935 research outputs found

    Polypyrrole grafts with poly[(methyl methacrylate)-CO-(2-(N-pyrrolyl)ethyl methacrylate)]

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    Cataloged from PDF version of article.Conducting polymer grafts of pyrrole and poly[(methyl methacrylate)-co-(2- (N-pyrrolyl) ethyl methacrylate)] containing 0.7% PEMA units were prepared by potentiostatic anodic polymerization of pyrrole in different electrolytic media. Grafting between copolymer and pyrrole was achieved in media where tetrabutylammonium fluoroborate and sodium perchlorate were used as the supporting electrolytes. Characterizations were made by using IT-IR, DSC, TGA, SEM, CV, and elemental analysis. The conductivities of the resultant polymers seemed to be in the order of pure polypyrrole prepared under the same conditions. Copyright o 1997 Elsevier Scienc

    Immobilization of invertase in conducting polymer matrices

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    Cataloged from PDF version of article.This paper reports a novel approach in the electrode immobilization of an enzyme, invertase, by electrochemical polymerization of pyrrole in the presence of enzyme. The polypyrrolelinvertase and polyamide/polypyrrole/invertase electrodes were constructed by the entrapment of enzyme in conducting matrices during electrochemical polymerization of pyrrole. This study involves the preparation and characterization of polypyrrole/invertase and polyamidelpolypyrrolelinvertase electrodes under conditions compatible with the enzyme. It demonstrates the effects of pH and temperature on the properties of enzyme electrode. Enzyme leakage tests were carried out during reuse number studies. The preparation of enzyme electrodes was done in two different electrolyte/ solvent systems. The enzyme serves as a sucrose electrode and retains its activity for several months. (c) 1997 Elsevier Science Limited. All rights reserve

    A photoelectron spectroscopic investigation of conducting polypyrolle-polyamide composite film

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    Cataloged from PDF version of article.X-ray photoelectron spectrum of the electrochemically prepared polypyrrole and polypyrrole-polyamide composite films exhibit an additional strong high binding energy peak at 402.0 eV corresponding to N+ moieties. Intensity of this peak is significantly reduced upon electrochemical reduction. Atomic concentrations derived from the observed N+ and F (stemming from the dopant BF4-) peaks reveal a slightly higher cation/anion ratio for this composite and suggest that the composite has a different chemical composition than the corresponding polymers. © 1995 Elsevier Science B.V.X-ray photoelectron spectrum of the electrochemically prepared polypyrrole and polypyrrole-polyamide composite films exhibit an additional strong high binding energy peak at 402.0 eV corresponding to N+ moieties. Intensity of this peak is significantly reduced upon electrochemical reduction. Atomic concentrations derived from the observed N+ and F (stemming from the dopant BF4-) peaks reveal a slightly higher cation/anion ratio for this composite and suggest that the composite has a different chemical composition than the corresponding polymers

    Bioactive surface design based on functional composite electrospun nanofibers for biomolecule immobilization and biosensor applications

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    Cataloged from PDF version of article.The combination of nanomaterials and conducting polymers attracted remarkable attention for development of new immobilization matrices for enzymes. Hereby, an efficient surface design was investigated by modifying the graphite rod electrode surfaces with one-step electrospun nylon 6,6 nanofibers or 4% (w/w) multiwalled carbon nanotubes (MWCNTs) incorporating nylon 6,6 nanofibers (nylon 6,6/4MWCNT). High-resolution transmission electron microscopy study confirmed the successful incorporation of the MWCNTs into the nanofiber matrix for nylon 6,6/4MWCNT sample. Then, these nanofibrous surfaces were coated with a conducting polymer, (poly-4-(4,7-di(thiophen-2-yl)-1H-benzo[d]imidazol-2-yl) benzaldehyde) (PBIBA) to obtain a high electroactive surface area as new functional immobilization matrices. Due to the free aldehyde groups of the polymeric structures, a model enzyme, glucose oxidase was efficiently immobilized to the modified surfaces via covalent binding. Scanning electron microscope images confirmed that the nanofibrous structures were protected after the electrodeposition step of PBIBA and a high amount of protein attachment was successfully achieved by the help of high surface to volume ratio of electroactive nanofiber matrices. The biosensors were characterized in terms of their operational and storage stabilities and kinetic parameters (K mapp and Imax). The resulting novel glucose biosensors revealed good stability and promising Imax values (10.03 and 16.67 μA for nylon 6,6/PBIBA and nylon 6,6/4MWCNT/PBIBA modified biosensors, respectively) and long shelf life (32 and 44 days for nylon 6,6/PBIBA and nylon 6,6/4MWCNT/PBIBA modified biosensors, respectively). Finally, the biosensor was tested on beverages for glucose detection. © 2014 American Chemical Society

    Electrochemically Obtained Insulating and Conducting Polymers and Composites of Acrylonitrile

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    Electrochemically obtained polyacrylonitrile and a commercial polyacrylonitrile were heat treated to improve their conductivities. The parameters chosen for heat treatment conditions were the temperature, treatment medium (vacuum or air) and, doping agent. The conductivity of all heat treated polymers was measured. The characterization of the heat treated polymers was made by IR analysis. The composite films of polyacrylonitrile with polypyyrole and polythiophene were electrochemically prepared at different compositions. The change in the conductivity of composites was analyzed as a function of the percent composition of the insulating component. IR, DSC, TGA and SEM analyses were used to characterize the polymer composites

    A legal approach to the Greek Turkish continental shelf dispute at the Aegean Sea

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    Cataloged from PDF version of article.This master’s thesis aims to analyze, in detail, the issue of the delimitation of the continental shelf areas in the Aegean Sea, which can be accepted as one of the most challenging disputes between Greece and Turkey. This research, while analyzing the nature of the dispute, the approaches of Greek and Turkish governments respectively and the applicable international legal rules, also aims to provide a permanent settlement proposal that would be fair and equitable to both sides.Toppare, Nevin AslıM.S

    Immobilization of cholesterol oxidase in a conducting copolymer of thiophene-3-yl acetic acid cholesteryl ester with pyrrole

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    Cholesterol oxidase has been immobilized in conducting copolymers of thiophene-3-yl acetic acid cholesteryl ester with pyrrole (CM/PPy) and polypyrrole (PPy) via electropolymerization. p-Toluene sulphonic acid was used as the supporting electrolyte. Kinetic parameters (V-max and K-m) and operational stability of enzyme electrodes were investigated. Surface morphology of the films was examined by scanning electron microscope

    A CONDUCTING COMPOSITE OF POLYPYRROLE .1. SYNTHESIS AND CHARACTERIZATION

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    A conducting composite of polypyrrole was prepared via electrochemical methods. A polyamide was used as the insulating matrix polymer. The characterization of the composite was done by FT-IR, SEM, TGA, DSC and pyrolysis studies. Conductivity and solubility studies together with spectroscopic methods reveal that H bonding exists between the two polymers and a possible grafting to a certain extent
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