrolytes.

    PubMed

    Akhtar, M Shaheer; Kwon, Soonji; Stadler, Florian J; Yang, O Bong

    2013-06-21

    Novel and highly effective composite electrolytes were prepared by combining the two dimensional graphene (Gra) and polyethylene oxide (PEO) for the solid electrolyte of dye sensitized solar cells (DSSCs). Gra sheets were uniformly coated by the polymer layer through the ester carboxylate bonding between oxygenated species on Gra sheets and PEO. The Gra-PEO composite electrolyte showed the large scale generation of iodide ions in a redox couple. From rheological analysis, the decrease in viscosity after the addition of LiI and I2 in the Gra-PEO electrolyte might be explained by the dipolar interactions being severely disrupted by the ionic interactions of Li(+), I(-), and I3(-) ions. A composite electrolyte with 0.5 wt% Gra presented a higher ionic conductivity (3.32 mS cm(-1)) than those of PEO and other composite electrolytes at room temperature. A high overall conversion efficiency (∼5.23%) with a very high short circuit current (JSC) of 18.32 mA cm(-2), open circuit voltage (VOC) of 0.592 V and fill factor (FF) of 0.48 was achieved in DSSCs fabricated with the 0.5 wt% Gra-PEO composite electrolyte. This enhanced photovoltaic performance might be attributed to the large scale formation of iodide ions in the redox electrolyte and the relatively high ionic conductivity.

  8. Ultrahigh molecular weight polyethylene/graphene oxide nanocomposites: wear characterization and biological response to wear particles.

    PubMed

    Suñer, S; Gowland, N; Craven, R; Joffe, R; Emami, N; Tipper, J L

    2016-12-09

    In the field of total joint replacements, polymer nanocomposites are being investigated as alternatives to ultrahigh molecular weight polyethylene (UHMWPE) for acetabular cup bearings. The objective of this study was to investigate the wear performance and biocompatibility of UHMWPE/graphene oxide (GO) nanocomposites. This study revealed that low concentrations of GO nanoparticles (0.5 wt %) do not significantly alter the wear performance of UHMWPE. In contrast, the addition of higher concentrations (2 wt %) led to a significant reduction in wear. In terms of biocompatibility, UHMWPE/GO wear particles did not show any adverse effects on L929 fibroblast and PBMNC viability at any of the concentrations tested over time. Moreover, the addition of GO to a UHMWPE matrix did not significantly affect the inflammatory response to wear particles. Further work is required to optimize the manufacturing processes to improve the mechanical properties of the nanocomposites and additional biocompatibility testing should be performed to understand the potential clinical application of these materials. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2016.

  9. Scaling law of poly(ethylene oxide) chain permeation through a nanoporous wall.

    PubMed

    Choudhury, Rudra Prosad; Galvosas, Petrik; Schönhoff, Monika

    2008-10-23

    This paper presents a study of the permeation of poly(ethylene oxide) (PEO) chains through the nanoporous wall of hollow polymeric capsules prepared by self-assembly of polyelectrolytes. We employ the method of pulsed field gradient (PFG) NMR diffusion to distinguish chains in different sites, i.e., in the capsule interior and free chains in the dispersion, by their respective diffusion coefficient. From a variation of the observation time, the time scale of the molecular exchange between both sites and thus the permeation rate constant is extracted from a two-site exchange model. Permeation rate constants show two different regimes with a different dependence on chain length. This suggests a transition between two different mechanisms of permeation as the molecular weight is increased. In either regime, the permeation time can be described by a scaling law tau approximately N (b) , with b = (4)/ 3 for short chains and b = (1)/ 3 for long chains. We discuss these exponents, which clearly differ from the theoretical predictions for chain translocation.

  10. Titanate nanotubes for reinforcement of a poly(ethylene oxide)/chitosan polymer matrix

    NASA Astrophysics Data System (ADS)

    Porras, R.; Bavykin, D. V.; Zekonyte, J.; Walsh, F. C.; Wood, R. J.

    2016-05-01

    Soft polyethylene oxide (PEO)/chitosan mixtures, reinforced with hard titanate nanotubes (TiNTs) by co-precipitation from aqueous solution, have been used to produce compact coatings by the ‘drop-cast’ method, using water soluble PEO polymer and stable, aqueous colloidal solutions of TiNTs. The effects of the nanotube concentration and their length on the hardness and modulus of the prepared composite have been studied using nanoindentation and nanoscratch techniques. The uniformity of TiNT dispersion within the polymer matrix has been studied using transmission electron microscopy (TEM). A remarkable increase in hardness and reduced Young’s modulus of the composites, compared to pure polymer blends, has been observed at a TiNT concentration of 25 wt %. The short (up to 30 min) ultrasound treatment of aqueous solutions containing polymers and a colloidal TiNT mixture prior to drop casting has resulted in some improvements in both hardness and reduced Young’s modulus of dry composite films, probably due to a better dispersion of ceramic nanotubes within the matrix. However, further (more than 1 h) treatment of the mixture with ultrasound resulted in a deterioration of the mechanical properties of the composite accompanied by a shortening of the nanotubes, as observed by the TEM.

  11. Influence of chain topology on polymer crystallization: poly(ethylene oxide) (PEO) rings vs. linear chains.

    PubMed

    Zardalidis, George; Mars, Julian; Allgaier, Jürgen; Mezger, Markus; Richter, Dieter; Floudas, George

    2016-10-04

    The absence of entanglements, the more compact structure and the faster diffusion in melts of cyclic poly(ethylene oxide) (PEO) chains have consequences on their crystallization behavior at the lamellar and spherulitic length scales. Rings with molecular weight below the entanglement molecular weight (M < Me), attain the equilibrium configuration composed from twice-folded chains with a lamellar periodicity that is half of the corresponding linear chains. Rings with M > Me undergo distinct step-like conformational changes to a crystalline lamellar with the equilibrium configuration. Rings melt from this configuration in the absence of crystal thickening in sharp contrast to linear chains. In general, rings more easily attain their extended equilibrium configuration due to strained segments and the absence of entanglements. In addition, rings have a higher equilibrium melting temperature. At the level of the spherulitic superstructure, growth rates are much faster for rings reflecting the faster diffusion and more compact structure. With respect to the segmental dynamics in their semi-crystalline state, ring PEOs with a steepness index of ∼34 form some of the "strongest" glasses.

  12. Dynamics of Water Associated with Lithium Ions Distributed in Polyethylene Oxide

    DOE PAGES

    Zhang, Zhe; Ohl, Michael; Diallo, Souleymane O.; ...

    2015-11-03

    We studied the dynamics of water in polyethylene oxide (PEO)/LiCl solution with quasielastic neutron scattering experiments and molecular dynamics (MD) simulations. Two different time scales of water diffusion representing interfacial water and bulk water dynamics have been identified. Furthermore, the measured diffusion coefficient of interfacial water remained 5–10 times smaller than that of bulk water, but both were slowed by approximately 50% in the presence of Li+. Detailed analysis of MD trajectories suggests that Li+ is favorably found at the surface of the hydration layer, and the probability to find the caged Li+ configuration formed by the PEO is lowermore » than for the noncaged Li+-PEO configuration. In both configurations, however, the slowing down of water molecules is driven by reorienting water molecules and creating water-Li+ hydration complexes. Moreover, performing the MD simulation with different ions (Na+ and K+) revealed that smaller ionic radius of the ions is a key factor in disrupting the formation of PEO cages by allowing spaces for water molecules to come in between the ion and PEO.« less

  13. New Aptes Cross-linked Polymers from Poly(ethylene oxide)s and Cyanuric Chloride for Lithium Batteries

    NASA Technical Reports Server (NTRS)

    Tigelaar, Dean M.; Meador, Mary Ann B.; Kinder, James D.; Bennett, William R.

    2005-01-01

    A new series of polymer electrolytes for use as membranes for lithium batteries are described. Electrolytes were made by polymerization between cyanuric chloride and diamino-terminated poly(ethylene oxide)s, followed by cross-linking via a sol-gel process. Thermal analysis and lithium conductivity of freestanding polymer films were studied. The effects of several variables on conductivity were investigated, such as length of backbone PEO chain, length of branching PEO chain, extent of branching, extent of cross-linking, salt content, and salt counterion. Polymer films with the highest percentage of PEO were found to be the most conductive, with a maximum lithium conductivity of 3.9 x 10(exp -5) S/cm at 25 C. Addition of plasticizer to the dry polymers increased conductivity by an order of magnitude.

  14. Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds

    PubMed Central

    Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md. Rakibul

    2016-01-01

    A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075–10 µM and 10–55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days. PMID:27367738

  15. Amperometric Biosensor Based on Zirconium Oxide/Polyethylene Glycol/Tyrosinase Composite Film for the Detection of Phenolic Compounds.

    PubMed

    Ahmad, Nor Monica; Abdullah, Jaafar; Yusof, Nor Azah; Ab Rashid, Ahmad Hazri; Abd Rahman, Samsulida; Hasan, Md Rakibul

    2016-06-29

    A phenolic biosensor based on a zirconium oxide/polyethylene glycol/tyrosinase composite film for the detection of phenolic compounds has been explored. The formation of the composite film was expected via electrostatic interaction between hexacetyltrimethylammonium bromide (CTAB), polyethylene glycol (PEG), and zirconium oxide nanoparticles casted on screen printed carbon electrode (SPCE). Herein, the electrode was treated by casting hexacetyltrimethylammonium bromide on SPCE to promote a positively charged surface. Later, zirconium oxide was mixed with polyethylene glycol and the mixture was dropped cast onto the positively charged SPCE/CTAB. Tyrosinase was further immobilized onto the modified SPCE. Characterization of the prepared nanocomposite film and the modified SPCE surface was investigated by scanning electron microscopy (SEM), Electrochemical Impedance Spectroscopy (EIS), and Cyclic voltamogram (CV). The developed biosensor exhibits rapid response for less than 10 s. Two linear calibration curves towards phenol in the concentrations ranges of 0.075-10 µM and 10-55 µM with the detection limit of 0.034 µM were obtained. The biosensor shows high sensitivity and good storage stability for at least 30 days.

  16. Extraction of americium in different oxidation states in a two-phase aqueous system based on poly(ethylene glycol)

    SciTech Connect

    Molochnikova, N.P.; Frenkel', B.F.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-09-01

    The extraction of americium in different states of oxidation was studied in a two-phase aqueous system based on poly(ethylene glycol). Conditions were found for the quantitative extraction of americium (III) and americium (V) from solutions of ammonium sulfate in the pH range of 3-5 and in the presence of arsenazo III. The composition of the complexes of americium with the reagent was determined; americium (III) reacts with arsenazo III in solutions of ammonium sulfate to form complexes with the composition of MeR and Me/sub 2/R. Characteristics of the absorption spectra of complexes of americium (III) and (V) with arsenazo III in ammonium sulfate solutions and in extracts based on aqueous solutions of poly(ethylene glycol) were found. The molar extinction coefficients of complexes of americium with arsenazo III were determined in these solutions.

  17. Field Effect Transistor Behavior in Electrospun Polyaniline/Polyethylene Oxide Demonstrated

    NASA Technical Reports Server (NTRS)

    Mueller, Carl H.; Theofylaktos, Onoufrios; Robinson, Daryl C.; Miranda, Felix A.

    2004-01-01

    Novel transistors and logic devices based on nanotechnology concepts are under intense development. The potential for ultra-low-power circuitry makes nanotechnology attractive for applications such as digital electronics and sensors. For NASA applications, nanotechnology offers tremendous opportunities for increased onboard data processing, and thus autonomous decisionmaking ability, and novel sensors that detect and respond to environmental stimuli with little oversight requirements. Polyaniline/polyethylene oxide (PANi/PEO) nanofibers are of interest because they have electrical conductivities that can be changed from insulating to metallic by varying the doping levels and conformations of the polymer chain. At the NASA Glenn Research Center, we have observed field effect transistor (FET) behavior in electrospun PANi/PEO nanofibers doped with camphorsulfonic acid. The nanofibers were deposited onto Au electrodes, which had been prepatterned onto oxidized silicon substrates. The preceding scanning electron image shows the device used in the transistor measurements. Saturation channel currents are observed at surprisingly low source/drain voltages (see the following graph). The hole mobility in the depletion regime is 1.4x10(exp -4)sq cm/V sec, whereas the one-dimensional charge density (at zero gate bias) is calculated to be approximately 1 hole per 50 two-ring repeat units of polyaniline, consistent with the rather high channel conductivity (approx.10(exp -3) S/cm). Reducing or eliminating the PEO content in the fiber is expected to enhance device parameters. Electrospinning is thus proposed as a simple method of fabricating one-dimensional polymer FET's.

  18. Polyethylene oxide additive-entrapped polyvinyl chloride as a new blood bag material.

    PubMed

    Lee, J H; Kim, K O; Ju, Y M

    1999-01-01

    Until now, most widely used blood bag material has been a plasticized polyvinyl chloride (PVC) because it has many desirable properties as a blood bag material. One of main concerns of using plasticized PVC as a blood bag material is the toxicity of the plasticizers that are leached out of the material. We tried to solve this problem by the addition of polyethylene oxide (PEO)-containing amphiphilic block copolymers as additives in the PVC. The PEO additives may play two roles: they can act as nontoxic plasticizers to PVC, and they can also act as blood-compatible surface modifiers. In this study, PEO additive-entrapped PVC films were prepared by the addition (up to 30 wt%) of PEO-alkyl carbon block copolymers or PEO-polypropylene oxide (PPO)-PEO triblock copolymers with different PEO chain lengths in the PVC. The prepared PEO additive-containing PVC films were characterized by the measurements of water contact angle, Fourier transform IR spectroscopy in the attenuated total reflectance mode, mechanical properties (tensile strength and elongation at break), water absorption, and stability of the PEO additives entrapped in the films. It was observed that the PEO additive-entrapped PVC films were flexible and transparent. It seems that the PEO additives are surface active, resulting in the considerable change of surface characteristics without a significant change of the mechanical properties of the films compared to the control PVC without any additives or a commercial blood bag. The adhesion of platelets on the film surfaces was significantly reduced by the addition of PEO additives. It seems that 10% addition of PEO additives is enough for the suppression of platelet adhesion on the surfaces. This study demonstrated that the use of PEO-containing block copolymers as additives to the PVC can be a feasible approach to prepare a new type of blood bag.

  19. Relationship between hydroperoxide concentration and average molar mass in thermo-oxidized polyethylene

    NASA Astrophysics Data System (ADS)

    Da Cruz, Manuela; Van Schoors, Laetitia; Colin, Xavier; Benzarti, Karim

    2014-05-01

    The aim of this research project is to investigate the oxidation mechanism of high density polyethylene (HDPE) used in outdoor applications, in order to establish in a near future, a non-empirical kinetic model for lifetime prediction. The present paper focuses on the changes in the hydroperoxide (POOH) concentration induced by thermo-oxidative ageing, and on their relationship with the evolution of the weight average molar mass (Mw) due both to chain scission and crosslinking processes. Thin HDPE films were aged at 110 and 140°C in air under atmospheric pressure. In a first part, changes in the POOH concentration versus ageing time were assessed by three different analytical methods previously reported in the literature: modulated differential scattering calorimetry (MDSC), Fourier transform Infra-Red spectrometry after chemical derivatization treatment with gaseous sulfur dioxide (SO2-FTIR), and iodometry. A comparison of experimental results revealed that these three methods provide very similar quantitative data on POOH accumulation, whereas iodometry tends to strongly underestimate the subsequent stage of POOH decomposition. It was thus suspected that iodometry does not only titrate POOH, but also other chemical species (presumably double bonds) formed when POOH decompose. Therefore, only MDSC and SO2-FTIR were considered as relevant methods for POOH titration. In a second part, changes in Mw versus ageing time were monitored by size exclusion chromatography (SEC). A sharp drop of Mw was first observed at the beginning of exposure, which was assigned to an intensive chain scission process. Then, in a second stage, a stabilization or even a substantial re-increase in Mw was observed, suggesting a competition between chain scission and crosslinking processes. As this second stage starts at the same time as POOH decomposition, it was concluded that there is a strong correlation between both phenomena, occurring respectively at the macromolecular and molecular

  20. Preservation of Mercury in Polyethylene Containers.

    ERIC Educational Resources Information Center

    Piccolino, Samuel Paul

    1983-01-01

    Reports results of experiments favoring use of 0.5 percent nitric acid with an oxidant (potassium dichromate or potassium permanganate) to preserve samples in polyethylene containers for mercury analysis. Includes procedures used and statistical data obtained from the experiments. (JN)

  1. Profiles in garbage: Polyethylene terephthalate

    SciTech Connect

    Miller, C.

    1997-11-01

    Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks -- along with salad dressing, fruit juices, peanut butter, and other household and consumer products -- use PET bottles. PET also is used for film, sheeting for cups and food trays, oven-safe trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early 1970s. Because it is an ``engineered`` resin, PET is more expensive than commodity resins such as high-density polyethylene (HDPE) and, for the same reason, it is usually the highest valued plastic recyclable.

  2. Controlled release of cefazolin sodium antibiotic drug from electrospun chitosan-polyethylene oxide nanofibrous Mats.

    PubMed

    Fazli, Yousef; Shariatinia, Zahra

    2017-02-01

    Antimicrobial electrospun chitosan-polyethylene oxide (CS-PEO) nanofibrous mats containing cefazolin, fumed silica (F. silica) and cefazolin-loaded fumed silica nanoparticles (NPs) were produced for biomedical applications. The FE-SEM images revealed that the F. silica and F. silica-cefazolin NPs had average diameters of 40±10 and 60±15nm, respectively. Also, the fibers diameters were approximately 160±30, 90±20 and 70±15nm for the pure CS-PEO, CS-PEO-1% F. silica and CS-PEO-1% F. silica-0.5% cefazolin nanofibrous mats, respectively indicating addition of F. silica and cefazolin loaded F. silica NPs to the CS-PEO mat led to decreasing the nanofiber diameter. Both of the CS-PEO mats containing 2.5% cefazolin and 1% F. silica-0.50% cefazolin showed 100% bactericidal activities against both S. aureus and E. coli bacteria. The cefazolin release from mats was sharply increased within first 24 and 6hours for the CS-PEO mats including 2.5% cefazolin and 1% F. silica-0.50% cefazolin but after that the drug was released very slowly. The improved hydrophilicity, higher tensile strength and sustained drug release for CS-PEO-1% F. silica-0.50% cefazolin suggested that it was the best nanocomposite tissue/device for biomedical applications among the mats CS-PEO-2.5% cefazolin and CS-PEO-1% F. silica. The wound healing ability of the CS-PEO-F. silica-cefazolin mat was evaluated on the wounded skins of the female Wistar rats and it was shown that the wounded skins of the rats were almost entirely healed after ten days using this mat as a wound dressing scaffold.

  3. Sustained release from hot-melt extruded matrices based on ethylene vinyl acetate and polyethylene oxide.

    PubMed

    Almeida, A; Brabant, L; Siepmann, F; De Beer, T; Bouquet, W; Van Hoorebeke, L; Siepmann, J; Remon, J P; Vervaet, C

    2012-11-01

    The aim of the present study was to evaluate the importance of matrix flexibility of hot-melt extruded (HME) ethylene vinyl acetate (EVA) matrices (with vinyl acetate (VA) contents of 9%, 15%, 28% and 40%), through the addition of hydrophilic polymers with distinct swelling capacity. Polyethylene oxide (PEO 100K, 1M and 7M) was used as swelling agent and metoprolol tartrate (MPT) as model drug. The processability via HME and drug release profiles of EVA/MPT/PEO formulations were assessed. Solid state characteristics, porosity and polymer miscibility of EVA/PEO matrices were evaluated by means of DSC, X-ray tomography and Raman spectroscopy. The processability via HME varied according to the VA content: EVA 40 and 28 were extruded at 90°C, whereas higher viscosity EVA grades (EVA 15 and 9) required a minimum extrusion temperature of 110°C to obtain high-quality extrudates. Drug release from EVA matrices depended on the VA content, PEO molecular weight and PEO content, matrix porosity as well as pore size distribution. Interestingly, the interplay of PEO leaching, matrix swelling, water influx and changes in matrix porosity influenced drug release: EVA 40- and 28-based matrices extruded with PEO of higher MW accelerated drug release, whereas for EVA 15- and 9-based matrices, drug release slowed down. These differences were related to the distinct polymer flexibility imposed by the VA content (lower VA content presents higher crystallinity and less free movement of the amorphous segments resulting in a higher rigidity). In all cases, diffusional mass transport seems to play a major role, as demonstrated by mathematical modeling using an analytical solution of Fick's second law. The bioavailability of EVA 40 and 28 matrices in dogs was not significantly different, independent of PEO 7M concentration.

  4. Mesoscopic simulation of a micellar poly(N-isopropyl acrylamide)-b-(polyethylene oxide) copolymer system

    NASA Astrophysics Data System (ADS)

    Bautista-Reyes, Rubén; Soto-Figueroa, César; Vicente, Luis

    2016-05-01

    In this article we studied the micellar formation of poly(N-isopropyl acrylamide)-b-polyethylene oxide (PNIPAM-b-PEO) copolymers in an aqueous system. From molecular simulations the dependence on temperature of the Flory-Huggins interaction parameter χ for PNIPAM and PEO in water is obtained and compared with available experimental results and values from other theoretical calculations. By means of dissipative particle dynamics (DPD) we then simulated the coil-globule transition for PNIPAM chains in water with a transition temperature of around 305 K. The simulations for PNIPAM-b-PEO copolymers showed that at room temperature the chains are miscible in an aqueous phase but with a temperature increase the system turns into micelles at T  =  305 K. The change in micelle anisotropy due to a different ratio PNIPAM/PEO of chains is also analyzed. What is observed is that for large PEO the large number of dissolved PEO chains gives a large corona size and the micelle is not spherical but obloide and as the number of PNIPAM is increased the micelle acquires a spherical shape. As an important application we considered the system micelle-water/anionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate [BMIM]+[PF6]-). By increasing the temperature of the system from 306 K it is shown that at T  =  345 K there is a transfer of the micelle from water to the ionic liquid phase and this was due to the change in the relative affinity of PEO to water and ionic liquid expressed by the change in χ. All the simulation outcomes are qualitatively consistent with experimental results and thus to our knowledge we give the first set of χ values for the interaction between PNIPAM and water in a wide range of temperature values.

  5. Nonfouling poly(ethylene oxide) layers end-tethered to polydopamine.

    PubMed

    Pop-Georgievski, Ognen; Verreault, Dominique; Diesner, Mark-Oliver; Proks, Vladimír; Heissler, Stefan; Rypáček, František; Koelsch, Patrick

    2012-10-09

    Nonfouling surfaces capable of reducing protein adsorption are highly desirable in a wide range of applications. Coating of surfaces with poly(ethylene oxide) (PEO), a water-soluble, nontoxic, and nonimmunogenic polymer, is most frequently used to reduce nonspecific protein adsorption. Here we show how to prepare dense PEO brushes on virtually any substrate by tethering PEO to polydopamine (PDA)-modified surfaces. The chain lengths of hetero-bifunctional PEOs were varied in the range of 45-500 oxyethylene units (M(n) = 2000-20,000). End-tethering of PEO chains was performed through amine and thiol headgroups from reactive polymer melts to minimize excluded volume effects. Surface plasmon resonance (SPR) was applied to investigate the adsorption of model protein solutions and complex biologic medium (human blood plasma) to the densely packed PEO brushes. The level of protein adsorption of human serum albumin and fibrinogen solutions was below the detection limit of the SPR measurements for all PEO chains end-tethered to PDA, thus exceeding the protein resistance of PEO layers tethered directly on gold. It was found that the surface resistance to adsorption of lysozyme and human blood plasma increased with increasing length and brush character of the PEO chains end-tethered to PDA with a similar or better resistance in comparison to PEO layers on gold. Furthermore, the chain density, thickness, swelling, and conformation of PEO layers were determined using spectroscopic ellipsometry (SE), dynamic water contact angle (DCA) measurements, infrared reflection-absorption spectroscopy (IRRAS), and vibrational sum-frequency-generation (VSFG) spectroscopy, the latter in air and water.

  6. Graphene oxide functionalized with silver@silica-polyethylene glycol hybrid nanoparticles for direct electrochemical detection of quercetin.

    PubMed

    Veerapandian, Murugan; Seo, Yeong-Tai; Yun, Kyusik; Lee, Min-Ho

    2014-08-15

    A direct electrochemical detection of quercetin based on functionalized graphene oxide modified on gold-printed circuit board chip was demonstrated in this study. Functionalized graphene oxide materials are prepared by the covalent reaction of graphene oxide with silver@silica-polyethylene glycol nanoparticles (~12.35nm). Functionalized graphene oxide electrode shows a well-defined voltammetric response in phosphate buffered saline and catalyzes the oxidation of quercetin to quinone without the need of an enzyme. Significantly, the functionalized graphene oxide modified electrode exhibited a higher sensitivity than pristine gold-printed circuit board and graphene oxide electrodes, a wide concentration range of 7.5 to 1040nM and detection limit of 3.57nM. Developed biosensor platform is selective toward quercetin in the presence of an interferent molecule.

  7. Chemical interaction of polyethylene matrix with vegetable fillers in biocomposites

    NASA Astrophysics Data System (ADS)

    Pantyukhov, Petr; Monakhova, Tatiana; Popov, Anatoly; Zykova, Anna

    2016-05-01

    The paper studies the diffusion of low molecular weight components from vegetable fillers into polyethylene matrix during the preparation of biocomposites. In order to identify the diffusible substances a model experiment used where the hexadecane acted as a model of polyethylene. It was determined that polyphenolic compounds and chlorophyll penetrate from vegetable fillers to hexadecane to the maximum extent. There was found a correlation between the amount of polyphenolic compounds diffusible from the fillers to hexadecane and thermal oxidation kinetics of real biocomposites based on polyethylene and vegetable fillers. Thus, it has been assumed the diffusion of polyphenols and chlorophyll from vegetable fillers into polyethylene matrix during the preparation of biocomposites.

  8. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene, chlorinated. 177.1610 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1610 Polyethylene, chlorinated. Chlorinated polyethylene identified in this section may be safely used as articles or components of articles that...

  9. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene, fluorinated. 177.1615 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1615 Polyethylene, fluorinated. Fluorinated polyethylene, identified in paragraph (a) of this section, may be safely used as food-contact articles...

  10. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Polyethylene. 573.780 Section 573.780 Food and... Listing § 573.780 Polyethylene. (a) Identity. Polyethylene consists of basic polymers manufactured by the catalytic polymerization of ethylene. (b) Specifications. (1) For the purposes of this section,...

  11. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene, fluorinated. 177.1615 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1615 Polyethylene, fluorinated. Fluorinated polyethylene, identified in paragraph (a) of this section, may be safely used as food-contact articles...

  12. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene, fluorinated. 177.1615 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1615 Polyethylene, fluorinated. Fluorinated polyethylene, identified in paragraph (a) of this section, may be safely used as food-contact articles...

  13. 76 FR 70896 - Polyethylene Glycol; Tolerance Exemption

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... AGENCY 40 CFR Part 180 Polyethylene Glycol; Tolerance Exemption AGENCY: Environmental Protection Agency... amu), 17,000; also known as polyethylene glycol, when used as an inert ingredient in a pesticide...(oxyethylene, minimum number average molecular weight (in amu), 17,000; also known as polyethylene...

  14. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Polyethylene. 573.780 Section 573.780 Food and... Listing § 573.780 Polyethylene. (a) Identity. Polyethylene consists of basic polymers manufactured by the catalytic polymerization of ethylene. (b) Specifications. (1) For the purposes of this section,...

  15. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Polyethylene. 573.780 Section 573.780 Food and... Listing § 573.780 Polyethylene. (a) Identity. Polyethylene consists of basic polymers manufactured by the catalytic polymerization of ethylene. (b) Specifications. (1) For the purposes of this section,...

  16. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene, chlorinated. 177.1610 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1610 Polyethylene, chlorinated. Chlorinated polyethylene identified in this section may be safely used as articles or components of articles that...

  17. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene, chlorinated. 177.1610 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1610 Polyethylene, chlorinated. Chlorinated polyethylene identified in this section may be safely used as articles or components of articles that...

  18. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Polyethylene. 573.780 Section 573.780 Food and... Listing § 573.780 Polyethylene. (a) Identity. Polyethylene consists of basic polymers manufactured by the catalytic polymerization of ethylene. (b) Specifications. (1) For the purposes of this section,...

  19. 21 CFR 573.780 - Polyethylene.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Polyethylene. 573.780 Section 573.780 Food and... Listing § 573.780 Polyethylene. (a) Identity. Polyethylene consists of basic polymers manufactured by the catalytic polymerization of ethylene. (b) Specifications. (1) For the purposes of this section,...

  20. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene, chlorinated. 177.1610 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1610 Polyethylene, chlorinated. Chlorinated polyethylene identified in this section may be safely used as articles or components of articles that...

  1. 21 CFR 177.1615 - Polyethylene, fluorinated.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene, fluorinated. 177.1615 Section 177... Components of Single and Repeated Use Food Contact Surfaces § 177.1615 Polyethylene, fluorinated. Fluorinated polyethylene, identified in paragraph (a) of this section, may be safely used as food-contact articles...

  2. 12-crown-4 ether-assisted enhancement of ionic conductivity and interfacial kinetics in polyethylene oxide electrolytes

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Di Stefano, S.

    1990-01-01

    The electrical and electrochemical properties of thin films of polyethylene oxide electrolytes with and without 12-crown-4 ether (12Cr4) are studied as a function of temperature and in the frequency regime from 100 kHz to 0.1 Hz. These measurements were made on electrolytes containing LiCF3SO3, LiBF4, or LiClO4 salts. At a given temperature, the bulk conductivity for a particular salt depends on the 12Cr4 concentration, reaching a maximum for a ratio of 12Cr4 to Li of 0.003.

  3. Experimental analysis of stabilizing effects of carbon nanotubes (CNTs) on thermal oxidation of poly(ethylene glycol)-CNT composites

    NASA Astrophysics Data System (ADS)

    Yamane, Shogo; Ata, Seisuke; Chen, Liang; Sato, Hiroaki; Yamada, Takeo; Hata, Kenji; Mizukado, Junji

    2017-02-01

    In this work, the thermal stabilization of poly(ethylene glycol) (PEG) by super-growth carbon nanotubes (SGCNTs) is studied by analyzing degraded compounds via high-resolution matrix-assisted laser diffusion ionization time-of-flight mass spectroscopy and IR techniques. SGCNTs successfully suppress the thermal oxidation of PEG, and the components of the degraded compounds change upon addition of SGCNTs to PEG. The SGCNTs quench mainly the RO radical generated by the initial chain scission of the Csbnd O bond of PEG, resulting in the suppression of the intermolecular proton abstraction.

  4. Morphology of poly(ethylene oxide) dissolved in a room temperature ionic liquid: a small angle neutron scattering study.

    PubMed

    Triolo, Alessandro; Russina, Olga; Keiderling, Uwe; Kohlbrecher, Joachim

    2006-02-02

    Solutions of deuterated poly(ethylene oxide) (d-PEO) in 1-butyl-3-methyl imidazolium tetrafluoroborate ([bmim][BF4]), a prototype room-temperature ionic liquid (RTIL), have been studied at room temperature over a range of polymer concentrations, using small angle neutron scattering (SANS), characterizing the conformation of PEO dissolved in RTILs. [bmim][BF4] behaves as a good solvent for d-PEO, which organizes in this solvent in non entangled random coils. These findings will help in optimizing the designing of microemulsions in these potentially environmentally friendly solvents.

  5. Ionic Conductivity of Poly(ethylene oxide)-Containing Block Copolymers at Order-Disorder and Order-Order Transitions

    NASA Astrophysics Data System (ADS)

    Wanakule, Nisita; Panday, Ashoutosh; Mullin, Scott; Balsara, Nitash

    2009-03-01

    The order-disorder transition (ODT) and order-order transition (OOT) of block copolymers with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salts are measured with a combination of small-angle x-ray scattering (SAXS) and birefringence. The block copolymers comprise of polyethylene oxide (PEO), a polymer with a higher dielectric constant that dissolves LiTFSI, and polystyrene (PS), a polymer with a lower dielectric constant that does not dissolve LiTFSI. Ionic conductivity of the block copolymers are measured through the observed ODT and OOT. The effect of morphology on the ionic conductivity will be presented and compared with literature results.

  6. On the interactions between poly(ethylene oxide) and graphite oxide: A comparative study by different computational methods

    NASA Astrophysics Data System (ADS)

    Garcia-Yoldi, I.; Álvarez, F.; Colmenero, J.

    2013-03-01

    The aim of this work is to investigate polymer...substrate interactions for a polymer nanocomposite material: poly(ethylene oxide) (PEO) confined in graphite oxide (GO). Six discrete and simplified models (one for PEO and five for GO) have been chosen in order to reproduce the most likely PEO...GO interactions. Twelve potential interaction energy curves have been built using the models and curve minima have been optimized using the 2nd order Møller-Plesset perturbation theory (MP2)/6-31+G(d) method. The intermolecular interactions have been analyzed in terms of distances, stabilities, and bond critical points properties revealing several dispersion assisted π-interactions and the most stable hydrogen bond interaction between the hydrogen of the GO hydroxyl groups and the oxygen of the PEO. MP2 results have been compared with five density functionals developed by Truhlar and Zhao (M05, M05-2X, M05-2X, M06-HF, and M06-L).

  7. Oxidation of Second Generation Sequentially Irradiated and Annealed Highly Cross-Linked X3™ Polyethylene Tibial Bearings.

    PubMed

    Kop, Alan M; Pabbruwe, Moreica B; Keogh, Catherine; Swarts, Eric

    2015-10-01

    Since the first use of ultra-high-molecular-weight polyethylene as a bearing material, research and development efforts have sought to improve wear resistance, increase longevity and lessen the potential for debris mediated adverse tissue responses. A series of second generation sequentially cross-linked and annealed tibial bearings were analysed after several bearings sent for routine retrieval analysis showed oxidative degradation including subsurface whitening, cracking and gross material loss. Evaluation incorporated visual and white banding assessment, mechanical testing and spectroscopy analysis. Whilst visual observation and white banding assessment confirmed oxidative changes, a decrease in mechanical properties and increasing ketone oxidation index as a function of time in vivo suggest time dependent oxidative degradation. Clinically relevant degradation of the sequentially cross-linked and annealed tibial bearings was observed.

  8. Waste product profile: Polyethylene terephthalate

    SciTech Connect

    Miller, C.

    1996-02-01

    Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks are the primary product packaged in PET. Salad dressing, peanut butter, and other household and consumer products also use PET bottles. PET is also used for film, sheeting for cups and food trays, ovenable trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early `70s. Because it is an ``engineered`` resin, it is more expensive than commodity resins such as high-density polyethylene (HDPE). The primary market for recycled PET is the fiber industry, which uses PET for carpet fiber, sweaters and other clothing, and for other uses. Recycled PET can also be used for food and beverage containers. Export markets, particularly Asian countries, are becoming increasingly important.

  9. Surface Functionalized Polyethylene Film.

    DTIC Science & Technology

    1986-06-01

    functionality into this oxidized surface layer. 2) Explored new techniques for analyzing the surfaces of organic polymeric solids. Contact angle titration...the study of the contact angle of water on organic solids as a function of pH--has proved particularly useful and extremely surface sensitive. 3

  10. Indium tin oxide films deposited by thermionic-enhanced DC magnetron sputtering on unheated polyethylene terephthalate polymer substrate

    SciTech Connect

    Lan, Y.F.; Peng, W.C.; Lo, Y.H.; He, J.L.

    2009-08-05

    Indium tin oxide thin films were deposited onto polyethylene terephthalate substrates via thermionic enhanced DC magnetron sputtering at low substrate temperatures. The structural, optical and electrical properties of these films are methodically investigated. The results show that compared with traditional sputtering, the films deposited with thermionic emission exhibit higher crystallinity, and their optical and electrical properties are also improved. Indium tin oxide films deposited by utilizing thermionic emission exhibit an average visible transmittance of 80% and an electrical resistivity of 4.5 x 10{sup -4} {Omega} cm, while films made without thermionic emission present an average visible transmittance of 74% and an electrical resistivity of 1.7 x 10{sup -3} {Omega} cm.

  11. Synthesis of eight-shaped poly(ethylene oxide) by the combination of Glaser coupling with ring-opening polymerization.

    PubMed

    Wang, Guowei; Fan, Xiaoshan; Hu, Bin; Zhang, Yannan; Huang, Junlian

    2011-10-18

    The eight-shaped poly(ethylene oxide) (PEO) is synthesized by a combination of Glaser coupling with ring-opening polymerization (ROP). Firstly, the star-shaped (PEO-OH)(4) is synthesized by ROP of ethylene oxide (EO) using pentaerythritol as an initiator and diphenylmethyl potassium (DPMK) as a deprotonated agent, and then the alkyne group is introduced onto the PEO arm-end to give (PEO-Alkyne)(4) in a NaH/tetrahydrofuran (THF) system. The intramolecular cyclization is carried out by a Glaser coupling reaction in a pyridine/CuBr/N,N,N',N",N"-pentamethyldiethylenetriamine (PMDETA) system at room temperature in an air atmosphere, and eight-shaped PEO was formed with high efficiency (almost 100%). The target polymers and intermediates were well characterized by SEC, MALDI-TOF MS, (1)H NMR and FT-IR in detail.

  12. Oxidation-Responsive and "Clickable" Poly(ethylene glycol) via Copolymerization of 2-(Methylthio)ethyl Glycidyl Ether.

    PubMed

    Herzberger, Jana; Fischer, Karl; Leibig, Daniel; Bros, Matthias; Thiermann, Raphael; Frey, Holger

    2016-07-27

    Poly(ethylene glycol) (PEG) is a widely used biocompatible polymer. We describe a novel epoxide monomer with methyl-thioether moiety, 2-(methylthio)ethyl glycidyl ether (MTEGE), which enables the synthesis of well-defined thioether-functional poly(ethylene glycol). Random and block mPEG-b-PMTEGE copolymers (Mw/Mn = 1.05-1.17) were obtained via anionic ring opening polymerization (AROP) with molecular weights ranging from 5 600 to 12 000 g·mol(-1). The statistical copolymerization of MTEGE with ethylene oxide results in a random microstructure (rEO = 0.92 ± 0.02 and rMTEG E = 1.06 ± 0.02), which was confirmed by in situ (1)H NMR kinetic studies. The random copolymers are thermoresponsive in aqueous solution, with a wide range of tunable transition temperatures of 88 to 28 °C. In contrast, mPEG-b-PMTEGE block copolymers formed well-defined micelles (Rh ≈ 9-15 nm) in water, studied by detailed light scattering (DLS and SLS). Intriguingly, the thioether moieties of MTEGE can be selectively oxidized into sulfoxide units, leading to full disassembly of the micelles, as confirmed by detection of pure unimers (DLS and SLS). Oxidation-responsive release of encapsulated Nile Red demonstrates the potential of these micelles as redox-responsive nanocarriers. MTT assays showed only minor effects of the thioethers and their oxidized derivatives on the cellular metabolism of WEHI-164 and HEK-293T cell lines (1-1000 μg·mL(-1)). Further, sulfonium PEG polyelectrolytes can be obtained via alkylation or alkoxylation of MTEGE, providing access to a large variety of functional groups at the charged sulfur atom.

  13. Analysis of long-term degradation behaviour of polyethylene mulching films with pro-oxidants under real cultivation and soil burial conditions.

    PubMed

    Briassoulis, Demetres; Babou, Epifaneia; Hiskakis, Miltiadis; Kyrikou, Ioanna

    2015-02-01

    Apart from the conventional polyethylene and the bio-based or mainly bio-based biodegradable in soil mulching films, polyethylene mulching films of controlled degradation in soil are already used in agriculture. The use of special pro-oxidants as additives is expected to accelerate the abiotic oxidation and the subsequent chain scission of the polymer under specific UV radiation or thermal degradation conditions, according to the literature. The role of pro-oxidants in the possible biodegradation of polyethylene has been theoretically supported through the use of controlled laboratory conditions. However, results obtained in real soil conditions, but also several laboratory test results, are not supporting these claims and the issue remains disputed. Mulching films made of linear low-density polyethylene (LLDPE) with pro-oxidants, after being used for one cultivation period in an experimental field with watermelon cultivation, were buried in the soil under real field conditions. This work presents the analysis of the degradation of the mulching films during the cultivation period as compared to the corresponding changes after a long soil burial period of 8.5 years. The combined effects of critical factors on the photochemical degradation of the degradable mulching LLDPE films with pro-oxidants under the cultivation conditions and their subsequent further degradation behaviour in the soil are analysed by testing their mechanical properties and through spectroscopic and thermal analysis.

  14. Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance

    SciTech Connect

    Beckman, J.S.; Minor, R.L. Jr.; White, C.W.; Repine, J.E.; Rosen, G.M.; Freeman, B.A.

    1988-05-15

    Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from <10 min to 40 h, reduced immunogenicity, and decreases sensitivity to proteolysis. Because PEG has surface active properties and can induce cell fusion, the authors hypothesized that PEG conjugation could enhance cell binding and association of normally membrane-impermeable enzymes. Incubation of cultured porcine aortic endothelial cells with /sup 125/I-PEG-catalase or /sup 125/I-PEG-superoxide dismutase produced a linear, concentration-dependent increase in cellular enzyme activity and radioactivity. Fluorescently labeled PEG-superoxide dismutase incubated with endothelial cells showed a vesicular localization. Mechanical injury to cell monolayers, which is known to stimulate endocytosis, further increased the uptake of fluorescent PEG-superoxide dismutase. Addition of PEG and PEG-conjugated enzymes perturbed the spin-label binding environment, indicative of producing an increase in plasma membrane fluidity. Thus, PEG conjugation to superoxide dismutase and catalase enhances cell association of these enzymes in a manner which increases cellular enzyme activities and provides prolonged protection from partially reduced oxygen species.

  15. Single electron states in polyethylene

    SciTech Connect

    Wang, Y.; MacKernan, D.; Cubero, D. E-mail: n.quirke@imperial.ac.uk; Coker, D. F.; Quirke, N. E-mail: n.quirke@imperial.ac.uk

    2014-04-21

    We report computer simulations of an excess electron in various structural motifs of polyethylene at room temperature, including lamellar and interfacial regions between amorphous and lamellae, as well as nanometre-sized voids. Electronic properties such as density of states, mobility edges, and mobilities are computed on the different phases using a block Lanczos algorithm. Our results suggest that the electronic density of states for a heterogeneous material can be approximated by summing the single phase density of states weighted by their corresponding volume fractions. Additionally, a quantitative connection between the localized states of the excess electron and the local atomic structure is presented.

  16. Shock induced dissociation of polyethylene

    SciTech Connect

    Morris, C.E.; Loughran, E.D.; Mortensen, G.F.; Gray, G.T. III; Shaw, M.S.

    1989-01-01

    To identify the physical processes occurring on the Hugoniot, shock-recovery experiments were performed. Cylindrical recovery systems were used that enabled a wide range of single-shock Hugoniot states to be examined. Mass spectroscopy was used to examine the gaseous dissociation products. X-ray and TEM measurements were made to characterize the post-shock carbon structures. A dissociation product equation of state is presented to interpret the observed results. Polyethylene (PE) samples that were multiply shocked to their final states dissociated at much higher pressures than single-shocked samples. 5 refs., 2 figs., 1 tab.

  17. Crystallization behaviour of poly(ethylene oxide) under confinement in the electrospun nanofibers of polystyrene/poly(ethylene oxide) blends.

    PubMed

    Samanta, Pratick; V, Thangapandian; Singh, Sajan; Srivastava, Rajiv; Nandan, Bhanu; Liu, Chien-Liang; Chen, Hsin-Lung

    2016-06-21

    We have studied the confined crystallization behaviour of poly(ethylene oxide) (PEO) in the electrospun nanofibers of the phase-separated blends of polystyrene (PS) and PEO, where PS was present as the major component. The size and shape of PEO domains in the nanofibers were considerably different from those in the cast films, presumably because of the nano-dimensions of the nanofibers and the extensional forces experienced by the polymer solution during electrospinning. The phase-separated morphology in turn influenced the crystallization behaviour of PEO in the blend nanofibers. At a PEO weight fraction of ≥0.3, crystallization occurred through a heterogeneous nucleation mechanism similar to that in cast blend films. However, as the PEO weight fraction in the blend nanofibers was reduced from 0.3 to 0.2, an abrupt transformation of the nucleation mechanism from the heterogeneous to predominantly homogenous type was observed. The change in the nucleation mechanism implied a drastic reduction of the spatial continuity of PEO domains in the nanofibers, which was not encountered in the cast film. The melting temperature and crystallinity of the PEO crystallites developed in the nanofibers were also significantly lower than those in the corresponding cast films. The phenomena observed were reconciled by the morphological observation, which revealed that the phase separation under the radial constraint of the nanofibers led to the formation of small-sized fibrillar PEO domains with limited spatial connectivity. The thermal treatment of the PS/PEO blend nanofibers above the glass transition temperature of PS induced an even stronger confinement effect on PEO crystallization.

  18. Miscibility of poly(lactic acid) and poly(ethylene oxide) solvent polymer blends and nanofibers made by solution blow spinning

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The miscibility of blends of poly(lactic acid) (PLA) and poly(ethylene oxide) (PEO) was studied in polymer solutions by dilute solution viscometry and in solution blow spun nanofibers by microscopy (SEM, TEM) and by thermal and spectral analysis. Three blends of PLA and PEO were solution blended in...

  19. Temperature dependence of the dielectric properties of metal-polymer composites based on zinc oxide nanoparticles stabilized in low-density polyethylene matrix

    NASA Astrophysics Data System (ADS)

    Ul'Zutuev, A. N.; Ushakov, N. M.

    2008-10-01

    We have studied the temperature dependence of the dielectric constant of composites based on low-density polyethylene and zinc oxide nanoparticles. Features related to the appearance of metastable states in the course of sequential heating-cooling cycles are revealed and mechanisms explaining this behavior are proposed.

  20. Conductivity and optical band gaps of polyethylene oxide doped with Li{sub 2}SO{sub 4} salt

    SciTech Connect

    Chapi, Sharanappa Raghu, S. Subramanya, K. Archana, K. Mini, V. Devendrappa, H.

    2014-04-24

    The conductivity and optical properties of Li{sub 2}SO{sub 4} doped polyethylene oxide (PEO) films were studied. The polymer electrolyte films are prepared using solution casting technique. The material phase change was confirmed by X-ray diffraction (XRD) technique. Optical absorption study was conducted using UV- Vis. Spectroscopy in the wavelength range 190–1100nm on pure and doped PEO films. The direct and indirect optical band gaps were found decreased from 5.81–4.51eV and 4.84–3.43eV respectively with increasing the Li{sub 2}SO{sub 4}. The conductivity found to increases with increasing the dopant concentration due to strong hopping mechanism at room temperature.

  1. High-density polyethylene facial implants show surface oxidation in SEM and EDX examination: a pilot study.

    PubMed

    Draenert, G F; Doeblinger, M; Draenert, M; Gosau, M

    2009-05-01

    Previous histopathological studies on explanted Medpor high-density polyethylene (HDPE) facial implants indicated signs of material destruction and claimed to observe phagocytized HDPE particles within the tissue samples beside the usual type IV reaction with severe fibrosis. We examined new and explanted Medpor material with scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDX). The implant surface of three patient-derived specimens showed significantly higher oxygenation in EDX analysis and morphological changes in SEM compared to the new unused material directly after opening of the package and after 1 year of exposure to air. Our preliminary findings indicate a possible oxidative biocorrosion in HDPE surgical implants. Further studies should confirm these pilot project results.

  2. Composite poly(ethylene oxide) electrolytes plasticized by N-alkyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide for lithium batteries.

    PubMed

    Wetjen, Morten; Navarra, Maria Assunta; Panero, Stefania; Passerini, Stefano; Scrosati, Bruno; Hassoun, Jusef

    2013-06-01

    We report a new class of quaternary polymer electrolyte membranes that comprise poly(ethylene oxide) (PEO), lithium trifluoromethanesulfonylimide (LiTFSI), N-alkyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PyrA,4 TFSI) as an ionic liquid, and a SiO₂ filler. The results of differential scanning calorimetry indicate that the addition of SiO₂ and different ionic liquids induces a decrease in the PEO melting enthalpy, which thereby increases the ionic conductivity and the Li transference number. The electrochemical stability is proved by using impedance spectroscopy and cyclic voltammetry. Galvanostatic cycling of Li/LiFePO₄ cells, which comprise the quaternary polymer electrolytes, revealed their superior performance compared to conventional PEO-Li salt electrolytes. In the course of this investigation, a synergistic effect of the combined ionic liquid-ceramic filler modification could be proved at temperatures close to 50 °C.

  3. Synthesis and morphological change in poly(ethylene oxide)-sodium chlorate based polymer electrolyte complex with polyaniline

    NASA Astrophysics Data System (ADS)

    Kunteppa, H.; Roy, Aashis S.; Koppalkar, Anil R.; Ambika Prasad, M. V. N.

    2011-11-01

    The composites of polyethylene oxide:polyaniline:sodium chlorate is prepared by stirring with anhydrous acetonitrile for 5-6 h to form homogeneous solutions/gels at different weight percentages. The composites are characterized by FTIR and SEM. The predominant peaks that appeared in FTIR spectra confirm the formation of PEO:PANI:NaClO 4 composites. It is found from the SEM studies that there is a significant change in the morphology of various weight percentages of NaClO 4 in PEO-PANI matrix, i.e. from ellipsoidal to square. DC conductivity behavior is seen due to hopping of polarons from one localized state to another that can be confirmed by Mott theory. It is observed from the DC conductivity and SEM studies that these composites can be promising candidates for solid state electrolytes.

  4. Effects of Salts and Ionic Liquids on the Thermodynamics of Poly(ethylene oxide)-Containing Block Copolymers

    NASA Astrophysics Data System (ADS)

    Wanakule, Nisita; Virgili, Justin; Teran, Alexander; Balsara, Nitash

    2010-03-01

    We explore the thermodynamics of block copolymers doped with the salt, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), and the ionic liquid, imidazolium bis(trifluoromethanesulfonyl) imide ([Im][TFSI]). The block copolymers comprise of polyethylene oxide (PEO), a polymer with a higher dielectric constant, and polystyrene (PS), a polymer with a lower dielectric constant. A combination of small-angle x-ray scattering (SAXS) and birefringence was used to determine morphology and order-to-disorder transition temperatures (ODT). Leibler's theory for microphase separation was employed to determine the effective Flory-Huggins interaction parameter. These values are compared to theoretically-determined values of the effective interaction parameter which were calculated with no adjustable parameters using a theory developed by Zhen-Gang Wang.

  5. A hydrated phospholipid polymer-grafted layer prevents lipid-related oxidative degradation of cross-linked polyethylene.

    PubMed

    Kyomoto, Masayuki; Moro, Toru; Yamane, Shihori; Takatori, Yoshio; Tanaka, Sakae; Ishihara, Kazuhiko

    2017-01-01

    The surface and substrate of a cross-linked polyethylene (CLPE) liner are designed to achieve resistance against oxidative degradation in the construction of hip joint replacements. In this study, we aimed to evaluate the oxidative degradation caused by lipid absorption of a highly hydrophilic nanometer-scaled thickness layer prepared by grafting a poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) layer and a high-dose gamma-ray irradiated CLPE with vitamin E blending (HD-CLPE[VE]). The HD-CLPE(VE) and PMPC-grafted HD-CLPE(VE) exhibited extremely high oxidation resistance regardless of lipid absorption, even though residual-free radical levels were detectable. The water wettability of the PMPC-grafted CLPE and PMPC-grafted HD-CLPE(VE) surfaces was considerably greater than that of untreated surfaces. The hydrated PMPC-grafted layer also exhibited extremely low solubility for squalene. Lipids such as squalene and cholesterol esters diminished the oxidation resistance of CLPE despite the vitamin E improvement. Notably, the PMPC-grafted surface was resistant to lipid absorption and diffusion as well as subsequent lipid-related oxidative degradation, likely because of the presence of the hydrated PMPC-grafted layer. Together, these results provide preliminary evidence that the resistance against lipid absorption and diffusion of a hydrated PMPC-grafted layer might positively affect the extent of resistance to the in vivo oxidation of orthopedic implants.

  6. Dynamics in entangled polyethylene melts

    NASA Astrophysics Data System (ADS)

    Salerno, K. Michael; Agrawal, Anupriya; Peters, Brandon L.; Perahia, Dvora; Grest, Gary S.

    2016-10-01

    Polymer dynamics creates distinctive viscoelastic behavior as a result of a coupled interplay of motion at the atomic length scale and motion of the entire macromolecule. Capturing the broad time and length scales of polymeric motion however, remains a challenge. Using linear polyethylene as a model system, we probe the effects of the degree of coarse graining on polymer dynamics. Coarse-grained (CG) potentials are derived using iterative Boltzmann inversion with λ methylene groups per CG bead (denoted CGλ) with λ = 2,3,4 and 6 from a fully-atomistic polyethylene melt simulation. By rescaling time in the CG models by a factor α, the chain mobility for the atomistic and CG models match. We show that independent of the degree of coarse graining, all measured static and dynamic properties are essentially the same once the dynamic scaling factor α and a non-crossing constraint for the CG6 model are included. The speedup of the CG4 model is about 3 times that of the CG3 model and is comparable to that of the CG6 model. Using these CG models we were able to reach times of over 500 μs, allowing us to measure a number of quantities, including the stress relaxation function, plateau modulus and shear viscosity, and compare directly to experiment.

  7. Diffusion of limonene in polyethylene.

    PubMed

    Limm, W; Begley, T H; Lickly, T; Hentges, S G

    2006-07-01

    Diffusion coefficients of limonene in various linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE) resins have been determined from sorption data using a thermogravimetric methodology. From these data, one can determine whether polymer synthesis parameters such as the choice of catalytic process or co-monomer result in substantial differences in how much food packaging additives might migrate to food. For example, LLDPE is currently manufactured using either one of two distinct catalytic processes: Ziegler-Natta (ZN) and metallocene, a single-site catalyst. ZN catalysis is a heterogeneous process that has dominated polyolefin synthesis over the last half-century. It involves a transition metal compound containing a metal-carbon bond that can handle repeated insertion of olefin units. In contrast, metallocene catalysis has fewer than 20 years of history, but has generated much interest due to its ability to produce highly stereospecific polymers at a very high yield. In addition to high stereospecificity, metallocene-catalysed polymers are significantly lower in polydispersity than traditional ZN counterparts. Absorption and desorption testing of heat-pressed films made from LLDPE and LDPE resins of varying processing parameters indicates that diffusion coefficients of limonene in these resins do not change substantially.

  8. Oxidized polyethylene films for orienting polar molecules for linear dichroism spectroscopy.

    PubMed

    Razmkhah, Kasra; Chmel, Nikola Paul; Gibson, Matthew I; Rodger, Alison

    2014-03-21

    Stretched polyethylene (PE) films have been used to orient small molecules for decades by depositing solutions on their surface and allowing the solvent to evaporate leaving the analyte absorbed on the polymer film. However, the non-polar hydrophobic nature of PE is an obstacle to aligning polar molecules and biological samples. In this work PE film was treated with oxygen plasma in order to increase surface hydrophilicity. Different treatment conditions were evaluated using contact angle measurement and X-ray photoelectron spectroscopy. Treated PE (PE(OX)) films are shown to be able to align molecules of different polarities including progesterone, 1-pyrenecarboxaldehyde, 4',6-diamidino-2-phenylindole (DAPI) and anthracene. The degree of alignment of each molecule was studied by running series of linear dichroism (LD) experiments and the polarizations of electronic transition moments were determined. For the first time optimal conditions (such as stretching factor and concentration of the sample) for stretched film LD were determined. PE(OX) aligning ability was compared to that of normal PE films. Progesterone showed a slightly better alignment on PE(OX) than PE. 1-Pyrenecarboxaldehyde oriented differently on the two different films which enabled transition moment assignment for this low symmetry molecule. DAPI (which does not align on PE) aligned well on PE(OX) and enabled us to obtain better LD data than had previously been collected with polyvinyl alcohol. Anthracene alignment and formation of dimers and higher order structures were studied in much more detail than previously possible, showing a variety of assemblies on PE and PE(OX) films.

  9. Polyethylene Glycol Camouflaged Earthworm Hemoglobin

    PubMed Central

    Moges, Selamawit; Nacharaju, Parimala; Roche, Camille; Dantsker, David; Palmer, Andre; Friedman, Joel M.

    2017-01-01

    Nearly 21 million components of blood and whole blood and transfused annually in the United States, while on average only 13.6 million units of blood are donated. As the demand for Red Blood Cells (RBCs) continues to increase due to the aging population, this deficit will be more significant. Despite decades of research to develop hemoglobin (Hb) based oxygen (O2) carriers (HBOCs) as RBC substitutes, there are no products approved for clinical use. Lumbricus terrestris erythrocruorin (LtEc) is the large acellular O2 carrying protein complex found in the earthworm Lumbricus terrestris. LtEc is an extremely stable protein complex, resistant to autoxidation, and capable of transporting O2 to tissue when transfused into mammals. These characteristics render LtEc a promising candidate for the development of the next generation HBOCs. LtEc has a short half-life in circulation, limiting its application as a bridge over days, until blood became available. Conjugation with polyethylene glycol (PEG-LtEc) can extend LtEc circulation time. This study explores PEG-LtEc pharmacokinetics and pharmacodynamics. To study PEG-LtEc pharmacokinetics, hamsters instrumented with the dorsal window chamber were subjected to a 40% exchange transfusion with 10 g/dL PEG-LtEc or LtEc and followed for 48 hours. To study the vascular response of PEG-LtEc, hamsters instrumented with the dorsal window chamber received multiple infusions of 10 g/dL PEG-LtEc or LtEc solution to increase plasma LtEc concentration to 0.5, then 1.0, and 1.5 g/dL, while monitoring the animals’ systemic and microcirculatory parameters. Results confirm that PEGylation of LtEc increases its circulation time, extending the half-life to 70 hours, 4 times longer than that of unPEGylated LtEc. However, PEGylation increased the rate of LtEc oxidation in vivo. Vascular analysis verified that PEG-LtEc showed the absence of microvascular vasoconstriction or systemic hypertension. The molecular size of PEG-LtEc did not change the

  10. Coarse-graining poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers using the MARTINI force field.

    PubMed

    Nawaz, Selina; Carbone, Paola

    2014-02-13

    The MARTINI coarse-grain (CG) force field is extended for a class of triblock block copolymers known as Pluronics. Existing MARTINI bead types are used to model the non-bonded part of the potential while single chain properties for both homopolymers, poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), are used to develop the bonded interactions. The new set of force field parameters reproduces structural and dynamical properties of high molecular weight homo- and copolymers. The CG model is moderately transferable in solvents of different polarity and concentration; however, the PEO homopolymer model presents a reduced thermodynamic transferability especially in water probably due to the lack of hydrogen bonds with the solvent. Our simulations of a monolayer of Pluronic L44 show polymer-brush-like characteristics for the PEO segments which protrude into the aqueous phase. Other membrane properties not easily accessible using experimental techniques such as its membrane thickness are also calculated.

  11. Mid-term survivorship and clinical outcomes of cobalt-chrome and oxidized zirconium on highly crosslinked polyethylene

    PubMed Central

    Petis, Stephen M.; Vasarhelyi, Edward M.; Lanting, Brent A.; Howard, James L.; Naudie, Douglas D.R.; Somerville, Lyndsay E.; McCalden, Richard W.

    2016-01-01

    Background The choice of bearing articulation for total hip arthroplasty in younger patients is amenable to debate. We compared mid-term patient-reported outcomes and survivorship across 2 different bearing articulations in a young patient cohort. Methods We reviewed patients with cobalt-chrome or oxidized zirconium on highly crosslinked polyethylene who were followed prospectively between 2004 and 2012. Kaplan–Meier analysis was used to determine predicted cumulative survivorship at 5 years with all-cause and aseptic revisions as the outcome. We compared patient-reported outcomes, including the Harris hip score (HHS), Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and Short-form 12 (SF-12) scores. Results A total of 622 patients were followed during the study period. Mean follow-up was 8.2 (range 2.0–10.6) years for cobalt-chrome and 7.8 (range 2.1–10.7) years for oxidized zirconium. Mean age was 54.9 ± 10.6 years for cobalt-chrome and 54.8 ± 10.7 years for oxidized zirconium. Implant survivorship was 96.0% (95% confidence interval [CI] 94.9%–97.1%) for cobalt-chrome and 98.7% (95% CI 98.0%–99.4%) for oxidized zirconium on highly crosslinked polyethylene for all-cause revisions, and 97.2% (95% CI 96.2%–98.2%) for cobalt-chrome and 99.0% (95% CI 98.4%–99.6%) for oxidized zirconium for aseptic revisions. An age-, sex- and diagnosis-matched comparison of the HHS, WOMAC and SF-12 scores demonstrated no significant changes in clinical outcomes across the groups. Conclusion Both bearing surface couples demonstrated excellent mid-term survivorship and outcomes in young patient cohorts. Future analyses on wear and costs are warranted to elicit differences between the groups at long-term follow-up. PMID:26812409

  12. Polyethylene glycol as a solid polymer electrolyte

    SciTech Connect

    Cha, D.K.; Park, S.M.

    1997-12-01

    Polymer electrolytes were prepared from polyethylene glycol (PEG)-lithium perchlorate complexes and characterized at a stainless steel electrode using a variety of electrochemical techniques. The charge transfer process was affected by the oxide film on the stainless steel electrode surface in the early stages of redox processes. The polymer electrolytes showed a transference number of 0.2 for Li{sup +}. The conductivity of the PEG-10000 electrolyte has been determined to be 4.7 {times} 10{sup {minus}5} S/cm. This rather high value is attributed to the anionic end groups increasing the polarity of the matrix.

  13. Conduction mechanisms in concentrated LiI-polyethylene oxide-Al{sub 2}O{sub 3}-based solid electrolytes

    SciTech Connect

    Golodnitsky, D.; Ardel, G.; Strauss, E.; Peled, E.; Lareah, Y.; Rosenberg, Y.

    1997-10-01

    The ionic conductivity of concentrated LiI-polyethylene oxide P(EO){sub n} high surface area oxide composite polymer electrolytes has been investigated. Two different Arrhenius dependences for concentrated composite polymer electrolytes (CPEs) have been identified. The first one is characterized by an inflection point at about 80 C, and the second, by a conductivity jump. The authors have suggested that in CPEs, where 3oxide matrix, Li salt to ethylene oxide ratio, copolymers, and solvents on polymer electrolyte conductivity (especially at T >T{sub k}orT{sub jump}) and on Ea have been studied (T{sub jump}=temperature of the conductivity jump). The addition of small quantities of ethylene carbonate, poly(methyl methacrylate), and polyacrylonitrile were found to be beneficial while poly(methyl acrylate), poly(butyl acrylate), and poly(vinylidene fluoride) additions made the polymer electrolyte stiffer and less conductive. MgO, Al{sub 2}O{sub 3}, and potassium aluminosilicate muscovite mica based CSEs have similar conductivity. Results clearly demonstrated the depression of CPE crystallinity by addition of fine Al{sub 2}O{sub 3} powder, ethylene carbonate, and poly(ethylene glycol) dimethyl ether, in agreement with the conductivity enhancement of the CPE.

  14. Effects of UV Aging on the Cracking of Titanium Oxide Layer on Poly(ethylene terephthalate) Substrate: Preprint

    SciTech Connect

    Zhang, Chao; Gray, Matthew H.; Tirawat, Robert; Larsen, Ross E.; Chen, Fangliang

    2016-04-18

    Thin oxide and metal films deposited on polymer substrates is an emerging technology for advanced reflectors for concentrated solar power applications, due to their unique combination of light weight, flexibility and inexpensive manufacture. Thus far, there is little knowledge on the mechanical integrity or structural persistence of such multi-layer thin film systems under long-term environmental aging. In this paper, the cracking of a brittle titanium dioxide layer deposited onto elasto-plastic poly(ethylene terephthalate) (PET) substrate is studied through a combination of experiment and modeling. In-situ fragmentation tests have been conducted to monitor the onset and evolution of cracks both on pristine and on samples aged with ultraviolet (UV) light. An analytical model is presented to simulate the cracking behavior and to predict the effects of UV aging. Based on preliminary experimental observation, the effect of aging is divided into three aspects and analyzed independently: mechanical property degradation of the polymer substrate; degradation of the interlayer between substrate and oxide coating; and internal stress-induced cracks on the oxide coating.

  15. Polyethylene glycol modified, cross-linked starch-coated iron oxide nanoparticles for enhanced magnetic tumor targeting.

    PubMed

    Cole, Adam J; David, Allan E; Wang, Jianxin; Galbán, Craig J; Hill, Hannah L; Yang, Victor C

    2011-03-01

    While successful magnetic tumor targeting of iron oxide nanoparticles has been achieved in a number of models, the rapid blood clearance of magnetically suitable particles by the reticuloendothelial system (RES) limits their availability for targeting. This work aimed to develop a long-circulating magnetic iron oxide nanoparticle (MNP) platform capable of sustained tumor exposure via the circulation and, thus, potentially enhanced magnetic tumor targeting. Aminated, cross-linked starch (DN) and aminosilane (A) coated MNPs were successfully modified with 5 kDa (A5, D5) or 20 kDa (A20, D20) polyethylene glycol (PEG) chains using simple N-Hydroxysuccinimide (NHS) chemistry and characterized. Identical PEG-weight analogues between platforms (A5 & D5, A20 & D20) were similar in size (140-190 nm) and relative PEG labeling (1.5% of surface amines - A5/D5, 0.4% - A20/D20), with all PEG-MNPs possessing magnetization properties suitable for magnetic targeting. Candidate PEG-MNPs were studied in RES simulations in vitro to predict long-circulating character. D5 and D20 performed best showing sustained size stability in cell culture medium at 37 °C and 7 (D20) to 10 (D5) fold less uptake in RAW264.7 macrophages when compared to previously targeted, unmodified starch MNPs (D). Observations in vitro were validated in vivo, with D5 (7.29 h) and D20 (11.75 h) showing much longer half-lives than D (0.12 h). Improved plasma stability enhanced tumor MNP exposure 100 (D5) to 150 (D20) fold as measured by plasma AUC(0-∞). Sustained tumor exposure over 24 h was visually confirmed in a 9L-glioma rat model (12 mg Fe/kg) using magnetic resonance imaging (MRI). Findings indicate that a polyethylene glycol modified, cross-linked starch-coated MNP is a promising platform for enhanced magnetic tumor targeting, warranting further study in tumor models.

  16. Crystallization studies of polyethylene -poly(ethylene glycol) graft copolymers

    NASA Astrophysics Data System (ADS)

    Mark, P. R.; Hovey, G. E.; Murthy, N. S.; Breitenkamp, K.; Kade, M.; Emerick, T.

    2006-03-01

    Structure and crystallization behavior of three copolymers obtained by grafting poly (ethylene glycol) (PEG) chains to polyethylene (PE) main chain was investigated by variable temperature x-ray diffraction and thermal analysis. The results show that PEG side chains and PE main chains crystallize into separate domains. This is especially true when grafted chains are long (50 and 100 repeat units), in which the PEG domains are same as in PEG homopolymer both in structure and in melting behavior. In the copolymer with shorter chains (25 repeat units), the PEG crystals are not distinct and melting is broad. The PEG domains can be dissolved in water or ethanol without altering the mechanical integrity of the film. PE crystallites in both samples are similar to that in PE homopolymer. For instance, the thermal expansion of the basal cell plane (a- and b-axes) of the PE domains agrees well with that of PE homopolymer over the entire temperature range from ambient to melt. However, the chain-axis dimension PE-lattice in the copolymer is shorter by ˜ 0.05 å and the basal dimensions are larger by ˜ 0.05 å. The changes in these dimensions due to the changes in the length of the grafted PEG chains were investigated.

  17. 21 CFR 177.1610 - Polyethylene, chlorinated.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... chlorinated polyethylene contains a maximum of 60 percent by weight of total chlorine, as determined by ASTM 1method D1303-55 (Reapproved 1979), “Standard Test Method for Total Chlorine in Vinyl Chloride...

  18. Structure and properties of radiation modified polyethylene

    NASA Astrophysics Data System (ADS)

    Ancharova, U. V.; Mikhailenko, M. A.; Sharafutdinov, M. R.; Tolochko, B. P.; Gerasimov, K. B.; Korobeynikov, M. V.; Bryazgin, A. A.

    2017-01-01

    Polyethylene was irradiated with intensive electron beam with different doses. Structure changes after irradiation ex situ and in situ during heating up to its melting point were studied using synchrotron radiation X-Ray diffraction and thermal analysis.

  19. Reuse of polyethylene waste in road construction.

    PubMed

    Raju, S S S V Gopala; Murali, M; Rengaraju, V R

    2007-01-01

    The cost of construction of flexible pavements depends on thickness of the pavement layers. The thickness of pavement mainly depends on the strength of the subgrade. By suitable improvement to the strength of the subgrade, considerable saving in the scarce resources and economy can be achieved. Because of their lightweight, easy handling, non-breakable and corrosion free nature, polyethylene have surpassed all other materials in utility. But polyethylene waste has been a matter of concern to environmentalists as it is non-biodegradable. In this investigation, an attempt has been made to study the improvement of California Bearing Ratio (CBR) value of soils stabilized with waste polyethylene bags. This alternative material is mixed in different proportions to the gravel and clay to determine the improvement ofCBR value. Use of the waste polyethylene bags observed to have a significant impact on the strength and economy in pavement construction, when these are available locally in large quantities.

  20. Effect of the nature of the counterion on the interaction between cesium and tetraalkylammonium dodecylsulfates and poly(ethylene oxide) or poly(vinylpyrolidone).

    PubMed

    Benrraou, Mohamed; Bales, Barney; Zana, Raoul

    2003-11-15

    The interaction between poly(ethylene oxide) or poly(vinylpyrrolidone) and cesium and tetraalkylammonium (tetramethyl to tetrabutyl ammonium) dodecylsulfate has been investigated by means of electrical conductivity measurements to determine the critical aggregation concentration (cac) of the surfactants in the presence of polymer. The cac values were compared to the values of the critical micellization concentration (cmc) of the surfactants in the absence of polymer. The value of the cac/cmc ratio increased with the radius of the counterion in the sequence: Na(+)poly(ethylene oxide) or poly(vinylpyrrolidone).

  1. Fabrication and study of properties of magnetite nanoparticles in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate

    SciTech Connect

    Loginova, T. P. Timofeeva, G. I.; Lependina, O. L.; Shandintsev, V. A.; Matyushin, A. A.; Khotina, I. A.; Shtykova, E. V.

    2016-01-15

    Magnetite nanoparticles have been formed for the first time in hybrid micelles of polystyrene-block-polyethylene oxide and sodium dodecyl sulfate in water by ultrasonic treatment at room temperature. An analysis by small-angle X-ray scattering and transmission electron microscopy (TEM) showed that magnetite nanoparticles in hybrid micelles of block copolymer and sodium dodecyl sulfate are polydesperse (have sizes from 0.5 to 20 nm). The specific magnetization of solid samples has been measured.

  2. Which polyesters can mimic polyethylene?

    PubMed

    Stempfle, Florian; Ortmann, Patrick; Mecking, Stefan

    2013-01-11

    Self-metathesis of erucic acid by [(PCy(3))(η-C-C(3)H(4)N(2)Mes(2))Cl(2)Ru = CHPh] (Grubbs second- generation catalyst) followed by catalytic hydrogenation and purification via the ester yields 1,26-hexacosanedioate (>99% purity). Polyesterification with 1,26-hexacosanediol, generated from the diester, affords polyester-26,26, which features a T(m) of 114 °C (T(c) = 92 °C, ΔH(m) = 160 J g(-1)). Ultralong-chain model polyesters-38,23 (T(m) = 109 °C) and -44,23 (T(m) = 111 °C), generated via multistep procedures including acyclic diene metathesis polymerization, underline that melting points of such aliphatic polyesters do not gradually increase with methylene sequence chain length. Available data suggest that to mimic linear polyethylenes thermal properties, even longer sequences, amounting to at least four times a fatty acid chain, fully incorporated in a linear fashion are required.

  3. Charge transport and glassy dynamics of poly(ethylene oxide)-based single-ion conductors under geometrical confinement

    NASA Astrophysics Data System (ADS)

    Runt, James; Iacob, Ciprian

    2015-03-01

    Segmental and local dynamics as well as charge transport are investigated in a series of poly(ethylene oxide)-based single-ion conductors (ionomers) with varying counterions (Li +, Na +) confined in uni-directional nanoporous silica membranes. The dynamics are explored over a wide frequency and temperature range by broadband dielectric relaxation spectroscopy. Slowing of segmental dynamics and a decrease in dc conductivity (strongly coupled with segmental relaxation) of the confined ionomers are associated with surface effects - resulting from interfacial hydrogen bonding between the host nanoporous silica membrane and the guest ionomers. These effects are significantly reduced or eliminated upon pore surface modification through silanization. The primary transport properties for the confined ionomers decrease by about one decade compared to the bulk ionomer. A model assuming reduced mobility of an adsorbed layer at the pore wall/ionomer interface is shown to provide a quantitative explanation for the decrease in effective transport quantities in non-silanized porous silica membranes. Additionally, the effect of confinement on ion aggregation in ionomers by using X-ray scattering will also be discussed. Supported by the National Science Foundation, Polymers Program.

  4. Synthesis of silica chemically bonded with poly(ethylene oxide) 4-arm, amine-terminated for copper cation removal.

    PubMed

    Kurczewska, Joanna; Schroeder, Grzegorz

    2010-12-01

    Chemically modified silica containing a poly(ethylene oxide) 4-arm, amine-terminated unit has been obtained in the multi-step synthesis. The synthesized material was characterized by elemental, thermogravimetric analysis and infrared spectroscopy. The surface morphology was analyzed by scanning electron microscopy. The support studied was applied for selective extraction of copper(II) [Cu(II)] from water solutions. The influence of different parameters (pH, amount of the support studied, and contact time) on the copper extraction was investigated. At the optimum conditions, the copper extraction was approximately 90%, significantly greater than that of the other coexisting ions--nickel(II) [Ni(II)], cobalt(II) [Co(II)], and manganese(II) [Mn(II)]. The exception was calcium(II) [Ca(II)], which reached 30% of the extraction percentage. The solid support retained its properties after treatment with different organic and inorganic solvents. The recovery of adsorbed Cu(II) ions was approximately 97%. The sorbent studied can be applied effectively for the pre-concentration of a low level of Cu(II) in the different water samples.

  5. Effects of 12-Crown-4 ether on the ionic conductivity and electrode kinetics of electrolytes in polyethylene oxide

    NASA Technical Reports Server (NTRS)

    Nagasubramanian, G.; Di Stefano, S.

    1990-01-01

    Results are described of investigations of the electrical and electrochemical properties of thin films of polyethylene oxide (PEO) electrolytes with and without 12-Crown-4 ether (12Cr4) as a function of temperature and in the frequency regime 100 kHz-0.1 Hz. These measurements were made for LiCF3SO3, LiBF4, and LiClO4 salts. At a given temperature, the bulk conductivity, sigma, (S/cm), for a particular salt, depends on the 12Cr4 concentration with sigma reaching a maximum at about 3 mM 12Cr4. Of the three salts studied, the sigma is the highest for PEO/LiBF4 with 3 mM 12Cr4. The ac and dc measurements yield a lower charge transfer resistance for 12Cr4-incorporated samples than for samples without. Plating/stripping of Li occurs at a potential closer to Li(+)/Li for 12Cr4 samples than those without. The conductivities of a thin (about 100 microns) and a thick (400 microns) films are similar.

  6. Dielectric and mechanical investigations on the hydrophilicity and hydrophobicity of polyethylene oxide modified on a silicon surface

    SciTech Connect

    Shang, Jing; Hong, Kunlun; Wang, Tao; Zhu, Dan; Shen, Jian

    2016-10-02

    Here, polyethylene oxide (PEO) has been widely used in biomedical fields. The antibiofouling property of the PEO-modified surface has been extensively investigated but is far from being fully understood. A series of PEOs with narrowly distributed molecular weight (Mw), synthesized with the technique of high vacuum anionic polymerization, have been successfully grafted onto the surface of silicon wafers. The power-law relationship between the thickness of the monolayer versus the Mw of the grafted PEO shows a scaling of 0.3, indicating compact condensing of the chains. The static contact angles show higher hydrophobicity for the layer of PEO with higher Mw, which can be attributed to the closely packed conformation of the chains with high density. The frequency shift of the contact resonance indicates that the Young’s modulus decreases and the loss factor increases with the increase in the Mw of PEO and the thickness of the PEO layers. Dielectric spectroscopy of bare or PEO-grafted wafers in the aqueous solutions reveals an interfacial polarization, which results from compositional and structural changes in the interface layer and depends on temperatures and salt concentrations. At a given grafting density, the PEO chains are swollen in pure water, demonstrating hydrophilic behavior, whereas they collapse in salt solutions, showing hydrophobic characteristics.

  7. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers

    SciTech Connect

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2012-01-06

    Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though their respective correlation times differ significantly. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments.

  8. Surfactant-assisted intercalation of high molecular weight poly(ethylene oxide) into vanadyl phosphate di-hydrate

    SciTech Connect

    Ferreira, Joao Paulo L.; Oliveira, Herenilton P.

    2012-03-15

    Graphical abstract: CuK{sub {alpha}} X-ray diffraction patterns of the VOPO{sub 4}/PEO (A) e VOPO{sub 4}/CTA (B) and VOPO{sub 4}/CTA/PEO (C). Highlights: Black-Right-Pointing-Pointer VOPO{sub 4}/PEO has been synthesized by using CTAB, thereby improving PEO intercalation. Black-Right-Pointing-Pointer The d-spacing increase from 1.30 nm (VOPO{sub 4}/PEO) to 2.94 nm (VOPO{sub 4}/CTA/PEO). Black-Right-Pointing-Pointer This strategy was viable for intercalation of PEO with high molecular weight. -- Abstract: A high molecular weight poly(ethylene oxide)/layered vanadyl phosphate di-hydrate intercalation compound was synthesized via the surfactant-assisted approach. Results confirmed that surfactant molecules were replaced with the polymer, while the lamellar structure of the matrix was retained, and that the material presents high specific surface area. In addition, intercalation produced a more thermally stable polymer as evidenced by thermal analysis.

  9. Hyperbranched double hydrophilic block copolymer micelles of poly(ethylene oxide) and polyglycerol for pH-responsive drug delivery.

    PubMed

    Lee, Sueun; Saito, Kyohei; Lee, Hye-Ra; Lee, Min Jae; Shibasaki, Yuji; Oishi, Yoshiyuki; Kim, Byeong-Su

    2012-04-09

    We report the synthesis of a well-defined hyperbranched double hydrophilic block copolymer of poly(ethylene oxide)-hyperbranched-polyglycerol (PEO-hb-PG) to develop an efficient drug delivery system. In specific, we demonstrate the hyperbranched PEO-hb-PG can form a self-assembled micellar structure on conjugation with the hydrophobic anticancer agent doxorubicin, which is linked to the polymer by pH-sensitive hydrazone bonds, resulting in a pH-responsive controlled release of doxorubicin. Dynamic light scattering, atomic force microscopy, and transmission electron microscopy demonstrated successful formation of the spherical core-shell type micelles with an average size of about 200 nm. Moreover, the pH-responsive release of doxorubicin and in vitro cytotoxicity studies revealed the controlled stimuli-responsive drug delivery system desirable for enhanced efficiency. Benefiting from many desirable features of hyperbranched double hydrophilic block copolymers such as enhanced biocompatibility, increased water solubility, and drug loading efficiency as well as improved clearance of the polymer after drug release, we believe that double hydrophilic block copolymer will provide a versatile platform to develop excellent drug delivery systems for effective treatment of cancer.

  10. Dielectric and Mechanical Investigations on the Hydrophilicity and Hydrophobicity of Polyethylene Oxide Modified on a Silicon Surface.

    PubMed

    Shang, Jing; Hong, Kunlun; Wang, Tao; Zhu, Dan; Shen, Jian

    2016-11-08

    Polyethylene oxide (PEO) has been widely used in biomedical fields. The antibiofouling property of the PEO-modified surface has been extensively investigated but is far from being fully understood. A series of PEOs with narrowly distributed molecular weight (Mw), synthesized with the technique of high vacuum anionic polymerization, have been successfully grafted onto the surface of silicon wafers. The power-law relationship between the thickness of the monolayer versus the Mw of the grafted PEO shows a scaling of 0.3, indicating compact condensing of the chains. The static contact angles show higher hydrophobicity for the layer of PEO with higher Mw, which can be attributed to the closely packed conformation of the chains with high density. The frequency shift of the contact resonance indicates that the Young's modulus decreases and the loss factor increases with the increase in the Mw of PEO and the thickness of the PEO layers. Dielectric spectroscopy of bare or PEO-grafted wafers in the aqueous solutions reveals an interfacial polarization, which results from compositional and structural changes in the interface layer and depends on temperatures and salt concentrations. At a given grafting density, the PEO chains are swollen in pure water, demonstrating hydrophilic behavior, whereas they collapse in salt solutions, showing hydrophobic characteristics.

  11. Poly(ethylene oxide) irradiated in the solid state, melt and aqueous solution—a DSC and WAXD study

    NASA Astrophysics Data System (ADS)

    Jurkin, Tanja; Pucić, Irina

    2012-09-01

    Interactions of the aggregate state of poly(ethylene oxide), PEO, and γ-irradiation conditions (total dose, atmosphere) on its thermal and crystalline properties were investigated by DSC and WAXD taking into account sample molecular mass and form. In PEO irradiated in the solid state and in the presence of oxygen, chain scission dominated over concurrent crosslinking up to 200 kGy, particularly in PEO powders, due to a large surface being in contact with air. In solid samples the degree of crystallinity and crystallite size increased with the dose up to 50 kGy, probably not just due to partial crystallization upon degradation of amorphous phase, but to recrystallization of broken tie molecules. The least changes in crystallinity and phase transformation temperatures occurred in solid films. A substantial decrease in crystallinity and transformation temperatures without the initial crystallinity increase was achieved in samples that were amorphous on irradiation, at temperatures above the PEO melting temperature and in aqueous solutions. Radiation crosslinking of the PEO aqueous solution in an inert atmosphere is the most suitable way to obtain a lower degree of crystallinity and phase transformation temperatures while preserving mechanical properties.

  12. Increased bioavailability of primaquine using poly(ethylene oxide) matrix extended-release tablets administered to beagle dogs

    PubMed Central

    Bertol, C D; Oliveira, P R; Kuminek, G; Rauber, G S; Stulzer, H K; Silva, M A S

    2011-01-01

    Primaquine (PQ) is used for the radical cure of Plasmodium vivax malaria and can cause serious side effects in some individuals. The development of an extended-release dosage with poly(ethylene oxide) as a hydrophilic polymer has been investigated to improve drug efficacy and tolerability. The aim of this study was to evaluate in vivo a new extended-release formulation of PQ (60 mg). The formulation was administered to beagle dogs and plasma PQ concentrations were compared to a conventional immediate-release formulation of PQ (60 mg). The evaluation was carried out using a validated high-performance liquid chromatography method using solid-phase extraction. Total PQ exposure in beagle dogs was 2.2 times higher (area under curve of 12 193 versus 5678 ng h/ml) and the elimination half-life of PQ was a 19-fold greater (12.95 hours versus 0.68 hours) with the extended-release tablets compared with the immediate-release tablets. These findings suggest that the extended-release formulation of PQ merits further evaluation for the treatment of P. vivax malaria and/or chemoprophylaxis. PMID:22185941

  13. A comparison of united atom, explicit atom, and coarse-grained simulation models for poly(ethylene oxide).

    PubMed

    Chen, Chunxia; Depa, Praveen; Sakai, Victoria García; Maranas, Janna K; Lynn, Jeffrey W; Peral, Inmaculada; Copley, John R D

    2006-06-21

    We compare static and dynamic properties obtained from three levels of modeling for molecular dynamics simulation of poly(ethylene oxide) (PEO). Neutron scattering data are used as a test of each model's accuracy. The three simulation models are an explicit atom (EA) model (all the hydrogens are taken into account explicitly), a united atom (UA) model (CH(2) and CH(3) groups are considered as a single unit), and a coarse-grained (CG) model (six united atoms are taken as one bead). All three models accurately describe the PEO static structure factor as measured by neutron diffraction. Dynamics are assessed by comparison to neutron time of flight data, which follow self-motion of protons. Hydrogen atom motion from the EA model and carbon/oxygen atom motion from the UA model closely follow the experimental hydrogen motion, while hydrogen atoms reinserted in the UA model are too fast. The EA and UA models provide a good description of the orientation properties of C-H vectors measured by nuclear magnetic resonance experiments. Although dynamic observables in the CG model are in excellent agreement with their united atom counterparts, they cannot be compared to neutron data because the time after which the CG model is valid is greater than the neutron decay times.

  14. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers

    NASA Astrophysics Data System (ADS)

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2012-01-01

    Nuclear magnetic resonance spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though lithium hopping is about ten times slower than the segmental motion. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and quasi-elastic neutron scattering experiments.

  15. Enhancement of stiffness, strength, ductility and toughness of poly(ethylene oxide) using phenoxy-grafted multiwalled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Yang, Bing-Xing; Shi, Jia-Hua; Pramoda, K. P.; Goh, Suat Hong

    2007-03-01

    Phenoxy (poly(hydroxyether of bisphenol-A), also known as poly(bisphenol-A-co-epichlorohydrin)) was grafted onto multiwalled carbon nanotubes (MWNTs) by a reactive blending process. Reactions between terminal glycidyl groups of phenoxy and carboxylic acid groups of acidified MWNTs resulted in the grafting of phenoxy chains onto MWNTs. The mechanical properties of composites of poly(ethylene oxide) (PEO) and phenoxy-grafted MWNTs were studied. The miscibility between PEO and phenoxy enabled the good dispersion of nanotubes in the PEO matrix as evidenced by polarized optical microscopy and transmission electron microscopy. The spherulite size of PEO progressively decreased with increasing amount of phenoxy-grafted MWNTs added. At an optimal MWNT content of 1.5 wt%, the addition of phenoxy-grafted MWNTs led to increases of storage modulus, Young's modulus, yield stress, tensile strength, ultimate strain, and toughness of PEO by 113, 228, 166, 442, 1240, and 4080%, respectively. Such simultaneous increases in stiffness, strength, ductility and toughness of a polymer by an additive are rather uncommon.

  16. Contribution toward comprehension of contact angle values on single polydimethylsiloxane and poly(ethylene oxide) polymer networks.

    PubMed

    Bouteau, Murielle; Cantin, Sophie; Fichet, Odile; Perrot, Françoise; Teyssié, Dominique

    2010-11-16

    The large application ranges of polydimethylsiloxane (PDMS) and poly(ethylene oxide) (PEO) based materials justify the importance of controlling polymer surface properties including morphology and wettability behavior. However, it appears that the reported contact angle values of PDMS surfaces show significant scattering which cannot always be interpreted in terms of sole chemical data. In addition, few values are reported concerning pure PEO surfaces, since the polymer generally swells in the presence of water. Thus, in order to correlate surface properties with sample preparation, several single PDMS and PEO polymer networks were synthesized with varying cross-linkers and different cross-linking densities. First, the sample surface topography was systematically analyzed by atomic force microscopy (AFM). It was proven that the removal process of the polymer film from the mold plays a significant role in surface topography according to the vitreous or rubbery state of the given polymer network at room temperature irrespective of mold surface treatment. AFM-scale smooth surfaces can be obtained for all the samples by removing them systematically from the mold at a temperature below the α-relaxation temperature. Dynamic water contact angles were then measured and the values analyzed as a function of cross-linker nature and cross-linking density.

  17. Poly(ethylene oxide)-Assisted Macromolecular Self-Assembly of Lignin in ABS Matrix for Sustainable Composite Applications

    DOE PAGES

    Akato, Kokouvi M.; Tran, Chau D.; Chen, Jihua; ...

    2015-11-05

    Here we report the compatibilization of biomass-derived lignin polymer in acrylonitrile butadiene styrene (ABS) thermoplastic matrix without loss of mechanical properties via poly(ethylene oxide) (PEO)-mediated macromolecular self-assembly. ABS was blended with lignin in different concentrations, and blends with 10 wt % PEO (relative to lignin) were prepared. The relative tensile strength improved slightly at low lignin content but diminished rapidly as the lignin content was increased. However, the inclusion of PEO as an interfacial adhesion promoter helped avoid deleterious effects. Dynamic mechanical analysis showed that PEO plasticized the hard phase and thus lowered the activation energy (Ea) for its relaxationmore » but caused stiffening of the soft phase and increased its Ea. Microscopy revealed that incorporating lignin in ABS led to the statistical dispersion of discrete lignin domains (300–1000 nm) which, after PEO addition, were reduced to smaller interconnected particles (200–500 nm). The lignin-extended partially renewable ABS resins showed shear-thinning behavior and reduced viscosity compared to neat ABS. The preferred lignin-loaded compositions reinforced with 20 vol % chopped carbon fibers exhibited mechanical performances (77–80 MPa) equivalent to those of reinforced ABS materials reportedly used in 3D printing applications. In conclusion, this approach could lower the cost of ABS while reducing its carbon footprint.« less

  18. Synthesis and Gelation Characteristics of Photo-Crosslinkable Star Poly(ethylene oxide-co-lactide-glycolide acrylate) Macromonomers

    PubMed Central

    Moeinzadeh, Seyedsina; Khorasani, Saied Nouri; Ma, Junyu; He, Xuezhong; Jabbari, Esmaiel

    2011-01-01

    Viability of encapsulated cells in situ crosslinkable macromonomers depends strongly on the minimum concentration of polymerization initiators and monomers required for gelation. Novel 4-arm poly(ethylene oxide-co-lactide-glycolide acrylate) (SPELGA) macromonomers were synthesized and characterized with respect to gelation, sol fraction, degradation, and swelling in aqueous solution. SPELGA macromonomers were crosslinked in the absence of N-vinyl-2-pyrrolidone (NVP) monomer to produce a hydrogel network with a shear modulus of 27±4 kPa. The shear modulus of the gels increased by 170-fold as the macromonomer concentration was increased from 10 to 25 wt%. Sol fraction ranged between 8–18%. Addition of only 0.4 mol% NVP to the polymerization mixture increased modulus by 2.2-fold from 27±4 (no NVP) to 60±10 kPa. The higher modulus was attributed to the dilution effect of polymer chains in the sol, by delaying the onset of diffusion-controlled reaction, and cross-propagation of the growing chains with network-bound SPELGA acrylates. Degradation of SPELGA gels depended on water content and density of hydrolytically degradable ester groups. PMID:21927508

  19. Direct measurement of interaction forces between bovine serum albumin and poly(ethylene oxide) in water and electrolyte solutions.

    PubMed

    Acuña, Sergio M; Bastías, José M; Toledo, Pedro G

    2017-01-01

    The net interaction between a probe tip coated with bovine serum albumin (BSA) protein and a flat substrate coated with poly(ethylene oxide) (PEO) polymer was measured directly on approach in water and electrolyte solutions using AFM. The approach force curve between the two surfaces was monotonically repulsive in water and in electrolyte solutions. At pH ~5, slightly above the isoelectric point (pI) of BSA, and at large distances, the force was dominated by electrostatic repulsion between the oxygen atoms of the incoming protein with those belonging to the ether groups of PEO. Such repulsive force and range decreased in NaCl. Under physiological conditions, pH 6, BSA is definitely charged and the electrostatic repulsion with ether groups in PEO appears at larger separation distances. Interestingly, at pH 4, below the pI of BSA, the repulsion decreased because of an attractive, although weak, electrostatic force that appeared between the ether groups in PEO and the positively charged amino groups of BSA. However, for all solution conditions, once compression of PEO begun, the net repulsion was always dominated by short-range polymeric steric repulsion and repulsive enthalpy penalties for breaking PEO-water bonds. Results suggest that PEO in mushroom conformation may also be effective in reducing biofouling.

  20. Tuning thin-film electrolyte for lithium battery by grafting cyclic carbonate and combed poly(ethylene oxide) on polysiloxane.

    PubMed

    Li, Jie; Lin, Yue; Yao, Hehua; Yuan, Changfu; Liu, Jin

    2014-07-01

    A tunable polysiloxane thin-film electrolyte for all-solid-state lithium-ion batteries was developed. The polysiloxane was synthesized by hydrosilylation of polymethylhydrosiloxane with cyclic [(allyloxy)methyl]ethylene ester carbonic acid and vinyl tris(2-methoxyethoxy)silane. (1) H NMR spectroscopy and gel-permeation chromatography demonstrated that the bifunctional groups of the cyclic propylene carbonate (PC) and combed poly(ethylene oxide) (PEO) were well grafted on the polysiloxane. At PC/PEO=6:4, the polysiloxane-based electrolyte had an ionic conductivity of 1.55 × 10(-4) and 1.50 × 10(-3)  S cm(-1) at 25 and 100 °C, respectively. The LiFePO4 /Li batteries fabricated with the thin-film electrolyte presented excellent cycling performance in the temperature range from 25 to 100 °C with an initial discharge capacity at a rate of 1 C of 88.2 and 140 mA h g(-1) at 25 and 100 °C, respectively.

  1. Preparation of Pure and Stable Chitosan Nanofibers by Electrospinning in the Presence of Poly(ethylene oxide).

    PubMed

    Mengistu Lemma, Solomon; Bossard, Frédéric; Rinaudo, Marguerite

    2016-10-26

    Electrospinning was employed to obtain chitosan nanofibers from blends of chitosans (CS) and poly(ethylene oxide) (PEO). Blends of chitosan (MW (weight-average molecular weight) = 102 kg/mol) and PEO (M (molecular weight) = 1000 kg/mol) were selected to optimize the electrospinning process parameters. The PEO powder was solubilized into chitosan solution at different weight ratios in 0.5 M acetic acid. The physicochemical changes of the nanofibers were determined by scanning electron microscopy (SEM), swelling capacity, and nuclear magnetic resonance (NMR) spectroscopy. For stabilization, the produced nanofibers were neutralized with K₂CO₃ in water or 70% ethanol/30% water as solvent. Subsequently, repeated washings with pure water were performed to extract PEO, potassium acetate and carbonate salts formed in the course of chitosan nanofiber purification. The increase of PEO content in the blend from 20 to 40 w% exhibited bead-free fibers with average diameters 85 ± 19 and 147 ± 28 nm, respectively. Their NMR analysis proved that PEO and the salts were nearly completely removed from the nanostructure of chitosan, demonstrating that the adopted strategy is successful for producing pure chitosan nanofibers. In addition, the nanofibers obtained after neutralization in ethanol-aqueous solution has better structural stability, at least for six months in aqueous solutions (phosphate buffer (PBS) or water).

  2. Nd:YVO4 laser direct ablation of indium tin oxide films deposited on glass and polyethylene terephthalate substrates.

    PubMed

    Wang, Jian-Xun; Kwon, Sang Jik; Han, Jae-Hee; Cho, Eou Sik

    2013-09-01

    A Q-switched diode-pumped neodymium-doped yttrium vanadate (Nd:YVO4, lambda = 1064 nm) laser was applied to obtain the indium tin oxide (ITO) patterns on flexible polyethylene terephthalate (PET) substrate by a direct etching method. After the ITO films were deposited on a soda-lime glass and PET substrate, laser ablations were carried out on the ITO films for various conditions and the laser ablated results on the ITO films were investigated and analyzed considering the effects of substrates on the laser etching. The laser ablated widths on ITO deposited on glass were found to be much narrower than those on ITO deposited on PET substrate, especially, at a higher scanning speed of laser beam such as 1000 mm/s and 2000 mm/s. As the thermal conductivity of glass substrate is about 7.5 times higher than that of PET, more thermal energy would be spread and transferred to lateral direction in the ITO film in case of PET substrate.

  3. Room temperature crystallization of indium tin oxide films on glass and polyethylene terephthalate substrates using rf plasma

    SciTech Connect

    Ohsaki, H.; Suzuki, M.; Shibayama, Y.; Kinbara, A.; Watanabe, T.

    2007-07-15

    The crystallization of amorphous indium tin oxide (ITO) films was achieved by rf (13.56 MHz) plasma treatment. Although the films were crystallized after 2 min, the sample temperature was lower than 90 deg. C without compulsory cooling even after 10 min of treatment and polyethylene terephthalate (PET) substrates had no damage. Plasma-crystallized sputtered ITO films have a bixbite structure and the resistivity reached to 1.6x10{sup -4} {omega}{center_dot}cm. ITO thin films have almost the same resistivity in both cases of PET and glass substrates used and plasma-treated PET ITO films have a bit higher resistivity than that of glass ITO films, while mass spectroscopy measurements indicated that ITO films deposited on PET substrates are expected to include no apparent gas species ejected from PET substrate. It was found that the plasma gas pressure is the key parameter for the effective crystallization and the appropriate gas pressure depends on the plasma gas species.

  4. Nanofibrous chitosan-polyethylene oxide engineered scaffolds: a comparative study between simulated structural characteristics and cells viability.

    PubMed

    Kazemi Pilehrood, Mohammad; Dilamian, Mandana; Mirian, Mina; Sadeghi-Aliabadi, Hojjat; Maleknia, Laleh; Nousiainen, Pertti; Harlin, Ali

    2014-01-01

    3D nanofibrous chitosan-polyethylene oxide (PEO) scaffolds were fabricated by electrospinning at different processing parameters. The structural characteristics, such as pore size, overall porosity, pore interconnectivity, and scaffold percolative efficiency (SPE), were simulated by a robust image analysis. Mouse fibroblast cells (L929) were cultured in RPMI for 2 days in the presence of various samples of nanofibrous chitosan/PEO scaffolds. Cell attachments and corresponding mean viability were enhanced from 50% to 110% compared to that belonging to a control even at packed morphologies of scaffolds constituted from pores with nanoscale diameter. To elucidate the correlation between structural characteristics within the depth of the scaffolds' profile and cell viability, a comparative analysis was proposed. This analysis revealed that larger fiber diameters and pore sizes can enhance cell viability. On the contrary, increasing the other structural elements such as overall porosity and interconnectivity due to a simultaneous reduction in fiber diameter and pore size through the electrospinning process can reduce the viability of cells. In addition, it was found that manipulation of the processing parameters in electrospinning can compensate for the effects of packed morphologies of nanofibrous scaffolds and can thus potentially improve the infiltration and viability of cells.

  5. Preparation of Pure and Stable Chitosan Nanofibers by Electrospinning in the Presence of Poly(ethylene oxide)

    PubMed Central

    Mengistu Lemma, Solomon; Bossard, Frédéric; Rinaudo, Marguerite

    2016-01-01

    Electrospinning was employed to obtain chitosan nanofibers from blends of chitosans (CS) and poly(ethylene oxide) (PEO). Blends of chitosan (MW (weight-average molecular weight) = 102 kg/mol) and PEO (M (molecular weight) = 1000 kg/mol) were selected to optimize the electrospinning process parameters. The PEO powder was solubilized into chitosan solution at different weight ratios in 0.5 M acetic acid. The physicochemical changes of the nanofibers were determined by scanning electron microscopy (SEM), swelling capacity, and nuclear magnetic resonance (NMR) spectroscopy. For stabilization, the produced nanofibers were neutralized with K2CO3 in water or 70% ethanol/30% water as solvent. Subsequently, repeated washings with pure water were performed to extract PEO, potassium acetate and carbonate salts formed in the course of chitosan nanofiber purification. The increase of PEO content in the blend from 20 to 40 w% exhibited bead-free fibers with average diameters 85 ± 19 and 147 ± 28 nm, respectively. Their NMR analysis proved that PEO and the salts were nearly completely removed from the nanostructure of chitosan, demonstrating that the adopted strategy is successful for producing pure chitosan nanofibers. In addition, the nanofibers obtained after neutralization in ethanol-aqueous solution has better structural stability, at least for six months in aqueous solutions (phosphate buffer (PBS) or water). PMID:27792192

  6. Li+ transport in poly(ethylene oxide) based electrolytes: neutron scattering, dielectric spectroscopy, and molecular dynamics simulations.

    PubMed

    Do, Changwoo; Lunkenheimer, Peter; Diddens, Diddo; Götz, Marion; Weiss, Matthias; Loidl, Alois; Sun, Xiao-Guang; Allgaier, Jürgen; Ohl, Michael

    2013-07-05

    The dynamics of Li(+) transport in polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imde mixtures are investigated by combining neutron spin-echo (NSE) and dielectric spectroscopy with molecular dynamics (MD) simulations. The results are summarized in a relaxation time map covering wide ranges of temperature and time. The temperature dependence of the dc conductivity and the dielectric α relaxation time is found to be identical, indicating a strong coupling between both. The relaxation times obtained from the NSE measurements at 0.05 Å(-1)

  7. Dielectric and mechanical investigations on the hydrophilicity and hydrophobicity of polyethylene oxide modified on a silicon surface

    DOE PAGES

    Shang, Jing; Hong, Kunlun; Wang, Tao; ...

    2016-10-02

    Here, polyethylene oxide (PEO) has been widely used in biomedical fields. The antibiofouling property of the PEO-modified surface has been extensively investigated but is far from being fully understood. A series of PEOs with narrowly distributed molecular weight (Mw), synthesized with the technique of high vacuum anionic polymerization, have been successfully grafted onto the surface of silicon wafers. The power-law relationship between the thickness of the monolayer versus the Mw of the grafted PEO shows a scaling of 0.3, indicating compact condensing of the chains. The static contact angles show higher hydrophobicity for the layer of PEO with higher Mw,more » which can be attributed to the closely packed conformation of the chains with high density. The frequency shift of the contact resonance indicates that the Young’s modulus decreases and the loss factor increases with the increase in the Mw of PEO and the thickness of the PEO layers. Dielectric spectroscopy of bare or PEO-grafted wafers in the aqueous solutions reveals an interfacial polarization, which results from compositional and structural changes in the interface layer and depends on temperatures and salt concentrations. At a given grafting density, the PEO chains are swollen in pure water, demonstrating hydrophilic behavior, whereas they collapse in salt solutions, showing hydrophobic characteristics.« less

  8. Enhanced lithium battery with polyethylene oxide-based electrolyte containing silane-Al2 O3 ceramic filler.

    PubMed

    Zewde, Berhanu W; Admassie, Shimelis; Zimmermann, Jutta; Isfort, Christian Schulze; Scrosati, Bruno; Hassoun, Jusef

    2013-08-01

    A solid polymer electrolyte prepared by using a solvent-free, scalable technique is reported. The membrane is formed by low-energy ball milling followed by hot-pressing of dry powdered polyethylene oxide polymer, LiCF3 SO3 salt, and silane-treated Al2 O3 (Al2 O3 -ST) ceramic filler. The effects of the ceramic fillers on the properties of the ionically conducting solid electrolyte membrane are characterized by using electrochemical impedance spectroscopy, XRD, differential scanning calorimeter, SEM, and galvanostatic cycling in lithium cells with a LiFePO4 cathode. We demonstrate that the membrane containing Al2 O3 -ST ceramic filler performs well in terms of ionic conductivity, thermal properties, and lithium transference number. Furthermore, we show that the lithium cells, which use the new electrolyte together with the LiFePO4 electrode, operate within 65 and 90 °C with high efficiency and long cycle life. Hence, the Al2 O3 -ST ceramic can be efficiently used as a ceramic filler to enhance the performance of solid polymer electrolytes in lithium batteries.

  9. Prediction of acetaminophen's solubility in poly(ethylene oxide) at room temperature using the Flory-Huggins theory.

    PubMed

    Yang, Min; Wang, Peng; Gogos, Costas

    2013-01-01

    Solid dispersion technologies such as hot-melt extrusion and spray drying are often used to enhance the solubility of poorly soluble drugs. The biggest challenge associated with solid dispersion systems is that amorphous drugs may phase-separate from the polymeric matrix and recrystallize during storage. A more fundamental understanding of drug-polymer mixtures is needed for the industry to embrace the solid dispersion technologies. In this study, a theoretical model based on Flory-Huggins lattice theory was utilized to predict the solubility of a model drug acetaminophen (APAP) in a semi-crystalline polymer poly(ethylene oxide) (PEO) at 300 K. The interaction parameter χ was calculated to be -1.65 from the depression of drug's melting temperature determined from rheological and differential scanning calorimetry analysis. The equilibrium solubility in amorphous PEO was estimated to be 11.7% at 300 K. Assuming no APAP molecules dissolve in the crystalline part of PEO, the adjusted theoretical solubility is around 2.3% considering PEO being 80% crystalline. The solubility of APAP in PEG 400 was calculated to be 14.6% by using the same χ value, close to the experimental measurement 17.1%. The drug's solubility could be altered noticeably by the change of both χ and polymer molecular weight. The study also suggests that the depression of drug's melting point is a good indicator for preliminary polymer screening. The polymer that reduces the melting point the most is likely to be most miscible with the drug.

  10. Controlled protein release from electrospun biodegradable fiber mesh composed of poly(epsilon-caprolactone) and poly(ethylene oxide).

    PubMed

    Kim, Taek Gyoung; Lee, Doo Sung; Park, Tae Gwan

    2007-06-29

    A blend mixture of poly(epsilon-caprolactone) (PCL) and poly(ethylene oxide) (PEO) was electrospun to produce fibrous meshes that could release a protein drug in a controlled manner. Various biodegradable polymers, such as poly(l-lactic acid) (PLLA), poly(epsilon-caprolactone) (PCL), and poly(d,l-lactic-co-glycolic acid) (PLGA) were dissolved, along with PEO and lysozyme, in a mixture of chloroform and dimethylsulfoxide (DMSO). The mixture was electrospun to produce lysozyme loaded fibrous meshes. Among the polymers, the PCL/PEO blend meshes showed good morphological stability upon incubation in the buffer solution, resulting in controlled release of lysozyme over an extended period with reduced initial bursts. With varying the PCL/PEO blending ratio, the release rate of lysozyme from the corresponding meshes could be readily modulated. The lysozyme release was facilitated by increasing the amount of PEO, indicating that entrapped lysozyme was mainly released out by controlled dissolution of PEO from the blend meshes. Lysozyme released from the electrospun fibers retained sufficient catalytic activity.

  11. 7Li NMR spectroscopy and ion conduction mechanism in mesoporous silica (SBA-15) composite poly(ethylene oxide) electrolyte

    NASA Astrophysics Data System (ADS)

    Reddy, M. Jaipal; Chu, Peter P.

    A composite of mesoporous silica (SBA-15) with a polyethylene oxide (PEO) polymer electrolyte is examined for use in various electrochemical devices. Incorporation of SBA-15 in a PEO:LiClO 4 polymer electrolyte facilitates salt dissociation, enhances ion conductivity, and improves miscibility between organic and inorganic moieties. Optimized conductivity is found at 10 wt.% SBA-15 composition, above this concentration the conductivity is reduced due to aggregation of a SBA-15:Li rich phase. Heating above melt temperature of PEO allows more of the polymer segments to interact with SBA-15. This results in a greater degree of disorder upon cooling, and the ion conductivity is enhanced. A 7Li MAS NMR study reveals three types of lithium-ion coordination. Two major types of conduction mechanism can be identified: one through conventional amorphous PEO; a second via hopping in a sequential manner by replacing the nearby vacancies ('holes') on the surface (both interior and exterior) of the SBA-15 channels.

  12. Oxidative renaturation of hen egg-white lysozyme in polyethylene glycol-salt aqueous two-phase systems.

    PubMed

    Lotwin, J; De Bernardez Clark, E

    1999-11-20

    Aqueous two-phase systems have been widely used for the separation and concentration of proteins. In this work we investigated the possibility of using aqueous two-phase system for the renaturation of inclusion body proteins by studying the effect of polyethylene glycol (PEG)-salt systems on the oxidative renaturation of hen egg-white lysozyme (HEWL) with guanidinium chloride (GdmCl) present in the system. To accomplish phase separation at moderately low concentrations of polymer and salt, the total GdmCl concentration had to be kept low (<1 M). The unfolded protein exhibited very low solubility under these conditions. In an attempt to increase the solubility of the protein, temperatures of 40, 50, and 60 degrees C were investigated. The effect of PEG molecular weight was also addressed. Best renaturation yields were obtained when using PEG 3400 and working at 50 degrees C. However, the total protein concentration had to be kept at a low level of 0.2 mg/mL. Lowering the total GdmCl concentration in the system resulted in increased aggregation.

  13. Poly(ethylene oxide)-Assisted Macromolecular Self-Assembly of Lignin in ABS Matrix for Sustainable Composite Applications

    SciTech Connect

    Akato, Kokouvi M.; Tran, Chau D.; Chen, Jihua; Naskar, Amit K.

    2015-11-05

    Here we report the compatibilization of biomass-derived lignin polymer in acrylonitrile butadiene styrene (ABS) thermoplastic matrix without loss of mechanical properties via poly(ethylene oxide) (PEO)-mediated macromolecular self-assembly. ABS was blended with lignin in different concentrations, and blends with 10 wt % PEO (relative to lignin) were prepared. The relative tensile strength improved slightly at low lignin content but diminished rapidly as the lignin content was increased. However, the inclusion of PEO as an interfacial adhesion promoter helped avoid deleterious effects. Dynamic mechanical analysis showed that PEO plasticized the hard phase and thus lowered the activation energy (Ea) for its relaxation but caused stiffening of the soft phase and increased its Ea. Microscopy revealed that incorporating lignin in ABS led to the statistical dispersion of discrete lignin domains (300–1000 nm) which, after PEO addition, were reduced to smaller interconnected particles (200–500 nm). The lignin-extended partially renewable ABS resins showed shear-thinning behavior and reduced viscosity compared to neat ABS. The preferred lignin-loaded compositions reinforced with 20 vol % chopped carbon fibers exhibited mechanical performances (77–80 MPa) equivalent to those of reinforced ABS materials reportedly used in 3D printing applications. In conclusion, this approach could lower the cost of ABS while reducing its carbon footprint.

  14. Protective effects of polyethylene oxide on the vascular and organ function of rats with severe hemorrhagic shock.

    PubMed

    Li, Qiang; Huang, Tao; Dong, Zhen

    2015-08-01

    This study examined the effects of polyethylene oxide (PEO) on the survival rate, hemodynamics, blood gas indexes, lactic acid levels, microcirculation, and inflammatory cytokine levels in rats subjected to severe hemorrhagic shock. The shocked rats were resuscitated with either Ringer's lactate solution or 20 ppm of PEO in Ringer's lactate solution for 1 h. It was found that infusion of PEO effectively improved the survival, metabolic acidosis, oxygen delivery, hyperlactacidemia, tissue perfusion, and inflammatory responses of rats subjected to hemorrhagic shock. In addition, we found, for the first time, that PEO showed protective effects on hepatic and renal injury, as evidenced by the significant decreases in the elevated levels of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, and creatinine caused by shock induction after infusion of PEO (p < 0.05, 60 min post-resuscitation by comparison with pre-resuscitation). All of these findings indicate that PEO exhibits strong therapeutic effects under conditions of severe hemorrhagic shock,which also provides theoretical and experimental bases for the clinical use of PEO.

  15. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide)-based lithium polyether-ester-sulfonate ionomers

    DOE PAGES

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; ...

    2012-01-06

    Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies formore » motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though their respective correlation times differ significantly. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments.« less

  16. Direct measurement of interaction forces between bovine serum albumin and poly(ethylene oxide) in water and electrolyte solutions

    PubMed Central

    Bastías, José M.; Toledo, Pedro G.

    2017-01-01

    The net interaction between a probe tip coated with bovine serum albumin (BSA) protein and a flat substrate coated with poly(ethylene oxide) (PEO) polymer was measured directly on approach in water and electrolyte solutions using AFM. The approach force curve between the two surfaces was monotonically repulsive in water and in electrolyte solutions. At pH ~5, slightly above the isoelectric point (pI) of BSA, and at large distances, the force was dominated by electrostatic repulsion between the oxygen atoms of the incoming protein with those belonging to the ether groups of PEO. Such repulsive force and range decreased in NaCl. Under physiological conditions, pH 6, BSA is definitely charged and the electrostatic repulsion with ether groups in PEO appears at larger separation distances. Interestingly, at pH 4, below the pI of BSA, the repulsion decreased because of an attractive, although weak, electrostatic force that appeared between the ether groups in PEO and the positively charged amino groups of BSA. However, for all solution conditions, once compression of PEO begun, the net repulsion was always dominated by short-range polymeric steric repulsion and repulsive enthalpy penalties for breaking PEO-water bonds. Results suggest that PEO in mushroom conformation may also be effective in reducing biofouling. PMID:28296940

  17. Interaction of poly(ethylene oxide) with the sodium dodecyl sulfate micelle interface studied with nitroxide spin probes

    SciTech Connect

    Kang, Y.S.; Kevan, L. )

    1994-08-04

    Electron spin resonance (ESR) line widths of 5-, 7-, 12-, and 16-doxylstearic acid (x-DSA) and tempo nitroxides versus the concentration of poly(ethylene oxide) (PEO) in sodium dodecyl sulfate (SDS) micelles show different trends. The ESR line widths of 5-, 7-, and 16-DSA increase with increasing concentration of PEO, which is interpreted as due to increasing viscosity in the environment of the nitroxide spin probe. The tempo and 12-DSA line widths were independent of the concentration of PEO. The line width showed the highest value for 5-DSA and the lowest value of tempo. The line width of x-DSA decreases from 5-DSA to a minimum value for 12-DSA and then increases somewhat for 16-DSA. This is interpreted as bending of the alkyl chain to provide different locations for the nitroxide moiety relative to the micelle interface. The relative distances of the nitroxide moiety of [chi]-DSA from deuterated water at the SDS micelle interface was measured by deuterium electron spin echo modulation. The distances increased from 5-DSA to 12-DSA and then decreased for 16-DSA. The interpretation of the DSR line width trend is supported by the deuterium modulation depth trend. 28 refs., 5 figs., 2 tabs.

  18. Micellization of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymers in aqueous solutions: Thermodynamics of copolymer association

    SciTech Connect

    Alexandridis, P.; Hatton, T.A. . Dept. of Chemical Engineering); Holzwarth, J.F. )

    1994-04-25

    The critical micellization temperature (cmt) and critical micellization concentration (cmc) values of 12 Pluronic poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) block copolymers, covering a wide range of molecular weights (2,900--14,600) and PPO/PEO ratios (0.19--1.79), were determined employing a dye solubilization method. A closed association model was found to describe adequately the copolymer micellization process for the majority of the Pluronics and used to obtain the standard free energies ([Delta]G[degree]), enthalpies ([Delta]H[degree]), and entropies ([Delta]S[degree]) of micellization. It was determined that the micellization process is entropy-driven and has an endothermic micellization enthalpy. The hydrophobic part of the Pluronics, PPO, was responsible for the micellization, apparently due to diminishing hydrogen bonding between water and PPO with increasing temperature. The cmc dependence on temperature and size of headgroup (PEO) of Pluronics follows a similar trend with lower molecular weight C[sub i]E[sub j] nonionic surfactants, the effect of temperature being more pronounced with the Pluronics. The PEO-PPO-PEO block copolymers were compared to PPO-PEO-PPO block and PEO-PPO random copolymers, in an attempt to probe the effect of molecular architecture in the formation of micelles. No micelles were observed in aqueous PPO-PEO-PPO block copolymer solutions with increasing temperature, up to the cloud point.

  19. Multiple phase transition and scaling law for poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer in aqueous solution.

    PubMed

    Liu, Sijun; Li, Lin

    2015-02-04

    The multiple phase transition and the scaling behavior of a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer (Pluronic F127, PEO100-PPO65-PEO100) have been studied by micro-differential scanning calorimetry and rheology. The scaling behavior of the triblock copolymer was examined using the Winter-Chambon criterion to obtain the critical gel temperature Tgel and the scaling exponent n. n was found to decrease linearly with increasing copolymer concentration. A stable hard gel was formed, but the hard gel was transformed into a soft gel upon further heating. Increasing copolymer concentration led to the increase in the temperature of hard-soft gel transition, while the sol-gel transition temperature decreased with increasing copolymer concentration. A phase diagram has been determined, which is able to classify unimers, micelles, hard gel, and soft gel regions upon heating. In addition, the scaling relation of the plateau modulus Ge with copolymer concentration was also obtained as Ge ≈ c(3.0) for both soft gel and hard gel.

  20. Development of Iron-Chelating Poly(ethylene terephthalate) Packaging for Inhibiting Lipid Oxidation in Oil-in-Water Emulsions.

    PubMed

    Johnson, David R; Tian, Fang; Roman, Maxine J; Decker, Eric A; Goddard, Julie M

    2015-05-27

    Foods such as bulk oils, salad dressings, and nutritionally fortified beverages that are susceptible to oxidative degradation are often packaged in poly(ethylene terephthalate) (PET) bottles with metal chelators added to the food to maintain product quality. In the present work, a metal-chelating active packaging material is designed and characterized, in which poly(hydroxamic acid) (PHA) metal-chelating moieties were grafted from the surface of PET. Biomimetic PHA groups were grafted in a two-step UV-initiated process without the use of a photoinitiator. Surface characterization of the films by attenuated total reflective Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM) suggested successful grafting and conversion of poly(hydroxyethyl acrylate) (PHEA) to PHA chelating moieties from the surface of PET. Colorimetric (ferrozine) and inductively coupled plasma mass spectroscopy (ICP-MS) assays demonstrated the ability of PET-g-PHA to chelate iron in a low-pH (3.0) environment containing a competitive metal chelator (citric acid). Lipid oxidation studies demonstrated the antioxidant activity of PET-g-PHA films in inhibiting iron-promoted oxidation in an acidified oil-in-water (O/W) emulsion model system (pH 3.0). Particle size and ζ-potential analysis indicated that the addition of PET-g-PHA films did not affect the physical stability of the emulsion system. This work suggests that biomimetic chelating moieties can be grafted from PET and effectively inhibit iron-promoted degradation reactions, enabling removal of metal-chelating additives from product formulations.

  1. Oxidation and haem loss kinetics of poly(ethylene glycol)-conjugated haemoglobin (MP4): dissociation between in vitro and in vivo oxidation rates.

    PubMed

    Vandegriff, Kim D; Malavalli, Ashok; Minn, Charles; Jiang, Eva; Lohman, Jeff; Young, Mark A; Samaja, Michele; Winslow, Robert M

    2006-11-01

    Haemoglobin-based oxygen carriers can undergo oxidation of ferrous haemoglobin into a non-functional ferric form with enhanced rates of haem loss. A recently developed human haemoglobin conjugated to maleimide-activated poly(ethylene glycol), termed MP4, has unique physicochemical properties (increased molecular radius, high oxygen affinity and low cooperativity) and lacks the typical hypertensive response observed with most cell-free haemoglobin solutions. The rate of in vitro MP4 autoxidation is higher compared with the rate for unmodified SFHb (stroma-free haemoglobin), both at room temperature (20-22 degrees C) and at 37 degrees C (P<0.001). This appears to be attributable to residual catalase activity in SFHb but not MP4. In contrast, MP4 and SFHb showed the same susceptibility to oxidation by reactive oxygen species generated by a xanthine-xanthine oxidase system. Once fully oxidized to methaemoglobin, the rate of in vitro haem loss was five times higher in MP4 compared with SFHb in the fast phase, which we assign to the beta subunits, whereas the slow phase (i.e. haem loss from alpha chains) showed similar rates for the two haemoglobins. Formation of MP4 methaemoglobin in vivo following transfusion in rats and humans was slower than predicted by its first-order in vitro autoxidation rate, and there was no appreciable accumulation of MP4 methaemoglobin in plasma before disappearing from the circulation. These results show that MP4 oxidation and haem loss characteristics observed in vitro provide information regarding the effect of poly(ethylene glycol) conjugation on the stability of the haemoglobin molecule, but do not correspond to the oxidation behaviour of MP4 in vivo.

  2. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene...

  3. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene...

  4. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene...

  5. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene...

  6. 40 CFR 721.1729 - Boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether. 721.1729 Section 721.1729 Protection... acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene glycol mono Me ether... identified as boric acid (H3BO3), mixed esters with polyethylene glycol mono-Bu ether and polyethylene...

  7. Design and formulation of nanoemulsions using 2-(poly(hexafluoropropylene oxide)) perfluoropropyl benzene in combination with linear perfluoro(polyethylene glycol dimethyl ether)

    PubMed Central

    Mountain, Gregory A.; Jelier, Benson J.; Bagia, Christina; Friesen, Chadron M.; Janjic, Jelena M.

    2014-01-01

    This is the first report where PFPAE aromatic conjugates and perfluoro(polyethylene glycol dimethyl ether) are combined and formulated as nanoemulsions with droplet size below 100 nm. A perfluoropolyalkylether (PFPAE) aromatic conjugate, 2-(poly(hexafluoropropylene oxide)) perfluoropropyl benzene, was used as fluorophilic-hydrophilic diblock (FLD) aimed at stabilizing perfluoro(polyethylene glycol dimethyl ether) nanoemulsions. Its effects on colloidal behaviors in triphasic (organic/fluorous/aqueous) nanoemulsions were studied. The addition of FLD construct to fluorous phase led to decrease in PFPAE nanoemulsion droplet size to as low as 85 nm. Prepared nanoemulsions showed high colloidal stability. Our results suggest that these materials represent viable novel approach to fluorous colloid systems design with potential for biomedical and synthetic applications. PMID:24976645

  8. In Vivo Oxidative Stability Changes of Highly Cross-Linked Polyethylene Bearings: An Ex Vivo Investigation.

    PubMed

    Rowell, Shannon L; Reyes, Christopher R; Malchau, Henrik; Muratoglu, Orhun K

    2015-10-01

    The development of highly cross-linked UHMWPEs focused on stabilizing radiation-induced free radicals as the sole precursor to oxidative degradation. However, secondary in vivo oxidation mechanisms have been discovered. After a preliminary post-operative analysis, we subjected highly cross-linked retrievals with 1-4 years in vivo durations and never-implanted controls to accelerated aging to predict the extent to which their oxidative stability was compromised in vivo. Lipid absorption, oxidation, and hydroperoxides were measured using infrared spectroscopy. Gravimetric swelling was used to measure cross-link density. After aging, all retrievals, except vitamin E-stabilized components, regardless of initial lipid levels or oxidation, showed significant oxidative degradation, demonstrated by subsurface oxidative peaks, increased hydroperoxides and decreased cross-link density, compared to their post-operative material properties and never-implanted counterparts, confirming oxidative stability changes.

  9. Novel poly(ethylene oxide)-b-poly(propylene oxide) copolymer-glucose conjugate by the microwave-assisted ring opening of a sugar lactone.

    PubMed

    Glisoni, Romina J; Sosnik, Alejandro

    2014-11-01

    In this work, we investigated for the first time the conjugation of gluconolactone to a poly(ethylene oxide)-poly(propylene oxide) block copolymer by a microwave-assisted ring opening reaction. The glucosylated copolymer was obtained with high yield (90%). A conjugation extent of approximately 100% was achieved within 15 min. The modification reduced the critical micellar concentration and increased the size of the micelles. The agglutination of the modified polymeric micelles by a soluble lectin that binds glucose confirmed the recognizability of the modified nanocarrier. Finally, the solubilization of darunavir, an anti-HIV protease inhibitor, showed a sharp increase of the aqueous solubility from 91 microgram/mL to 14.2 and 18.9 mg/mL for 10% w/v pristine and glucosylated polymeric micelles, respectively.

  10. Quantifying the effects of sterilization and aging on the oxidative degradation and wear of crosslinked and conventional polyethylene used in total joint replacement

    NASA Astrophysics Data System (ADS)

    Willie, Bettina Maria

    2005-07-01

    Nearly 500,000 total knee and hip replacements are performed annually in the United States. The generation of ultra-high molecular weight polyethylene (PE) particulate wear debris and associated osteolysis has increasingly become the predominant cause of revision operation. Research has shown that radiation sterilization in air results in increased oxidative degradation and accelerated wear of PE components. The overall goal of this work was to better understand the effect of sterilization, radiation crosslinking, and aging on the oxidative degradation and wear performance of PE components in order to improve clinical outcomes in total joint replacement. The data indicated that after four years of real-time shelf aging, PE that was radiation sterilized in air or nitrogen had significantly greater oxidative degradation compared to PE that was sterilized with either gas plasma or ethylene oxide. After two years of real-time shelf aging, negligible oxidation occurred with minimal changes in density and percent crystallinity, indicating that oxidative degradation was not an issue in the highly crosslinked and conventional polyethylene components examined. The differences measured between time zero and two years shelf aging may be likely explained by instrumentation error or variation within polyethylene manufacturing lots. Data suggest that current manufacturing and packaging technologies have successfully avoided oxidative degradation during shelf aging. Shelf aging may not be a concern in highly crosslinked or conventional polyethylene with current packaging technologies. Conventional PE tibial components had significantly greater percent area of premelt total surface damage compared to crosslinked PE tibial components. However, conventional PE tibial components did not have a significantly different percent area of postmelt total surface damage compared to crosslinked PE tibial components. Data indicated that in vivo duration was a significant predictor of premelt

  11. Radiation-induced oxidation of ultra-high molecular weight polyethylene (UHMWPE) powder by gamma rays and electron beams: A clear dependence of dose rate

    NASA Astrophysics Data System (ADS)

    Wang, Honglong; Xu, Lu; Hu, Jiangtao; Wang, Mouhua; Wu, Guozhong

    2015-10-01

    Oxidation is an important effect of irradiation on polyethylene in air. In this work, oxidation of ultra-high molecular weight polyethylene (UHMWPE) powder (ca. 110 μm in diameter) induced by gamma rays (γ ray) and electron beams (EB) in air resulted in some large differences in properties, such as oxidative scission due to dose rate differences. However, other properties, such as surface wettability and thermal stability were not that greatly affected. The dose-rates used were 0.0019 kGy/s from a cobalt-60 gamma source and 92 kGy/s from an electron beam. The chemical structure, oxidation level, surface wettability and thermal stability of irradiated UHMWPE were analyzed by FT-IR, XPS, TGA and the static contact angle. Hydrophilic carboxyl and carbonyl groups were present on the surface of irradiated UHMWPE after irradiation in air, resulting in a decrease in the contact angle. After irradiation at 300 kGy, the gel content of the γ ray-irradiated UHMWPE samples decreased to almost zero, while that of EB irradiated UHMWPE decreased to 57%. For UHMWPE powder irradiated by gamma rays at lower doses, radiation-induced oxidation was complete and consistent with a simple theoretic estimation. Surface wettability was primarily affected by surface oxidation, and the oxidation level of UHMWPE could be easily predicted.

  12. Polymeric compositions incorporating polyethylene glycol as a phase change material

    DOEpatents

    Salyer, Ival O.; Griffen, Charles W.

    1989-01-01

    A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

  13. Crystalline structure of the poly(ethylene oxide)--p-nitrophenol complex; 2: Fourier transform infrared spectroscopy

    SciTech Connect

    Damman, P.; Point, J.J. . Service de Chimie-Physique et Thermodynamique)

    1994-07-04

    The authors have previously reported the existence of a crystalline compound made of poly(ethylene oxide) (PEO) and p-nitrophenol (pnp). From x-ray fiber patterns on stretched and spherulitic samples of this complex, a triclinic unit cell (a = 1.172 nm, b = 0.555 nm, c = 1.557 nm, [alpha] = 90.7[degree], [beta] = 87.1[degree], and [gamma] = 104.0[degree]) was deduced; the unit cell contains 6 PEO monomeric units and 4 pnp molecules, in agreement with the stoichiometry deduced from the phase diagram. The aim of this paper is to elucidate the conformation of the PEO chains and the mutual arrangement of the PEO and pnp molecules in the unit cell. To carry out this, the authors studied the dichroism of the IR bands of pnp in two differently oriented samples, namely, in stretched samples and in spherulites. The benzene rings are found to be perpendicular to the c crystallographic parameter (chain axis), and the 1--4 axis of pnp is found to be parallel to the a* reciprocal parameter. These observations completely determine the orientation of the pnp molecules in the unit cell. The conformation of the polymeric chains in the complex is not helical as in pure PEO. From the C[sub 2h] factor group of the PEO molecules, deduced from the FTIR observations, and the normal mode analysis of hydrogenated and deuterated PEO, they propose the (t[sub 2]gt[sub 2]gt[sub 3]t[sub 2]g[prime]t[sub 2]g[prime]t[sub 3]) glide type conformation. In conclusion, it appears that in the PEO--pnp complex a stack of pnp molecules stabilizes the surrounding PEO molecules in this new conformation.

  14. The influence of guaifenesin and ketoprofen on the properties of hot-melt extruded polyethylene oxide films.

    PubMed

    Crowley, Michael M; Fredersdorf, Anke; Schroeder, Britta; Kucera, Shawn; Prodduturi, Suneela; Repka, Michael A; McGinity, James W

    2004-08-01

    Films containing polyethylene oxide (PEO) and a model drug, either guaifenesin (GFN) or ketoprofen (KTP), were prepared by hot-melt extrusion. The thermal properties of the hot-melt extruded films were investigated using differential scanning calorimetry (DSC). Scanning electron microscopy (SEM) was used to examine the surface morphology of the films, and wide angle X-ray diffraction (XRD) was used to investigate the crystalline properties of the polymer, drugs and physical mixtures as well as the solid state structure of the films. The stability of the polymer was studied using gel permeation chromatography. The mechanical properties, including percent elongation and tensile strength of the films, were determined on an Instron according to American Society for Testing Materials (ASTM) procedures. The Hansen solubility parameter was calculated using the Hoftyzer or van Krevelen method to estimate the likelihood of drug--polymer miscibility. Both GFN and KTP were stable during the extrusion process. Melting points corresponding to the crystalline drugs were not observed in the films. Crystallization of GFN on the surface of the film was observed at all concentrations studied, however KTP crystallization did not occur until reaching the 15% level. Guaifenesin and ketoprofen were found to decrease drive load, increase PEO stability and plasticize the polymer during extrusion. The Hansen solubility parameters predicted miscibility between PEO and KTP and poor miscibility between PEO and GFN. The predictions of the solubility parameters were in agreement with the XRD and SEM results. The percent elongation decreased with increasing GFN concentrations and significantly increased with increasing levels of KTP. Both GFN and KTP decreased the tensile strength of the extruded film.

  15. Spontaneous crystallinity loss of drugs in the disordered regions of poly(ethylene oxide) in the presence of water.

    PubMed

    Marsac, Patrick J; Romary, Daniel P; Shamblin, Sheri L; Baird, Jared A; Taylor, Lynne S

    2008-08-01

    The physical stability of active pharmaceutical ingredients (APIs) formulated in the crystalline state may be compromised in the presence of excipients. In the present study, it is shown that at high relative humidity, several model crystalline drugs compacted into a matrix of poly(ethylene oxide) (PEO) may dissolve into the disordered regions of the polymer. The purpose of this project is to identify both the physicochemical properties of the API and the polymer which may lead to such a transformation and the mechanism of transformation. Crystalline drugs and PEO were physically mixed, compressed into tablets, and stored in a dessicator at 94% RH. The physical state of the drug and the polymer were determined using Raman spectroscopy and X-ray powder diffraction. The solubility of each drug in PEG 400 was measured by ultraviolet spectroscopy, the thermal properties of each compound were measured using differential scanning calorimetry, and the amount of water sorbed into these systems from the vapor phase was determined by gravimetric analysis. A spontaneous loss of crystallinity was observed for many of the model drugs when stored at high relative humidity and in the presence of PEO. In the absence of PEO, no changes in the crystalline material were observed. However, the structure of PEO was dramatically altered when exposed to high relative humidity. Specifically, it was found that PEO undergoes a very slow deliquescence increasing the disordered fraction of the polymer which facilitates the "dissolution" of the crystalline drug into these disordered regions. The degree of transformation, estimated from Raman spectroscopy, was found to qualitatively correlate with the aqueous solubility of the compounds. It can be concluded that for the systems studied here, the phase stability of the polymer was compromised at high relative humidity and the polymer underwent deliquescence. The equilibrium phase of several of the crystalline drugs studied here was then altered

  16. Performance of polymer electrolyte based on chitosan blended with poly(ethylene oxide) for plasmonic dye-sensitized solar cell

    NASA Astrophysics Data System (ADS)

    Buraidah, M. H.; Teo, L. P.; Au Yong, C. M.; Shah, Shahan; Arof, A. K.

    2016-07-01

    Chitosan and poly(ethylene oxide) powders have been mixed in different weight ratios. To each mixture, a fixed amount of ammonium iodide has been added. All mixtures have been dissolved in 1% acetic acid solution to form polymer blend electrolyte films by the solution cast technique. X-ray diffraction indicates that the polymer blend electrolytes are amorphous. Fourier transform infrared spectroscopy shows shifting of the amine, carboxamide and Csbnd Osbnd C bands to lower wavenumbers indicating the occurrence of complexation. Electrochemical impedance spectroscopy has been used to study the electrical properties of the samples. The ionic conductivity for 55 wt.% chitosan-45 wt.% NH4I electrolyte system is 3.73 × 10-7 S cm-1 at room temperature and is increased to 3.66 × 10-6 S cm-1 for the blended film (16.5 wt.% chitosan-38.5 wt.% PEO)-45 wt.% NH4I film. Dye-sensitized solar cells (DSSCs) have been fabricated by sandwiching the polymer electrolyte between the TiO2/dye photoelectrode and Pt counter electrode. DSSCs fabricated exhibits short-circuit current density (Jsc) of 2.71 mA cm-2, open circuit voltage (Voc) of 0.58 V and efficiency of 0.78% with configuration ITO/TiO2/N3 dye/(16.5 wt.% chitosan-38.5 wt.% PEO)-45 wt.% NH4I(+I2)/Pt/ITO and Jsc of 2.84 mA cm-2, Voc of 0.58 V and efficiency of 1.13% with configuration ITO/TiO2 + Ag nanoparticles/N3 dye/(16.5 wt.% chitosan-38.5 wt.% PEO)-45 wt.% NH4I(+I2)/Pt/ITO.

  17. Interchain coupled chain dynamics of poly(ethylene oxide) in blends with poly(methyl methacrylate): Coupling model analysis

    NASA Astrophysics Data System (ADS)

    Ngai, K. L.; Wang, Li-Min

    2011-11-01

    Quasielastic neutron scattering and molecular dynamics simulation data from poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA) blends found that for short times the self-dynamics of PEO chain follows the Rouse model, but at longer times past tc = 1-2 ns it becomes slower and departs from the Rouse model in dependences on time, momentum transfer, and temperature. To explain the anomalies, others had proposed the random Rouse model (RRM) in which each monomer has different mobility taken from a broad log-normal distribution. Despite the success of the RRM, Diddens et al. [Eur. Phys. Lett. 95, 56003 (2011)] extracted the distribution of friction coefficients from the MD simulations of a PEO/PMMA blend and found that the distribution is much narrower than expected from the RRM. We propose a simpler alternative explanation of the data by utilizing alone the observed crossover of PEO chain dynamics at tc. The present problem is just a special case of a general property of relaxation in interacting systems, which is the crossover from independent relaxation to coupled many-body relaxation at some tc determined by the interaction potential and intermolecular coupling/constraints. The generality is brought out vividly by pointing out that the crossover also had been observed by neutron scattering from entangled chains relaxation in monodisperse homopolymers, and from the segmental α-relaxation of PEO in blends with PMMA. The properties of all the relaxation processes in connection with the crossover are similar, despite the length scales of the relaxation in these systems are widely different.

  18. Structural effect of glyme-Li(+) salt solvate ionic liquids on the conformation of poly(ethylene oxide).

    PubMed

    Chen, Zhengfei; McDonald, Samila; Fitzgerald, Paul A; Warr, Gregory G; Atkin, Rob

    2016-06-01

    The conformation of 36 kDa polyethylene oxide (PEO) dissolved in three glyme-Li(+) solvate ionic liquids (SILs) has been investigated by small angle neutron scattering (SANS) and rheology as a function of concentration and compared to a previously studied SIL. The solvent quality of a SIL for PEO can be tuned by changing the glyme length and anion type. Thermogravimetric analysis (TGA) reveals that PEO is dissolved in the SILs through Li(+)-PEO coordinate bonds. All SILs (lithium triglyme bis(trifluoromethanesulfonyl)imide ([Li(G3)]TFSI), lithium tetraglyme bis(pentafluoroethanesulfonyl)imide ([Li(G4)]BETI), lithium tetraglyme perchlorate ([Li(G4)]ClO4) and the recently published [Li(G4)]TFSI) are found to be moderately good solvents for PEO but solvent quality decreases in the order [Li(G4)]TFSI ∼ [Li(G4)]BETI > [Li(G4)]ClO4 > [Li(G3)]TFSI due to decreased availability of Li(+) for PEO coordination. For the same glyme length, the solvent qualities of SILs with TFSI(-) and BETI(-) anions ([Li(G4)]TFSI and [Li(G4)]BETI) are very similar because they weakly coordinate with Li(+), which facilitates Li(+)-PEO interactions. [Li(G4)]ClO4 presents a poorer solvent environment for PEO than [Li(G4)]BETI because ClO4(-) binds more strongly to Li(+) and thereby hinders interactions with PEO. [Li(G3)]TFSI is the poorest PEO solvent of these SILs because G3 binds more strongly to Li(+) than G4. Rheological and radius of gyration (Rg) data as a function of PEO concentration show that the PEO overlap concentrations, c* and c**, are similar in the three SILs.

  19. Crystallization of poly(ethylene oxide) with acetaminophen--a study on solubility, spherulitic growth, and morphology.

    PubMed

    Yang, Min; Gogos, Costas

    2013-11-01

    A simple, sensitive, efficient, and novel method analyzing the number of spherulitic nuclei was proposed to estimate the solubility of a model drug acetaminophen (APAP) in poly(ethylene oxide) (PEO). At high crystallization temperature (323 K), 10% APAP-PEO had the same low number of spherulitic nuclei as pure PEO, indicating that APAP and PEO were fully miscible. At low crystallization temperature (303 K), the number of nuclei for 10% APAP-PEO was significantly higher, suggesting that APAP was oversaturated and therefore recrystallized and acted as a nucleating agent. Based on the results obtained, the solubility of APAP in PEO is possibly between the concentration of 0.1% and 1% at 303 K. The spherulitic growth rate G of PEO was found to decrease with increasing APAP concentration, suggesting that APAP is most likely functioning as a chemical defect and is either rejected from or included in the PEO crystals during chain folding. APAP could possibly locate in the inter-spherulitic, inter-fibrillar, inter-lamellar, or intra-lamellar regions of PEO. At 323 K, the morphology of 10% APAP-PEO is more dendritic than spherulitic with large unfilled space in between dendrites and spherulites, which is a sign of one or the combination of the four modes of segregation. An extensive spherulitic nucleation and growth kinetics study using the classical theoretical relationships, for example, the Hoffman-Lauritzen (HL) and Avrami theories, was conducted. Both microscopic and differential scanning calorimetric (DSC) analysis yielded similar values for the nucleation constant Kg as well as the fold surface free energy σe and work of chain folding q. The values of σe and q increased with APAP concentration, indicating that the chain folding of PEO was hindered by APAP.

  20. Electric-double-layer doping of WSe2 field-effect transistors using polyethylene-oxide cesium perchlorate

    NASA Astrophysics Data System (ADS)

    Fathipour, Sara; Pandey, Pratyush; Fullerton-Shirey, Susan; Seabaugh, Alan

    2016-12-01

    Electric double layers (EDLs) formed between polyethylene oxide cesium perchlorate and multilayer WSe2 field-effect transistors (FETs) are explored as a means for contact and access region doping. In this application, the electric double layer is formed using a top field plate or a side gate and then locked into place by cooling of the device below the glass transition temperature of the polymer. A dual work-function Ti/Pd contact is used to form the Schottky contacts with Ti as the n-contact and Pd as the p-contact and these are evaporated in a single evaporation. Using the EDL doping technique, sheet carrier density and current density are as high as (4.9 ± 1.9) × 1013 cm-2 and 58 μA/μm for n-doping and (3.5 ± 1.9) × 1013 cm-2 and 50 μA/μm for p-doping for the highest channel conductivities. The weak temperature dependence of the transfer characteristics at high doping levels reveals that the current in the Schottky contacts is dominated by tunneling with a contact resistance of 1 kΩ μm for the p-branch and 3.4 kΩ μm for the n-branch, comparable to the best WSe2 FET reports. At the highest carrier densities, the temperature coefficient of the conductance becomes negative as the mobility of the channel controls the temperature dependence. Using EDL doping, n-FET and p-FET configurations are demonstrated.

  1. Dispersion fraction enhances cellular growth of carbon nanotube and aluminum oxide reinforced ultrahigh molecular weight polyethylene biocomposites.

    PubMed

    Patel, Anup Kumar; Balani, Kantesh

    2015-01-01

    Ultrahigh molecular weight polyethylene (UHMWPE) is widely used as bone-replacement material for articulating surfaces due to its excellent wear resistance and low coefficient of friction. But, the wear debris, generated during abrasion between mating surfaces, leads to aseptic loosening of implants. Thus, various reinforcing agents are generally utilized, which may alter the surface and biological properties of UHMWPE. In the current work, the cellular response of compression molded UHMWPE upon reinforcement of bioactive multiwalled carbon nanotubes (MWCNTs) and bioinert aluminum oxide (Al2O3) is investigated. The phase retention and stability were observed using X-ray diffraction, Raman spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The reinforcement of MWCNTs and Al2O3 has shown to alter the wettability (from contact angle of ~88°±2° to ~118°±4°) and surface energy (from ~23.20 to ~17.75 mN/m) of composites with respect to UHMWPE, without eliciting any adverse effect on cytocompatibility for the L929 mouse fibroblast cell line. Interestingly, the cellular growth of the L929 mouse fibroblast cell line is observed to be dominated by the dispersion fraction of surface free energy (SFE). After 48 h of incubation period, a decrease in metabolic activity of MWCNT-Al2O3 reinforced composites is attributed to apatite formation that reduces the dispersion fraction of surface energy. The mineralized apatite during incubation was confirmed and quantified by energy dispersive spectroscopy and X-ray diffraction respectively. Thus, the dispersion fraction of surface free energy can be engineered to play an important role in achieving enhanced metabolic activity of the MWCNT-Al2O3 reinforced UHMWPE biopolymer composites.

  2. Interchain coupled chain dynamics of poly(ethylene oxide) in blends with poly(methyl methacrylate): coupling model analysis.

    PubMed

    Ngai, K L; Wang, Li-Min

    2011-11-21

    Quasielastic neutron scattering and molecular dynamics simulation data from poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA) blends found that for short times the self-dynamics of PEO chain follows the Rouse model, but at longer times past t(c) = 1-2 ns it becomes slower and departs from the Rouse model in dependences on time, momentum transfer, and temperature. To explain the anomalies, others had proposed the random Rouse model (RRM) in which each monomer has different mobility taken from a broad log-normal distribution. Despite the success of the RRM, Diddens et al. [Eur. Phys. Lett. 95, 56003 (2011)] extracted the distribution of friction coefficients from the MD simulations of a PEO/PMMA blend and found that the distribution is much narrower than expected from the RRM. We propose a simpler alternative explanation of the data by utilizing alone the observed crossover of PEO chain dynamics at t(c). The present problem is just a special case of a general property of relaxation in interacting systems, which is the crossover from independent relaxation to coupled many-body relaxation at some t(c) determined by the interaction potential and intermolecular coupling/constraints. The generality is brought out vividly by pointing out that the crossover also had been observed by neutron scattering from entangled chains relaxation in monodisperse homopolymers, and from the segmental α-relaxation of PEO in blends with PMMA. The properties of all the relaxation processes in connection with the crossover are similar, despite the length scales of the relaxation in these systems are widely different.

  3. Pyrolysis result of polyethylene waste as fuel for solid oxide fuel cell with samarium doped-ceria (SDC)-carbonate as electrolyte

    NASA Astrophysics Data System (ADS)

    Syahputra, R. J. E.; Rahmawati, F.; Prameswari, A. P.; Saktian, R.

    2017-02-01

    In this research, the result of pyrolysis on polyethylene was used as fuel for a solid oxide fuel cell (SOFC). The pyrolysis result is a liquid which consists of hydrocarbon chains. According to GC-MS analysis, the hydrocarbons mainly consist of C7 to C20 hydrocarbon chain. Then, the liquid was applied to a single cell of NSDC-L | NSDC | NSDC-L. NSDC is a composite SDC (samarium doped-ceria) with sodium carbonate. Meanwhile, NSDC-L is a composite of NSDC with LiNiCuO (LNC). NSDC and LNC were analyzed by X-ray diffraction to understand their crystal structure. The result shows that presence of carbonate did not change the crystal structure of SDC. SEM EDX analysis for fuel cell before and after being loaded with polyethylene oil to get information of element diffusion to the electrolyte. Meanwhile, the conductivity properties were investigated through impedance measurement. The presence of carbonate even increases the electrical conductivity. The single cell test with the pyrolysis result of polyethylene at 300 – 600 °C, found that the highest power density is at 600 °C with the maximum power density of 0.14 mW/cm2 and open circuit voltage of 0.4 Volt. Elemental analysis at three point spots of single cell NDSC-L |NSDC|NSDC-L found that a migration of ions was occurred during fuel operation at 300 – 600 °C.

  4. Ear reconstruction with porous polyethylene implants.

    PubMed

    Berghaus, Alexander; Stelter, Klaus; Naumann, Andreas; Hempel, John Martin

    2010-01-01

    This article describes a surgical technique using porous polyethylene as the framework material for ear reconstruction. In comparison to the use of rib cartilage, porous polyethylene - first described by Berghaus in 1982 - provides better definition and projection as well as congruency with the opposite side. Hospitalization time is significantly shorter. There are less surgical interventions than with traditional microtia operations that use rib cartilage, and the patient is spared the additional procedure needed to remove the rib cartilage, with all the associated complications as well as the resulting thorax scar. Also, reconstruction can take place at an earlier age, which is advantageous for those concerned. Using porous polyethylene as the frame material, a temporoparietal flap and full-thickness skin cover, we have been able to achieve very convincing results over recent years.

  5. Recent advances in polyethylene separator technology

    NASA Astrophysics Data System (ADS)

    Weighall, M. J.

    The well known technical and production benefits of polyethylene separator materials over other separator materials have prompted a dramatic increase in polyethylene separator usage in recent years. Separator trends in the United States from 1980 to 1996, and in Europe from 1987 to 1992, are shown. The manufacturing process for polyethylene separators is outlined, with particular emphasis on the latest advances in manufacturing technology. These improvements have resulted in a higher quality product, and also benefit the environment because of the sophisticated oil extraction and solvent recovery system. The product quality improvements resulting from the latest manufacturing technology include consistent conformance to dimensional specifications, low electrical resistance, close control of residual oil content, virtual elimination of pinholes, and good running properties on the battery manufacturers' plate enveloping machines. The material can also be manufactured with a very thin backweb to reduce electrical resistance still further.

  6. Contact urticaria due to polyethylene gloves.

    PubMed

    Sugiura, Keiji; Sugiura, Mariko; Shiraki, Rika; Hayakawa, Ritsuko; Shamoto, Mikihiro; Sasaki, Kazumi; Itoh, Akira

    2002-05-01

    We report a rare case of contact urticaria due to polyethylene gloves. The patient, a 46-year-old cook, had had had chronic urticaria since 1985, and first visited our hospital in June 2000. We began by prescribing antihistamine and antiallergenic drugs for him, but his condition did not improve. From a detailed interview, we established that when he put on polyethylene gloves at work, his condition worsened. We suspected some component of his gloves to be the cause of his symptoms. Prick and scratch tests with a solution extracted from his gloves showed a wheal-and-flare reaction at 15 min. We advised him to wear a cotton shirt under his clothes in daily life, and to put on cotton gloves under his polyethylene gloves while at work. Subsequently, the size and the number of wheals were markedly smaller and the subject's symptoms were reduced.

  7. Nasal reconstruction using porous polyethylene implants.

    PubMed

    Romo, T; Sclafani, A P; Jacono, A A

    2000-01-01

    Nasal reconstruction presents a significant challenge to the facial plastic surgeon. The dual goals of reconstruction are restoration of the desired aesthetic nasal contour and an improved nasal airway. Autologous cartilage and bone are considered optimal grafting material, but their supply is often limited and harvesting entails additional morbidity. Many synthetic materials have been introduced in nasal reconstruction, but high infection and extrusion rates limited their use. Porous high density polyethylene implants present an alternative to autologous material as they allow for fibrovascular ingrowth, leading to stability of the implant and decreased rates of infection. Herein we describe the use of porous high density polyethylene implants for reconstruction of the platyrrhine nose and in revision rhinoplasty. The use of preformed nasal-dorsal tip and alar batten implants are described, as well as the use of columellar strut and premaxillary plumper implants. We believe that porous high density polyethylene implants provide a safe, desirable alternative in functional and aesthetic nasal reconstruction.

  8. Radiative Cooling With Pigmented Polyethylene Foils

    NASA Astrophysics Data System (ADS)

    Niklasson, Gunnar A.; Eriksson, Tord S.

    1989-03-01

    Polyethylene foils containing a nonabsorbing pigment can be suitable for radiative cooling because of their high reflectance of solar radiation combined with a high transmittance in the atmospheric window region in the thermal infrared. We have studied the optical properties in the wavelength range 0.3-50 μm of extruded polyethylene foils containing various amounts of 0.23 μm diameter Ti02 particles. It appears that the foils can prevent heating of an underlying material, even when directly illuminated by the sun. The total transmittance and reflectance of the Ti02-polyethylene foils were compared with multiple scattering calculations. Lorenz-Mie theory was used to model the scattering and absorption of a single TiO2 sphere. The single scattering parameters were then introduced into the four flux theory, by which the transmittance and reflectance were calculated. We find a satisfactory agreement between theory and experiments in most cases.

  9. Effect of peptide secondary structure on adsorption and adsorbed film properties on end-grafted polyethylene oxide layers.

    PubMed

    Binazadeh, M; Zeng, H; Unsworth, L D

    2014-01-01

    Poly-l-lysine (PLL), in α-helix or β-sheet configuration, was used as a model peptide for investigating the effect of secondary structures on adsorption events to poly(ethylene oxide) (PEO) modified surfaces formed using θ solvents. Circular dichroism results showed that the secondary structure of PLL persisted upon adsorption to Au and PEO modified Au surfaces. Quartz crystal microbalance with dissipation (QCM-D) was used to characterize the chemisorbed PEO layer in different solvents (θ and good solvents), as well as the sequential adsorption of PLL in different secondary structures (α-helix or β-sheet). QCM-D results suggest that chemisorption of PEO 750 and 2000 from θ solutions led to brushes 3.8 ± 0.1 and 4.5 ± 0.1 nm thick with layer viscosities of 9.2 ± 0.8 and 4.8 ± 0.5 cP, respectively. The average number of H2O per ethylene oxides, while in θ solvent, was determined as ~0.9 and ~1.2 for the PEO 750 and 2000 layers, respectively. Upon immersion in good solvent (as used for PLL adsorption experiments), the number of H2O per ethylene oxides increased to ~1.5 and ~2.0 for PEO 750 and 2000 films, respectively. PLL adsorbed masses for α-helix and β-sheet on Au sensors was 231 ± 5 and 1087 ± 14 ng cm(-2), with layer viscosities of 2.3 ± 0.1 and 1.2 ± 0.1 cP, respectively; suggesting that the α-helix layer was more rigid, despite a smaller adsorbed mass, than that of β-sheet layers. The PEO 750 layer reduced PLL adsorbed amounts to ~10 and 12% of that on Au for α-helices and β-sheets respectively. The PLL adsorbed mass to PEO 2000 layers dropped to ~12% and 4% of that on Au, for α-helix and β-sheet respectively. No significant differences existed for the viscosities of adsorbed α-helix and β-sheet PLL on PEO surfaces. These results provide new insights into the fundamental understanding of the effects of secondary structures of peptides and proteins on their surface adsorption.

  10. 76 FR 8770 - Polyethylene Terephthalate (Pet) Film From Korea

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-15

    ... From the Federal Register Online via the Government Publishing Office ] INTERNATIONAL TRADE COMMISSION Polyethylene Terephthalate (Pet) Film From Korea AGENCY: United States International Trade... full five-year review concerning the antidumping duty order on polyethylene terephthalate (PET)...

  11. Long-term Radiographic Assessment of Cemented Polyethylene Acetabular Cups

    PubMed Central

    Isaac, Graham; Porter, Neil; Fisher, John; Older, John

    2008-01-01

    In vitro studies demonstrating excessive wear in polyethylene cups sterilized using gamma irradiation and stored in air led to the abandonment of this sterilization technique. We evaluated the clinical wear performance of a metal femoral component on a polyethylene cup in a hip prosthesis from a selected subset of implants in a group of patients followed for at least 20 years and assessed the time dependency of variation in penetration rates. We measured penetration in 33 polyethylene cups in 25 patients who had a Charnley low-friction arthroplasty between 1982 and 1984. All patients had Charnley Ogee® cups implanted for more than 20 years and sterilized using the gamma irradiation in air technique. If degradation occurred over time in vivo, it was not reflected by an increased penetration rate with increasing time in vivo; even after 20 years of implantation, the degree of wear remained low. This suggests gamma irradiation affects wear on ultra-high-molecular-weight polyethylene by reducing wear secondary to the crosslinking, by increasing wear as shown through in vitro studies of heavily oxidized samples, or by oxidation resulting from prolonged shelf life. The effect of progressive oxidation in vivo does not appear to affect wear in vivo. Level of Evidence: Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence. PMID:18196419

  12. One-step sonochemical synthesis of a graphene oxide-manganese oxide nanocomposite for catalytic glycolysis of poly(ethylene terephthalate)

    NASA Astrophysics Data System (ADS)

    Park, Gle; Bartolome, Leian; Lee, Kyoung G.; Lee, Seok Jae; Kim, Do Hyun; Park, Tae Jung

    2012-06-01

    Ultrasound-assisted synthesis of a graphene oxide (GO)-manganese oxide nanocomposite (GO-Mn3O4) was conducted without further modification of GO or employing secondary materials. With the GO nanoplate as a support, potassium permanganate oxidizes the carbon atoms in the GO support and gets reduced to Mn3O4. An intensive ultrasound method could reduce the number of reaction steps and temperature, enhance the reaction rate and furthermore achieve a Mn3O4 phase. The composite was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The coverage and crystallinity of Mn3O4 were controlled by changing the ratio of permanganate to GO dispersion. The synthesized nanocomposite was used as a catalyst for poly(ethylene terephthalate) (PET) depolymerization into its monomer, bis(2-hydroxylethyl) terephthalate (BHET). The highest monomer yield of 96.4% was obtained with the nanocomposite containing the lowest amount of Mn3O4, while PET glycolysis with the Mn3O4 without GO yielded 82.7% BHET.Ultrasound-assisted synthesis of a graphene oxide (GO)-manganese oxide nanocomposite (GO-Mn3O4) was conducted without further modification of GO or employing secondary materials. With the GO nanoplate as a support, potassium permanganate oxidizes the carbon atoms in the GO support and gets reduced to Mn3O4. An intensive ultrasound method could reduce the number of reaction steps and temperature, enhance the reaction rate and furthermore achieve a Mn3O4 phase. The composite was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). The coverage and crystallinity of Mn3O4 were controlled by changing the ratio of permanganate to GO dispersion. The synthesized nanocomposite was used as a catalyst for poly(ethylene

  13. Release of bacteriocins from nanofibers prepared with combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO).

    PubMed

    Heunis, Tiaan; Bshena, Osama; Klumperman, Bert; Dicks, Leon

    2011-01-01

    Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA produced by Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO) dissolved in N,N-dimethylformamide (DMF). Both peptides were released from the nanofibers with a high initial burst and retained 88% of their original antimicrobial activity at 37 °C. Nanofibers have the potential to serve as carrier matrix for bacteriocins and open a new field in developing controlled antimicrobial delivery systems for various applications.

  14. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  15. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene resins, carboxyl modified. 177.1600... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface...

  16. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  17. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  18. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene resins, carboxyl modified. 177.1600... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface...

  19. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  20. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene glycol (400) monolaurate. 178.3760 Section 178.3760 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400)...

  1. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  2. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  3. 76 FR 54791 - Polyethylene Terephthalate (PET) Film From Korea

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-02

    ... COMMISSION Polyethylene Terephthalate (PET) Film From Korea Determination On the basis of the record \\1... antidumping duty order on polyethylene terephthalate (PET) film from Korea would not be likely to lead to... contained in USITC Publication 4254 (August 2011), entitled Polyethylene Terephthalate (PET) Film from...

  4. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  5. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene resins, carboxyl modified. 177.1600... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface...

  6. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene resins, carboxyl modified. 177.1600... Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface...

  7. 40 CFR 721.6493 - Amidoamine modified polyethylene glycol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amidoamine modified polyethylene... Specific Chemical Substances § 721.6493 Amidoamine modified polyethylene glycol (generic). (a) Chemical... as an amidoamine modified polyethylene glycol (PMN P-99-0645) is subject to reporting under...

  8. 21 CFR 177.1600 - Polyethylene resins, carboxyl modified.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene resins, carboxyl modified. 177.1600... Use Food Contact Surfaces § 177.1600 Polyethylene resins, carboxyl modified. Carboxyl-modified polyethylene resins may be safely used as the food-contact surface of articles intended for use in contact...

  9. 21 CFR 178.3760 - Polyethylene glycol (400) monolaurate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene glycol (400) monolaurate. 178.3760... SANITIZERS Certain Adjuvants and Production Aids § 178.3760 Polyethylene glycol (400) monolaurate. Polyethylene glycol (400) monolaurate containing not more than 0.1 percent by weight of ethylene...

  10. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1630 Polyethylene phthalate polymers. Polyethylene phthalate...

  11. Evaluation of Paulownia elongata wood polyethylene composites

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paulownia wood flour (PWF), a byproduct of milling lumber, was employed as a bio-filler and blended with high density polyethylene (HDPE) via extrusion. Paulownia wood (PW) shavings were milled through a 1-mm screen then separated via shaking into various particle fractions using sieves (#30 - < #2...

  12. DNP with Trityl Radicals in Deuterated Polyethylene

    NASA Astrophysics Data System (ADS)

    Wang, Li; Meyer, W.; Berlin, A.; Herick, J.; Hess, C.; Reicherz, G.

    2016-02-01

    Chemically doping with trityl radicals was performed in fully deuterated polyethylene. The behavior of paramagnetic centers has been investigated by ESR X-band spectrometer. The highest deuteron polarization was 8% at 2.5 T and 1 K with a spin concentration of 3 × 1019 spins/g.

  13. Herbicide dissipation from low density polyethylene mulch

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field and laboratory studies were conducted to examine herbicide dissipation when applied to low density polyethylene (LDPE) mulch for dry scenarios vs. washing off with water. In field studies, halosulfuron, paraquat, carfentrazone, glyphosate, and flumioxazin were applied to black 1.25-mil LDPE at...

  14. High-pressure vibrational properties of polyethylene

    NASA Astrophysics Data System (ADS)

    Fontana, Luca; Santoro, Mario; Bini, Roberto; Vinh, Diep Q.; Scandolo, Sandro

    2010-11-01

    The pressure evolution of the vibrational spectrum of polyethylene was investigated up to 50 GPa along different isotherms by Fourier-transform infrared and Raman spectroscopy and at 0 K by density-functional theory calculations. The infrared data allow for the detection of the orthorhombic Pnam to monoclinic P21/m phase transition which is characterized by a strong hysteresis both on compression and decompression experiments. However, an upper and lower boundary for the transition pressure are identified. An even more pronounced hysteresis is observed for the higher-pressure transition to the monoclinic A2/m phase. The hysteresis does not allow in this case the determination of a well defined P-T transition line. The ambient structural properties of polyethylene are fully recovered after compression/decompression cycles indicating that the polymer is structurally and chemically stable up to 50 GPa. A phase diagram of polyethylene up to 50 GPa and 650 K is proposed. Analysis of the pressure evolution of the Davydov splittings and of the anomalous intensification with pressure of the IR active wagging mode provides insight about the nature of the intermolecular interactions in crystalline polyethylene.

  15. Immobilization of natural anti-oxidants on carbon nanotubes and aging behavior of ultra-high molecular weight polyethylene-based nanocomposites

    NASA Astrophysics Data System (ADS)

    Dintcheva, Nadka Tzankova; Arrigo, Rossella; Gambarotti, Cristian; Guenzi, Monica; Carroccio, Sabrina; Cicogna, Francesca; Filippone, Giovanni

    2014-05-01

    The use of natural antioxidants is an attractive way to formulate nanocomposites with extended durability and with potential applications in bio-medical field. In this work, Vitamin E (VE) in the form of α-tocopherol and Quercetin (Q) are physically immobilized on the outer surface of multi-walled carbon nanotubes (CNTs). Afterward, the CNTs-VE and CNTs-Q are used to formulate thermally stable ultra high molecular weight polyethylene based nanocomposites. The obtained results in the study of the thermo-oxidation behavior suggest a beneficial effect of the natural anti-oxidant carbon nanotubes systems. The unexpected excellent thermo-resistance of the nanocomposites seems to be due to a synergistic effect of the natural anti-oxidant and carbon nanotubes, i.e. strong interaction between CNT surface and anti-oxidant molecules. Particularly, these interactions cause the formation of structural defects onto outer CNT surfaces, which, in turn, increase the CNT radical scavenging activity.

  16. Direction of polyethylene separator development for the SLI market

    SciTech Connect

    Navarrete, J.

    1997-12-01

    Recent separator advancements have improved the oxidation stability and puncture resistance of Polyethylene (PE) separators. These improvements, at the same time, have been accomplished even as the market continues to demand separators with lower backweb thickness. Results of development work to evaluate improved oxidation resistance is presented. Evaluation of separator characteristics as well as separator performance in a battery are presented and form the basis for an improved separator design.

  17. Nuclear magnetic resonance investigation of dynamics in poly(ethylene oxide) based polyether-ester-sulfonate ionomers

    NASA Astrophysics Data System (ADS)

    Roach, David J.

    Nuclear magnetic resonance (NMR) spectroscopy has been utilized to investigate the dynamics of poly(ethylene oxide)-based lithium sulfonate ionomer samples that have low glass transition temperatures. 1H and 7Li spin-lattice relaxation times (T1) of the bulk polymer and lithium ions, respectively, were measured and analyzed in samples with a range of ion contents. The temperature dependence of T1 values along with the presence of minima in T1 as a function of temperature enabled correlation times and activation energies to be obtained for both the segmental motion of the polymer backbone and the hopping motion of lithium cations. Similar activation energies for motion of both the polymer and lithium ions in the samples with lower ion content indicate that the polymer segmental motion and lithium ion hopping motion are correlated in these samples, even though lithium hopping is about ten times slower than the segmental motion. A divergent trend is observed for correlation times and activation energies of the highest ion content sample with 100% lithium sulfonation due to the presence of ionic aggregation. Details of the polymer and cation dynamics on the nanosecond timescale are discussed and complement the findings of X-ray scattering and Quasi Elastic Neutron Scattering experiments. Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (T g) have been investigated using solid-state nuclear magnetic resonance (NMR). Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components and relative mobilities of the polymer backbone of a suite of. lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of

  18. Poly(ethylene oxide)-silica hybrids entrapping sensitive dyes for biomedical optical pH sensors: Molecular dynamics and optical response

    NASA Astrophysics Data System (ADS)

    Fabbri, Paola; Pilati, Francesco; Rovati, Luigi; McKenzie, Ruel; Mijovic, Jovan

    2011-06-01

    Polymer-silica hybrid nanocomposites prepared by sol-gel process based on triethoxisilane-terminated poly(ethylene oxide) chains and tetraethoxysilane as silica precursor, doped with organic pH sensitive dyes, have been prepared and their suitability for use as sensors coupled with plastic optic fibers has been evaluated. Sensors were prepared by immobilizing a drop of the hybrid materials onto the tip of a multi-mode poly(methyl methacrylate) optical fiber. The performance of the optical sensor in terms of sensitivity and response time was tested in different experimental conditions, and was found to be markedly higher than analogous sensors present on the market. The very fast kinetic of the hybrid's optical response was supported by studies performed at the molecular level by broadband dielectric relaxation spectroscopy (DRS), investigated over a wide range of frequency and temperature, showing that poly(ethylene oxide) chains maintain their dynamics even when covalently bonded to silica domains, which decrease the self-association interactions and promote motions of polymer chain segments. Due to the fast response kinetic observed, these pH optical sensors result suitable for the fast-detection of biomedical parameters, i.e. fast esophageous pH-metry.

  19. Degradation of degradable starch-polyethylene plastics in a compost environment

    SciTech Connect

    Johnson, K.E.; Pometto, A.L. III; Nikolov, Z.L. )

    1993-04-01

    Degradable plastics have differing degradation rates. Three types of degradation of polyethylene in the starch-polyethylene polymers can occur: chemical degradation, photodegradation, and biological degradation. This study examines all three types of degradation in 11 commercially produced degradable starch-polyethylene bags. Different rates for chemical and photo-degradation were found within a 20 day or an 8-week period. Results indicated that both the 70[degree]C oven and HT-HH film treatments were appropriate methods to evaluate oxidative degradation. In a compost environment, oxygen tension on the surface of the film appears to be the rate-limiting component for both chemical and biological degradation. Levels of starch in all bags was similar, so the prooxidant additive was critical in promoting the oxidative degradation of polyethylene. The Fe-Mn additive displayed the best catalytic activity. This study overall confirms degradation of starch-polyethylene plastics in a natural environment. 17 refs., 6 figs., 2 tabs.

  20. Enzymatic hydrolysis of poly(ethylene furanoate).

    PubMed

    Pellis, Alessandro; Haernvall, Karolina; Pichler, Christian M; Ghazaryan, Gagik; Breinbauer, Rolf; Guebitz, Georg M

    2016-10-10

    The urgency of producing new environmentally-friendly polyesters strongly enhanced the development of bio-based poly(ethylene furanoate) (PEF) as an alternative to plastics like poly(ethylene terephthalate) (PET) for applications that include food packaging, personal and home care containers and thermoforming equipment. In this study, PEF powders of various molecular weights (6, 10 and 40kDa) were synthetized and their susceptibility to enzymatic hydrolysis was investigated for the first time. According to LC/TOF-MS analysis, cutinase 1 from Thermobifida cellulosilytica liberated both 2,5-furandicarboxylic acid and oligomers of up to DP4. The enzyme preferentially hydrolyzed PEF with higher molecular weights but was active on all tested substrates. Mild enzymatic hydrolysis of PEF has a potential both for surface functionalization and monomers recycling.

  1. Analytical rheology of metallocene-catalyzed polyethylenes

    NASA Astrophysics Data System (ADS)

    Shanbhag, Sachin; Takeh, Arsia

    2011-03-01

    A computational algorithm that seeks to invert the linear viscoelastic spectrum of single-site metallocene-catalyzed polyethylenes is presented. The algorithm uses a general linear rheological model of branched polymers as its underlying engine, and is based on a Bayesian formulation that transforms the inverse problem into a sampling problem. Given experimental rheological data on unknown single-site metallocene- catalyzed polyethylenes, it is able to quantitatively describe the range of values of weight-averaged molecular molecular weight, MW , and average branching density, bm , consistent with the data. The algorithm uses a Markov-chain Monte Carlo method to simulate the sampling problem. If, and when information about the molecular weight is available through supplementary experiments, such as chromatography or light scattering, it can easily be incorporated into the algorithm, as demonstrated. Financial support from NSF DMR 0953002.

  2. Comparative wear tests of ultra-high molecular weight polyethylene and cross-linked polyethylene.

    PubMed

    Harsha, A P; Joyce, Tom J

    2013-05-01

    Wear particle-induced osteolysis is a major concern in hip implant failure. Therefore, recent research work has focussed on wear-resistant materials, one of the most important of which is cross-linked polyethylene. In view of this, the objective of this study was to compare the in vitro wear performance of cross-linked polyethylene to traditional ultra-high molecular weight polyethylene. In order to mimic appropriate in vivo conditions, a novel high-capacity wear tester called a circularly translating pin-on-disc was used. The results of this in vitro study demonstrated that the wear rate for cross-linked polyethylene was about 80% lower than that of conventional ultra-high molecular weight polyethylene. This difference closely matches in vivo results reported in the literature for total hip replacements that use the two biopolymers. The in vitro results were also verified against ASTM F732-00 (standard test method for wear testing of polymeric materials for use in total joint prostheses). The 50-station circularly translating pin-on-disc proved to be a reliable device for in vitro wear studies of orthopaedic biopolymers.

  3. Polyethylene solidification of low-level wastes

    SciTech Connect

    Kalb, P.D.; Colombo, P.

    1985-02-01

    This topical report describes the results of an investigation on the solidification of low-level radioactive waste in polyethylene. Waste streams selected for this study included those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those which remain problematic for solidification using contemporary agents (ion exchange resins). Four types of commercially available low-density polyethylenes were employed which encompass a range of processing and property characteristics. Process development studies were conducted to ascertain optimal process control parameters for successful solidification. Maximum waste loadings were determined for each waste and polyethylene type. Property evaluation testing was performed on laboratory-scale specimens to assess the potential behavior of actual waste forms in a disposal environment. Waste form property tests included water immersion, deformation under compressive load, thermal cycling and radionuclide leaching. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash, and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported. 37 refs., 33 figs., 22 tabs.

  4. Grafting functional antioxidants on highly crosslinked polyethylene

    NASA Astrophysics Data System (ADS)

    Al-Malaika, S.; Riasat, S.; Lewucha, C.

    2016-05-01

    The problem of interference of antioxidants, such as hindered phenols, with peroxide-initiated crosslinking of polyethylene was addressed through the use of functional (reactive) graftable antioxidants (g-AO). Reactive derivatives of hindered phenol and hindered amine antioxidants were synthesised, characterised and used to investigate their grafting reactions in high density polyethylene; both non-crosslinked (PE) and highly peroxide-crosslinked (PEXa). Assessment of the extent of in-situ grafting of the antioxidants, their retention after exhaustive solvent extraction in PE and PEXa, and the stabilising performance of the grafted antioxidants (g-AO) in the polymer were examined and benchmarked against conventionally stabilised crosslinked & non-crosslinked polyethylene. It was shown that the functional antioxidants graft to a high extent in PEXa, and that the level of interference of the g-AOs with the polymer crosslinking process was minimal compared to that of conventional antioxidants which bear the same antioxidant function. The much higher level of retention of the g-AOs in PEXa after exhaustive solvent extraction, compared to that of the corresponding conventional antioxidants, accounts for their superior long-term thermal stabilising performance under severe extractive conditions.

  5. Polyethylene glycol grafted flower-like cupric nano oxide for the hollow-fiber solid-phase microextraction of hexaconazole, penconazole, and diniconazole in vegetable samples.

    PubMed

    Zendegi-Shiraz, Amene; Sarafraz-Yazdi, Ali; Es'haghi, Zarrin

    2016-08-01

    A simple, rapid, highly efficient, and reliable sample preparation method has been developed for the extraction and analysis of triazole pesticides from cucumber, lettuce, bell pepper, cabbage, and tomato samples. This new sorbent in the hollow-fiber solid-phase microextraction method is based on the synthesis of polyethylene glycol-polyethylene glycol grafted flower-like cupric oxide nanoparticles using sol-gel technology. Afterward, the analytes were analyzed by high-performance liquid chromatography with ultraviolet detection. The main parameters that affect microextraction efficiency were evaluated and optimized. This method has afforded good linearity ranges (0.5-50 000 ng/mL for hexaconazol, 0.012-50 000 ng/mL for penconazol, and 0.02-50 000 ng/mL for diniconazol), adequate precision (2.9-6.17%, n = 3), batch-to-batch reproducibility (4.33-8.12%), and low instrumental LODs between 0.003 and 0.097 ng/mL (n = 8). Recoveries and enrichment factors were 85.46-97.47 and 751-1312%, respectively.

  6. Effect of poly(ethylene oxide)-silane graft molecular weight on the colloidal properties of iron oxide nanoparticles for biomedical applications.

    PubMed

    Barrera, Carola; Herrera, Adriana P; Bezares, Nayla; Fachini, Estevão; Olayo-Valles, Roberto; Hinestroza, Juan P; Rinaldi, Carlos

    2012-07-01

    The size, charge, and stability of colloidal suspensions of magnetic nanoparticles with narrow size distribution and grafted with poly(ethylene glycol)-silane of different molecular weights were studied in water, biological buffers, and cell culture media. X-ray photoelectron spectroscopy provided information on the chemical nature of the nanoparticle surface, indicating the particle surfaces consisted of a mixture of amine groups and grafted polymer. The results indicate that the exposure of the amine groups on the surface decreased as the molecular weight of the polymer increased. The hydrodynamic diameters correlated with PEG graft molecular weight and were in agreement with a distributed density model for the thickness of a polymer shell end-grafted to a particle core. This indicates that the particles obtained consist of single iron oxide cores coated with a polymer brush. Particle surface charge and hydrodynamic diameter were measured as a function of pH, ionic strength, and in biological buffers and cell culture media. DLVO theory was used to analyze the particle stability considering electrostatic, magnetic, steric, and van der Waals interactions. Experimental results and colloidal stability theory indicated that stability changes from electrostatically mediated for a graft molecular weight of 750 g/mol to sterically mediated at molecular weights of 1000 g/mol and above. These results indicate that a graft molecular weight above 1000 g/mol is needed to produce particles that are stable in a wide range of pH and ionic strength, and in cell culture media.

  7. Filler effect of ionic liquid attached titanium oxide on conducting property of poly(ethylene oxide)/poly(methyl methacrylate) composite electrolytes.

    PubMed

    Lee, Lyungyu; Kim, Ick-Jun; Yang, Sunhye; Kim, Seok

    2014-10-01

    Composite polymer electrolytes (CPEs) were prepared by containing blend of poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) as a host polymer, propylene carbonate as a plasticizer, and LiClO4 as a salt. By an addition of a various content of ionic liquid attached TiO2 (IL-TiO2) to above electrolytes, the effects were studied. As a result, by increasing the IL-TiO2 content, the crystallinity of PEO was decreased and the ionic conductivity was increased. The ionic conductivity of CPEs was dependent on the content of IL-TiO2 and showed the highest value of 1.05 x 10(-4) S/cm at 9 wt.%. However, when IL-TiO2 content exceeds 9 wt.%, the ionic conductivity was decreased due to the slow ionic transport due to immiscibility or aggregation of the IL-TiO2 filler within the polymer film matrix.

  8. Preparation of extruded polyethylene/chitosan blends compatibilized with polyethylene-graft-maleic anhydride.

    PubMed

    Quiroz-Castillo, J M; Rodríguez-Félix, D E; Grijalva-Monteverde, H; Del Castillo-Castro, T; Plascencia-Jatomea, M; Rodríguez-Félix, F; Herrera-Franco, P J

    2014-01-30

    Novel films of polyethylene and chitosan were obtained using extrusion. These polymers have interesting properties, and processing them with methods that are of high use in the industry, such as the extrusion method, can have a significant effect on the potential applications of these materials. The individual materials were thermally characterized; after this, extruded films of low density polyethylene and chitosan mixtures were prepared with the addition of polyethylene-graft-maleic anhydride as a compatibilizer for the blends, and glycerol, as a plasticizer for chitosan. The use of compatibilizer and plasticizer agents improved the processability and compatibility of the mixtures, as well as their mechanical properties, as revealed by mechanical property measurements and scanning electron microscopy. It was possible to prepare blends with a maximum chitosan content of 20 wt%. The material stiffness increased with the increase of chitosan in the sample. FTIR studies revealed the existence of an interaction between the compatibilizer and chitosan.

  9. Patient sensitivity to polyethylene particles with cemented total hip arthroplasty.

    PubMed

    Ise, Kentaro; Kawanabe, Keiichi; Matsusaki, Takashi; Shimizu, Motoyuki; Onishi, Eijiro; Nakamura, Takashi

    2007-10-01

    To determine whether sensitivity to polyethylene particles varies among patients, we studied 25 patients who had undergone total hip arthroplasty. We used pelvic radiographs to measure annual polyethylene wear and the area of osteolysis. The ratio of the area of osteolysis to the volumetric polyethylene wear was defined as sensitivity index. Adherent cells from peripheral blood were cocultured with polyethylene particles, and the amount of bone-resorptive cytokines was measured. The amount of interleukin-6, but not of interleukin-1beta or tumor necrosis factor-alpha, released from adherent cells in the in vitro experiment correlated with the in vivo sensitivity indices. This technique appears capable of predicting the development of polyethylene-induced osteolysis, allowing surgeons to avoid using polyethylene as the bearing surface in patients at risk for osteolysis.

  10. Lactosylated poly(ethylene oxide)-poly(propylene oxide) block copolymers for potential active targeting: synthesis and physicochemical and self-aggregation characterization

    NASA Astrophysics Data System (ADS)

    Cuestas, María L.; Glisoni, Romina J.; Mathet, Verónica L.; Sosnik, Alejandro

    2013-01-01

    Aiming to develop polymeric self-assembly nanocarriers with potential applications in active drug targeting to the liver, linear and branched poly(ethylene oxide)-poly(propylene oxide) amphiphiles were conjugated to lactobionic acid (LA), a disaccharide of galactose and gluconic acid, by the conventional Steglich esterification reaction. The conjugation was confirmed by ATR/FT-IR, 1H-NMR, and 13C-NMR spectroscopy. Elemental analysis and MALDI-TOF mass spectrometry were employed to elucidate the conjugation extent and the final molecular weight, respectively. The critical micellar concentration (CMC), the size and size distribution and zeta potential of the pristine and modified polymeric micelles under different conditions of pH and temperature were characterized by dynamic light scattering (DLS). Conjugation with LA favored the micellization process, leading to a decrease of the CMC with respect to the pristine counterpart, this phenomenon being independent of the pH and the temperature. At 37 °C, micelles made of pristine copolymers showed a monomodal size distribution between 12.8 and 24.4 nm. Conversely, LA-conjugated micelles showed a bimodal size pattern that comprised a main fraction of relatively small size (11.6-22.2 nm) and a second one with remarkably larger sizes of up to 941.4 nm. The former corresponded to single micelles, while the latter would indicate a secondary aggregation phenomenon. The spherical morphology of LA-micelles was visualized by transmission electron microscopy (TEM). Finally, to assess the ability of the LA-conjugated micelles to interact with lectin-like receptors, samples were incubated with concanavalin A at 37 °C and the size and size distribution were monitored by DLS. Findings indicated that regardless of the relatively weak affinity of this vegetal lectin for galactose, micelles underwent agglutination probably through the interaction of a secondary site in the lectin with the gluconic acid unit of LA.

  11. The yield behavior of polyethylene tubes subjected to biaxial loadings

    NASA Technical Reports Server (NTRS)

    Semeliss, M.; Wong, R.; Tuttle, M.

    1990-01-01

    High-density polyethylene is subjected to biaxial states of stress to examine the yield behavior of the semicrystalline thermoplastic under constant octahedral shear-stress rates. Combinations of internal pressures and axial loads are applied to thin-walled tubes of polyethylene, and the strain response in the axial and hoop directions are measured. The polyethylene specimens are found to be anisotropic, and the experimental measurements are compared to yield criteria that are applicable to isotropic and anisotropic materials.

  12. Powder Production From Waste Polyethylene Terephthalate (PET) Water Bottles

    DTIC Science & Technology

    2014-06-01

    Powder Production From Waste Polyethylene Terephthalate (PET) Water Bottles by Anit Giri, Frank Kellogg, Kyu Cho, and Marc Pepi ARL-MR...871 June 2014 Powder Production From Waste Polyethylene Terephthalate (PET) Water Bottles Anit Giri and Frank Kellogg Bowhead Science and...Polyethylene Terephthalate (PET) Water Bottles 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Anit Giri, * Frank

  13. Effect of poly(ethylene oxide) on ionic conductivity and electrochemical properties of poly(vinylidenefluoride) based polymer gel electrolytes prepared by electrospinning for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Prasanth, Raghavan; Shubha, Nageswaran; Hng, Huey Hoon; Srinivasan, Madhavi

    2014-01-01

    Effect of poly(ethylene oxide) on the electrochemical properties of polymer electrolyte based on electrospun, non-woven membrane of PVdF is demonstrated. Electrospinning process parameters are controlled to get a fibrous membrane consisting of bead-free, uniformly dispersed thin fibers with diameter in the range of 1.5-1.9 μm. The membrane with good mechanical strength and porosity exhibits high uptake when activated with the liquid electrolyte of lithium salt in a mixture of organic solvents. The polymer gel electrolyte shows ionic conductivity of 4.9 × 10-3 S cm-1 at room temperature. Electrochemical performance of the polymer gel electrolyte is evaluated in Li/polymer electrolyte/LiFePO4 coin cell. Good performance with low capacity fading on charge-discharge cycling is demonstrated.

  14. A mechanistic study explaining the synergistic viscosity increase obtained from polyethylene oxide (PEO) and {beta}-naphthalene sulfonate (BNS) in shotcrete

    SciTech Connect

    Pickelmann, J.; Plank, J.

    2012-11-15

    In shotcrete, a combination of polyethylene oxide (PEO) and {beta}-naphthalene sulfonate (BNS) is commonly applied to reduce rebound. Here, the mechanism for the synergistic viscosity increase resulting from this admixture combination was investigated via x-ray diffraction (XRD), infrared and nuclear magnetic resonance (NMR) spectroscopy. It was found that the electron-rich aromatic rings present in BNS donate electrons to the alkyl protons of PEO and thus increase the electron density there. This rare interaction is known as CH-{pi} interaction and leads to the formation of a supramolecular structure whereby PEO chains bind weakly to BNS molecules. Through this mechanism a polymer network exhibiting exceptionally high molecular weight and thus viscosity is formed. Among polycondensates, sulfanilic acid-phenol-formaldehyde (SPF) provides even higher synergy with PEO than BNS while melamine (PMS), acetone (AFS) or polycarboxylate (PCE) based superplasticizers do not work at all. Effectiveness of lignosulfonates is dependent on their degree of sulfonation.

  15. Controlling solidification and fiber diameter of Polyethylene oxide nanofibers electrospun from aqueous solution by controlling the partial pressure of water vapor

    NASA Astrophysics Data System (ADS)

    Tripatanasuwan, Sureeporn; Zhong, Zhenxin; Reneker, Darrell

    2007-03-01

    Electrospinning is widely in research attention due to its cost effectiveness and straightforwardness for making nanofibers. During the electrospinning process, a charged jet is elongated by repulsive force between electrical charges carried by the jet. The charged jet develops spiral path due to the electrically driven bending instability, which make it possible for the jet to elongate and produce nanofibers in a small space. Solidification has been identified as an important factor that determines the diameter of electrospun nanofibers. The elongation and thinning of a charged jet stops as the charged jet is solidified. Controlling solidification of the charged jet by controlling of partial vapor of water in electrospinning of polyethylene oxide from aqueous solution has been demonstrated in this study. As the partial vapor of water increase, the solidification process of the charged jet becomes slower, allowing elongation of charged jet to continue.

  16. Synthesis and Characterization of Luminescent Eu(TTA)3phen in a Poly(ethylene oxide) Matrix for Detecting Traces of Water

    NASA Astrophysics Data System (ADS)

    Choi, Pu-Reun; Park, Hyung-Ho; Koo, Eunhae

    2013-05-01

    The water vapor transmission rate (WVTR) is limited to 10-6 g/m2/day for flexible organic light-emitting diodes. However, it is difficult to measure permeability as low as 10-6 g/m2/day with current commercial testing methods. To address this need, a developed optochemical method which is extremely sensitive to oxygen or water shows promise. In this study, an Eu complex is synthesized and characterized as a fluorescent probe for detecting traces of water molecules. The Eu-complex film dispersed in poly(ethylene oxide) has strong red fluorescence that is easily quenched by a trace of water. Based on the photoluminescence spectra, the detection limit of the film to water appears to be below 1.0 × 10-9 g/cc. This suggests that the Eu-complex film can be used as a film sensor to measure WVTRs below 10-6 g/m2/day.

  17. Physical, thermodynamics, and transport properties for carbon dioxide and nitrous oxide in solutions of diethanolamine or di-2-propanolamine in polyethylene glycol

    SciTech Connect

    Davis, R.A.; Menendez, R.E.; Sandall, O.C. . Dept. of Chemical and Nuclear Engineering)

    1993-01-01

    Several properties important for the absorption of carbon dioxide and nitrous oxide in solutions of diethanolamine (DEA) or di-2-propanolamine (DIPA) and polyethylene glycol (PEG 400, average molecular weight 400) were determined experimentally. These properties include the density and viscosity of the amine-PEG 400 solutions, the physical solubility and diffusivity of CO[sub 2] in PEG 400, and the physical solubility and diffusivity of N[sub 2]O in DEA-PEG 400 and DIPA-PEG 400 solutions. The results were obtained for 0-300 wt% amine in PEG 400 over the temperature range of 20-40C. The results were correlated for temperature and composition dependence.

  18. Radioprotection by polyethylene glycol-protein complexes in mice

    SciTech Connect

    Gray, B.H.; Stull, R.W.

    1983-03-01

    Polyethylene glycol of about 5000 D was activated with cyanuric chloride, and the activated compound was complexed to each of three proteins. Polyethylene glycol-superoxide dismutase and polyethylene glycol-catalase were each radioprotectants when administered prophylactically to female B6CBF1 mice before irradiation. The dose reduction factor for these mice was 1.2 when 5000 units of polyethylene glycol-catalase was administered before /sup 60/Co irradiation. Female B6CBF1 mice administered prophylactic intravenous injections of catalase, polyethylene glycol-albumin, or heat-denatured polyethylene glycol-catalase had survival rates similar to phosphate-buffered saline-injected control mice following /sup 60/Co irradiation. Polyethylene glycol-superoxide dismutase and polyethylene glycol-catalase have radioprotective activity in B6CBF1 mice, which appears to depend in part on enzymatic activities of the complex. However, no radioprotective effect was observed in male C57BL/6 mice injected with each polyethylene glycol-protein complex at either 3 or 24 hr before irradiation. The mechanism for radioprotection by these complexes may depend in part on other factors.

  19. Sign change of the Soret coefficient of poly(ethylene oxide) in water/ethanol mixtures observed by thermal diffusion forced Rayleigh scattering.

    PubMed

    Kita, Rio; Wiegand, Simone; Luettmer-Strathmann, Jutta

    2004-08-22

    Soret coefficients of the ternary system of poly(ethylene oxide) in mixed water/ethanol solvent were measured over a wide solvent composition range by means of thermal diffusion forced Rayleigh scattering. The Soret coefficient S(T) of the polymer was found to change sign as the water content of the solvent increases with the sign change taking place at a water mass fraction of 0.83 at a temperature of 22 degrees C. For high water concentrations, the value of S(T) of poly(ethylene oxide) is positive, i.e., the polymer migrates to the cooler regions of the fluid, as is typical for polymers in good solvents. For low water content, on the other hand, the Soret coefficient of the polymer is negative, i.e., the polymer migrates to the warmer regions of the fluid. Measurements for two different polymer concentrations showed a larger magnitude of the Soret coefficient for the smaller polymer concentration. The temperature dependence of the Soret coefficient was investigated for water-rich polymer solutions and revealed a sign change from negative to positive as the temperature is increased. Thermodiffusion experiments were also performed on the binary mixture water/ethanol. For the binary mixtures, the Soret coefficient of water was observed to change sign at a water mass fraction of 0.71. This is in agreement with experimental results from the literature. Our results show that specific interactions (hydrogen bonds) between solvent molecules and between polymer and solvent molecules play an important role in thermodiffusion for this system.

  20. Patterned functional carbon fibers from polyethylene

    SciTech Connect

    Hunt, Marcus A; Saito, Tomonori; Brown, Rebecca H; Kumbhar, Amar S; Naskar, Amit K

    2012-01-01

    Patterned, continuous carbon fibers with controlled surface geometry were produced from a novel melt-processible carbon precursor. This portends the use of a unique technique to produce such technologically innovative fibers in large volume for important applications. The novelties of this technique include ease of designing and fabricating fibers with customized surface contour, the ability to manipulate filament diameter from submicron scale to a couple of orders of magnitude larger scale, and the amenable porosity gradient across the carbon wall by diffusion controlled functionalization of precursor. The geometry of fiber cross-section was tailored by using bicomponent melt-spinning with shaped dies and controlling the melt-processing of the precursor polymer. Circular, trilobal, gear-shaped hollow fibers, and solid star-shaped carbon fibers of 0.5 - 20 um diameters, either in self-assembled bundle form, or non-bonded loose filament form, were produced by carbonizing functionalized-polyethylene fibers. Prior to carbonization, melt-spun fibers were converted to a char-forming mass by optimizing the sulfonation on polyethylene macromolecules. The fibers exhibited distinctly ordered carbon morphologies at the outside skin compared to the inner surface or fiber core. Such order in carbon microstructure can be further tuned by altering processing parameters. Partially sulfonated polyethylene-derived hollow carbon fibers exhibit 2-10 fold surface area (50-500 m2/g) compared to the solid fibers (10-25 m2/g) with pore sizes closer to the inside diameter of the filaments larger than the sizes on the outer layer. These specially functionalized carbon fibers hold promise for extraordinary performance improvements when used, for example, as composite reinforcements, catalyst support media, membranes for gas separation, CO2 sorbents, and active electrodes and current collectors for energy storage applications.

  1. Nonlinear viscoelastic characterization of thin polyethylene film

    NASA Technical Reports Server (NTRS)

    Wilbeck, J. S.

    1981-01-01

    In order to understand the state of stress and strain in a typical balloon fabricated from thin polyethylene film, experiment data in the literature reviewed. It was determined that the film behaves as a nonlinear viscoelasticity material and should be characterized accordingly. A simple uniaxial, nonlinear viscoelastic model was developed for predicting stress given a certain strain history. The simple model showed good qualitative agreement with results of constant rate, uniaxial accurately predicting stresses for cyclic strain histories typical of balloon flights. A program was outlined which will result in the development of a more complex nonlinear viscoelastic model.

  2. Polyethylene terephthalate thin films; a luminescence study

    NASA Astrophysics Data System (ADS)

    Carmona-Téllez, S.; Alarcón-Flores, G.; Meza-Rocha, A.; Zaleta-Alejandre, E.; Aguilar-Futis, M.; Murrieta S, H.; Falcony, C.

    2015-04-01

    Polyethylene Terephthalate (PET) films doped with Rare Earths (RE3+) have been deposited on glass by spray pyrolysis technique at 240 °C, using recycled PET and (RE3+) chlorides as precursors. Cerium, terbium, dysprosium and europium were used as dopants materials, these dopants normally produce luminescent emissions at 450, 545, 573 and 612 nm respectively; the doped films also have light emissions at blue, green, yellow and red respectively. All RE3+ characteristic emissions were observed at naked eyes. Every deposited films show a high transmission in the visible range (close 80% T), films surfaces are pretty soft and homogeneous. Films thickness is around 3 μm.

  3. Biocompatible composites of ultrahigh molecular weight polyethylene

    NASA Astrophysics Data System (ADS)

    Panin, S. V.; Kornienko, L. A.; Suan, T. Nguen; Ivanova, L. P.; Korchagin, M. A.; Chaikina, M. V.; Shilko, S. V.; Pleskachevskiy, Yu. M.

    2015-10-01

    Mechanical and tribotechnical characteristics of biocompatible, antifriction and extrudable composites based on ultrahigh molecular weight polyethylene (UHMWPE) as well as hybrid matrix "UHMWPE + PTFE" with biocompatible hydroxyapatite filler under the dry friction and boundary lubrication were investigated. A comparative analysis of effectiveness of adding the hydroxyapatite to improve the wear resistance of composites based on these two matrices was performed. It is shown that the wear intensity of nanocomposites based on the hybrid matrix is lower than that for the composites based on pure UHMWPE. Possibilities of using the composites of the polymer "UHMWPE-PTFE" mixture as a material for artificial joints implants are discussed.

  4. 78 FR 2365 - Polyethylene Terephthalate Film, Sheet and Strip From India: Partial Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Partial... request an administrative review of the antidumping duty (AD) order on polyethylene terephthalate film... Polyester Film, Inc., SKC, Inc., and Toray Plastics (America), Inc. \\3\\ See Polyethylene Terephthalate...

  5. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. 870.3470 Section 870.3470 Food and Drugs... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. (a) Identification. An intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene is a...

  6. 78 FR 28192 - Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-14

    ... International Trade Administration Polyethylene Retail Carrier Bags From Thailand: Preliminary Results of... administrative review of the antidumping duty order on polyethylene retail carrier bags (PRCBs) from Thailand... antidumping duty order is polyethylene retail carrier bags, which are currently classified under...

  7. 78 FR 48147 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-07

    ...] Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Countervailing Duty... the countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip (PET film..., the products covered are all gauges of raw, pretreated, or primed polyethylene terephthalate...

  8. 77 FR 73010 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates; Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-07

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab... (the Department) is conducting an administrative review of the antidumping duty order on polyethylene...- treated, or primed polyethylene terephthalate film, whether extruded or co-extruded. Excluded...

  9. 78 FR 9668 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results... polyethylene terephthalate film (PET Film) from Taiwan.\\1\\ This review covers two respondents, Shinkong.... \\1\\ See Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary Results...

  10. 75 FR 81570 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-28

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary... semiannual new shipper review (NSR) under the antidumping duty order on polyethylene terephthalate film... Fair Value and Antidumping Duty Order: Polyethylene Terephthalate Film, Sheet, and Strip from India,...

  11. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. 870.3470 Section 870.3470 Food and Drugs... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. (a) Identification. An intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene is a...

  12. 77 FR 9892 - Polyethylene Terephthalate Film, Sheet and Strip from India: Preliminary Intent to Rescind...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip from India: Preliminary... polyethylene terephthalate film, sheet and strip from India covering the period January 1, 2010, through... Vacmet and Polypacks. See Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission,...

  13. 78 FR 48651 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan; Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-09

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan; Preliminary... conducting an administrative review of the antidumping duty order on polyethylene terephthalate film, sheet... preliminary results. \\1\\ See Polyethylene Terephthalate Film, Sheet and Strip from Taiwan: Partial...

  14. 77 FR 73428 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-10

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic... the antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film'') from... Duty Administrative Review: Polyethylene Terephthalate Film, Sheet, and Strip from the...

  15. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. 870.3470 Section 870.3470 Food and Drugs... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. (a) Identification. An intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene is a...

  16. 75 FR 6634 - Polyethylene Terephthalate Film, Sheet, and Strip from India: Final Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip from India: Final Results... the preliminary results of administrative review of the countervailing duty order on polyethylene..., 2007. See Polyethylene Terephthalate Film, Sheet, and Strip from India: Preliminary Results...

  17. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. 870.3470 Section 870.3470 Food and Drugs... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. (a) Identification. An intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene is a...

  18. 76 FR 76365 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab...) is conducting an administrative review of the antidumping duty order on polyethylene terephthalate... from the UAE. See Polyethylene Terephthalate Film, Sheet, and Strip From Brazil, the People's...

  19. 76 FR 76948 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results...) issued the preliminary results of the administrative review of polyethylene terephthalate film, sheet and... Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Countervailing...

  20. 77 FR 19634 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission of Countervailing Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-02

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission of... an administrative review of the countervailing duty (CVD) order on polyethylene terephthalate film... administrative review with respect to Vacmet and Polypacks. See Polyethylene Terephthalate Film, Sheet and...

  1. 78 FR 50029 - Polyethylene Terephthalate Film, Sheet and Strip From Brazil: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-16

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From Brazil: Preliminary... Commerce (the Department) initiated an administrative review of the antidumping duty order on polyethylene... Preliminary Results of the Antidumping Duty Administrative Review of Polyethylene Terephthalate Film,...

  2. 21 CFR 870.3470 - Intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. 870.3470 Section 870.3470 Food and Drugs... polypropylene, polyethylene terephthalate, or polytetrafluoroethylene. (a) Identification. An intracardiac patch or pledget made of polypropylene, polyethylene terephthalate, or polytetrafluoroethylene is a...

  3. 78 FR 76567 - Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride Monopolyisobutylene Derivs...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-18

    ... AGENCY 40 CFR Part 180 Tall Oil, Polymer With Polyethylene Glycol and Succinic Anhydride... oil, polymer with polyethylene glycol and succinic anhydride monopolyisobutylene derivs. (CAS Reg. No... residues of tall oil, polymer with polyethylene glycol and succinic anhydride monopolyisobutylene...

  4. Influence of poly(ethylene oxide)-based copolymer on protein adsorption and bacterial adhesion on stainless steel: modulation by surface hydrophobicity.

    PubMed

    Yang, Yi; Rouxhet, Paul G; Chudziak, Dorota; Telegdi, Judit; Dupont-Gillain, Christine C

    2014-06-01

    The aim of the present work is to study the adhesion of Pseudomonas NCIMB 2021, a typical aerobic marine microorganism, on stainless steel (SS) substrate. More particularly, the potential effect on adhesion of adsorbed poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer is investigated. Bacterial attachment experiments were carried out using a modified parallel plate flow chamber, allowing different surface treatments to be compared in a single experiment. The amount of adhering bacteria was determined via DAPI staining and fluorescence microscopy. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface chemical composition of SS and hydrophobized SS before and after PEO-PPO-PEO adsorption. The adsorption of bovine serum albumin (BSA), a model protein, was investigated to test the resistance of PEO-PPO-PEO layers to protein adsorption. The results show that BSA adsorption and Pseudomonas 2021 adhesion are significantly reduced on hydrophobized SS conditioned with PEO-PPO-PEO. Although PEO-PPO-PEO is also found to adsorb on SS, it does not prevent BSA adsorption nor bacterial adhesion, which is attributed to different PEO-PPO-PEO adlayer structures on hydrophobic and hydrophilic surfaces. The obtained results open the way to a new strategy to reduce biofouling on metal oxide surfaces using PEO-PPO-PEO triblock copolymer.

  5. Structural and optical properties of Ag-doped copper oxide thin films on polyethylene napthalate substrate prepared by low temperature microwave annealing

    SciTech Connect

    Das, Sayantan; Alford, T. L.

    2013-06-28

    Silver doped cupric oxide thin films are prepared on polyethylene naphthalate (flexible polymer) substrates. Thin films Ag-doped CuO are deposited on the substrate by co-sputtering followed by microwave assisted oxidation of the metal films. The low temperature tolerance of the polymer substrates led to the search for innovative low temperature processing techniques. Cupric oxide is a p-type semiconductor with an indirect band gap and is used as selective absorption layer solar cells. X-ray diffraction identifies the CuO phases. Rutherford backscattering spectrometry measurements confirm the stoichiometry of each copper oxide formed. The surface morphology is determined by atomic force microscopy. The microstructural properties such as crystallite size and the microstrain for (-111) and (111) planes are calculated and discussed. Incorporation of Ag led to the lowering of band gap in CuO. Consequently, it is determined that Ag addition has a strong effect on the structural, morphological, surface, and optical properties of CuO grown on flexible substrates by microwave annealing. Tauc's plot is used to determine the optical band gap of CuO and Ag doped CuO films. The values of the indirect and direct band gap for CuO are found to be 2.02 eV and 3.19 eV, respectively.

  6. Degradation of Green Polyethylene by Pleurotus ostreatus

    PubMed Central

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Ribeiro, Karla Veloso Gonçalves; Mendes, Igor Rodrigues; Kasuya, Maria Catarina Megumi

    2015-01-01

    We studied the biodegradation of green polyethylene (GP) by Pleurotus ostreatus. The GP was developed from renewable raw materials to help to reduce the emissions of greenhouse gases. However, little information regarding the biodegradation of GP discarded in the environment is available. P. ostreatus is a lignocellulolytic fungus that has been used in bioremediation processes for agroindustrial residues, pollutants, and recalcitrant compounds. Recently, we showed the potential of this fungus to degrade oxo-biodegradable polyethylene. GP plastic bags were exposed to sunlight for up to 120 days to induce the initial photodegradation of the polymers. After this period, no cracks, pits, or new functional groups in the structure of GP were observed. Fragments of these bags were used as the substrate for the growth of P. ostreatus. After 30 d of incubation, physical and chemical alterations in the structure of GP were observed. We conclude that the exposure of GP to sunlight and its subsequent incubation in the presence of P. ostreatus can decrease the half-life of GP and facilitate the mineralization of these polymers. PMID:26076188

  7. Nanostructurization and thermal properties of polyethylenes' welds

    NASA Astrophysics Data System (ADS)

    Galchun, Anatoliy; Korab, Nikolay; Kondratenko, Volodymyr; Demchenko, Valeriy; Shadrin, Andriy; Anistratenko, Vitaliy; Iurzhenko, Maksym

    2015-03-01

    As it is known, polyethylene (PE) is one of the common materials in the modern world, and PE products take the major share on industrial and trade markets. For example, various types of technical PE like PE-63, PE-80, and PE-100 have wide industrial applications, i.e., in construction, for pipeline systems etc. A rapid development of plastics industry outstrips detailed investigation of welding processes and welds' formation mechanism, so they remain unexplored. There is still no final answer to the question how weld's microstructure forms. Such conditions limit our way to the understanding of the problem and, respectively, prevent scientific approaches to the welding of more complicated (from chemical point of view) types of polymers than PE. Taking into account state-of-the-art, the article presents results of complex studies of PE weld, its structure, thermophysical and operational characteristics, analysis of these results, and basing on that some hypotheses of welded joint and weld structure formation. It is shown that welding of dissimilar types of polyethylene, like PE-80 and PE-100, leads to the formation of better-ordered crystallites, restructuring the crystalline phase, and amorphous areas with internal stresses in the welding zone.

  8. Recycling of irradiated high-density polyethylene

    NASA Astrophysics Data System (ADS)

    Navratil, J.; Manas, M.; Mizera, A.; Bednarik, M.; Stanek, M.; Danek, M.

    2015-01-01

    Radiation crosslinking of high-density polyethylene (HDPE) is a well-recognized modification of improving basic material characteristics. This research paper deals with the utilization of electron beam irradiated HDPE (HDPEx) after the end of its lifetime. Powder of recycled HDPEx (irradiation dose 165 kGy) was used as a filler into powder of virgin low-density polyethylene (LDPE) in concentrations ranging from 10% to 60%. The effect of the filler on processability and mechanical behavior of the resulting mixtures was investigated. The results indicate that the processability, as well as mechanical behavior, highly depends on the amount of the filler. Melt flow index dropped from 13.7 to 0.8 g/10 min comparing the lowest and the highest concentration; however, the higher shear rate the lower difference between each concentration. Toughness and hardness, on the other hand, grew with increasing addition of the recycled HDPEx. Elastic modulus increased from 254 to 450 MPa and material hardness increased from 53 to 59 ShD. These results indicate resolving the problem of further recycling of irradiated polymer materials while taking advantage of the improved mechanical properties.

  9. Degradation of Green Polyethylene by Pleurotus ostreatus.

    PubMed

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Ribeiro, Karla Veloso Gonçalves; Mendes, Igor Rodrigues; Kasuya, Maria Catarina Megumi

    2015-01-01

    We studied the biodegradation of green polyethylene (GP) by Pleurotus ostreatus. The GP was developed from renewable raw materials to help to reduce the emissions of greenhouse gases. However, little information regarding the biodegradation of GP discarded in the environment is available. P. ostreatus is a lignocellulolytic fungus that has been used in bioremediation processes for agroindustrial residues, pollutants, and recalcitrant compounds. Recently, we showed the potential of this fungus to degrade oxo-biodegradable polyethylene. GP plastic bags were exposed to sunlight for up to 120 days to induce the initial photodegradation of the polymers. After this period, no cracks, pits, or new functional groups in the structure of GP were observed. Fragments of these bags were used as the substrate for the growth of P. ostreatus. After 30 d of incubation, physical and chemical alterations in the structure of GP were observed. We conclude that the exposure of GP to sunlight and its subsequent incubation in the presence of P. ostreatus can decrease the half-life of GP and facilitate the mineralization of these polymers.

  10. Development of an extremely wear-resistant ultra high molecular weight polyethylene for total hip replacements.

    PubMed

    McKellop, H; Shen, F W; Lu, B; Campbell, P; Salovey, R

    1999-03-01

    Osteolysis induced by ultra high molecular weight polyethylene wear debris is one of the primary factors limiting the lifespan of total hip replacements. Crosslinking polyethylene is known to improve its wear resistance in certain industrial applications, and crosslinked polyethylene acetabular cups have shown improved wear resistance in two clinical studies. In the present study, crosslinked polyethylene cups were produced by two methods. Chemically crosslinked cups were produced by mixing a peroxide with ultra high molecular weight polyethylene powder and then molding the cups directly to shape. Radiation-crosslinked cups were produced by exposing conventional extruded ultra high molecular weight polyethylene bar stock to gamma radiation at various doses from 3.3 to 100 Mrad (1 Mrad = 10 kGy), remelting the bars to extinguish residual free radicals (i.e., to minimize long-term oxidation), and then machining the cups by conventional techniques. In hip-joint simulator tests lasting as long as 5 million cycles, both types of cross-linked cups exhibited dramatically improved resistance to wear. Artificial aging of the cups by heating for 30 days in air at 80 degrees C induced oxidation of the chemically crosslinked cups. However, a chemically crosslinked cup that was aged 2.7 years at room temperature had very little oxidation. Thus, whether substantial oxidation of chemically crosslinked polyethylene would occur at body temperature remains unclear. The radiation-crosslinked remelted cups exhibited excellent resistance to oxidation. Because crosslinking can reduce the ultimate tensile strength, fatigue strength, and elongation to failure of ultra high molecular weight polyethylene, the optimal crosslinking dose provides a balance between these physical properties and the wear resistance of the implant and might substantially reduce the incidence of wear-induced osteolysis with total hip replacements.

  11. Processing, Characterization and Fretting Wear of Zinc Oxide and Silver Nanoparticles Reinforced Ultra High Molecular Weight Polyethylene Biopolymer Nanocomposite

    NASA Astrophysics Data System (ADS)

    Alam, Fahad; Kumar, Anil; Patel, Anup Kumar; Sharma, Rajeev K.; Balani, Kantesh

    2015-04-01

    Ultra-high molecular weight polyethylene (UHMWPE) is the most widely used biopolymer for articulating surfaces, such as an acetabular cup liner interfacing with a metal/ceramic femoral head. However, the formation of wear debris leads to the aseptic loosening of implants. Thus, in order to improve the life span via enhancing the fretting wear resistance, UHMWPE is reinforced with ZnO/Ag nanoparticles. It is envisaged that the ZnO/Ag addition will also exhibit antibacterial properties. In the current study, the synergetic effect of the reinforcement of ZnO/Ag nanoparticles (0-3 wt.% combinations) on the fretting wear behavior of a UHMWPE matrix is assessed. The phase characterization of compression- molded UHMWPE-Ag-ZnO biopolymer nanocomposites has elicited the retention of starting phases. All samples were processed at >98% density using compression molding. Silver and ZnO reinforcement showed enhanced hardness ~20.4% for U3A and 42.0% for U3Z. Fretting wear performance was evaluated at varying loads (5-15 N), keeping in mind the weight at different joints, with constant frequency (5 Hz) as well as amplitude of oscillation (100 µm). Laser surface profilometry showed change of wear volume from 8.6 × 10-5 mm3 for neat polymer to 5.8 × 10-5 mm3 with 1 wt.% Ag + 1 wt.% ZnO reinforcement (at 15 N load). Consequently, the mechanics of resistance offered by Ag and ZnO is delineated in the UHMWPE matrix. Further, S. aureus viability reduction is ~28.7% in cases with 1 wt.% Ag addition, ~42.5% with 1 wt.% ZnO addition, but synergistically increase to ~58.6% and 47.1% when each of Ag and ZnO is added with 1 wt.% and 3 wt.%, respectively (when compared to that of the UHMWPE control sample). Increased wear resistance and superior bioactivity and enhanced anti-bacterial properties of 1 wt.% Ag + 1 wt.% ZnO and 3 wt.% Ag + 3 wt.% ZnO shows the potential use of ZnO-Ag-UHMWPE biopolymer composites as an articulating surface.

  12. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  13. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  14. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  15. 21 CFR 177.1630 - Polyethylene phthalate polymers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene phthalate polymers. 177.1630 Section... (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD ADDITIVES: POLYMERS Substances for Use as... polymers. Polyethylene phthalate polymers identified in this section may be safely used as, or...

  16. Poly(ethylene oxide)-co-poly(propylene oxide)-based gel electrolyte with high ionic conductivity and mechanical integrity for lithium-ion batteries.

    PubMed

    Wang, Shih-Hong; Hou, Sheng-Shu; Kuo, Ping-Lin; Teng, Hsisheng

    2013-09-11

    Using gel polymer electrolytes (GPEs) for lithium-ion batteries usually encounters the drawback of poor mechanical integrity of the GPEs. This study demonstrates the outstanding performance of a GPE consisting of a commercial membrane (Celgard) incorporated with a poly(ethylene oxide)-co-poly(propylene oxide) copolymer (P(EO-co-PO)) swelled by a liquid electrolyte (LE) of 1 M LiPF6 in carbonate solvents. The proposed GPE stably holds LE with an amount that is three times that of the Celgard-P(EO-co-PO) composite. This GPE has a higher ionic conductivity (2.8×10(-3) and 5.1×10(-4) S cm(-1) at 30 and -20 °C, respectively) and a wider electrochemical voltage range (5.1 V) than the LE-swelled Celgard because of the strong ion-solvation power of P(EO-co-PO). The active ion-solvation role of P(EO-co-PO) also suppresses the formation of the solid-electrolyte interphase layer. When assembling the GPE in a Li/LiFePO4 battery, the P(EO-co-PO) network hinders anionic transport, producing a high Li+ transference number of 0.5 and decreased the polarization overpotential. The Li/GPE/LiFePO4 battery delivers a discharge capacity of 156-135 mAh g(-1) between 0.1 and 1 C-rates, which is approximately 5% higher than that of the Li/LE/LiFePO4 battery. The IR drop of the Li/GPE/LiFePO4 battery was 44% smaller than that of the Li/LE/LiFePO4. The Li/GPE/LiFePO4 battery is more stable, with only a 1.2% capacity decay for 150 galvanostatic charge-discharge cycles. The advantages of the proposed GPE are its high stability, conductivity, Li+ transference number, and mechanical integrity, which allow for the assembly of GPE-based batteries readily scalable to industrial levels.

  17. Degradation of electron-irradiated polyethylene studied by positron annihilation lifetime spectroscopy

    NASA Astrophysics Data System (ADS)

    Onodera, K.; Oka, T.; Kino, Y.; Sekine, T.

    2017-01-01

    Degradation of electron beam irradiated high-density polyethylene was studied by positron annihilation lifetime spectroscopy (PALS), micro-FT-IR, and gel fraction measurements. The obtained results indicated that ortho-positronium intensity is influenced not only by the irradiation but also the post oxidation, which illustrates that PALS may be a promising tool to monitor/evaluate the degradation of polyethylene induced by irradiation and long-term storage.

  18. Preparation and Electrical Property of Polypyrrole-Polyethylene Composite

    NASA Astrophysics Data System (ADS)

    Yoshino, Katsumi; Yin, Xiao Hong; Morita, Shigenori; Nakanishi, Yutaka; Nakagawa, Shinichi; Yamamoto, Hideo; Watanuki, Toshiro; Isa, Isao

    1993-02-01

    Polypyrrole-polyethylene composites have been prepared by pressing the mixture of polypyrrole coated and non-coated polyethylene spheres. Electrical conductivity is enhanced by more than 16 orders of magnitude and its activation energy decreases remarkably at concentration of polypyrrole coated polyethylene above around 10-20%, which corresponds to effective polypyrrole concentration of 0.1-0.2%. These characteristics can be explained by a percolation model. That is, at this concentration electrodes are bridged by conducting channel of doped polypyrrole. Thermoelectric power increases in proportion to absolute temperature and is independent on concentration of polypyrrole coated polyethylene sphere above 30%, which support the percolation model. The electrical property of this polypyrrole-polyethylene composite is found to be stable up to 160°C. The application of this composite to the semiconducting layer of a cable has been proposed.

  19. Investigation of space charge distribution of low-density polyethylene/GO-GNF (graphene oxide from graphite nanofiber) nanocomposite for HVDC application.

    PubMed

    Kim, Yoon Jin; Ha, Son-Tung; Lee, Gun Joo; Nam, Jin Ho; Ryu, Ik Hyun; Nam, Su Hyun; Park, Cheol Min; In, Insik; Kim, Jiwan; Han, Chul Jong

    2013-05-01

    This paper reported a research on space charge distribution in low-density polyethylene (LDPE) nanocomposites with different types of graphene and graphene oxide (GO) at low filler content (0.05 wt%) under high DC electric field. Effect of addition of graphene oxide or graphene, its dispersion in LDPE polymer matrix on the ability to suppress space charge generation will be investigated and compared with MgO/LDPE nanocomposite at the same filler concentration. At an applied electric field of 80 kV/mm, a positive packet-like charge was observed in both neat LDPE, MgO/LDPE, and graphene/LDPE nanocomposites, whereas only little homogenous space charge was observed in GO/LDPE nanocomposites, especially with GO synthesized from graphite nano fiber (GNF) which is only -100 nm in diameter. Our research also suggests that dispersion of graphene oxide particles on the polymer matrix plays a significant role to the performance of nanocomposites on suppressing packet-like space charge. From these results, it is expected that nano-sized GO synthesized from GNF can be a promising filler material to LDPE composite for HVDC applications.

  20. Evaluation of the drug solubility and rush ageing on drug release performance of various model drugs from the modified release polyethylene oxide matrix tablets.

    PubMed

    Shojaee, Saeed; Nokhodchi, Ali; Maniruzzaman, Mohammed

    2017-02-01

    Hydrophilic matrix systems are currently some of the most widely used drug delivery systems for controlled-release oral dosage forms. Amongst a variety of polymers, polyethylene oxide (PEO) is considered an important material used in pharmaceutical formulations. As PEO is sensitive to thermal oxidation, it is susceptible to free radical oxidative attack. The aim of this study was to investigate the stability of PEO based formulations containing different model drugs with different water solubility, namely propranolol HCl, theophylline and zonisamide. Both polyox matrices 750 and 303 grade were used as model carriers for the manufacture of tablets stored at 40 °C. The results of the present study suggest that the drug release from the matrix was affected by the length of storage conditions, solubility of drugs and the molecular weight of the polymers. Generally, increased drug release rates were prevalent in soluble drug formulations (propranolol) when stored at the elevated temperature (40 °C). In contrast, it was not observed with semi soluble (theophylline) and poorly soluble (zonisamide) drugs especially when formulated with PEO 303 polymer. This indicates that the main parameters controlling the drug release from fresh polyox matrices are the solubility of the drug in the dissolution medium and the molecular weight of the polymer. DSC traces indicated that that there was a big difference in the enthalpy and melting points of fresh and aged PEO samples containing propranolol, whereas the melting point of the aged polyox samples containing theophylline and zonisamide was unaffected. Graphical abstract ᅟ.

  1. Vibrational spectroscopy of ultra-high molecular weight polyethylene hip prostheses: influence of the sterilisation method on crystallinity and surface oxidation

    NASA Astrophysics Data System (ADS)

    Taddei, Paola; Affatato, Saverio; Fagnano, Concezio; Bordini, Barbara; Tinti, Anna; Toni, Aldo

    2002-08-01

    Due to its high strength and low creep, ultra-high molecular weight polyethylene (UHMWPE) has been used for 30 years in the replacement of damaged articulating cartilage for total joint replacement surgery. In this study, micro-Raman spectroscopy was used to investigate the effects of the sterilisation method (gamma and ethylene oxide (EtO) treatment) on the crystallinity changes of UHMWPE acetabular cups. The crystallinity of the cups was evaluated by micro-Raman spectroscopy coupled to the partial least square (PLS) regression as a function of the inner surface position. Unworn gamma-sterilised cups were found to be significantly more crystalline than the EtO-sterilised ones. No significant differences were observed between the crystallinity values of worn (in in vitro tests) and unworn cups for each type of sterilisation, showing that the changes in surface crystallinity were mainly caused by irradiation rather than by mechanical friction during the in vitro wear tests. These results were discussed in relation to gravimetric measurements, which revealed at the end of the in vitro tests, a higher mean weight loss for the EtO-sterilised cups than for the gamma-sterilised ones. No significant amounts of oxidative degradation products were detected by IR spectroscopy in the inner surface of the EtO-sterilised worn and unworn cups. Regarding the gamma-sterilised cups, the oxidation level appeared to be slightly higher in the centre of the worn cups than on their borders.

  2. Purification and characterization of polyethylene glycol dehydrogenase involved in the bacterial metabolism of polyethylene glycol.

    PubMed Central

    Kawai, F; Kimura, T; Tani, Y; Yamada, H; Kurachi, M

    1980-01-01

    Polyethylene glycol (PEG) dehydrogenase in crude extracts of a PEG 20,000-utilizing mixed culture was purified 24 times by precipitation with ammonium sulfate, solubilization with laurylbetaine, and chromatography with diethylamino-ethyl-cellulose, hydroxylapatite, and Sephadex G-200. The purified enzyme was confirmed to be homogeneous by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The molecular weight of the enzyme, which appeared to consist of four identical subunits, was 2.4 X 10(5). The enzyme was stable below 35 degrees C and in the pH range of 7.5 to 9.0. The optimum pH and temperature of the activity were around 8.0 and 60 degrees C, respectively. The enzyme did not require any metal ions for activity and oxidized various kinds of PEGs, among which PEG 6,000 was the most active substrate. The apparent Km values for tetraethylene glycol and PEG 6,000 were about 10.0 and 3.0 mM, respectively. Images PMID:6999995

  3. The adhesion of oxygen-plasma treated poly(ethylene) and poly(ethylene terephthlate) films

    SciTech Connect

    Holton, S.L.; Kinloch, A.J.; Watts, J.F.

    1996-12-31

    The effects of low-pressure oxygen-plasma treatment on the surfaces of poly(ethylene) (PE) and poly(ethylene terephthlate) (PET) films and its influence on the adhesion of PE/PET laminates were assessed. The 90{degree} peel test was used to estimate the adhesive fracture energy, G{sub c} for the laminates. XPS, SEM and AFM were used to analyse the treated films and fracture surfaces. Significant improvements in bond strength occurred within very short treatment times (5s at 50W) with the maximum adhesion occurring after 300s. For longer treatment times the bond strengths decrease slightly. G{sub c} values were found to be low when PET was the peel arm. When PE was the peel arm, the G{sub c} values were substantially larger using the current analysis.

  4. Crystallization Studies of Blends of Low Density Polyethylene and High Density Polyethylene

    NASA Astrophysics Data System (ADS)

    Puig, C.; Gomez, S.; Castañeda, R.

    1997-03-01

    The incorporation of low density polyethylene (LDPE) segments within the high density polyethylene (HDPE) lamellae on cooling from the molten state is investigated using differential scanning calorimetry. Rich LDPE blends (>80%) on quenching from the melt exhibited partial cocrystallization. Two endotherms on heating are observed, the LDPE is the main component of the low melting endotherm whereas the HDPE is the main component of the high melting endotherm. A depression in the high melting temperature peak is observed. In addition, on subsequent treatment the crystallization behaviour under controlled conditions of the low melting component in quenched blends is studied and it shows a shift in the crystallization temperature when compared with pure LDPE. After reheating a depression in the low melting temperature with increasing HDPE content in the blend is observed. The effect of cooling conditions used from the melt on the cocrystallization between the two polymers is studied.

  5. Degradation of crosslinked polyethylene in water by gamma-irradiation

    NASA Astrophysics Data System (ADS)

    Matsui, Tatsuro; Takano, Tadao; Takayama, Shigeru; Ito, Masayuki; Narisawa, Ikuo

    2002-02-01

    The degradation of crosslinked polyethylene by gamma-irradiation in water was studied. Change in the physical properties and the growth of carbonyl group after irradiation showed a good correlation. The degradation observed at 80°C is the least, and that at 60°C is the severest. The distribution of the oxidized layer in the sample was measured and was also calculated from the diffusion model using the observed parameters. Comparison of both results suggest that some products caused by gamma-irradiation of water supress the degradation of XLPE at 80°C.

  6. Investigation of Raman spectra of polyethylene terephthalate

    NASA Astrophysics Data System (ADS)

    Zhu, Changjun; Tong, Na; Song, Lixin; Zhang, Guoqing

    2015-08-01

    Raman spectrometry was employed to study the characteristics of Raman spectra of polyethylene terephthalate (PET), which were treated with sodium hydroxide, sulfuric acid and copper sulfate, respectively. Raman spectra under different conditions were obtained and the characteristics of the Raman spectra were analyzed. The morphology structures were observed under different conditions using Atomic Force Microscope. The results show that the spectral intensity of PET treated with sodium hydroxide is higher than that untreated between 200-1750 cm-1, while the intensity of PET treated with sodium hydroxide is lower than that untreated beyond 1750 cm-1 and the fluorescence background of Raman spectra is decreased. The spectral intensity of PET treated with sulfuric acid is remarkably reduced than that untreated, and the intensity of PET treated with copper sulphate is much higher than that untreated.

  7. Polyethylene glycol-grafted polystyrene particles.

    PubMed

    Meng, Fenghua; Engbers, Gerard H M; Feijen, Jan

    2004-07-01

    Densely pegylated particles that can serve as a model system for artificial cells were prepared by covalently grafting amino polyethylene glycol (PEG, molecular weight 3400 or 5000) onto carboxyl polystyrene particles (PS-COOH) using carbodiimide chemistry. PEG-modified particles (PS-PEG) were characterized by determination of the PEG surface concentration, zeta-potential, size, and morphology. Under optimized grafting conditions, a dense "brush-like" PEG layer was formed. A PEG surface concentration of approximately 60 pmol/cm2, corresponding with an average distance between grafted PEG chains of approximately 17 A can be realized. It was shown that grafting of PEG onto PS-COOH reduced the adsorption of proteins from human plasma (85 vol %) in phosphate-buffered saline up to 90%.

  8. Impact behavior of hydroxyapatite reinforced polyethylene composites.

    PubMed

    Zhang, Y; Tanner, K E

    2003-01-01

    Hydroxyapatite particulate reinforced high density polyethylene composite (HA-HDPE) has been developed as a bone replacement material. The impact behavior of the composites at 37 degrees C has been investigated using an instrumented falling weight impact testing machine. The fracture surfaces were examined using SEM and the fracture mechanisms are discussed. It was found that the fracture toughness of HA-HDPE composites increased with HDPE molecular weight, but decreased with increasing HA volume fraction. Examination of fracture surfaces revealed weak filler/matrix interfaces which can debond easily to enable crack initiation and propagation. Increasing HA volume fraction increases the interface area, and more cracks can form and develop, thus decreasing the impact resistance of the composites. Another important factor for the impact behavior of the composites is the matrix. At higher molecular weight, HDPE is able to sustain more plastic deformation and dissipates more impact energy, hence improving the impact property.

  9. Depolymerization of polyethylene terephthalate in supercritical methanol

    NASA Astrophysics Data System (ADS)

    Goto, Motonobu; Koyamoto, Hiroshi; Kodama, Akio; Hirose, Tsutomu; Nagaoka, Shoji

    2002-11-01

    The degradation of polyethylene terephthalate (PET) in supercritical methanol was investigated with the aim of developing a process for chemical recycling of waste plastics. A batch reactor was used at temperatures of 573-623 K under an estimated pressure of 20 MPa for a reaction time of 2-120 min. PET was decomposed to its monomers, dimethyl terephthalate and ethylene glycol, by methanolysis in supercritical methanol. The reaction products were analysed using size-exclusion chromatography, gas chromatography-mass spectrometry, and reversed-phase liquid chromatography. The molecular weight distribution of the products was obtained as a function of reaction time. The yields of monomer components of the decomposition products including by-products were measured. Continuous kinetics analysis was performed on the experimental data.

  10. Li + grafting of ion irradiated polyethylene

    NASA Astrophysics Data System (ADS)

    Švorčík, V.; Rybka, V.; Vacík, J.; Hnatowicz, V.; Öchsner, R.; Ryssel, H.

    1999-02-01

    Foils of oriented polyethylene (PE) were irradiated with 63 keV Ar + and 155 keV Xe + ions to different fluences at room temperature and then doped from water solution of LiCl. The as irradiated and irradiated plus doped samples were examined by IR, EPR and neutron depth profiling (NDP) technique. The sheet resistance was also measured by the standard two points method. After Li salt doping of ion modified layer of PE, a reaction between degraded macromolecules and Li occur and thus a new chemical structure C-Li + is formed. Owing to the presence of these cations on the polymer chain, the irradiated plus doped layer exhibits higher electric conductivity compared to as-irradiated ones.

  11. Simulation of melting in crystalline polyethylene

    NASA Astrophysics Data System (ADS)

    Zubova, E. A.; Balabaev, N. K.; Musienko, A. I.; Gusarova, E. B.; Mazo, M. A.; Manevitch, L. I.; Berlin, A. A.

    2012-06-01

    We carry out a molecular dynamics simulation of the first stages of constrained melting in crystalline polyethylene (PE). When heated, the crystal undergoes two structural phase transitions: from the orthorhombic (O) phase to the monoclinic (M) phase, and then to the columnar (C), quasi-hexagonal, phase. The M phase represents the tendency to the parallel packing of planes of PE zigzags, and the C phase proves to be some kind of oriented melt. We follow both the transitions O→M and M→C in real time and establish that, at their beginning, the crystal tries (and fails) to pass into the partially ordered phases similar to the RI and RII phases of linear alkanes, correspondingly. We discuss the molecular mechanisms and driving forces of the observed transitions, as well as the reasons why the M and C phases in PE crystals substitute for the rotator phases in linear alkanes.

  12. Vacuum Outgassing of High Density Polyethylene

    SciTech Connect

    Dinh, L N; Sze, J; Schildbach, M A; Chinn, S C; Maxwell, R S; Raboin, P; McLean II, W

    2008-08-11

    A combination of thermogravimetric analysis (TGA) and temperature programmed decomposition (TPD) was employed to identify the outgassing species, the total amount of outgassing, and the outgassing kinetics of high density polyethylene (HDPE) in a vacuum environment. The isoconversional kinetic analysis was then used to analyze the outgassing kinetics and to predict the long-term outgassing of HDPE in vacuum applications at ambient temperature. H{sub 2}O and C{sub n}H{sub x} with n as high as 9 and x centering around 2n are the major outgassing species from solid HDPE, but the quantities evolved can be significantly reduced by vacuum baking at 368 K for a few hours prior to device assembly.

  13. Thermal analysis of polyethylene + X% carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Lozovyi, Fedir; Ivanenko, Kateryna; Nedilko, Sergii; Revo, Sergiy; Hamamda, Smail

    2016-02-01

    The aim of this research is to study the influence of the multi-walled carbon nanotubes (MWCNTs) on the thermomechanical and structural properties of high-density polyethylene. Several, complementary experimental techniques were used, namely, dilatometry, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), Raman spectroscopy, and infrared (IR) spectroscopy. Dilatometry data showed that nanocomposites exhibit anisotropic behavior, and intensity of the anisotropy depends on the MWCNT concentration. The shapes of the dilatometric curves of the nanocomposites under study differ significantly for the radial and longitudinal directions of the samples. DSC results show that MWCNTs weekly influence calorimetry data, while Raman spectra show that the I D/ I G ratio decreases when MWCNT concentration increases. The IR spectra demonstrate improvement of the crystallinity of the samples as the content in MWCNTs rises.

  14. Acetone transport in poly(ethylene terephthalate)

    NASA Astrophysics Data System (ADS)

    Ouyang, Hao; Chen, Che-Chen

    1997-05-01

    Organic solvents like acetone can penetrate into poly(ethylene terephthalate) (PET). The model of case I (Fickian) and case II (swelling) is employed to study the phenomenon of mass transport. This model is successful in explaining the behavior of mass transport in an amorphous polymer, for example, poly(methyl methacrylate) (PMMA). The characteristic parameters, diffusivity D and velocity v, can be obtained from the analysis of experimental data. The mass transport in PET is different from that in PMMA. It is accompanied by a large-scale structural rearrangement, which leads to induced crystallization of the original amorphous state. This is the so-called "solvent-induced crystallization." Acetone-induced crystallization was confirmed by x-ray diffraction. The differential scanning calorimetry thermograms of acetone-treated PET show that the crystallization peak disappears and the glass transition temperature decreases.

  15. Stress crack testing of polyethylene geomembranes

    NASA Astrophysics Data System (ADS)

    Halse, Y. H.; Koerner, R. M.; Lord, A. E., Jr.

    The sensitivity of high density polyethylene (HDPE) geomembranes to stress cracking is evaluated under accelerated conditions at a constant stress. The test specimens are in accordance with ASTM D-1822, and are of the dumbbell shape with a constant length in the central section. The accelerated testing conditions consist of a 10 percent Igepal wetting solution in tap water, at a constant temperature of 50 C. The applied stresses are from 30 to 50 percent of the yield stress. It was found that most commercially available HDPE sheet material performs quite well in this type of test. Only one specimen in 80 showed any evidence of cracking and this may have been caused by other reasons. Testing of field fabricated seams, however, resulted in relatively large numbers of cracked specimens. Many of these test specimens showed signs of overgrinding and/or overheating. The results indicate that great care and excellent workmanship are required in the field fabrication of HDPE seams.

  16. Renewable polyethylene mimics derived from castor oil.

    PubMed

    Türünç, Oĝuz; Montero de Espinosa, Lucas; Meier, Michael A R

    2011-09-01

    An increasing number of reports on the syntheses of carbohydrate- and plant oil-based polymers has been published in ongoing efforts to produce plastic materials from renewable resources. Although many of these polymers are biodegradable and this is a desirable property for certain applications, in some cases non-degradable polymers are needed for long-term use purposes. Polyolefins are one of the most important classes of materials that have already taken their places in our daily life. On the other hand, their production relies on fossil resources. Therefore, within this contribution, we discuss synthetic routes toward a number of polyethylene mimics derived from fatty acids via thiol-ene and ADMET polymerization reactions in order to establish more sustainable routes toward this important class of polymers. Two different diene monomers were thus prepared from castor oil derived platform chemicals, their polymerization via the two mentioned routes was optimized and compared to each other, and their thermal properties were investigated.

  17. Viscoplastic tearing of polyethylene thin film

    NASA Astrophysics Data System (ADS)

    Hegyi, Dezso; Pellegrino, Sergio

    2015-05-01

    Recent advances in noncontact strain measurement techniques and large-strain constitutive modeling of the linear low-density polyethylene film used in NASA superpressure balloons StratoFilm 420 are combined to provide a novel measurement technique for the tear propagation critical value of the J-integral. Previously these measurements required complex test configurations and procedures. It is found that the critical value of the J-integral increases by approximately 50 % when the strain rate is decreased from 1.33×10-4 s-1 to 1.33×10-5 s-1. It is shown that there is good correlation between measurements made on uniaxially loaded dogbone samples and circular diaphragms loaded by pressure, both with a 2-mm-wide slit in the middle. This result indicates that more extensive studies of strain-rate dependence may be made with the simpler, uniaxial test configuration.

  18. Dextran and polymer polyethylene glycol (PEG) coating reduce both 5 and 30 nm iron oxide nanoparticle cytotoxicity in 2D and 3D cell culture.

    PubMed

    Yu, Miao; Huang, Shaohui; Yu, Kevin Jun; Clyne, Alisa Morss

    2012-01-01

    Superparamagnetic iron oxide nanoparticles are widely used in biomedical applications, yet questions remain regarding the effect of nanoparticle size and coating on nanoparticle cytotoxicity. In this study, porcine aortic endothelial cells were exposed to 5 and 30 nm diameter iron oxide nanoparticles coated with either the polysaccharide, dextran, or the polymer polyethylene glycol (PEG). Nanoparticle uptake, cytotoxicity, reactive oxygen species (ROS) formation, and cell morphology changes were measured. Endothelial cells took up nanoparticles of all sizes and coatings in a dose dependent manner, and intracellular nanoparticles remained clustered in cytoplasmic vacuoles. Bare nanoparticles in both sizes induced a more than 6 fold increase in cell death at the highest concentration (0.5 mg/mL) and led to significant cell elongation, whereas cell viability and morphology remained constant with coated nanoparticles. While bare 30 nm nanoparticles induced significant ROS formation, neither 5 nm nanoparticles (bare or coated) nor 30 nm coated nanoparticles changed ROS levels. Furthermore, nanoparticles were more toxic at lower concentrations when cells were cultured within 3D gels. These results indicate that both dextran and PEG coatings reduce nanoparticle cytotoxicity, however different mechanisms may be important for different size nanoparticles.

  19. Detection of cracks in polyethylene components of retrieved knee joint prostheses.

    PubMed

    Koizumi, M; Tomita, N; Tamai, S; Oonishi, H; Ikada, Y

    1998-01-01

    Subsurface cracks that had formed in polyethylene artificial knee components were observed nondestructively with a new method, scanning acoustic tomography (SAT). Standardization of the SAT observation was done by in-vitro rolling fatigue testing on an unimplanted ultra high molecular weight polyethylene (UHMWPE) knee component. Retrieved knee components were of two types; KOM (Kyocera, Kyoto, Japan) sterilized with ethylene oxide gas, and MG (Zimmer, IN, USA) sterilized with gamma-irradiation. The SAT images revealed cracks in all the retrieved components, and these existed mainly 0. 3-1.0 mm from the surface. Comparison of crack formation in each portion of the contact area of the polyethylene components showed that the middle portion of the MG type had the highest concentration of cracks. When the distribution of compressive stress on the polyethylene components was assessed by mechanical testing, the strongest compressive stress was seen in the middle portion of MG type components.

  20. β-NMR measurements of lithium ion transport in thin films of pure and lithium-salt-doped poly(ethylene oxide).

    PubMed

    McKenzie, Iain; Harada, Masashi; Kiefl, Robert F; Levy, C D Philip; MacFarlane, W Andrew; Morris, Gerald D; Ogata, Shin-Ichi; Pearson, Matthew R; Sugiyama, Jun

    2014-06-04

    β-Detected nuclear spin relaxation of (8)Li(+) has been used to study the microscopic diffusion of lithium ions in thin films of poly(ethylene oxide) (PEO), where the implanted lithium ions are present in extremely low concentration, and PEO with 30 wt % LiCF3SO3 over a wide range of temperatures both above and below the glass transition temperature. Recent measurements by Do et al. [Phys. Rev. Lett. 2013, 111, 018301] found that the temperature dependence of the Li(+) conductivity was identical to that of the dielectric α relaxation and was well described by the Vogel-Fulcher-Tammann relation, implying the α relaxation dominates the Li(+) transport process. In contrast, we find the hopping of Li(+) in both samples in the high temperature viscoelastic phase follows an Arrhenius law and depends significantly on the salt content. We propose that the hopping of Li(+) between cages involves motion of the polymer but that it is only for long-range diffusion where the α relaxation plays an important role.

  1. Presentation of a novel model of chitosan- polyethylene oxide-nanohydroxyapatite nanofibers together with bone marrow stromal cells to repair and improve minor bone defects

    PubMed Central

    Emamgholi, Asgar; Rahimi, Mohsen; Kaka, Gholamreza; Sadraie, Seyed Homayoon; Najafi, Saleh

    2015-01-01

    Objective(s): Various methods for repairing bone defects are presented. Cell therapy is one of these methods. Bone marrow stromal cells (BMSCs) seem to be suitable for this purpose. On the other hand, lots of biomaterials are used to improve and repair the defect in the body, so in this study we tried to produce a similar structure to the bone by the chitosan and hydroxyapatite. Materials and Methods: In this study, the solution of chitosan-nanohydroxyapatite-polyethylene oxide (PEO) Nanofibers was produced by electrospinning method, and then the BMSCs were cultured on this solution. A piece of chitosan-nanohydroxyapatite Nanofibers with BMSCs was placed in a hole with the diameter of 1 mm at the distal epiphysis of the rat femur. Then the biomechanical and radiographic studies were performed. Results: Biomechanical testing results showed that bone strength was significantly higher in the Nanofiber/BMSCs group in comparison with control group. Also the bone strength in nanofiber/BMSCs group was significant, but in nanofiber group was nearly significant. Radiographic studies also showed that the average amount of callus formation (radio opacity) in nanofiber and control group was not significantly different. The callus formation in nanofiber/BMSCs group was increased compared to the control group, and it was not significant in the nanofiber group. Conclusion: Since chitosan-nanohydroxyapatite nanofibers with BMSCs increases the rate of bone repair, the obtained cell-nanoscaffold shell can be used in tissue engineering and cell therapy, especially for bone defects. PMID:26523221

  2. A novel chitosan-polyethylene oxide nanofibrous mat designed for controlled co-release of hydrocortisone and imipenem/cilastatin drugs.

    PubMed

    Fazli, Yousef; Shariatinia, Zahra; Kohsari, Iraj; Azadmehr, Amirreza; Pourmortazavi, Seied Mahdi

    2016-11-20

    Antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofibrous mats containing ZnO nanoparticles (NPs) and hydrocortisone-imipenem/cilastatin-loaded ZnO NPs were produced by electrospinning technique. The FE-SEM images displayed that the spherical ZnO NPs were ∼70-200nm in size and the CS-PEO nanofibers were very uniform and free of any beads which had average diameters within the range of ∼20-130nm. For all of the nanofibrous mats, the water uptakes were the highest in acidic medium but they were decreased in the buffer and the least swellings were obtained in the alkaline environment. The drug incorporated mat preserved its bactericidal activity even after it was utilized in the release experiment for 8days in the PBS buffer. The hydrocortisone release was increased to 82% within first 12h while the release rate of imipenem/cilastatin was very much slower so that 20% of the drug was released during this period of time suggesting this nanofibrous mat is very suitable to inhibit inflammation (by hydrocortisone) and infection (using imipenem/cilastatin antibiotic and ZnO NPs) principally for the wound dressing purposes.

  3. Impedance study of the interface between lithium, polyaniline, lithium-doped MnO 2 and modified poly(ethylene oxide) electrolyte

    NASA Astrophysics Data System (ADS)

    Baochen, Wang; Li, Feng; Yongyao, Xia

    1993-03-01

    Impedance study was carried out for the interfaces between lithium, polyaniline (PAn), lithium-doped MnO 2 and modified poly(ethylene oxide) (PEO) electrolyte under various conditions. The interfacial charge-transfer resistance Rct on PEO/PAn, Rct on PEO/LiMn 2O 4 increase with depth-of-discharge and decrease after the charge of the cell containing modified PEO as electrolyte. The charge-transfer resistance Rct on PEO/PAn is higher than Rct on PEO/LiMn 2O 4 under the same condition, since inserted species and mechanism are different for both cases. In the case of PAn, an additional charge-transfer resistance might be related to the electronic conductivity change in discharge/charge potential range, as it was evident from a voltammetry curve. With increasing cycle numbers, the charge-transfer resistance increases gradually. The impedance results also have shown that at low frequency the diffusion control is dominant in the process of the charge and discharge of Li/PEO/PAn or Li/PEO/LiMn 2O 4 cell. The diffusion coefficients have been calculated from impedance data.

  4. Impedance study of the interfaces between lithium, polyaniline, lithium-doped MnO2 and modified poly(ethylene oxide) electrolyte

    NASA Astrophysics Data System (ADS)

    Wang, Baochen; Feng, Li; Xia, Yongyao

    1993-03-01

    Impedance study was carried out for the interfaces between lithium, polyaniline (PAn), lithium-doped MnO2 and modified poly(ethylene oxide) (PEO) electrolyte under various conditions. The interfacial charge-transfer resistances R(sub ct) on PEO/PAn, R(sub ct) on PEO/LiMn2O increas e with depth-of-discharge and decrease after the charge of the cell containing modified PEO as electrolyte. The charge-transfer resistance R(sub ct) on PEO/PAn is higher than R(sub ct) on PEO/LiMn2O4 under the same condition, since inserted species and mechanism are different for both cases. In the case of PAn, an additional charge-transfer resistance might be related to the electronic conductivity change in discharge/charge potential range, as it was evident from a voltammetry curve. With increasing cycle numbers, the charge-transfer resistance increases gradually. The impedance results also have shown that at low frequency the diffusion control is dominant in the process of the charge and discharge of Li/PEO/PAn or Li/PEO/LiMn2O4 cell. The diffusion coefficients have been calculated from impedance data.

  5. Enhanced Lithium Ion Transport in Poly(ethylene glycol) Diacrylate-Supported Solvate Ionogel Electrolytes via Chemically Cross-linked Ethylene Oxide Pathways.

    PubMed

    D'Angelo, Anthony J; Panzer, Matthew J

    2017-02-02

    Lithium-ion solvate ionic liquids (SILs), consisting of complexed Li(+) cations and a weakly basic anion, represent an emergent class of nonvolatile liquid electrolytes suitable for lithium-based electrochemical energy storage. In this report, solid-state, flexible solvate ionogel electrolytes are synthesized via UV-initiated free radical polymerization/cross-linking of poly(ethylene glycol) diacrylate (PEGDA) in situ within the [Li(G4)][TFSI] electrolyte, which is formed by an equimolar mixture of lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and tetraglyme (G4). Ion diffusivity measurements reveal enhanced Li(+) diffusion in PEGDA-supported solvate ionogels, as compared to poly(methyl methacrylate)-supported gels that lack ethylene oxide chains. At 21 vol% PEGDA, a maximum Li(+) transport number of 0.58 and a room temperature ionic conductivity of 0.43 mS/cm have been achieved in a solvate ionogel electrolyte that exhibits an elastic modulus of 0.47 MPa. These results demonstrate the importance of polymer scaffold selection on solvate ionogel electrolyte performance for advanced lithium-based batteries.

  6. Nanoscale confinement effects on the relaxation dynamics in networks of diglycidyl ether of bisphenol-A and low-molecular-weight poly(ethylene oxide).

    PubMed

    Kalogeras, Ioannis M; Stathopoulos, Andreas; Vassilikou-Dova, Aglaia; Brostow, Witold

    2007-03-22

    Thermoplastic poly(ethylene oxide) (PEO) (Mw(PEO) approximately 4000) has been used to prepare thermosetting nanocomposites incorporating diglycidyl ether of bisphenol A (DGEBA) epoxy oligomer. Blends with various PEO/DGEBA weight ratios were cured using stoichiometric portions of 4,4'-diaminodiphenylmethane. The resulting semi-interpenetrating polymer networks were studied by several techniques. Nanoscale confinement effects, thermal (glass transition, melting and crystallization temperatures) and structural features of our materials are similar to those for networks with much higher Mw(PEO) and different curing agents; however, the polyether crystallization onset occurs in our case at a lower PEO concentration; shorter PEO chains organize themselves more easily into crystalline domains. Very low estimates of the k parameter of the Gordon-Taylor equation, used to fit the compositional dependences of the dielectric and calorimetric glass transition temperatures, and a strong plasticization of the motion of the glyceryl segments (beta-relaxation) in the epoxy resin were observed. These illustrate an intensified weakening in the strength of the intermolecular interactions in the modified networks, as compared to the high strength of the self-association of hydroxyls in the neat resin. The significance of hydrogen-bonding interactions between the components for obtaining structurally homogeneous thermoset-i-thermoplastic networks is discussed.

  7. Quantitative control of poly(ethylene oxide) surface antifouling and biodetection through azimuthally enhanced grating coupled-surface plasmon resonance sensing

    NASA Astrophysics Data System (ADS)

    Sonato, Agnese; Silvestri, Davide; Ruffato, Gianluca; Zacco, Gabriele; Romanato, Filippo; Morpurgo, Margherita

    2013-12-01

    Grating Coupled-Surface Plasmon reflectivity measurements carried out under azimuth and polarization control (GC-SPR φ ≠ 0°) were used to optimize the process of gold surface dressing with poly(ethylene oxide) (PEO) derivatives of different molecular weight, with the final goal to maximize the discrimination between specific and non-specific binding events occurring at the surface. The kinetics of surface deposition of thiol-ending PEOs (0.3, 2 and 5 kDa), introduced as antifouling layers, was monitored. Non-specific binding events upon immersion of the surfaces into buffers containing either 0.1% bovine serum albumin or 1% Goat Serum, were evaluated as a function of polymer size and density. A biorecognition event between avidin and biotin was then monitored in both buffers at selected low and high polymer surface densities and the contribution of analyte and fouling elements to the signal was precisely quantified. The 0.3 kDa PEO film was unable to protect the surface from non-specific interactions at any tested density. On the other hand, the 2 and 5 kDa polymers at their highest surface densities guaranteed full protection from non-specific interactions from both buffers. These densities were reached upon a long deposition time (24-30 h). The results pave the way toward the application of this platform for the detection of low concentration and small dimension analytes, for which both non-fouling and high instrumental sensitivity are fundamental requirements.

  8. β - NMR Measurements of Lithium Ion Transport in Thin Films of Pure and Lithium-Salt-Doped Poly(ethylene oxide)

    NASA Astrophysics Data System (ADS)

    McKenzie, Iain; Harada, Masashi; Cortie, David L.; Kiefl, Robert F.; Levy, C. D. Philip; Macfarlane, W. Andrew; McFadden, Ryan M. L.; Morris, Gerald D.; Ogata, Shin-Ichi; Pearson, Matthew R.; Sugiyama, Jun

    2015-03-01

    β - Detected nuclear spin relaxation of 8Li+ has been used to study the microscopic diffusion of lithium ions in thin films of poly(ethylene oxide) (PEO), PEO with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), PEO with lithium triflate (LiTf) and PEO with lithium trifluoroacetic acid (LiTFA) with monomer-to-salt ratios of 8.3:1. Hopping of Li + above ~ 250 K follows an Arrhenius law in all of the films. Diffusion of Li+ is fastest in pure PEO and decreases in order LiTFSI >LiTf >LiTFA. We observed the activation energy for hopping (EA) and the intrinsic hop rate (τ0-1) both increasing in order LiTFA

  9. Chemical modification of wheat protein-based natural polymers: grafting and cross-linking reactions with poly(ethylene oxide) diglycidyl ether and ethyl diamine.

    PubMed

    Kurniawan, Lusiana; Qiao, Greg G; Zhang, Xiaoqing

    2007-09-01

    Mobile poly(ethylene oxide) diglycidyl ether (PEODGE) segments were chemically grafted onto a soluble wheat protein (WP), and different network structures were formed via coupling reactions with ethyl diamine (EDA) in different PEODGE/EDA (PE) ratios. When the PE ratio was 1:1, linear PEs were the predominant segments grafted onto WP chains and the whole WP-PEODGE-EDA (WPE) system was still soluble with an increased molecular weight. Reducing the amount of EDA in the systems produced insoluble cross-linked WPE networks. The broad distribution of network structures and chain mobility resulted in a broad glass transition for the WPE materials. However, the glass transition started at lower temperatures, and the materials became flexible at room temperature. The PE segments were present in all rigid, intermediate, and mobile phases in WPE networks, while the proportion of mobile WP chains was increased as a result of the plasticization effect from the mobile PE segments. The mobility of the most mobile component lipid was also restricted to some extent when forming the cross-linked WPE networks. The study demonstrated that the formation of different network structures with PE segments could significantly improve the flexibility of WP materials, vary the solubility, and modify the mechanical performance of WP-based natural polymer materials.

  10. Conformational sensitivity of conjugated poly(ethylene oxide)-poly(amidoamine) molecules to cations adducted upon electrospray ionization - a mass spectrometry, ion mobility and molecular modeling study.

    PubMed

    Tintaru, Aura; Chendo, Christophe; Wang, Qi; Viel, Stéphane; Quéléver, Gilles; Peng, Ling; Posocco, Paola; Pricl, Sabrina; Charles, Laurence

    2014-01-15

    Tandem mass spectrometry and ion mobility spectrometry experiments were performed on multiply charged molecules formed upon conjugation of a poly(amidoamine) (PAMAM) dendrimer with a poly(ethylene oxide) (PEO) linear polymer to evidence any conformational modification as a function of their charge state (2+ to 4+) and of the adducted cation (H(+)vs Li(+)). Experimental findings were rationalized by molecular dynamics simulations. The G0 PAMAM head-group could accommodate up to three protons, with protonated terminal amine group enclosed in a pseudo 18-crown-6 ring formed by the PEO segment. This particular conformation enabled a hydrogen bond network which allowed long-range proton transfer to occur during collisionally activated dissociation. In contrast, lithium adduction was found to mainly occur onto oxygen atoms of the polyether, each Li(+) cation being coordinated by a 12-crown-4 pseudo structure. As a result, for the studied polymeric segment (Mn=1500gmol(-1)), PEO-PAMAM hybrid molecules exhibited a more expanded shape when adducted to lithium as compared to proton.

  11. Conformational and Dynamic Properties of Poly(ethylene oxide) in an Ionic Liquid: Development and Implementation of a First-Principles Force Field.

    PubMed

    McDaniel, Jesse G; Choi, Eunsong; Son, Chang-Yun; Schmidt, J R; Yethiraj, Arun

    2016-01-14

    The conformational properties of polymers in ionic liquids are of fundamental interest but not well understood. Atomistic and coarse-grained molecular models predict qualitatively different results for the scaling of chain size with molecular weight, and experiments on dilute solutions are not available. In this work, we develop a first-principles force field for poly(ethylene oxide) (PEO) in the ionic liquid 1-butyl 3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) using symmetry adapted perturbation theory (SAPT). At temperatures above 400 K, simulations employing both the SAPT and OPLS-AA force fields predict that PEO displays ideal chain behavior, in contrast to previous simulations at lower temperature. We therefore argue that the system shows a transition from extended to more compact configurations as the temperature is increased from room temperature to the experimental lower critical solution temperature. Although polarization is shown to be important, its implicit inclusion in the OPLS-AA force is sufficient to describe the structure and energetics of the mixture. The simulations emphasize the difference between ionic liquids from typical solvents for polymers.

  12. On-line sample preconcentration by sweeping and poly(ethylene oxide)-mediated stacking for simultaneous analysis of nine pairs of amino acid enantiomers in capillary electrophoresis.

    PubMed

    Lin, En-Ping; Lin, Kai-Cheng; Chang, Chia-Wei; Hsieh, Ming-Mu

    2013-09-30

    This study proposes a sensitive method for the simultaneous separation and concentration of 9 pairs of amino acid enantiomers by combining poly(ethylene oxide) (PEO)-based stacking, β-cyclodextrin (β-CD)-mediated micellar electrokinetic chromatography (MEKC), and 9-fluoroenylmethyl chloroformate (FMOC) derivatization. The 9 pairs of FMOC-derivatized amino acid enantiomers were baseline separated using a discontinuous system, and the buffer vials contained a solution of 150 mM Tris-borate (TB), 12.5% (v/v) isopropanol (IPA), 0.5% (w/v) PEO, 35 mM sodium taurodeoxycholate (STDC), and 35 mM β-CD, and the capillary was filled with a solution of 1.5 M TB, 12.5% (v/v) IPA, 35 mM STDC, and 35 mM β-CD. Based on the difference in viscosity between the sample zone and PEO solution and because of the STDC sweeping, the discontinuous system effectively stacked 670 nL of the 9 pairs of FMOC-derivatized amino acid enantiomers without losing chiral resolution. Consequently, the limits of detection for the 9 pairs of FMOC-derivatized amino acid enantiomers were reduced to 40-60 nM. This method was successfully used to determine d-Tryptophan (Trp), l-Trp, d-Phenylalanine (Phe), l-Phe, d-Glutamic acid (Glu), and l-Glu in various types of beers.

  13. A new solid polymer electrolyte incorporating Li10GeP2S12 into a polyethylene oxide matrix for all-solid-state lithium batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Yanran; Wu, Chuan; Peng, Gang; Chen, Xiaotian; Yao, Xiayin; Bai, Ying; Wu, Feng; Chen, Shaojie; Xu, Xiaoxiong

    2016-01-01

    Li10GeP2S12 (LGPS) is incorporated into polyethylene oxide (PEO) matrix to fabricate composite solid polymer electrolyte (SPE) membranes. The lithium ion conductivities of as-prepared composite membranes are evaluated, and the optimal composite membrane exhibits a maximum ionic conductivity of 1.21 × 10-3 S cm-1 at 80 °C and an electrochemical window of 0-5.7 V. The phase transition behaviors for electrolytes are characterized by DSC, and the possible reasons for their enhanced ionic conductivities are discussed. The LGPS microparticles, acting as active fillers incorporation into the PEO matrix, have a positive effect on the ionic conductivity, lithium ion transference number and electrochemical stabilities. In addition, two kinds of all-solid-state lithium batteries (LiFeO4/SPE/Li and LiCoO2/SPE/Li) are fabricated to demonstrate the good compatibility between this new SPE membrane and different electrodes. And the LiFePO4/Li battery exhibits fascinating electrochemical performance with high capacity retention (92.5% after 50 cycles at 60 °C) and attractive capacities of 158, 148, 138 and 99 mAh g-1 at current rates of 0.1 C, 0.2 C, 0.5 C and 1 C at 60 °C, respectively. It is demonstrated that this new composite SPE should be a promising electrolyte applied in solid state batteries based on lithium metal electrode.

  14. Formulation and in vitro evaluation of floating tablets of hydroxypropyl methylcellulose and polyethylene oxide using ranitidine hydrochloride as a model drug

    PubMed Central

    Gharti, KP; Thapa, P; Budhathoki, U; Bhargava, A

    2012-01-01

    The present study was carried out with an objective of preparation and in vitro evaluation of floating tablets of hydroxypropyl methyl cellulose (HPMC) and polyethylene oxide (PEO) using ranitidine hydrochloride as a model drug. The floating tablets were based on effervescent approach using sodium bicarbonate a gas generating agent. The tablets were prepared by dry granulation method. The effect of polymers concentration and viscosity grades of HPMC on drug release profile was evaluated. The effect of sodium bicarbonate and stearic acid on drug release profile and floating properties were also investigated. The result of in vitro dissolution study showed that the drug release profile could be sustained by increasing the concentration of HPMC K15MCR and Polyox WSR303. The formulation containing HPMC K15MCR and Polyox WSR303 at the concentration of 13.88% showed 91.2% drug release at the end of 24 hours. Changing the viscosity grade of HPMC from K15MCR to K100MCR had no significant effect on drug release profile. Sodium bicarbonate and stearic acid in combination showed no significant effect on drug release profile. The formulations containing sodium bicarbonate 20 mg per tablet showed desired buoyancy (floating lag time of about 2 minutes and total floating time of >24 hours). The present study shows that polymers like HPMC K15MCR and Polyox WSR303 in combination with sodium bicarbonate as a gas generating agent can be used to develop sustained release floating tablets of ranitidine hydrochloride. PMID:23493037

  15. Simulation of synaptic short-term plasticity using Ba(CF3SO3)2-doped polyethylene oxide electrolyte film

    PubMed Central

    Chang, C. T.; Zeng, F.; Li, X. J.; Dong, W. S.; Lu, S. H.; Gao, S.; Pan, F.

    2016-01-01

    The simulation of synaptic plasticity using new materials is critical in the study of brain-inspired computing. Devices composed of Ba(CF3SO3)2-doped polyethylene oxide (PEO) electrolyte film were fabricated and with pulse responses found to resemble the synaptic short-term plasticity (STP) of both short-term depression (STD) and short-term facilitation (STF) synapses. The values of the charge and discharge peaks of the pulse responses did not vary with input number when the pulse frequency was sufficiently low(~1 Hz). However, when the frequency was increased, the charge and discharge peaks decreased and increased, respectively, in gradual trends and approached stable values with respect to the input number. These stable values varied with the input frequency, which resulted in the depressed and potentiated weight modifications of the charge and discharge peaks, respectively. These electrical properties simulated the high and low band-pass filtering effects of STD and STF, respectively. The simulations were consistent with biological results and the corresponding biological parameters were successfully extracted. The study verified the feasibility of using organic electrolytes to mimic STP. PMID:26739613

  16. Polyethylene Oxide Films Polymerized by Radio Frequency Plasma-Enhanced Chemical Vapour Phase Deposition and Its Adsorption Behaviour of Platelet-Rich Plasma

    NASA Astrophysics Data System (ADS)

    Hu, Wen-Juan; Xie, Fen-Yan; Chen, Qiang; Weng, Jing

    2008-10-01

    We present polyethylene oxide (PEO) functional films polymerized by rf plasma-enhanced vapour chemical deposition (rf-PECVD) on p-Si (100) surface with precursor ethylene glycol dimethyl ether (EGDME) and diluted Ar in pulsed plasma mode. The influences of discharge parameters on the film properties and compounds are investigated. The film structure is analysed by Fourier transform infrared (FTIR) spectroscopy. The water contact angle measurement and atomic force microscope (AFM) are employed to examine the surface polarity and to detect surface morphology, respectively. It is concluded that the smaller duty cycle in pulsed plasma mode contributes to the rich C-O-C (EO) group on the surfaces. As an application, the adsorption behaviour of platelet-rich plasma on plasma polymerization films performed in-vitro is explored. The shapes of attached cells are studied in detail by an optic invert microscope, which clarifies that high-density C-O-C groups on surfaces are responsible for non-fouling adsorption behaviour of the PEO films.

  17. Organic-inorganic random copolymers from methacrylate-terminated poly(ethylene oxide) with 3-methacryloxypropylheptaphenyl polyhedral oligomeric silsesquioxane: synthesis via RAFT polymerization and self-assembly behavior.

    PubMed

    Wei, Kun; Li, Lei; Zheng, Sixun; Wang, Ge; Liang, Qi

    2014-01-14

    In this contribution, we report the synthesis of organic-inorganic random polymers from methacrylate-terminated poly(ethylene oxide) (MAPEO) (Mn = 950) and 3-methacryloxypropylheptaphenyl polyhedral oligomeric silsesquioxane (MAPOSS) macromers via reversible addition-fragmentation chain transfer (RAFT) polymerization with 4-cyano-4-(thiobenzoylthio) valeric acid (CTBTVA) as the chain transfer agent. The organic-inorganic random copolymers were characterized by means of (1)H NMR spectroscopy, gel permeation chromatography (GPC) and differential scanning calorimetry (DSC). The results of GPC indicate that the polymerizations were carried out in a controlled fashion. Transmission electron microscopy (TEM) showed that the organic-inorganic random copolymers in bulk were microphase-separated and the POSS microdomains were formed via POSS-POSS interactions. In aqueous solutions the organic-inorganic random copolymers were capable of self-assembling into spherical nanoobjects as evidenced by transmission electron microscopy (TEM) and dynamic laser scattering (DLS). The self-assembly behavior of the organic-inorganic random copolymers was also found to occur in the mixtures with the precursors of epoxy. The nanostructures were further fixed via subsequent curing reaction and thus the organic-inorganic nanocomposites were obtained. The formation of nanophases in epoxy thermosets was confirmed by transmission electron microscopy (TEM) and dynamic mechanical thermal analysis (DMTA). The organic-inorganic nanocomposites displayed the enhanced surface hydrophobicity as evidenced by surface contact angle measurements.

  18. Dynamics of a poly(ethylene oxide) tracer in a poly(methyl methacrylate) matrix: remarkable decoupling of local and global motions.

    PubMed

    Haley, Jeffrey C; Lodge, Timothy P

    2005-06-15

    The tracer diffusion coefficient of unentangled poly(ethylene oxide) (PEO, M=1000 gmol) in a matrix of poly(methyl methacrylate) (PMMA, M=10 000 gmol) has been measured over a temperature range from 125 to 220 degrees C with forced Rayleigh scattering. The dynamic viscosities of blends of two different high molecular weight PEO tracers (M=440 000 and 900 000 gmol) in the same PMMA matrix were also measured at temperatures ranging from 160 to 220 degrees C; failure of time-temperature superposition was observed for these systems. The monomeric friction factors for the PEO tracers were extracted from the diffusion coefficients and the rheological relaxation times using the Rouse model. The friction factors determined by diffusion and rheology were in good agreement, even though the molecular weights of the tracers differed by about three orders of magnitude. The PEO monomeric friction factors were compared with literature data for PEO segmental relaxation times measured directly with NMR. The monomeric friction factors of the PEO tracer in the PMMA matrix were found to be from two to six orders of magnitude greater than anticipated based on direct measurements of segmental dynamics. Additionally, the PEO tracer terminal dynamics are a much stronger function of temperature than the corresponding PEO segmental dynamics. These results indicate that the fastest PEO Rouse mode, inferred from diffusion and rheology, is completely separated from the bond reorientation of PEO detected by NMR. This result is unlike other blend systems in which global and local motions have been compared.

  19. Mesoscale simulation of the formation and dynamics of lipid-structured poly(ethylene oxide)-block-poly(methyl methacrylate) diblock copolymers.

    PubMed

    Mu, Dan; Li, Jian-Quan; Feng, Sheng-Yu

    2015-05-21

    Twelve poly(ethylene oxide)-block-poly(methyl methacrylate) (PEO-b-PMMA) copolymers with lipid-like structures were designed and investigated by MesoDyn simulation. Spherical and worm-like micelles as well as bicontinuous, lamellar and defected lamellar phases were obtained. A special structure, designated B2412, with two lipid structures connected by their heads, was found to undergo four stages prior to forming a spherical micelle phase. Two possible assembly mechanisms were found via thermodynamic and dynamic process analyses; namely, the fusion and fission of micelles in dynamic equilibrium during the adjustment stage. Water can be encapsulated into these micelles, which can affect their size, particularly in low concentration aqueous solutions. The assignment of weak negative charges to the hydrophilic EO blocks resulted in a clear effect on micelle size. Surprisingly, the largest effect was observed with EO blocks with -0.5 e, wherein an ordered perfect hexagonal phase was formed. The obtained results can be applied in numerous fields of study, including adsorption, catalysis, controlled release and drug delivery.

  20. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  1. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene glycol (mean molecular weight 200-9... Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene... chapter. (c) The provisions of paragraph (b) of this section are not applicable to polyethylene...

  2. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  3. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  4. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Polyethylene glycol (mean molecular weight 200-9... Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol... polyethylene glycol 400 shall be used to determine the total ethylene and diethylene glycol content...

  5. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  6. 40 CFR 721.7255 - Polyethyleneamine crosslinked with substituted polyethylene glycol (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... substituted polyethylene glycol (generic). 721.7255 Section 721.7255 Protection of Environment ENVIRONMENTAL... substituted polyethylene glycol (generic). (a) Chemical substance and significant new uses subject to... substituted polyethylene glycol with substituted polyethylene glycol (PMN P-01-833) is subject to...

  7. Creep behavior of 6 micrometer linear low density polyethylene film

    NASA Technical Reports Server (NTRS)

    Simpson, J. M.; Schur, W. W.

    1993-01-01

    Creep tests were performed to provide material characteristics for a 6.4-micron polyethylene film used to construct high altitude balloons. Results suggest simple power law relationships are adequate for stresses below about 4.83 MPa.

  8. TECHNICAL GUIDANCE DOCUMENT: THE FABRICATION OF POLYETHYLENE FML FIELD SEAMS

    EPA Science Inventory

    This technical guidance document is meant to augment the numerous construction quality control and construction assurance (CQC and CQA) guidelines that are presently available for high density polyethylene (HDPE) liner installation and inspection.

  9. Polyethylene/Boron Composites for Radiation Shielding Applications

    SciTech Connect

    Harrison, Courtney; Grulke, Eric; Burgett, Eric; Hertel, Nolan

    2008-01-21

    Multifunctional composites made with boron are absorbers of low energy nuetrons, and could be used for structural shielding materials. Polyethylene/boron carbide composites were fabricated using conventional polymer processing techniques, and were evaluated for mechanical and radiation shielding properties. Addition of neat boron carbide (powder and nanoparticles) to an injection molding grade HPDE showed superior mechanical properties compared to neat HDPE. Radiation shielding measurements of a 2 wt% boron carbide composite were improved over those of the neat polyethylene.

  10. The mechanical properties of density graded hemp/polyethylene composites

    NASA Astrophysics Data System (ADS)

    Dauvegis, Raphaël; Rodrigue, Denis

    2015-05-01

    In this work, the production and mechanical characterization of density graded biocomposites based on high density polyethylene and hemp fibres was performed. The effect of coupling agent addition (maleated polyethylene) and hemp content (0-30%) was studied to determine the effect of hemp distribution (graded content) inside the composite (uniform, linear, V and Λ). Tensile and flexural properties are reported to compare the structures, especially in terms of their stress-strain behaviors under tensile loading.

  11. Polyethylene terephthalate degradation under reactor neutron irradiation

    NASA Astrophysics Data System (ADS)

    Chikaoui, K.; Izerrouken, M.; Djebara, M.; Abdesselam, M.

    2017-01-01

    This paper is devoted to study the defects generated by reactor neutron in polyethylene terephthalate (PET) films. The explored fast neutron fluence ranges from 2.02×1016 to 2.07×1018 n cm-2. The induced damages were investigated using ultraviolet-visible spectrophotometry (UV-vis), Fourier Transform Infrared spectrometry (FTIR) and X-ray diffraction (XRD). The UV-vis spectra show important changes indicating the degradation of the chemical structure and the creation of new chromophores. FTIR spectra reveal that the intensities of the different absorption bands decrease linearly under fast neutron irradiation. The internal reference band at 1410 cm-1 is used to follow the overall damage during irradiation. The 1342 cm-1 band corresponding to CH2 wagging of trans conformation of crystalline phase show a sharpe linear decrease as the fast neutrons fluence goes up. The creation of the monosubstituted benzene, investigated using the 1610 cm-1 band. It shows a linear increase with fast neutron fluence. It is found from XRD analysis that the diffraction peak (100) intensity is drastically reduced after irradiation at 2.02×1016 n cm-2.

  12. Polarimetric studies of polyethylene terephtalate flexible substrates

    NASA Astrophysics Data System (ADS)

    Stchakovsky, M.; Garcia-Caurel, E.; Warenghem, M.

    2008-12-01

    Polymer sheets are currently used worldwide in a wide range of applications. The manufacturing process of these sheets involves extruding machines that stretch the material in both lateral and longitudinal directions with respect to the machine direction, thus inducing birefringence. In most cases, the film obtained is optically biaxial. Polarimetric spectroscopy (Ellipsometry and Mueller Matrix) combined with conoscopic observation are the methods of choice to study these properties. In this work we report an analysis of commercially available polyethylene terephtalate (PET) films used as substrate for food packaging as well as for embedded electronic devices such as solar cells or flexible displays. Initial observation of these films through polarizing microscope in conoscopic mode reveals first the trace of optical axis plane with respect to the film surface and second, whether the optical axis is acute or not. This preliminary study allows optimal sample positioning for further polarimetric studies. The measurements and modelling are done in both reflection and transmission mode on several spectroscopic polarimetric setups from UV to NIR. The models give as a main result, the dielectric tensor of the film as well as its orientation with respect to the laboratory reference frame.

  13. Doping of ion implanted polyethylene with metallocarborane

    NASA Astrophysics Data System (ADS)

    Hnatowicz, V.; Vacík, J.; Červená, J.; Švorčík, V.; Rybka, V.; Popok, V.; Fink, D.; Klett, R.

    1995-11-01

    Polyethylene samples implanted with 150 keV F + ions to the doses from 5 × 10 13-1 × 10 15cm -2 were exposed to 0.05 M water solution of metallocarborane [(C 2B 9H 11) 2Co]Cs at temperatures of 24, 50 and 85°C, and the diffusion and incorporation of elements in the sample surface layer were studied using Rutherford back-scattering and neutron depth profiling techniques. The amount of incorporated B and Cs atoms was found to be an increasing function of the temperature for all implanted doses. The indiffusion and incorporation of the [(C 2B 9H 11) 2Co] - anion and the Cs + cation proceed separately and the final {B}/{Cs} ratio is well below metallocarborane stoichiometry in most cases. The total amount of incorporated Cs and B atoms and their depth profiles depend on the implanted dose in very complicated manner. For lower implanted doses anomalous depth profiles of B and Cs, roughly following calculated profiles of electronic energy loss of F + ions are observed.

  14. Theory of the deformation of aligned polyethylene

    PubMed Central

    Hammad, A.; Swinburne, T. D.; Hasan, H.; Del Rosso, S.; Iannucci, L.; Sutton, A. P.

    2015-01-01

    Solitons are proposed as the agents of plastic and viscoelastic deformation in aligned polyethylene. Interactions between straight, parallel molecules are mapped rigorously onto the Frenkel–Kontorova model. It is shown that these molecular interactions distribute an applied load between molecules, with a characteristic transfer length equal to the soliton width. Load transfer leads to the introduction of tensile and compressive solitons at the chain ends to mark the onset of plasticity at a well-defined yield stress, which is much less than the theoretical pull-out stress. Interaction energies between solitons and an equation of motion for solitons are derived. The equation of motion is based on Langevin dynamics and the fluctuation–dissipation theorem and it leads to the rigorous definition of an effective mass for solitons. It forms the basis of a soliton dynamics in direct analogy to dislocation dynamics. Close parallels are drawn between solitons in aligned polymers and dislocations in crystals, including the configurational force on a soliton. The origins of the strain rate and temperature dependencies of the viscoelastic behaviour are discussed in terms of the formation energy of solitons. A failure mechanism is proposed involving soliton condensation under a tensile load. PMID:26339196

  15. Final report on the safety assessment of polyethylene.

    PubMed

    2007-01-01

    Polyethylene is an ethylene polymer used for a variety of purposes in cosmetics as an abrasive, adhesive, binder or bulking agent, an emulsion stabilizer, a film former, an oral care agent, and as a nonaqueous viscosity-increasing agent. Polyethylene is also used in food packaging materials and medical products, including prosthetics. The molecular weight of Polyethylene as used in cosmetics varies over a wide range. The lowest reported molecular weight is 198 Daltons and the highest is 150,000. In any given polymer preparation, there can be a broad range of molecular weights. Cellular and tissue responses to Polyethylene, determined as part of implant biocompatibility testing, include fibrous connective tissue build-up around the implant material that varies as a function of the physical form of the implant material. Specific assays for osteoblast proliferation and collagen synthesis demonstrated a reduction as a function of exposure to Polyethylene particles that is inversely related to particle size. The effect of Polyurethane particles on monocyte-derived macrophages, however, had a stimulatory effect, prolonging the survival of these cells in culture. The LD50 for Polyethylene, with an average molecular weight of 450, in rats was > 2000 mg/kg. For Polyethylene with an average molecular weight of 655, the LD50 was > 5.0 g/kg. Toxicity testing in rats shows no adverse effects at Polyethylene (molecular weight not given) doses of 7.95 g/kg or at 1.25%, 2.50%, or 5.00% in feed for 90 days. Dermal irritation studies on rabbits in which 0.5 g of Polyethylene (average molecular weight of 450) was administered in 0.5 ml of water caused no irritation or corrosive effects; Polyethylene with an average molecular weight of 655 was a mild irritant. Polyethylene (average molecular weight of 450) did not cause dermal sensitization in guinea pigs tested with 50% Polyethylene (w/w) in arachis oil BP. Polyethylene, with a molecular weight of 450 and a molecular weight of 655

  16. Launch Vehicle with Combustible Polyethylene Case Gasification Chamber Design Basis

    NASA Astrophysics Data System (ADS)

    Yemets, V.

    A single-stage launch vehicle equipped with a combustible tank shell of polyethylene and a moving propulsion plant is proposed. The propulsion plant is composed of a chamber for the gasification of the shell, a compressor of pyrolysed polyethylene and a magnetic powder obturator. It is shown that the “dental” structure of the gasification chamber is necessary to achieve the necessary contact area with the polyethylene shell. This conclusion is drawn from consideration of the thermo- physical properties of polyethylene, calculating quasisteady temperature field in the gasification chamber, estimating gasification rate of polyethylene, launch vehicle shortening rate and area of gasification. Experimental determination of the gasification rate is described. The gasification chamber specific mass as well as the propulsion plant weight-to-thrust ratio are estimated under some assumptions concerning the obturator and compressor. Combustible launch vehicles are compared with conventional launch vehicles taking into consideration their payload mass ratios. Combustible launchers are preferable as small launchers for micro and nano satellites. Reusable versions of such launchers seem suitable if polyethylene tank shells filled with metal or metal hydride fine dusts are used.

  17. Synthesis and dose interval dependent hepatotoxicity evaluation of intravenously administered polyethylene glycol-8000 coated ultra-small superparamagnetic iron oxide nanoparticle on Wistar rats.

    PubMed

    Rajan, Balan; Sathish, Shanmugam; Balakumar, Subramanian; Devaki, Thiruvengadam

    2015-03-01

    Superparamagnetic iron oxide nanoparticles are being used in medical imaging, drug delivery, cancer therapy, and so on. However, there is a direct need to identify any nanotoxicity associated with these nanoparticles. However uncommon, drug-induced liver injury (DILI) is a major health concern that challenges pharmaceutical industry and drug regulatory agencies alike. In this study we have synthesized and evaluated the dose interval dependent hepatotoxicity of polyethylene glycol-8000 coated ultra-small superparamagnetic iron oxide nanoparticles (PUSPIOs). To assess the hepatotoxicity of intravenously injected PUSPIOs, alterations in basic clinical parameters, hematological parameters, hemolysis assay, serum levels of liver marker enzymes, serum and liver lipid peroxidation (LPO) levels, enzymatic antioxidant levels, and finally histology of liver, kidney, spleen, lung, brain, and heart tissues were studied in control and experimental Wistar rat groups over a 30-day period. The results of our study showed a significant increase in the aspartate transaminase (AST) enzyme activity at a dose of 10mg/kg b.w. PUSPIOs twice a week. Besides, alanine transaminase (ALT), alkaline phosphatase (ALP), and gamma-glutamyl transferase (γGT) enzyme activity showed a slender increase when compared with control experimental groups. A significant increase in the serum and liver LPO levels at a dose of 10mg/kg b.w. PUSPIOs twice a week was also observed. Histological analyses of liver, kidney, spleen, lung, brain and heart tissue samples showed no obvious uncharacteristic changes. In conclusion, PUSPIOs were found to posses excellent biocompatibility and Wistar rats showed much better drug tolerance to the dose of 10mg/kg b.w. per week than the dose of 10mg/kg b.w. twice a week for the period of 30 days.

  18. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...

  19. [UHMWPE - polyethylene for articulating surfaces of joint replacements].

    PubMed

    Pokorný, David; Sosna, Antonín; Šlouf, Miroslav; Fulín, Petr; Štefan, Jan; Landor, Ivan

    2016-01-01

    The introduction of artificial joint replacement constitutes a breakthrough method of treatment for severe joint disease for millions of people worldwide.Annual increase in the number of primary replacement and also increasing demands on the longevity of joint replacements are leading to increased demands on wear resistance of articular surface. Ultra-high molecular weight polyethylene (UHMWPE) is still most commonly used material for the production of articular surface. It was introduced into clinical practice in the 60s of the 20th century. Physical-chemical properties of UHMWPE are subject of many studies. These lead gradually to its improvement in terms of higher wear resistance while maintaining the stability against oxidative degradation.The main objective of this review is to summarize the basic properties of high-molecular weight polyethylene which are important for its use in orthopaedic practice and to explain the possibilities of its modification and sterilization. Knowledge of the latest trends about this material helps to orthopaedic surgeons get oriented in the issues and then to choose for their patients implants with the highest implant longevity.

  20. Horseradish Peroxidase Inactivation: Heme Destruction and Influence of Polyethylene Glycol

    PubMed Central

    Mao, Liang; Luo, Siqiang; Huang, Qingguo; Lu, Junhe

    2013-01-01

    Horseradish peroxidase (HRP) mediates efficient conversion of many phenolic contaminants and thus has potential applications for pollution control. Such potentially important applications suffer however from the fact that the enzyme becomes quickly inactivated during phenol oxidation and polymerization. The work here provides the first experimental data of heme consumption and iron releases to support the hypothesis that HRP is inactivated by heme destruction. Product of heme destruction is identified using liquid chromatography with mass spectrometry. The heme macrocycle destruction involving deprivation of the heme iron and oxidation of the 4-vinyl group in heme occurs as a result of the reaction. We also demonstrated that heme consumption and iron releases resulting from HRP destruction are largely reduced in the presence of polyethylene glycol (PEG), providing the first evidence to indicate that heme destruction is effectively suppressed by co-dissolved PEG. These findings advance a better understanding of the mechanisms of HRP inactivation. PMID:24185130

  1. Formation of high-stress phase and extrusion of polyethylene due to nanoconfinements during Ziegler-Natta polymerization inside nanochannels.

    PubMed

    Nair, Sujith; Naredi, Prabhat; Kim, Seong H

    2005-06-30

    Polyethylene nanofibers were synthesized by heterogeneous Ziegler-Natta polymerization inside nanochannels of robust anodized aluminum oxide (AAO) membranes. The polymerization catalysts were chemisorbed at the inner wall of the nanochannels and monomers were provided through diffusion from the outside. Polyethylene is produced inside the nanochannels in the 10-20 mum region from the channel entrance. Polyethylene fibers were extruded from the nanochannels up to 3-5 mum during the polymerization. X-ray diffraction, differential scanning calorimetry, and Fourier transform infrared analyses indicated formation of a highly stressed crystalline structure although the polymerization was carried out without any external pressure or mechanical work. The highly stressed phase formation inside nanochannels and some degree of polyethylene nanofiber extrusion from nanochannels were attributed to catalytic production of excess amounts of polyethylene inside nanoconfined templates.

  2. Extraction of actinides into aqueous polyethylene glycol solutions from carbonate media in the presence of alizarin complexone

    SciTech Connect

    Molochnikova, N.P.; Frenkel', V.Ya.; Myasoedov, B.F.; Shkinev, V.M.; Spivakov, B.Ya.; Zolotov, Yu.A.

    1987-01-01

    Actinide extraction in a two-phase aqueous system based on polyethylene glycol from carbonate solutions of various compositions in presence of alizarin complexone is studied. It is shown that the nature of the alkali metals affects actinide extraction into the polyethylene glycol phase. Tri- and tetravalent actinides are extracted maximally from sodium carbonate solutions. Separation of actinides in different oxidation states is more effective in potassium carbonate solutions. The behavior of americium in different oxidation states in the system carbonate-polyethylene glycol-complexone is studied. The possibility of extraction separation of microamount of americium(V) from curium in carbonate solutions in presence of alizarin complexone is shown.

  3. Study on ternary low density polyethylene/linear low density polyethylene/thermoplastic starch blend films.

    PubMed

    Sabetzadeh, Maryam; Bagheri, Rouhollah; Masoomi, Mahmood

    2015-03-30

    In this work, low-density polyethylene/linear low-density polyethylene/thermoplastic starch (LDPE/LLDPE/TPS) films are prepared with the aim of obtaining environmentally friendly materials containing high TPS content with required packaging properties. Blending of LDPE/LLDPE (70/30 wt/wt) with 5-20 wt% of TPS and 3 wt% of PE-grafted maleic anhydride (PE-g-MA) is performed in a twin-screw extruder, followed by the blowing process. Differential scanning calorimetric results indicate starch has more pronounced effect on crystallization of LLDPE than LDPE. Scanning electron micrograph shows a fairly good dispersion of TPS in PE matrices. Fourier transfer infrared spectra confirm compatibility between polymers using PE-g-MA as the compatibilizer. Storage modulus, loss modulus and complex viscosity increase with incorporation of starch. Tensile strength and elongation-at-break decrease from 18 to 10.5 MPa and 340 to 200%, respectively when TPS increases from 5 to 20%. However, the required mechanical properties for packaging applications are attained when 15 wt% starch is added, as specified in ASTM D4635. Finally 12% increase in water uptake is achieved with inclusion of 15 wt% starch.

  4. Structure-property relationship in polyethylene reinforced by polyethylene-grafted multi-walled carbon nanotubes.

    PubMed

    Causin, Valerio; Yang, Bing-Xing; Marega, Carla; Goh, Suat Hong; Marigo, Antonio

    2008-04-01

    Polyethylene-grafted multiwalled carbon nanotubes (PE-g-MWNT) were used to reinforce polyethylene (PE). The nanocomposites possessed not only improved stiffness and strength, but also increased ductility and toughness. The effects on the structure and morphology of composites due to pristine multiwalled carbon nanotubes (MWNT) and PE-g-MWNT were studied and compared using small angle X-ray scattering (SAXS), wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC). The SAXS long period, crystalline layer thickness and crystallinity of polymer lamellar stacks were found to decrease significantly in MWNT composites, while the decreases were much smaller in PE-g-MWNT composites. PE-g-MWNT allowed a more efficient and unhindered crystallization at a lamellar level, while MWNT disrupted the order of lamellar stacks, probably because of their tendency to aggregate. The SAXS crystallinity and the mechanical properties of the composites showed similar trends as a function of MWNT content. This suggested that the improvement of the interfacial strength between polymer and carbon nanotubes was a result of synergistic effects of better dispersion of the filler, better stress transfer, due to the grafting of polymer and MWNT, and the nucleation of a crystalline phase around MWNT. The latter effect was confirmed by measurements of kinetics of non-isothermal crystallization.

  5. Dynamics in entangled polyethylene melts [Multi time scale dynamics in entangled polyethylene melts

    SciTech Connect

    Salerno, K. Michael; Agrawal, Anupriya; Peters, Brandon L.; Perahia, Dvora; Grest, Gary S.

    2016-10-10

    Polymer dynamics creates distinctive viscoelastic behavior as a result of a coupled interplay of motion at the atomic length scale and motion of the entire macromolecule. Capturing the broad time and length scales of polymeric motion however, remains a challenge. Using linear polyethylene as a model system, we probe the effects of the degree of coarse graining on polymer dynamics. Coarse-grained (CG) potentials are derived using iterative Boltzmann inversion with λ methylene groups per CG bead (denoted CGλ) with λ = 2,3,4 and 6 from a fully-atomistic polyethylene melt simulation. By rescaling time in the CG models by a factor α, the chain mobility for the atomistic and CG models match. We show that independent of the degree of coarse graining, all measured static and dynamic properties are essentially the same once the dynamic scaling factor α and a non-crossing constraint for the CG6 model are included. The speedup of the CG4 model is about 3 times that of the CG3 model and is comparable to that of the CG6 model. Furthermore, using these CG models we were able to reach times of over 500 μs, allowing us to measure a number of quantities, including the stress relaxation function, plateau modulus and shear viscosity, and compare directly to experiment.

  6. Dynamics in entangled polyethylene melts [Multi time scale dynamics in entangled polyethylene melts

    DOE PAGES

    Salerno, K. Michael; Agrawal, Anupriya; Peters, Brandon L.; ...

    2016-10-10

    Polymer dynamics creates distinctive viscoelastic behavior as a result of a coupled interplay of motion at the atomic length scale and motion of the entire macromolecule. Capturing the broad time and length scales of polymeric motion however, remains a challenge. Using linear polyethylene as a model system, we probe the effects of the degree of coarse graining on polymer dynamics. Coarse-grained (CG) potentials are derived using iterative Boltzmann inversion with λ methylene groups per CG bead (denoted CGλ) with λ = 2,3,4 and 6 from a fully-atomistic polyethylene melt simulation. By rescaling time in the CG models by a factormore » α, the chain mobility for the atomistic and CG models match. We show that independent of the degree of coarse graining, all measured static and dynamic properties are essentially the same once the dynamic scaling factor α and a non-crossing constraint for the CG6 model are included. The speedup of the CG4 model is about 3 times that of the CG3 model and is comparable to that of the CG6 model. Furthermore, using these CG models we were able to reach times of over 500 μs, allowing us to measure a number of quantities, including the stress relaxation function, plateau modulus and shear viscosity, and compare directly to experiment.« less

  7. Effect of amine functionalized polyethylene on clay-silver dispersion for polyethylene nanocomposites

    NASA Astrophysics Data System (ADS)

    Sánchez-Valdes, S.; Ibarra-A, M. C.; Ramírez-V, E.; Ramos-V, L. F.; Martinez-C, J. G.; Romero-G, J.; Ledezma-P, A. S.; Rodriguez-F, O. S.

    2014-08-01

    The compatibilization provided by maleic anhydride (MA) and 2-[2-(dimethylamino)-ethoxy] ethanol (DMAE) functionalized polyethylene for forming polyethylene-based nanocomposites was studied and compared. MA was grafted into PE by melt mixing to obtain PEgMA (compatibilizer 1), thereafter, PEgMA was reacted with DMAE and an antioxidant also by melt mixing to obtain PAgDMAE (compatibilizer 2). These compatibilizers were reacted using ultrasound with a solution of AgNO3 0.04 M and Ethylene glycol. Ammonium hydroxide was added in a ratio of 2:1 molar with respect to silver nitrate. These silver coated compatibilizers were mixed with PE and nano-clay (Cloisite I28E), thus forming the different hybrid PE-clay-silver nanocomposites. FTIR confirmed the formation of these two compatibilizers. All the compatibilized nanocomposites had better filler (clay and silver) dispersion and exfoliation compared to the uncompatibilized PE nanocomposites. X-ray diffraction, mechanical and antimicrobial properties attained showed that the PEgDMAE produced the better dispersed PE, clay and silver nanocomposites. The obtained nanocomposites showed outstanding antimicrobial properties against bacteria, Escherichia coli and fungus, Aspergillus niger. It is concluded that the PEgDMAE offers an outstanding capability for preparing nanocomposites with highly exfoliated and dispersed filler into the PE matrix.

  8. In vitro and in vivo evaluation of a new nanocomposite, containing high density polyethylene, tricalcium phosphate, hydroxyapatite, and magnesium oxide nanoparticles.

    PubMed

    Pourdanesh, Fereydoun; Jebali, Ali; Hekmatimoghaddam, Seyedhossein; Allaveisie, Azra

    2014-07-01

    In this study, a new nanocomposite, which contained high density polyethylene (HDPE), tricalcium phosphate (Ca3(PO4)2) nanoparticles (TCP NPs), hydroxyapatite nanoparticles (HA NPs), and magnesium oxide nanoparticles (MgO NPs) was prepared. As in vitro experiment, human osteoblasts (HOB) cells were exposed to pristine HDPE and its nanocomposite for a period of 1, 4, and 7 days at 37 °C, and then different assays were carried out, including osteoblast cell proliferation, Trypan blue staining, cell viability, alkaline phosphatase (ALP), and cell adhesion. Antibacterial property of pristine HDPE and its nanocomposite was evaluated, and also their mechanical properties were measured after 2 and 4 months. As in vivo experiment, pristine HDPE and its nanocomposite were separately implanted on calvarium bone of rabbits, and tissue inflammation and osteogenesis were investigated after 2, 4, and 6 months. In case of HOB cells treated with HDPE or nanocomposite, as incubation time was increased, cell proliferation, live/dead ratio, and cell viability were decreased. But, the ALP activity and cell adhesion of HOB cells which treated with nanocomposite were raised after increase of incubation time. This study demonstrated that although the mechanical properties of nanocomposite were similar to HDPE sheet, but their antibacterial property was not similar. The in vivo experiment showed that both pristine HDPE and its nanocomposite had same inflammation responses. Interestingly, osteogenesis was observed after 2 months at bone/nanocomposite interface, and was highly increased after 4 and 6 months. It must be noted that such pattern was not seen at bone/HDPE interface.

  9. Q-switched erbium doped fiber laser based on single and multiple walled carbon nanotubes embedded in polyethylene oxide film as saturable absorber

    NASA Astrophysics Data System (ADS)

    Ahmed, M. H. M.; Ali, N. M.; Salleh, Z. S.; Rahman, A. A.; Harun, S. W.; Manaf, M.; Arof, H.

    2015-01-01

    A passive, stable and low cost Q-switched Erbium-doped fiber laser (EDFL) is demonstrated using both single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs), which are embedded in polyethylene oxide (PEO) film as a saturable absorber (SA). The film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation operating at wavelength of 1533.6 nm. With SWCNTs, the laser produces a stable pulse train with repetition rate and pulse width ranging from 9.52 to 33.33 kHz and 16.8 to 8.0 μs while varying the 980 nm pump power from 48.5 mW to 100.4 mW. On the other hand, with MWCNTs, the repetition rate and pulse width can be tuned in a wider range of 6.12-33.62 kHz and 9.5- 4.2 μs, respectively as the pump power increases from 37.9 to 120.6 mW. The MWCNTs produce the pulse train at a lower threshold and attain a higher repetition rate compared to the SWCNTs. This is due to thicker carbon nanotubes layer of the MWCNTs which provides more absorption and consequently higher damage threshold. The Q-switched EDFL produces the highest pulse energy of 531 nJ at pump power of 37.9 mW with the use of MWCNTs-PEO SA.

  10. Multifunctional Photosensitizer Grafted on Polyethylene Glycol and Polyethylenimine Dual-Functionalized Nanographene Oxide for Cancer-Targeted Near-Infrared Imaging and Synergistic Phototherapy.

    PubMed

    Luo, Shenglin; Yang, Zhangyou; Tan, Xu; Wang, Yang; Zeng, Yiping; Wang, Yu; Li, Changming; Li, Rong; Shi, Chunmeng

    2016-07-13

    The integration of photodynamic therapy (PDT) with photothermal therapy (PTT) offers improved efficacy in cancer phototherapy. Herein, a PDT photosensitizer (IR-808) with cancer-targeting ability and near-infrared (NIR) sensitivity was chemically conjugated to both polyethylene glycol (PEG)- and branched polyethylenimine (BPEI)-functionalized nanographene oxide (NGO). Because the optimal laser wavelength (808 nm) of NGO for PTT is consistent with that of IR-808 for PDT, the IR-808-conjugated NGO sheets (NGO-808, 20-50 nm) generated both large amounts of reactive oxygen species (ROS) and local hyperthermia as a result of 808 nm laser irradiation. With PEG- and BPEI-modified NGO as the carrier, the tumor cellular uptake of NGO-808 exhibited higher efficacy than that of strongly hydrophobic free IR-808. Through evaluation with both human and mouse cancer cells, NGO-808 was demonstrated to provide significantly enhanced PDT and PTT effects compared to individual PDT using IR-808 or PTT using NGO. Furthermore, NGO-808 preferentially accumulated in cancer cells as mediated by organic-anion transporting polypeptides (OATPs) overexpressed in many cancer cells, providing the potential for highly specific cancer phototherapy. Using the targeting ability of NGO-808, in vivo NIR fluorescence imaging enabled tumors and their margins to be clearly visualized at 48 h after intravenous injection, providing a theranostic platform for imaging-guided cancer phototherapy. Remarkably, after a single injection of NGO-808 and 808 nm laser irradiation for 5 min, the tumors in two tumor xenograft models were ablated completely, and no tumor recurrence was observed. After treatment with NGO-808, no obvious toxicity was detected in comparison to control groups. Thus, high-performance cancer phototherapy with minimal side effects was afforded from synergistic PDT/PTT treatment and cancer-targeted accumulation of NGO-808.

  11. Drug release, cell adhesion and wound healing evaluations of electrospun carboxymethyl chitosan/polyethylene oxide nanofibres containing phenytoin sodium and vitamin C.

    PubMed

    Zarandi, Mohammad Amin; Zahedi, Payam; Rezaeian, Iraj; Salehpour, Alireza; Gholami, Mehdi; Motealleh, Behrooz

    2015-08-01

    In this work, N, O-carboxymethyl chitosan (CMCS) samples from virgin chitosan (CS) were synthesised and CMCS/polyethylene oxide (PEO) (50/50) blend nanofibrous samples were successfully electrospun from their aqueous solution. The electrospinning conditions to achieve smooth and fine diameter nanofibrous mats were optimised via D-optimal design approach. Afterwards, vitamin C and phenytoin sodium (PHT-Na) were added to these samples for producing wound dressing materials. H-nuclear magnetic resonance, scanning electron microscopy and Fourier transform infrared tests for the evaluation of functionalised CS, morphology and biodegradability studies of CMCS/PEO blend nanofibrous samples were applied. The kinetic and drug release mechanism for vitamin C and PHT-Na drug-loaded electrospun samples were also investigated by UV-vis spectrophotometer and high performance liquid chromatography, respectively. The results showed an approximately similar drug release rate of the two drugs and followed Higuchi's kinetic model. The stem cells viability and their adhesion on the surface of the samples containing PHT-Na and vitamin C were carried out using MTT assay and the best cells' biocompatibility was obtained using both drugs into the CMCS/PEO nanofibrous samples. Moreover, the in vivo animal wound model results revealed that the electrospun samples containing vitamin C and PHT-Na (1%) had a remarkable efficiency in the wounds' closure and their healing process compared with vitamin C/PHT-Na (50/50) ointment. Finally, the histology observations showed that the wound treated with optimised electrospun samples containing two drugs enabled regeneration of epidermis layers due to collagen fibres accumulation followed by granulating tissues formation without necrosis.

  12. Dynamics of poly(ethylene oxide) in a blend with poly(methyl methacrylate): A quasielastic neutron scattering and molecular dynamics simulations study

    SciTech Connect

    Genix, A.-C.; Arbe, A.

    2005-09-01

    In this paper, we have addressed the question of the dynamic miscibility in a blend characterized by very different glass-transition temperatures, T{sub g}, for the components: poly(ethylene oxide) and poly(methyl methacrylate) (PEO/PMMA). The combination of quasielastic neutron scattering with isotopic labeling and fully atomistic molecular dynamics simulations has allowed us to selectively investigate the dynamics of the two components in the picosecond--10 nanoseconds scale at temperatures close and above the T{sub g} of the blend. The main focus was on the PEO component, i.e., that of the lowest T{sub g}, but first we have characterized the dynamics of the other component in the blend and of the pure PEO homopolymer as reference. In the region investigated, the dynamics of PMMA in the blend is strongly affected by the {alpha}-methyl rotation; an additional process detected in the experimental window 65 K above the blend-T{sub g} can be identified as the merged {alpha}{beta} process of this component that shows strong deviations from Gaussian behavior. On the other hand, pure PEO displays entropy driven dynamics up to very large momentum transfers. Such kind of motion seems to freeze when the PEO chains are in the blend. There, we have directly observed a very heterogeneous and moreover confined dynamics for the PEO component. The presence of the hardly moving PMMA matrix leads to the creation of little pockets of mobility where PEO can move. The characteristic size of such confined islands of mobility might be estimated to be of {approx_equal}1 nm. These findings are corroborated by the simulation study, which has been an essential support and guide in our data analysis procedure.

  13. Chemical stability and bioadhesive properties of an ester prodrug of Delta 9-tetrahydrocannabinol in poly(ethylene oxide) matrices: effect of formulation additives.

    PubMed

    Thumma, Sridhar; Majumdar, Soumyajit; ElSohly, Mahmoud A; Gul, Waseem; Repka, Michael A

    2008-10-01

    The objective of the present research was to stabilize a novel hemiglutarate ester prodrug of Delta(9)-tetrahydrocannabinol (THC), in polyethylene oxide (PEO) polymeric matrices produced by hot-melt fabrication, for systemic delivery of THC through the oral transmucosal route. For this purpose, the influence of pH modifiers and antioxidants employed as stabilizing agents in these matrices was investigated. Based on the stability studies, two final formulations were made, and the stability of the active was assessed in these systems. In addition, the bioadhesive properties of PEO matrices were studied as a function of bioadhesive polymer type and concentration, contact time, drug loading and wetting time. Of all of the polymers investigated, bioadhesion was highest with Carbopol 971p. Bioadhesion increased with bioadhesive polymer concentration and wetting time to a certain level beyond which there was no further contribution. Both the contact time and drug loading influenced the bioadhesion. Severe degradation of the prodrug was observed during storage, even at room temperature (75% at the end of 3 months). Incorporation of the stabilizing agents in the PEO matrices reduced the degradation of the prodrug considerably. Citric acid was the most effective of all of the pH modifiers studied. Among the various antioxidants utilized, degradation was observed least in presence of BHT and ascorbic acid. Only 7.6% and 8.2% of prodrug degraded in these matrices, respectively, as compared to the PEO-only matrices (59.4%) at the end of 3 months at 25 degrees C/60% RH. The prodrug was very stable in both of the final formulations at the end of the 3 months at 40 degrees C/75% RH.

  14. Dynamics of a poly(ethylene oxide) tracer in a poly(methyl methacrylate) matrix: Remarkable decoupling of local and global motions

    NASA Astrophysics Data System (ADS)

    Haley, Jeffrey C.; Lodge, Timothy P.

    2005-06-01

    The tracer diffusion coefficient of unentangled poly(ethylene oxide) (PEO, M =1000g/mol) in a matrix of poly(methyl methacrylate) (PMMA, M =10000g/mol) has been measured over a temperature range from 125to220°C with forced Rayleigh scattering. The dynamic viscosities of blends of two different high molecular weight PEO tracers (M =440000 and 900000g/mol) in the same PMMA matrix were also measured at temperatures ranging from 160to220°C; failure of time-temperature superposition was observed for these systems. The monomeric friction factors for the PEO tracers were extracted from the diffusion coefficients and the rheological relaxation times using the Rouse model. The friction factors determined by diffusion and rheology were in good agreement, even though the molecular weights of the tracers differed by about three orders of magnitude. The PEO monomeric friction factors were compared with literature data for PEO segmental relaxation times measured directly with NMR. The monomeric friction factors of the PEO tracer in the PMMA matrix were found to be from two to six orders of magnitude greater than anticipated based on direct measurements of segmental dynamics. Additionally, the PEO tracer terminal dynamics are a much stronger function of temperature than the corresponding PEO segmental dynamics. These results indicate that the fastest PEO Rouse mode, inferred from diffusion and rheology, is completely separated from the bond reorientation of PEO detected by NMR. This result is unlike other blend systems in which global and local motions have been compared.

  15. Dynamics of poly(ethylene oxide) in a blend with poly(methyl methacrylate): a quasielastic neutron scattering and molecular dynamics simulations study.

    PubMed

    Genix, A-C; Arbe, A; Alvarez, F; Colmenero, J; Willner, L; Richter, D

    2005-09-01

    In this paper, we have addressed the question of the dynamic miscibility in a blend characterized by very different glass-transition temperatures, Tg, for the components: poly(ethylene oxide) and poly(methyl methacrylate) (PEO/PMMA). The combination of quasielastic neutron scattering with isotopic labeling and fully atomistic molecular dynamics simulations has allowed us to selectively investigate the dynamics of the two components in the picosecond-10 nanoseconds scale at temperatures close and above the Tg of the blend. The main focus was on the PEO component, i.e., that of the lowest Tg, but first we have characterized the dynamics of the other component in the blend and of the pure PEO homopolymer as reference. In the region investigated, the dynamics of PMMA in the blend is strongly affected by the alpha-methyl rotation; an additional process detected in the experimental window 65 K above the blend-Tg can be identified as the merged alphabeta process of this component that shows strong deviations from Gaussian behavior. On the other hand, pure PEO displays entropy driven dynamics up to very large momentum transfers. Such kind of motion seems to freeze when the PEO chains are in the blend. There, we have directly observed a very heterogeneous and moreover confined dynamics for the PEO component. The presence of the hardly moving PMMA matrix leads to the creation of little pockets of mobility where PEO can move. The characteristic size of such confined islands of mobility might be estimated to be of approximately 1 nm. These findings are corroborated by the simulation study, which has been an essential support and guide in our data analysis procedure.

  16. Wear of highly crosslinked polyethylene acetabular components

    PubMed Central

    Callary, Stuart A; Solomon, Lucian B; Holubowycz, Oksana T; Campbell, David G; Munn, Zachary; Howie, Donald W

    2015-01-01

    Background and purpose Wear rates of highly crosslinked polyethylene (XLPE) acetabular components have varied considerably between different published studies. This variation is in part due to the different techniques used to measure wear and to the errors inherent in measuring the relatively low amounts of wear in XLPE bearings. We undertook a scoping review of studies that have examined the in vivo wear of XLPE acetabular components using the most sensitive method available, radiostereometric analysis (RSA). Methods A systematic search of the PubMed, Scopus, and Cochrane databases was performed to identify published studies in which RSA was used to measure wear of XLPE components in primary total hip arthroplasty (THA). Results 18 publications examined 12 primary THA cohorts, comprising only 260 THAs at 2–10 years of follow-up. The mean or median proximal wear rate reported ranged from 0.00 to 0.06 mm/year. However, differences in the manner in which wear was determined made it difficult to compare some studies. Furthermore, differences in RSA methodology between studies, such as the use of supine or standing radiographs and the use of beaded or unbeaded reference segments, may limit future meta-analyses examining the effect of patient and implant variables on wear rates. Interpretation This scoping review confirmed the low wear rates of XLPE in THA, as measured by RSA. We make recommendations to enhance the standardization of reporting of RSA wear results, which will facilitate early identification of poorly performing implants and enable a better understanding of the effects of surgical and patient factors on wear. PMID:25301435

  17. A comparison of the wear and physical properties of silane cross-linked polyethylene and ultra-high molecular weight polyethylene.

    PubMed

    Sakoda, H; Voice, A M; McEwen, H M; Isaac, G H; Hardaker, C; Wroblewski, B M; Fisher, J

    2001-12-01

    Cross-linked polyethylenes are being introduced widely in acetabular cups in hip prostheses as a strategy to reduce the incidence of wear debris-induced osteolysis. It will be many years before substantial clinical data can be collected on the wear of these new materials. Silane cross-linked polyethylene (XLPE) was introduced into clinical practice in a limited series of acetabular cups in 1986 articulating against 22.225-mm alumina ceramic femoral heads and showed reduced wear rates compared with conventionally sterilized (gamma irradiation in air) ultra-high molecular weight polyethylene (UHMWPE). We compared the wear of XLPE manufactured in 1986 with the wear of UHMWPE manufactured in 1986 in nonirradiated and irradiated forms. In the nonirradiated forms, the wear of XLPE was 3 times less than UHWMPE when articulating against smooth counterfaces. The nonirradiated materials did not show signs of oxidation. In the irradiated forms, only UHMWPE showed high levels of oxidation, and this caused a substantial increase in wear. Antioxidants added to XLPE during processing gave resistance to oxidative degradation. When sliding against scratched counterfaces, the wear of UHMWPE increased by a factor of 2 to 3 times. Against the same scratched counterfaces, the wear of XLPE increased dramatically by 30 to 200 times. This difference may be attributed to the reduction in toughness of XLPE. Clinically, XLPE has been articulated against damage-resistant ceramic heads, and this probably has been an important factor in contributing to reduced wear. New cross-linked polyethylenes differ considerably from XLPE. This study indicates that it is prudent to examine the wear of new polyethylenes under a range of conditions that may occur in vivo.

  18. Electron beam induced modification of poly(ethylene terephthalate) films

    NASA Astrophysics Data System (ADS)

    Vasiljeva, I. V.; Mjakin, S. V.; Makarov, A. V.; Krasovsky, A. N.; Varlamov, A. V.

    2006-10-01

    Electron beam processing of poly(ethylene terephthalate) (PET) films is found to promote significant changes in the melting heat, intrinsic viscosity and polymer film-liquid (water, isooctane and toluene) boundary surface tension. These properties are featured with several maximums depending on the absorbed dose and correlating with the modification of PET surface functionality. Studies using adsorption of acid-base indicators and IR-spectroscopy revealed that the increase of PET surface hydrophilicity is determined by the oxidation of methylene and methyne groups. Electron beam treatment of PET films on the surface of N-vinylpyrrolidone aqueous solution provided graft copolymerization with this comonomer at optimum process parameters (energy 700 keV, current 1 mA, absorbed dose 50 kGy).

  19. Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms

    PubMed Central

    Nalawade, Triveni Mohan; Bhat, Kishore; Sogi, Suma H. P.

    2015-01-01

    Aim: The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro. Materials and Methods: Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study. Results: All vehicles

  20. Comparison of stabilization by Vitamin E and 2,6-di-tert-butylphenols during polyethylene radio-thermal-oxidation

    NASA Astrophysics Data System (ADS)

    Richaud, Emmanuel

    2014-10-01

    This paper reports a compilation of data for PE+Vitamin E and 2,6-di-tert-butylphenols oxidation in radio-thermal ageing. Data unambiguously show that Vitamin E reacts with Prad and POOrad whereas 2,6-di-tert-butyl phenols only react with POOrad. Kinetic parameters of the stabilization reactions for both kinds of antioxidants were tentatively extracted from phenol depletion curves, and discussed regarding the structure of the stabilizer. They were also used for completing an existing kinetic model used for predicting the stabilization by antioxidants. This one permits to compare the efficiency of stabilizer with dose rate or sample thickness.

  1. Preparation and solution behavior of a thermoresponsive diblock copolymer of poly(ethyl glycidyl ether) and poly(ethylene oxide).

    PubMed

    Ogura, Michihiro; Tokuda, Hiroyuki; Imabayashi, Shin-ichiro; Watanabe, Masayoshi

    2007-08-28

    A thermoresponsive diblock copolymer, poly(ethyl glycidyl ether)-block-poly(ethylene oxide) (PEGE-b-PEO), is synthesized by successive anionic ring-opening polymerization of ethyl glycidyl ether and ethylene oxide using 2-phenoxyethanol as a starting material, and its solution behavior is elucidated in water. In a dilute 1 wt % solution, the temperature-dependent alteration in the polymer hydrodynamic radius (RH) is measured in the temperature range between 5 and 45 degrees C by pulse-gradient spin-echo NMR and dynamic light scattering. The RH value increased with temperature in two steps, where the first step at 15 degrees C corresponds to the core-shell micelle formation and the second step at 40 degrees C corresponds to the aggregation of the core-shell micelles. The formation of the core-shell micelles is supported by the solubilization of a dye (1,6-diphenyl-1,3,5-hexatriene) in the hydrophobic core, which is recognized for a copolymer solution in the temperature range between 20 and 40 degrees C. In this temperature range, the core-shell micelles and the unimers coexist and the fraction of the former gradually increases with increasing temperature, suggesting equilibrium between the micelles and the unimers. In the concentrated regime (40 wt % solution), the solution forms a gel and the small-angle X-ray scattering measurements reveal the successive formation of hexagonal and lamellar liquid crystal phases with increasing temperature.

  2. Factors affecting polyethylene wear in total knee arthroplasty.

    PubMed

    Kuster, Markus S; Stachowiak, Gwidon W

    2002-02-01

    A complication of total knee arthroplasty (TKA) is fatigue-type wear, which can destroy a tibial inlay in <10 years. This deleterious wear mechanism occurs during cyclic loading if the yield stress of polyethylene is exceeded. Because increased stress on and within the polyethylene inlay is associated with increased wear, it is important to reduce the inlay stress by either activity restrictions or conformity changes of design. All stress parameters are more sensitive to conformity changes (eg, design changes) than to load changes (eg, activity restrictions). However, the reduction of stress on and within the polyethylene through increased conformity will increase the stress at the tibial fixation interfaces. An attempt was made to solve this problem with the introduction of mobile-bearing designs. Many mobile-bearing designs exist with good long-term results. One important difference among the various designs is the amount of flexion range with full conformity between the femoral component and the tibial inlay. Although a single radius design reduces polyethylene stress throughout the flexion range, it may be disadvantageous for a revision design to intraoperatively adapt to different degrees of constraint. Aseptic loosening and osteolysis due to small abrasive and adhesive wear particles have also been reported as a cause of failure. The design and material parameters affecting polyethylene wear in TKAs, as well as the potential detrimental effects of wear particle size, are the key issues in defining the life of a TKA.

  3. Evaluation of porous polyethylene for external ear reconstruction.

    PubMed

    Shanbhag, A; Friedman, H I; Augustine, J; von Recum, A F

    1990-01-01

    Autogenous rib cartilage and silicone rubber are materials currently used for ear reconstruction. Increased morbidity and operative time with rib cartilage grafts and a high rate of extrusion with silicone implants render them less than ideal for reconstruction of the human ear. The purpose of the current investigation is to determine the efficacy of porous polyethylene as an alternative synthetic material for ear reconstruction. Porous polyethylene and silicone rubber discs of equal sizes in two thicknesses were implanted in lieu of the cartilage in the external ear of eight baboons. Histological evaluation of the sites after nine weeks revealed excellent anchorage of the thin porous polyethylene implants (1.5 mm) in the surrounding tissues. Silicone rubber implants, however, were encapsulated in a thickened granulation tissue capsule. When thicker implants (3.0 mm) were used, exposure or extrusion occurred in all cases. Porous polyethylene implants demonstrated only partial exposure; half of the silicone rubber implants were extruded; and the other two silicone rubber implants were almost completely extruded. Porous polyethylene was thus better incorporated into the soft tissues than silicone rubber as long as the overlying soft tissues were not stressed by an oversized implant or inadequate soft tissue coverage.

  4. Modeling uptake of hydrophobic organic contaminants into polyethylene passive samplers.

    PubMed

    Thompson, Jay M; Hsieh, Ching-Hong; Luthy, Richard G

    2015-02-17

    Single-phase passive samplers are gaining acceptance as a method to measure hydrophobic organic contaminant (HOC) concentration in water. Although the relationship between the HOC concentration in water and passive sampler is linear at equilibrium, mass transfer models are needed for nonequilibrium conditions. We report measurements of organochlorine pesticide diffusion and partition coefficients with respect to polyethylene (PE), and present a Fickian approach to modeling HOC uptake by PE in aqueous systems. The model is an analytic solution to Fick's second law applied through an aqueous diffusive boundary layer and a polyethylene layer. Comparisons of the model with existing methods indicate agreement at appropriate boundary conditions. Laboratory release experiments on the organochlorine pesticides DDT, DDE, DDD, and chlordane in well-mixed slurries support the model's applicability to aqueous systems. In general, the advantage of the model is its application in the cases of well-agitated systems, low values of polyethylene-water partioning coefficients, thick polyethylene relative to the boundary layer thickness, and/or short exposure times. Another significant advantage is the ability to estimate, or at least bound, the needed exposure time to reach a desired CPE without empirical model inputs. A further finding of this work is that polyethylene diffusivity does not vary by transport direction through the sampler thickness.

  5. [Growth of microfungi on the external polyethylene anticorrosive coating of oil-gas pipes].

    PubMed

    Subbota, A G; Chuenko, A I; Ostapiuk, S N

    2014-01-01

    The authors have studied the resistance of external anticorrosive polyethylene coat of oil-gas pipes (based on the high-density polyethylene, HDPE) to the action of microfungi, natural contamination, fungistatic and fungicide activity. It was found that the intensity of growth of standard test cultures on the surface of polyethylene coat increases in terms which imitate mineral and organic contaminations, and this results in the decrease of the index of its resistance to the action of microfungi. The microfungi, found in the process of study of natural contamination of polyethylene coat and its components, are presented by six species, Alternaria sp. most frequently occurring among them. The presence of admixtures of nitrogenic and phosphoric organic substances in chemical composition of control standards of adhesive and HDPE, which were not exposed to the influence of microfungi, was established by the method of IR spectroscopy. Changes of the IR spectra were noticed in the surface layer of high density polyethylene pellets under the influence of Penicillium funiculosum 171703 that evidences for the process of its slow oxidation. It is assumed that the damaging of the coating components is due to the presence in their chemical composition of impurities of nitrogen- and phosphorus-containing compounds that are easily absorbed by microscopic fungi.

  6. Enhanced adherence of mouse fibroblast and vascular cells to plasma modified polyethylene.

    PubMed

    Reznickova, Alena; Novotna, Zdenka; Kolska, Zdenka; Kasalkova, Nikola Slepickova; Rimpelova, Silvie; Svorcik, Vaclav

    2015-01-01

    Since the last decade, tissue engineering has shown a sensational promise in providing more viable alternatives to surgical procedures for harvested tissues, implants and prostheses. Biomedical polymers, such as low-density polyethylene (LDPE), high-density polyethylene (HDPE) and ultra-high molecular weight polyethylene (UHMWPE), were activated by Ar plasma discharge. Degradation of polymer chains was examined by determination of the thickness of ablated layer. The amount of an ablated polymer layer was measured by gravimetry. Contact angle, measured by goniometry, was studied as a function of plasma exposure and post-exposure aging times. Chemical structure of modified polymers was characterized by angle resolved X-ray photoelectron spectroscopy. Surface chemistry and polarity of the samples were investigated by electrokinetic analysis. Changes in surface morphology were followed using atomic force microscopy. Cytocompatibility of plasma activated polyethylene foils was studied using two distinct model cell lines; VSMCs (vascular smooth muscle cells) as a model for vascular graft testing and connective tissue cells L929 (mouse fibroblasts) approved for standardized material cytotoxicity testing. Specifically, the cell number, morphology, and metabolic activity of the adhered and proliferated cells on the polyethylene matrices were studied in vitro. It was found that the plasma treatment caused ablation of the polymers, resulting in dramatic changes in their surface morphology and roughness. ARXPS and electrokinetic measurements revealed oxidation of the polymer surface. It was found that plasma activation has a positive effect on the adhesion and proliferation of VSMCs and L929 cells.

  7. LDL oxidation, antioxidant capacity and growth of cultured grey mullet ( Mugil cephalus ) fed dietary sorghum distillery residue pretreated with polyethylene glycol.

    PubMed

    Lee, Shin Mei; Cheng, Hui Ling; Pan, Bonnie Sun

    2009-09-09

    Dietary sorghum distillery residue (SDR) showed antioxidant and blood thinning effects on grey mullet during winter, but inhibited their growth. The objective of this study was to establish a preliminary treatment of the dietary SDR with polyethylene glycol (PEG), a tannin-binding agent, to enhance growth and blood antioxidant capacity of grey mullet ( Mugil cephalus ) feed. The feeding trial was carried out from June to November. The water temperature was between 25 and 30 degrees C; the specific growth rate of mullet was reduced significantly by feeding diet containing 20% SDR in comparison to fish fed the control diet or diet containing 20% SDR and PEG. In the period of October-November, the water temperature decreased to 19-25 degrees C; the specific growth rates of the 20% SDR-PEG group and the 20% SDR group were 0.13 and 0.19% day(-1), respectively, significantly higher than those fed the control diet (0.07% day(-1)). Feeding with 20% SDR or 20% SDR-PEG diets resulted in prolonged lag phase of low-density lipoprotein (LDL) oxidation compared to fish fed the control diet. The total antioxidant capacity of the plasma of the grey mullet fed 20% SDR-PEG was 1.24 mmol/L, significantly higher than those in the fish fed 20% SDR diet (0.84 mmol/L) or the control (0.72 mmol/L). In vivo observations found that preliminary treatment of SDR with PEG eliminated the endogenous undesirable growth inhibitory factors but maintained its protective effects against LDL oxidation in blood and improved the total antioxidant capacity and cold adaptation of grey mullet. The ethanol extract of SDR contained 31.9 +/- 7.8 mg/g gallic acids equivalent. The concentration needed to scavenge 50% of the DPPH radicals (IC(50)) was 0.86 mg/mL. Increased gallic acid equivalent and decreased IC(50) of DPPH scavenging activity of SDR fed to fish increased the total antioxidant capacity in blood plasma of grey mullet significantly.

  8. Highly mobile segments in crystalline poly(ethylene oxide){sub 8}:NaPF{sub 6} electrolytes studied by solid-state NMR spectroscopy

    SciTech Connect

    Luo, Huan; Liang, Xinmiao; Wang, Liying; Zheng, Anmin; Liu, Chaoyang; Feng, Jiwen

    2014-02-21

    Two types of high-crystallinity poly(ethylene oxide)/NaPF{sub 6} electrolytes with ethylene oxide (EO)/Na molar ratios of 8:1 and 6:1, termed as PEO{sub 8}:NaPF{sub 6} and PEO{sub 6}:NaPF{sub 6} with M{sub w} = 6000 g mol{sup −1} were prepared, and their ionic conductivity, structure, and segmental motions were investigated and compared. PEO{sub 8}:NaPF{sub 6} polymer electrolyte exhibits the room-temperature ionic conductivity 7.7 × 10{sup −7} S cm{sup −1} which is about five times higher than the PEO{sub 6}:NaPF{sub 6}. By variable-temperature measurements of static powder spectra and {sup 1}H spin-lattice relaxation time in rotation frame ({sup 1}H T{sub 1ρ}), we demonstrate that crystalline segments are more highly mobile in the crystalline PEO{sub 8}:NaPF{sub 6} with higher ionic conductivity than in the PEO{sub 6}:NaPF{sub 6} with lower ionic conductivity. The large-angle reorientation motion of polymer segments in the PEO{sub 8}:NaPF{sub 6} onsets at lower temperature (∼233 K) with a low activation energy 0.31 eV that is comparable with that of the pure PEO crystal. Whereas, the large-angle reorientation motion of polymer segments in the PEO{sub 6}:NaPF{sub 6} starts around 313 K with a high activation energy of 0.91 eV. As a result of the temperature-enhanced large-angle reorientations, the {sup 13}C static powder lineshape changes markedly from a low-temperature wide pattern with apparent principal values of chemical shift δ{sub 33} < δ{sub 22} < δ{sub 11} to a high-temperature narrow pattern of uniaxial chemical shift anisotropy δ{sub 33} > δ{sub 22} (δ{sub 11}). It is suggested that the segmental motion in crystalline PEO-salt complex promotes ionic conductivity.

  9. Interfacial interactions between polyethylene matrix and clay layers in polyethylene/clay nanocomposites

    NASA Astrophysics Data System (ADS)

    Abu-Zurayk, R.

    2015-10-01

    Polyethylene/clay nanocomposites were prepared as blown films using different formulae (clay contents (4 and 6 wt%) and compatibilizer/clay ratio (1/2, 1.0, 2.0)). Structure and mechanical behaviour were tested. It was found that blown film extrusion process decreased the tactoids size and consequently enhanced the exfoliation degree of the clay layers inside the polymer matrix, which is due to the elongational stress during extrusion. Addition of clay had some effects on mechanical behaviour. There was an increase of yield strength (max 32%). Yield strength is related to the interfacial interaction between the polymer and the clay layers in the nanocomposites, which would be enhanced by enhancing the compatibility between polymer and clay layers. Correlation analysis showed good correlation between compatibility and interfacial interaction parameters, and between parameters of interfacial interaction, structure and yield strength.

  10. Hydration of polyethylene glycol-grafted liposomes.

    PubMed

    Tirosh, O; Barenholz, Y; Katzhendler, J; Priev, A

    1998-03-01

    This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG2000 binds 136 +/- 4 molecules of water. For PEG2000 covalently attached to the lipid molecules organized in micelles, the water binding increases to 210 +/- 6 water molecules. This demonstrates that the two different structural configurations of the PEG2000, a random coil in the case of the free PEG and a brush in the case of DHP-PEG2000 micelles, differ in their hydration level. Ultrasound absorption changes in liposomes reflect mainly the heterophase fluctuations and packing defects in the lipid bilayer. The PEG-induced excess ultrasound absorption of the lipid bilayer at 7.7 MHz for PEG-lipid concentrations over 5 mol % indicates the increase in the relaxation time of the headgroup rotation due to PEG-PEG interactions. The adiabatic compressibility (calculated from ultrasound velocity and density) of the lipid bilayer of the liposome increases monotonically with PEG-lipid concentration up to approximately 7 mol %, reflecting release of water from the lipid headgroup region. Elimination of this water, induced by grafted PEG, leads to a decrease in bilayer defects and enhanced lateral packing of the phospholipid acyl chains. We assume that the dehydration of the lipid headgroup region in conjunction with the increase of the hydration of the outer layer by grafting PEG in brush configuration are responsible for increasing thermodynamic stability of the liposomes at 5-7 mol % of PEG-lipid. At higher PEG-lipid concentrations, compressibility and partial volume of the lipid phase

  11. Hydration of polyethylene glycol-grafted liposomes.

    PubMed Central

    Tirosh, O; Barenholz, Y; Katzhendler, J; Priev, A

    1998-01-01

    This study aimed to characterize the effect of polyethylene glycol of 2000 molecular weight (PEG2000) attached to a dialkylphosphatidic acid (dihexadecylphosphatidyl (DHP)-PEG2000) on the hydration and thermodynamic stability of lipid assemblies. Differential scanning calorimetry, densitometry, and ultrasound velocity and absorption measurements were used for thermodynamic and hydrational characterization. Using a differential scanning calorimetry technique we showed that each molecule of PEG2000 binds 136 +/- 4 molecules of water. For PEG2000 covalently attached to the lipid molecules organized in micelles, the water binding increases to 210 +/- 6 water molecules. This demonstrates that the two different structural configurations of the PEG2000, a random coil in the case of the free PEG and a brush in the case of DHP-PEG2000 micelles, differ in their hydration level. Ultrasound absorption changes in liposomes reflect mainly the heterophase fluctuations and packing defects in the lipid bilayer. The PEG-induced excess ultrasound absorption of the lipid bilayer at 7.7 MHz for PEG-lipid concentrations over 5 mol % indicates the increase in the relaxation time of the headgroup rotation due to PEG-PEG interactions. The adiabatic compressibility (calculated from ultrasound velocity and density) of the lipid bilayer of the liposome increases monotonically with PEG-lipid concentration up to approximately 7 mol %, reflecting release of water from the lipid headgroup region. Elimination of this water, induced by grafted PEG, leads to a decrease in bilayer defects and enhanced lateral packing of the phospholipid acyl chains. We assume that the dehydration of the lipid headgroup region in conjunction with the increase of the hydration of the outer layer by grafting PEG in brush configuration are responsible for increasing thermodynamic stability of the liposomes at 5-7 mol % of PEG-lipid. At higher PEG-lipid concentrations, compressibility and partial volume of the lipid phase

  12. Initial Stages of Pyrolysis of Polyethylene

    NASA Astrophysics Data System (ADS)

    Popov, Konstantin V.

    Combustion and flammability of plastics are important topics of practical interest directly related to fire safety and recycling of polymeric materials; pyrolysis of the solid is the initial step of its combustion. One of the main ways to study such complicated processes is through detailed mechanistic modeling, in which the process is represented by a set of many elementary reactions. Mechanistic modeling of combustion of plastics is considerably hindered by the lack of necessary kinetic data. In virtually all existing models of polymer pyrolysis the majority of kinetic data used are derived from the corresponding gas phase values of smaller species. The use of gas phase rate constants is, generally, not justified without an experimental justification. In the first part of the work the influence of condensed phase on the rate of scission of a carbon-carbon bond (the reaction that initiates pyrolysis and combustion) in polyethylene (PE) was studied using the method of Reactive Molecular Dynamics (RMD). A method based on a two-step kinetic mechanism was developed to decouple the cage effect from the kinetics of the reaction under study. It was observed that under the conditions of condensed phase the rate constant of C-C bond scission in PE decreased by an order of magnitude compared to that obtained in vacuum. It was also shown that under the conditions of polymer melt the rate constant does not depend on the length of the polymer chain. In the second part of the work the kinetics of liquid phase and gas phase products of PE pyrolysis were studied experimentally using Gas Chromatography and Nuclear Magnetic Resonance. Based on the assumption of applicability of gas phase kinetic data for C-C scission reaction and beta-scission reaction under the conditions of polymer melt, rate constants of hydrogen transfer, radical addition to double bonds, and radical recombination were determined via kinetic modeling of the experimental results. The obtained values of the rate

  13. Poly(ethylene oxide)-bonded stationary phase for separation of inorganic anions in capillary ion chromatography.

    PubMed

    Linda, Roza; Lim, Lee Wah; Takeuchi, Toyohide

    2013-06-14

    A tosylated-poly(ethylene oxide) (PEO) reagent was reacted with primary amino groups of an aminopropylsilica packing material (TSKgel NH2-60) in acetonitrile to form PEO-bonded stationary phase. The reaction was a single and simple step reaction. The prepared stationary phase was able to separate inorganic anions. The retention behavior of six common inorganic anions on the prepared stationary phase was examined under various eluent conditions in order to clarify its separation/retention mechanism. The elution order of the tested anions was iodate, bromate, bromide, nitrate, iodide, and thiocyanate, which was similar as observed in common ion chromatography. The retention of inorganic anions could be manipulated by ion exchange interaction which is expected that the eluent cation is coordinated among the PEO chains and it works as the anion-exchange site. Cations and anions of the eluent therefore affected the retention of sample anions. We demonstrated that the retention of the analyte anions decreased with increasing eluent concentration. The repeatability of retention time for the six anions was satisfactory on this column with relative standard deviation values from 1.1 to 4.3% when 10mM sodium chloride was used as the eluent. Compared with the unmodified TSKgel NH2-60, the prepared stationary phase retained inorganic anions more strongly and the selectivity was also improved. The present stationary phase was applied for the determination of inorganic anions contained in various water samples.

  14. A bifunctional poly(ethylene glycol) silane immobilized on metallic oxide-based nanoparticles for conjugation with cell targeting agents

    SciTech Connect

    Kohler, Nathan J.; Fryxell, Glen E.; Zhang, Miqin

    2004-06-16

    A trifluoroethylester-terminal poly (ethylene glycol) (PEG) silane was synthesized and self-assembled on iron oxide nanoparticles. The nanoparticle system thus prepared has the flexibility to conjugate with cell targeting agents having either carboxylic and amine terminal groups for a number of biomedical applications, including magnetic resonance imaging (MRI) and controlled drug delivery. The trifluoroethylester silane was synthesized by modifying a PEG diacid to form the corresponding bistrifluoroethylester (TFEE), followed by a reaction with 3-aminopropyltriethoxysilane (APS). The APS coupled with PEG chains confers the stability of PEG self-assembled monolayers (SAMs) and increases the PEG packing density on nanoparticles by establishing hydrogen bonding between the carbonyl and amine groups present within the monolayer structure. The success of the synthesis of the PEG TEFE silane was confirmed with 1H NMR and Fourier transform infrared spectroscopy (FTIR). The conjugating flexibility of the PEG TEFE was demonstrated with folic acid having carboxylic acid groups and amine terminal groups respectively and confirmed by FTIR. TEM analysis showed the dispersion of nanoparticles before and after they were coated with PEG and folic acid.

  15. Comparison of Conventional Polyethylene Wear and Signs of Cup Failure in Two Similar Total Hip Designs

    PubMed Central

    Pace, Thomas B.; Keith, Kevin C.; Snider, Rebecca G.; Tanner, Stephanie L.; DesJardins, John D.

    2013-01-01

    Multiple factors have been identified as contributing to polyethylene wear and debris generation of the acetabular lining. Polyethylene wear is the primary limiting factor in the functional behavior and consequent longevity of a total hip arthroplasty (THA). This retrospective study reviewed the clinical and radiographic data of 77 consecutive THAs comparing in vivo polyethylene wear of two similar acetabular cup liners. Minimum follow-up was 7 years (range 7–15). The incidence of measurable wear in a group of machined liners sterilized with ethylene oxide and composed of GUR 1050 stock resin was significantly higher (61%) than the compression-molded, GUR 1020, O2-free gamma irradiation sterilized group (24%) (P = 0.0004). Clinically, at a 9-year average followup, both groups had comparable HHS scores and incidence of thigh or groin pain, though the machined group had an increased incidence of osteolysis and annual linear wear rate. PMID:23662210

  16. Small angle x-ray scattering study of the interaction of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) triblock copolymers with lipid bilayers.

    SciTech Connect

    Firestone, M. A.; Wolf, A. C.; Seifert, S.; Univ. Chicago

    2003-11-01

    The relationship between molecular architecture and the nature of interactions with lipid bilayers has been studied for a series of poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers using small-angle X-ray scattering (SAXS) and thermal analysis (differential scanning calorimetry, DSC). The number of molecular repeat units in the hydrophobic poly(propylene oxide), PPO, block has been found to be a critical determinant of the nature of triblock copolymer-lipid bilayer association. For dimyristoyl-sn-glycero-3-phosphocholine (DMPC)-based biomembrane structures, polymers possessing a PPO chain length commensurate with the acyl chain dimensions of the lipid bilayer yield highly ordered, swollen lamellar structures consistent with well-integrated (into the lipid bilayer) PPO blocks. Triblock copolymers of lesser PPO chain length yield materials with structural characteristics similar to a simple dispersion of DMPC in water. Increasing the concentration (from 4 to 12 mol %) of well-integrated triblock copolymers enhances the structural ordering of the lamellar phase, while concentrations exceeding 16 mol % result in the formation of a hexagonal phase. Examination of temperature-induced changes in the structure of these mesophases (complex fluids) reveals that if the temperature is reduced sufficiently, all compositions exclude polymer and thus exhibit the characteristic SAXS pattern for hydrated DMPC bilayers. Increasing the temperature promotes better insertion of the polymers possessing PPO chain lengths sufficient for membrane insertion. No temperature-induced structural changes are observed in compositions prepared with PEO-PPO-PEO polymers that feature PPO length insufficient to permit full incorporation into the lipid bilayer.

  17. Space radiation transport properties of polyethylene-based composites.

    PubMed

    Kaul, R K; Barghouty, A F; Dahche, H M

    2004-11-01

    Composite materials that can serve as both effective shielding materials against cosmic-ray and energetic solar particles in deep space, as well as structural materials for habitat and spacecraft, remain a critical and mission enabling component in mission planning and exploration. Polyethylene is known to have excellent shielding properties due to its low density, coupled with high hydrogen content. Polyethylene-fiber reinforced composites promise to combine this shielding effectiveness with the required mechanical properties of structural materials. Samples of polyethylene-fiber reinforced epoxy matrix composite 1-5 cm thick were prepared at the NASA Marshall Space Flight Center and tested against a 500 MeV/nucleon Fe beam at the HIMAC facility of NIRS in Chiba, Japan. This paper presents measured and calculated results for the radiation transport properties of these samples.

  18. Space radiation transport properties of polyethylene-based composites

    NASA Technical Reports Server (NTRS)

    Kaul, R. K.; Barghouty, A. F.; Dahche, H. M.

    2004-01-01

    Composite materials that can serve as both effective shielding materials against cosmic-ray and energetic solar particles in deep space, as well as structural materials for habitat and spacecraft, remain a critical and mission enabling component in mission planning and exploration. Polyethylene is known to have excellent shielding properties due to its low density, coupled with high hydrogen content. Polyethylene-fiber reinforced composites promise to combine this shielding effectiveness with the required mechanical properties of structural materials. Samples of polyethylene-fiber reinforced epoxy matrix composite 1-5 cm thick were prepared at the NASA Marshall Space Flight Center and tested against a 500 MeV/nucleon Fe beam at the HIMAC facility of NIRS in Chiba, Japan. This paper presents measured and calculated results for the radiation transport properties of these samples.

  19. Radiation Transport Properties of Polyethylene-Fiber Composites

    NASA Technical Reports Server (NTRS)

    Kaul, Raj K.; Barghouty, A. F.; Dahche, H. M.

    2003-01-01

    Composite materials that can both serve as effective shielding materials against cosmic-ray and energetic solar particles in deep space as well as structural materials for habitat and spacecraft remain a critical and mission enabling piece in mission planning and exploration. Polyethylene is known to have excellent shielding properties due to its low density coupled with high hydrogen content. Polyethylene fiber reinforced composites promise to combine this shielding effectiveness with the required mechanical properties of structural materials. Samples of Polyethylene-fiber reinforced epoxy matrix composite 1-5 cm thick were prepared at NASA's Marshall Space Flight Center and tested against 500 MeV/nucleon Fe beam at the HIMAC facility of NIRS in Chiba, Japan. This paper presents measured and calculated results for the radiation transport properties of these samples.

  20. The radiation improvement of polyethylene prostheses. A preliminary study.

    PubMed

    Grobbelaar, C J; du Plessis, T A; Marais, F

    1978-08-01

    The radiation crosslinking of high-density polyethylene prostheses was investigated over a wide range of doses in the presence and absence of gaseous crosslinking agents. It was found that in the bulk polymer the crosslinking pattern is completely different from the homogeneous crosslinking that occurs in polymer films. The presence of crosslinking agents causes highly crosslinked polymer to be formed on the surface while the bulk of the polymer is largely unaffected--which is explained in terms of diffusion phenomena. This surface crosslinking has a profound effect on the mechanical properties of the prostheses and restricts cold flow and deformation of the polymer without sacrificing the excellent abrasion-resistance properties of the polyethylene when subjected to high pressures. Based on this research a number of high-density polyethylene knee prostheses have been radiation-crosslinked and the results in vitro appear to be very promising.

  1. Phase diagrams of low-density polyethylene-alkylbenzene systems

    NASA Astrophysics Data System (ADS)

    Ilyasova, A. N.; Kudryavtsev, Y. V.; Lebedeva, T. N.; Levashova, I. V.; Flyagina, Yu. A.; Pochivalov, K. V.

    2017-03-01

    Complete phase diagrams for mixtures of low-density polyethylene with p- and m-xylene are plotted by optical means in developing the concept of which partially crystalline polymers are microstructured liquids. It is shown that in contrast to the ones presented in the literature, both diagrams contain the solubility boundary curve of the low-molecular weight component in the polymer, above which the polyethylene has the structure of a single-phase gel (crosslinks formed by crystallites and amorphous regions saturated with xylene). At the figurative point on the diagrams, a situation is observed in which the dissolution of all the liquid contained in the initial two-phase system in the polymer is accompanied by its simultaneous complete amorphization. The parameters of the figurative point allow us to estimate the thermodynamic affinity of different alkylbenzenes toward polyethylene.

  2. Conventional Versus Cross-Linked Polyethylene for Total Hip Arthroplasty.

    PubMed

    Surace, Michele F; Monestier, Luca; Vulcano, Ettore; Harwin, Steven F; Cherubino, Paolo

    2015-09-01

    The clinical and radiographic outcomes of 88 patients who underwent primary total hip arthroplasty with either conventional polyethylene or cross-linked polyethylene (XLPE) from the same manufacturer were compared. There were no significant differences between the 2 subpopulations regarding average age, gender, side affected, or prosthetic stem and cup size. The average follow-up was 104 months (range, 55 to 131 months). To the authors' knowledge, this is the longest follow-up for this particular insert. Clinical and radiographic evaluations were performed at 1, 3, 6, and 12 months and then annually. Results showed that XLPE has a significantly greater wear reduction than that of standard polyethylene in primary total hip arthroplasty. At the longest available follow-up for these specific inserts, XLPE proved to be effective in reducing wear.

  3. Wear of gamma-crosslinked polyethylene acetabular cups against roughened femoral balls.

    PubMed

    McKellop, H; Shen, F W; DiMaio, W; Lancaster, J G

    1999-12-01

    Crosslinking of ultrahigh molecular weight polyethylene has been shown to markedly improve its wear resistance in clinical studies and laboratory tests using hip joint simulators. However, because most of the laboratory studies have been done under clean conditions using prosthesis-quality, highly polished counterfaces, there is concern regarding how well an intentionally crosslinked polyethylene acetabular cup will resist abrasion by a femoral ball that has been damaged by third-body abrasion in vivo. To investigate this, conventional and radiation crosslinked-remelted acetabular cups of ultra-high molecular weight polyethylene were tested in a hip joint simulator bearing against smooth femoral balls and against balls with moderate and severe roughening. Cups were tested with and without aging to accelerate any oxidative degradation. The crosslinked cups were produced by exposing extruded GUR 4150 bar stock of ultrahigh molecular weight polyethylene to 5 Mrad gamma radiation under a partial vacuum and then the bars were remelted to extinguish residual free radicals. Artificial aging at 70 degrees C under 5 atm oxygen for 14 days induced negligible oxidation in the crosslinked and remelted material. Against smooth balls, the wear of the crosslinked cups, with or without aging, averaged approximately 15% of that of the conventional cups. Against the moderately rough balls, the wear rate of the conventional cups was unchanged, whereas the wear rate increased slightly for the nonaged and aged crosslinked cups, but was still only 26% and 20% of that of the conventional cups, respectively. Against extremely rough balls, the mean wear rates increased markedly for each material such that during the final 1 million cycle interval, the average wear rates of the nonaged and the aged crosslinked cups were 72% and 47% of that of the conventional cups, respectively. That is, the crosslinked polyethylene showed substantially better wear resistance than conventional polyethylene

  4. Irradiation of linear polyethylene - Partitioning between sol and gel.

    NASA Technical Reports Server (NTRS)

    Rijke, A. M.; Mandelkern, L.

    1971-01-01

    Investigation of the importance of chain-scission processes and of the applicability of the general theory of network formation to polyethylene with respect to critical conditions for gelation, using molecular weight fractions of linear polyethylene irradiated at 133 C. The partitioning between sol and gel was found to adhere to the theory just beyond the gel point. Deviations from theory occurred as the irradiation dosage was increased. It was concluded that main-chain scission at the temperatures concerned is not a significant process.

  5. Systematic studies of morphological changes of precision polyethylene.

    PubMed

    Few, Chip S; Wagener, Kenneth B; Thompson, Donovan L

    2014-01-01

    The morphological changes of polyethylenes bearing precisely spaced "defects" are reviewed, focusing on the effects of defect frequency, size, and functionality on crystallization and crystalline structure. The precise defect interval is imparted through acyclic diene metathesis polymerization of structurally symmetric diene monomers. Studies have included structural characterization by differential scanning calorimetry, wide-angle X-ray scattering, small-angle X-ray scattering (SAXS), and infrared spectroscopy. The collective results are presented separately for functionalized polyethylenes and for those containing alkyl chain branches, as these two classes of polymers vary greatly in morphology.

  6. Radicals contributing to preirradiation graft polymerization onto porous polyethylene

    NASA Astrophysics Data System (ADS)

    Uezu, Kazuya; Saito, Kyoichi; Furusaki, Shintaro; Sugo, Takanobu; Ishigaki, Isao

    Porous polyethylene hollow fiber was irradiated by an electron beam at 160 kGy and 8 kGy/min. The concentrations of the radicals such as alkyl, allyl and peroxy were determined by analyzing an integral form of ESR spectra. The comparison of the decay of the radicals with and without contact with air demonstrated that the key radical contributing to the preirradiation graft polymerization is the alkyl radical. The decay of the alkyl radical was simulated by the diffusion-controlled model in the spherical crystallites of polyethylene.

  7. Stresses in polyethylene liners in a semiconstrained ankle prosthesis.

    PubMed

    Miller, M C; Smolinski, P; Conti, S; Galik, K

    2004-10-01

    A finite element model of a semiconstrained ankle implant with the tibia and fibula was constructed so that the stresses in the polyethylene liner could be computed. Two different widths of talar components were studied and proximal boundary conditions were computed from an inverse process providing a load of five times body weight appropriately distributed across the osseous structures. von Mises stresses indicated small regions of localized yielding and contact stresses that were similar to those in acetabular cup liners. A wider talar component with 36% more surface area reduced contact stress and von Mises stresses at the center of the polyethylene component by 17%.

  8. Polyethylene oxide surfaces of variable chain density by chemisorption of PEO-thiol on gold: adsorption of proteins from plasma studied by radiolabelling and immunoblotting.

    PubMed

    Unsworth, Larry D; Sheardown, Heather; Brash, John L

    2005-10-01

    The mechanisms involved in the inhibition of protein adsorption by polyethylene oxide (PEO) are not completely understood, but it is believed that PEO chain length, chain density and chain conformation all play a role. In this work, surfaces formed by chemisorption of PEO-thiol to gold were investigated: the effects of PEO chain density, chain length (600, 750, 2000 and 5000 MW) and end-group (-OH, -OCH3) on protein adsorption from plasma are reported. Similar to previous single protein adsorption studies (L.D. Unsworth et al., Langmuir 2005;21:1036-41) it was found that, of the different surfaces investigated, PEO layers formed from solutions near the cloud point adsorbed the lowest amount of fibrinogen from plasma. Layers of hydroxyl-terminated PEO of MW 600 formed under these low solubility conditions showed almost complete suppression (versus controls) of the Vroman effect, with 20+/-1 ng/cm2 adsorbed fibrinogen at the Vroman peak and 6.7+/-0.6 ng/cm2 at higher plasma concentration. By comparison, Vroman peak adsorption was 70+/-20 and 50+/-3 ng/cm2, respectively, for 750-OCH3 and 2000-OCH3 layers formed under low solubility conditions; adsorption on these surfaces at higher plasma concentration was 16+/-9 and 12+/-3 ng/cm2. Thus in addition to the effect of solution conditions noted previously, the results of this study also suggest a chain end group effect which inhibits fibrinogen adsorption to, and/or facilitates displacement from, hydroxyl terminated PEO layers. Fibrinogen adsorption from plasma was not significantly different for surfaces prepared with PEO of molecular weight 750 and 2000 when the chain density was the same ( approximately 0.5 chains/nm2) supporting the conclusion that chain density may be the key property for suppression of protein adsorption. The proteins eluted from the surfaces after contact with plasma were investigated by SDS-PAGE and immunoblotting. A number of proteins were detected on the various surfaces including fibrinogen

  9. Solid state nuclear magnetic resonance investigation of polymer backbone dynamics in poly(ethylene oxide) based lithium and sodium polyether-ester-sulfonate ionomers

    NASA Astrophysics Data System (ADS)

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2013-05-01

    Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (Tg) have been investigated using solid-state nuclear magnetic resonance. Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components of the polymer backbone (PEO spacer and isophthalate groups) and their relative mobilities for a suite of lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of cation content and identity. Each of the main backbone components exhibit distinct motions, following the trends expected for motional characteristics based on earlier Quasi Elastic Neutron Scattering and 1H spin-lattice relaxation rate measurements. Previous 1H and 7Li spin-lattice relaxation measurements focused on both the polymer backbone and cation motion on the nanosecond timescale. The studies presented here assess the slower timescale motion of the polymer backbone allowing for a more comprehensive understanding of the polymer dynamics. The temperature dependences of 13C linewidths were used to both qualitatively and quantitatively examine the effects of cation content and identity on PEO spacer mobility. Variable contact time 1H-13C CP-MAS experiments were used to further assess the motions of the polymer backbone on the microsecond timescale. The motion of the PEO spacer, reported via the rate of magnetization transfer from 1H to 13C nuclei, becomes similar for T ˜x 1{.1} Tg in all ionic samples, indicating that at similar elevated reduced temperatures the motions of the polymer backbones on the microsecond timescale become insensitive to ion interactions. These results present an improved picture, beyond those of previous findings, for the

  10. Phase structures and morphologies determined by competitions among self-organization, crystallization, and vitrification in a disordered poly(ethylene oxide)-b-polystyrene diblock copolymer

    NASA Astrophysics Data System (ADS)

    Zhu, Lei; Chen, Yan; Zhang, Anqiu; Calhoun, Bret H.; Chun, Moonseok; Quirk, Roderic P.; Cheng, Stephen Z. D.; Hsiao, Benjamin S.; Yeh, Fengji; Hashimoto, Takeji

    1999-10-01

    A poly(ethylene oxide)-b-polystyrene (PEO-b-PS) diblock copolymer having a number-average molecular weight (M¯n) of 11 000 g/mol in the PEO blocks and an M¯n of 5200 g/mol in the PS blocks has been synthesized (with a volume fraction of the PEO blocks of 0.66 in the molten state). Differential scanning calorimetry results show that this copolymer possesses a single endotherm, which is attributed to the melting of the PEO-block crystals. Based on real-time resolved synchrotron small-angle x-ray scattering (SAXS) observations, the diblock copolymer is in a disordered state above the glass transition temperature of the PS-rich phase (TPSg), which has been determined to be 44.0 °C during cooling using dilatometer mode in thermomechanical measurements. The order-disorder transition temperature (TODT) for this diblock copolymer is thus experimentally inaccessible. Depending upon different isothermal crystallization temperatures quenched from the disordered state (Tqs), four cases can be investigated in order to understand the phase relationships among self-organization, crystallization of the PEO blocks, and vitrification of the PS-rich phase: the region where the Tq is above the TPSg, the regions where the Tq is near but slightly higher or lower than the TPSg; and the region where the Tq is below the TPSg. Utilizing simultaneous SAXS and wide angle x-ray-diffraction experiments, it can be seen that lamellar crystals of the PEO blocks in the first case grow with little morphological constraint due to initial disordered phase morphology. As the Tq approaches but is still slightly higher than the TPSg, as in the second case, the PEO-block crystals with a greater long period (L) than that of the disordered state start to grow. The initial disordered phase morphology is gradually destroyed, at least to a major extent. When the Tq is near but slightly lower than the TPSg, the crystallization takes place largely within the existing phase morphology. Only a gradual shift of

  11. Solid State Nuclear Magnetic Resonance Investigation of Polymer Backbone Dynamics in Poly(Ethylene Oxide) Based Lithium and Sodium Polyether-ester-sulfonate Ionomers

    SciTech Connect

    Roach, David J.; Dou, Shichen; Colby, Ralph H.; Mueller, Karl T.

    2013-01-01

    Polymer backbone dynamics of single ion conducting poly(ethylene oxide) (PEO)-based ionomer samples with low glass transition temperatures (Tg) have been investigated using solid-state nuclear magnetic resonance (NMR). Experiments detecting 13C with 1H decoupling under magic angle spinning (MAS) conditions identified the different components of the polymer backbone (PEO spacer and isophthalate groups) and their relative mobilities for a suite of lithium- and sodium-containing ionomer samples with varying cation contents. Variable temperature (203-373 K) 1H-13C cross-polarization MAS (CP-MAS) experiments also provided qualitative assessment of the differences in the motions of the polymer backbone components as a function of cation content and identity. Each of the main backbone components exhibit distinct motions, following the trends expected for motional characteristics based on earlier Quasi Elastic Neutron Scattering and 1H spin-lattice relaxation rate measurements. Previous 1H and 7Li spin-lattice relaxation measurements focused on both the polymer backbone and cation motion on the nanosecond timescale. The studies presented here assess the slower timescale motion of the polymer backbone allowing for a more comprehensive understanding of the polymer dynamics. The temperature dependences of 13C linewidths were used to both qualitatively and quantitatively examine the effects of cation content and identity on PEO spacer mobility. Variable contact time 1H-13C CP-MAS experiments were used to further assess the motions of the polymer backbone on the microsecond timescale. The motion of the PEO spacer, reported via the rate of magnetization transfer from 1H to 13C nuclei, becomes similar for T ≳ 1.1 Tg in all ionic samples, indicating that at similar elevated reduced temperatures the motions of the polymer backbones on the microsecond timescale become insensitive to ion interactions. These results present an improved picture, beyond those of previous findings, for

  12. Impact of torsion and stretching on the thermal conductivity of polyethylene strands

    NASA Astrophysics Data System (ADS)

    Tu, Runchun; Liao, Quanwen; Zeng, Lingping; Liu, Zhichun; Liu, Wei

    2017-03-01

    A single polyethylene chain was reported to have a high metal-like thermal conductivity (TC), which stands in sharp contrast to the thermally insulating feature of common bulk polyethylene materials. This work numerically investigates the impact of torsion and stretching on the TC of polyethylene strands by using equilibrium molecular dynamics simulations. The simulation results show that torsion slightly reduces the TC of a single polyethylene chain. In contrast, the heat conduction of polyethylene strands could be slightly enhanced under torsional loading with a specific torsional angle. Particularly, an apparent improvement of TC of polyethylene strands is achieved by combining torsion and stretching functions. It is found that the TC of torsional polyethylene strands is sensitive to torsional patterns. Our study proposes a specific torsional pattern of polyethylene strands that significantly enhances the heat conduction of the original counterpart. This study will play an essential role in guiding the improvements of thermal conduction property of polymers.

  13. 76 FR 39855 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet and strip...

  14. 76 FR 39855 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-07

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in... administrative review of the countervailing duty order on polyethylene terephthalate film, sheet and strip...

  15. 76 FR 58248 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, In Part, of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-20

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, In... (CVD) order on polyethylene terephthalate film, sheet and strip from India covering the period...

  16. 77 FR 25684 - Polyethylene Retail Carrier Bags From Thailand: Rescission of Antidumping Duty Administrative Review

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-01

    ... International Trade Administration Polyethylene Retail Carrier Bags From Thailand: Rescission of Antidumping... Commerce (the Department) initiated an administrative review of the antidumping duty order on polyethylene... a notice of initiation of an administrative review of the ] antidumping duty order on...

  17. 78 FR 2369 - Polyethylene Terephthalate Film, Sheet and Strip From India: Partial Rescission of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Partial... (CVD) order on polyethylene terephthalate film, sheet and strip from India covering the period...

  18. 78 FR 47276 - Polyethylene Terephthalate (PET) Film, Sheet, and Strip From India: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-05

    ... International Trade Administration Polyethylene Terephthalate (PET) Film, Sheet, and Strip From India: Final... of the countervailing duty order on polyethylene terephthalate (PET) film, sheet, and strip (``PET film'') from India. The Department finds that revocation of this countervailing duty order...

  19. 76 FR 18156 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of... polyethylene terephthalate film, sheet and strip from India covering the period January 1, 2009,...

  20. Experimental and modeling approaches for the formation of hydroperoxide during the auto-oxidation of polymers: Thermal-oxidative degradation of polyethylene oxide

    NASA Astrophysics Data System (ADS)

    Chen, Liang; Yamane, Shogo; Sago, Tomohiro; Hagihara, Hideaki; Kutsuna, Shuzo; Uchimaru, Tadafumi; Suda, Hiroyuki; Sato, Hiroaki; Mizukado, Junji

    2016-07-01

    ROOH was a key intermediate compound in oxidation of polymer because it was only source of radOH radicals. ROOH was believed to be produced by ROOrad abstraction H-atom from polymer, which is thermodynamically unfavorable, but it may be facilitated due to the high polymer concentration. However, ROOH also could be produced by ROOrad reaction with HO2rad. For examining the formation scheme of ROOH, kinetics and mechanism for the thermal-oxidative degradation of PEO at 473 K in air was investigated by using the experimental and modeling approaches. The contribution of HO2rad reaction with ROOrad to the formation of ROOH was estimated.

  1. Polyethylene composites containing a phase change material having a C14 straight chain hydrocarbon

    DOEpatents

    Salyer, Ival O.

    1987-01-01

    A composite useful in thermal energy storage, said composite being formed of a polyethylene matrix having a straight chain alkyl hydrocarbon incorporated therein, said polyethylene being crosslinked to such a degree that said polyethylene matrix is form stable and said polyethylene matrix is capable of absorbing at least 10% by weight of said straight chain alkyl hydrocarbon; the composite is useful in forming pellets or sheets having thermal energy storage characteristics.

  2. A study of the relationship between lithium ion transport and structure and dynamic behavior in polyethylene oxide-melt/LiClO4 battery electrolytes.

    SciTech Connect

    Selser, James C

    2009-07-07

    An experimental study of the canonical SPE (“solid” polymer electrolyte) for rechargeable “rocking chair” lithium/polymer batteries, viz. LiClO4 dissolved in molten poly(ethylene oxide) (PEO), was carried out under DOE grant FG02-04ER15573. In this study, an improved understanding was obtained of the relationship between lithium ion transport and polymer behavior in these SPEs. Among other applications, these sturdy temperature-tolerant and powerful light-weight batteries would be used in electric and electric-hybrid vehicles to reduce greenhouse gas emissions, to store unused electrical energy for peak demand loads and as compact, light-weight energy sources for aircraft and spacecraft. During the period of the grant, the American/Canadian partnership company “Avestor” fabricated and successfully demonstrated a telecommunications application of shoe-box sized batteries and representatives from Avestor visited our research lab at UNLV. They found our results interesting and relevant to their work and invited us to visit Avestor and present a talk about our efforts at UNLV. Unfortunately Avestor (who was scheduled to build a battery production facility in Apex, Nevada just North of Las Vegas) folded before the visit could be made. In the grant work, two well characterized PEO samples having molar masses distinctly below and distinctly above the melt entanglement molar mass were used and three laser light scattering techniques employed as the principal noninvasive methods of investigating liquid poly(ethylene oxide) (PEO)/LiClO4 SPEs. These investigations considered the effects of temperature, dissolved salt concentration and scattering wavevector on SPE behavior. Classical or “static” light scattering and the dynamic light scattering techniques of photon correlation spectroscopy (PCS) and Fabry-Perot interferometry (FPI) were used to study SPE static, low frequency and high frequency dynamic behaviors, respectively. Static measurements provided

  3. Ultra High Molecular Weight Polyethylene: Mechanics, Morphology, and Clinical Behavior

    PubMed Central

    Sobieraj, MC; Rimnac, CM

    2013-01-01

    Ultra high molecular weight polyethylene (UHMWPE) is a semicrystalline polymer that has been used for over four decades as a bearing surface in total joint replacements. The mechanical properties and wear properties of UHMWPE are of interest with respect to the in vivo performance of UHMWPE joint replacement components. The mechanical properties of the polymer are dependent on both its crystalline and amorphous phases. Altering either phase (i.e., changing overall crystallinity, crystalline morphology, or crosslinking the amorphous phase) can affect the mechanical behavior of the material. There is also evidence that the morphology of UHMWPE, and, hence, its mechanical properties evolve with loading. UHMWPE has also been shown to be susceptible to oxidative degradation following gamma radiation sterilization with subsequent loss of mechanical properties. Contemporary UHMWPE sterilization methods have been developed to reduce or eliminate oxidative degradation. Also, crosslinking of UHMWPE has been pursued to improve the wear resistance of UHMWPE joint components. The 1st generation of highly crosslinked UHMWPEs have resulted in clinically reduced wear; however, the mechanical properties of these materials, such as ductility and fracture toughness, are reduced when compared to the virgin material. Therefore, a 2nd generation of highly crosslinked UHMWPEs are being introduced to preserve the wear resistance of the 1st generation while also seeking to provide oxidative stability and improved mechanical properties. PMID:19627849

  4. 76 FR 70965 - Polyethylene Retail Carrier Bags From Thailand: Correction to the Amended Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-16

    ... International Trade Administration Polyethylene Retail Carrier Bags From Thailand: Correction to the Amended... review of the antidumping duty order on polyethylene retail carrier bags from Thailand for the period... review of the antidumping duty order on polyethylene retail carrier bags from Thailand. See...

  5. 76 FR 47540 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-05

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET... Determination of Sales at Less Than Fair Value and Antidumping Duty Order: Polyethylene Terephthalate...

  6. 76 FR 76941 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-09

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet and strip (PET Film... are listed in the ``Final Results of Review'' section, below. \\1\\ See Polyethylene Terephthalate...

  7. 78 FR 9670 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-11

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results... order on polyethylene terephthalate film (PET Film) from India.\\1\\ This review covers three respondents... the ``Final Results of Review'' section below. \\1\\ See Polyethylene Terephthalate Film, Sheet,...

  8. 75 FR 36679 - Polyethylene Retail Carrier Bags From China, Malaysia, and Thailand; Determinations

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-28

    ... COMMISSION Polyethylene Retail Carrier Bags From China, Malaysia, and Thailand; Determinations On the basis...)), that revocation of the antidumping duty orders on polyethylene retail carrier bags from China, Malaysia... Publication 4160 (June 2010), entitled Polyethylene Retail Carrier Bags from China, Malaysia, and...

  9. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  10. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  11. 76 FR 9745 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-22

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Final Results...) published the preliminary results of administrative review of the antidumping duty order on polyethylene terephthalate film (PET Film) from Taiwan. See Polyethylene Terephthalate Film, Sheet, and Strip From...

  12. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol...)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (PMN P-09-628) is subject...

  13. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  14. 75 FR 78968 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates: Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-17

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab...) is conducting an administrative review of the antidumping duty order on polyethylene terephthalate... on PET Film from the UAE. See Polyethylene Terephthalate Film, Sheet, and Strip From Brazil,...

  15. 75 FR 10758 - Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation of Antidumping Duty and...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip from India: Initiation of...) orders on Polyethylene Terephthalate Film, Sheet and Strip (PET Film) from India. The Department... Less Than Fair Value and Antidumping Duty Order: Polyethylene Terephthalate Film, Sheet, and Strip...

  16. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  17. 75 FR 36359 - Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for Preliminary Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-25

    ... International Trade Administration Polyethylene Retail Carrier Bags From Thailand: Extension of Time Limit for...) published in the Federal Register the antidumping duty order on polyethylene retail carrier bags from Thailand. See Antidumping Duty Order: Polyethylene Retail Carrier Bags From Thailand, 69 FR 48204 (August...

  18. 75 FR 34699 - Polyethylene Retail Carrier Bags from Thailand: Rescission of Antidumping Duty Administrative...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-18

    ... International Trade Administration Polyethylene Retail Carrier Bags from Thailand: Rescission of Antidumping... order on polyethylene retail carrier bags from Thailand. The period of review is August 1, 2008, through... September 22, 2009, in response to requests from the Polyethylene Retail Carrier Bag Committee and...

  19. 75 FR 49902 - Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-16

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Taiwan: Preliminary... ] administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET...: Polyethylene Terephthalate Film, Sheet, and Strip (PET Film) from Taiwan, 67 FR 46566 (July 1, 2002). On July...

  20. 77 FR 2959 - Polyethylene Retail Carrier Bags From the People's Republic of China: Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... International Trade Administration Polyethylene Retail Carrier Bags From the People's Republic of China... polyethylene retail carrier bags (PRCBs) from the People's Republic of China (PRC) with respect to Dongguan... PRCBs from the PRC. See Antidumping Duty Order: Polyethylene Retail Carrier Bags From the...

  1. 77 FR 46687 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-06

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET... Determination of Sales at Less Than Fair Value and Antidumping Duty Order: Polyethylene Terephthalate...

  2. 78 FR 77649 - Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab Emirates; Preliminary...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-24

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the United Arab... antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET Film) from the United Arab... primed polyethylene terephthalate film, whether extruded or co-extruded. Excluded are metallized...

  3. 76 FR 68137 - Polyethylene Retail Carrier Bags From Thailand: Amended Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-03

    ...] Polyethylene Retail Carrier Bags From Thailand: Amended Final Results of Antidumping Duty Administrative Review... On September 28, 2011, the Department of Commerce (the Department) published Polyethylene Retail... ministerial error pursuant to 19 CFR 351.224(c) from the Polyethylene Retail Carrier Bag Committee and...

  4. 76 FR 30908 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results...) issued the preliminary results of the new shipper review of polyethylene terephthalate film, sheet and... INFORMATION: Background Since the issuance of Polyethylene Terephthalate Film, Sheet, and Strip From...

  5. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  6. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  7. 76 FR 30910 - Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results of Countervailing...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-27

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From India: Final Results...) issued the preliminary results of the new shipper review of polyethylene terephthalate film, sheet and... Polyethylene Terephthalate Film, Sheet, and Strip From India: Preliminary Results of Countervailing Duty...

  8. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Pentenylated polyethylene glycol... New Uses for Specific Chemical Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt... identified generically as pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject...

  9. 75 FR 22842 - Polyethylene Retail Carrier Bags From Indonesia, Taiwan, and Vietnam

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ... COMMISSION Polyethylene Retail Carrier Bags From Indonesia, Taiwan, and Vietnam Determinations On the basis... imports from Vietnam of polyethylene retail carrier bags (PRCBs), provided for in subheading 3923.21.00 of... (April 2010), entitled Polyethylene Retail Carrier Bags from Indonesia, Taiwan, and...

  10. 76 FR 11203 - Polyethylene Retail Carrier Bags From the People's Republic of China: Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-01

    ... International Trade Administration Polyethylene Retail Carrier Bags From the People's Republic of China... polyethylene retail carrier bags (PRCBs) from the People's Republic of China (PRC) with respect to Dongguan... Order: Polyethylene Retail Carrier Bags From the People's Republic of China, 69 FR 48201 (August 9,...

  11. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  12. 75 FR 65450 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-25

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of... the antidumping duty order on polyethylene terephthalate film, sheet and strip from India for the period July 1, 2009 through December 31, 2009. See Polyethylene Terephthalate Film, Sheet and Strip...

  13. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  14. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  15. 77 FR 14501 - Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of Time Limit for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-12

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Extension of...) order on polyethylene terephthalate film, sheet and strip from India covering the period July 1, 2010... respect to Vacmet and Polypacks on September 20, 2011. See Polyethylene Terephthalate Film, Sheet...

  16. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  17. 40 CFR 721.10546 - Pentenylated polyethylene glycol sulfate salt (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Pentenylated polyethylene glycol... New Uses for Specific Chemical Substances § 721.10546 Pentenylated polyethylene glycol sulfate salt... identified generically as pentenylated polyethylene glycol sulfate salt (PMN P-04-340) is subject...

  18. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol...)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (PMN P-09-628) is subject...

  19. 76 FR 75870 - Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Notice of Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-05

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Korea: Notice of... polyethylene terephthalate film, sheet, ] and strip from Korea on July 28, 2011.\\1\\ This review covers one... the antidumping duty order on polyethylene terephthalate film, sheet, and strip from Korea with...

  20. 78 FR 67113 - Polyethylene Terephthalate Film, Sheet and Strip From India and Taiwan: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-08

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India and Taiwan...'') initiated the second sunset review of the antidumping duty orders on Polyethylene Terephthalate Film, Sheet... Value and Antidumping Duty Order: Polyethylene Terephthalate Film, Sheet, and Strip from India, 67...

  1. 77 FR 1668 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in... administrative review of the countervailing duty (CVD) order on polyethylene terephthalate film, sheet and strip... administrative review with respect to Vacmet and Polypacks on September 20, 2011. See Polyethylene...

  2. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (generic). 721.10518 Section... Substances § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (PMN P-11-48) is subject...

  3. 21 CFR 172.820 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Polyethylene glycol (mean molecular weight 200-9... ADDITION TO FOOD FOR HUMAN CONSUMPTION Multipurpose Additives § 172.820 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used in food...

  4. 40 CFR 721.10518 - Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl ether- and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (generic). 721.10518 Section... Substances § 721.10518 Diethylene glycol, polymer with diisocyanatoalkane, polyethylene glycol monomethyl... diisocyanatoalkane, polyethylene glycol monomethyl ether- and fluorinatedalkanol-blocked (PMN P-11-48) is subject...

  5. 76 FR 48122 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary Results of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-08

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Preliminary... administrative review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (PET... Department published the antidumping duty order on PET film from Brazil. See Polyethylene Terephthalate...

  6. 40 CFR 721.10360 - 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol mono...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-(triethoxysilyl)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (generic). 721.10360... Substances § 721.10360 1-Substituted propane, 3-(triethoxysilyl)-, reaction products with polyethylene glycol...)-, reaction products with polyethylene glycol mono-(branched tridecyl) ether (PMN P-09-628) is subject...

  7. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  8. 76 FR 57715 - Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea: Revocation of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-16

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the Republic of Korea... its third sunset review of the antidumping duty order on polyethylene terephthalate film, sheet, and... existing antidumping duty order on polyethylene terephthalate film, sheet, and strip from the Republic...

  9. 75 FR 75172 - Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-02

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From Brazil: Final Results...) published the preliminary results of the administrative review of the antidumping duty order on polyethylene... covering PET film from Brazil and invited interested parties to comment. See Polyethylene...

  10. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  11. 21 CFR 178.3750 - Polyethylene glycol (mean molecular weight 200-9,500).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Polyethylene glycol (mean molecular weight 200-9..., PRODUCTION AIDS, AND SANITIZERS Certain Adjuvants and Production Aids § 178.3750 Polyethylene glycol (mean molecular weight 200-9,500). Polyethylene glycol identified in this section may be safely used as...

  12. 77 FR 3730 - Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in Part, of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-25

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet and Strip From India: Rescission, in... administrative review of the antidumping duty (AD) order on polyethylene terephthalate film, sheet and strip from... respect to Vacmet and Polypacks on September 20, 2011. See Polyethylene Terephthalate Film, Sheet...

  13. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  14. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  15. 78 FR 88 - Polyethylene Retail Carrier Bags From the People's Republic of China: Rescission of Antidumping...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    ... International Trade Administration Polyethylene Retail Carrier Bags From the People's Republic of China... rescinding its administrative review of the antidumping duty order on polyethylene retail carrier bags (PRCBs..., through July 31, 2012.\\1\\ On August 31, 2012, the petitioners, the Polyethylene Retail Carrier...

  16. 40 CFR 721.3900 - Alkyl polyethylene glycol phosphate, potassium salt.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Alkyl polyethylene glycol phosphate... Specific Chemical Substances § 721.3900 Alkyl polyethylene glycol phosphate, potassium salt. (a) Chemical... as alkyl polyethylene glycol phosphate, potassium salt (P-90-481), is subject to reporting under...

  17. 21 CFR 573.800 - Polyethylene glycol (400) mono- and dioleate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Polyethylene glycol (400) mono- and dioleate. 573... DRINKING WATER OF ANIMALS Food Additive Listing § 573.800 Polyethylene glycol (400) mono- and dioleate. (a) The food additive polyethylene glycol (400) mono- and dioleate meets the following...

  18. 78 FR 79400 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Initiation...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-30

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic... a request for a new shipper review of the antidumping duty order on polyethylene terephthalate film.... SUPPLEMENTARY INFORMATION: Background The antidumping duty order on polyethylene terephthalate film, sheet,...

  19. 78 FR 35245 - Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic of China: Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-12

    ... International Trade Administration Polyethylene Terephthalate Film, Sheet, and Strip From the People's Republic... review of the antidumping duty order on polyethylene terephthalate film, sheet, and strip (``PET film... review (``POR'') is November 1, 2010, through October 31, 2011. \\1\\ See Polyethylene Terephthalate...

  20. 21 CFR 878.5000 - Nonabsorbable poly(ethylene terephthalate) surgical suture.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Nonabsorbable poly(ethylene terephthalate... Devices § 878.5000 Nonabsorbable poly(ethylene terephthalate) surgical suture. (a) Identification. Nonabsorbable poly(ethylene terephthalate) surgical suture is a multifilament, nonabsorbable, sterile,...