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Polymeric polypyrroles

To increase the stability of the phenothiazine dye CMEs, investigations of the electrochemical reactions of redox proteins at polymer CMEs have been undertaken. One example of such a study is the heterogeneous redox reaction of Cyt c at an electrochemically polymerized polypyrrole-methylene blue (PPy-MB) film CME. Figure 17 shows the cyclic voltammetric response that occurs during the preparation of this CME by potential... [Pg.729]

E.A., Ocampo, A.L., Espinosa-Medina, M.A. and Sebastian, P.J. 2003. A modified Nafion membrane with in situ polymerized polypyrrole for the direct methanol fuel cell. LPower Soj. 124 59-64. [Pg.446]

Keywords Carbon nanotubes, carbon nanofibers, fullerene, graphene, nanocomposites, polyacetylene, polyaniline, polymerization, polypyrrole... [Pg.229]

Xue and Tm [21] modified SPEEK membranes with chemically in situ polymerized polypyrrole (PPy). It was found that the solution uptake and the swelling ratio of the SPEEK/PPy decreased upon incorporation of PPy. At temperatures >60°C, the membrane in 10 vol% methanol began to lose its mechanical stabihty. XRD analysis showed that the structure was almost amorphous. The DSC and TGA measurements showed that the microstructure change of SPEEK/PPy membranes cannot be removed, even after drying the membranes. The incorporation of PPy into the SPEEK matrix decreased methanol permeation and proton conductivity. It was suggested that this is likely due to PPy particles blocking the methanol and protons. [Pg.248]

Xue, S. and G. Yin, Proton exchange membranes based on modified sulfonated poly(ether ether ketone) membranes with chemically in situ polymerized polypyrrole , Electrochem. Acta, 52 (2006) 847-853. [Pg.251]

The morphology of poly(vinylacetate)-polypyrrole composite film is very different from that of polymer blend prepared from the solution polymerization. Polypyrrole aggregates are connected with each other in the former case, which results in a polypyrrole network throughout the composite, while polypyrrole aggregates are separated from each other in the latter case. It is expected in the former case that a spinodal decomposition occurs during the phase separation process because of sudden changes in the concentration of pyrrole and ferric chloride as well as the viscosity of poly (vinylacetate). These sudden changes are caused by the evaporation of solvent. [Pg.308]

The first example of the use of a polymer electrolyte as a medium for an electrochemical reaction is the electrochemical synthesis of conducting polymers [105,106]. Electrochemical polymerization of pyrrole, using ion-conducting polymers as a solid electrolyte, produced polypyrrole-polymer electrolyte bilayer composites in situ [106]. Figure 28 shows a schematic representation of the electrochemical polymerization of pyrrole (Py) by using a polymer electrolyte. The polymer electrolytes used were PEO network polymers in which several kinds of salts were dissolved. The polymer electrolyte film in which pyrrole had been incorporated was sandwiched between two electrodes, and the polymerization was carried out under galvanostatic conditions. When the electrodes were removed from the polymer electrolyte after polymerization, polypyrrole (PPy X") grew on the surface of the polymer electrolyte in contact with the anode (see Fig. 28). As a result, polypyrrole-polymer electrolyte bilayer composites were obtained. The... [Pg.423]

Functionalized conducting monomers can be deposited on electrode surfaces aiming for covalent attachment or entrapment of sensor components. Electrically conductive polymers (qv), eg, polypyrrole, polyaniline [25233-30-17, and polythiophene/23 2JJ-J4-j5y, can be formed at the anode by electrochemical polymerization. For integration of bioselective compounds or redox polymers into conductive polymers, functionalization of conductive polymer films, whether before or after polymerization, is essential. In Figure 7, a schematic representation of an amperomethc biosensor where the enzyme is covalendy bound to a functionalized conductive polymer, eg, P-amino (polypyrrole) or poly[A/-(4-aminophenyl)-2,2 -dithienyl]pyrrole, is shown. Entrapment of ferrocene-modified GOD within polypyrrole is shown in Figure 7. [Pg.46]

Because of its physical properties, polypyrrole has been cited as a unique building block for intelligent polymeric materials, ie, it has characteristics which make it capable of sensing, information processing, and response actuation (48). [Pg.359]

Significant variations in the properties of polypyrrole [30604-81-0] ate controlled by the electrolyte used in the polymerization. Monoanionic, multianionic, and polyelectrolyte dopants have been studied extensively (61—67). Properties can also be controlled by polymerization of substituted pyrrole monomers, with substitution being at either the 3 position (5) (68—71) or on the nitrogen (6) (72—75). An interesting approach has been to substitute the monomer with a group terminated by an ion, which can then act as the dopant in the oxidized form of the polymer forming a so-called self-doped system such as the one shown in (7) (76—80). [Pg.37]

In all cases of electrochemicaHy or chemically polymerized unsubstituted polypyrrole, the final polymer is intractable in both the conducting and insulating forms. In contrast, a broad number of substituted polythiophenes have been found to be processible both from solution and in the melt. The most studied of these systems ate the poly(3-alkylthiophenes) (P3AT). [Pg.37]

FIGURE 4-13 Structures of common polymeric coatings (a) Nafion, (b) polyvinyllferro-cene (c) polyvinylpyridine id) polypyrrole. [Pg.119]

Here we introduce a personal point of view about the interactions between conducting polymers and electrochemistry their synthesis, electrochemical properties, and electrochemical applications. Conducting polymers are new materials that were developed in the late 1970s as intrinsically electronic conductors at the molecular level. Ideal monodimensional chains of poly acetylene, polypyrrole, polythiophene, etc. can be seen in Fig. 1. One of the most fascinating aspects of these polymeric... [Pg.308]

Figure 37. Lateral section of a polymeric film during the nucleation and growth of the conducting zones after a potential step. (Reprinted from T. F. Otero, H.-J. Grande, and J. Rodriguez, A new model for electrochemical oxidation of polypyrrole under conformational relaxation control. /. Electroanal. Chem. 394, 211, 1995, Figs. 2-5. Copyright 1995. Reprinted with permission from Elsevier Science.)... Figure 37. Lateral section of a polymeric film during the nucleation and growth of the conducting zones after a potential step. (Reprinted from T. F. Otero, H.-J. Grande, and J. Rodriguez, A new model for electrochemical oxidation of polypyrrole under conformational relaxation control. /. Electroanal. Chem. 394, 211, 1995, Figs. 2-5. Copyright 1995. Reprinted with permission from Elsevier Science.)...
Figure 51. Arrhenius plot of ln 1/(3 [ Q t)ldt2]) from data corresponding to Fig. 54. The conformational energy consumed per mole of polymeric segments in the absence of any external electric field (AH) can be obtained from the slope. (Reprinted from T. F. Otero and H.-J. Grande, Reversible 2D to 3D electrode transition in polypyrrole films. Colloid Surf. A. 134, 85, 1998, Figs. 4-9. Copyright 1998. Reproduced with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25, 1055 Amsterdam, The Netherlands.)... Figure 51. Arrhenius plot of ln 1/(3 [ Q t)ldt2]) from data corresponding to Fig. 54. The conformational energy consumed per mole of polymeric segments in the absence of any external electric field (AH) can be obtained from the slope. (Reprinted from T. F. Otero and H.-J. Grande, Reversible 2D to 3D electrode transition in polypyrrole films. Colloid Surf. A. 134, 85, 1998, Figs. 4-9. Copyright 1998. Reproduced with kind permission of Elsevier Science-NL, Sara Burgerhartstraat 25, 1055 Amsterdam, The Netherlands.)...
Polymerization at constant current is most convenient for controlling the thickness of the deposited film. Charges of ca. 0.3, 0.2, and 0.08 C cm-2 are required to produce 1 fim of polypyrrole,59 poly(3-methylthio-phene)60 (no data are available for polythiophene), and polyaniline 43 respectively. Although these values can reasonably be used to estimate the thicknesses of most electrochemically formed conducting polymer films, it should be noted that they have considerable (ca. 30%) uncertainties. For each polymer, the relationship between charge and film thickness can... [Pg.554]

Cyclic voltammetric studies involving polymers, 558 and the nature of charge carriers, 561 and the nucleation loop, 557 of poly (3-methylthiophene), 564 and parallel-band electrodes, 570 Cyclic voltammograms as a function of scan rate, 559 involving polymerization, 559 with polyanaline, 566 of polypyrrole film, 581... [Pg.629]

In 1979, Diaz et al. produced the first flexible, stable polypyrrole (PPy) film with high conductivity (1(X) Scm ). The substance was polymerized on a Pt-electrode by anodic oxidation in acetonitrile. The then known chemical methods of synthesis " usually produced low conductivity powders from the monomers. By contrast, electropolymerization in organic solvents formed smooth and manageable films of good conductivity. Thus, this technique soon gained general currency, stimulating further electropolymerization experiments with other monomers. In 1982, Tourillon... [Pg.3]

Further interesting redox modified polypyrrole films were prepared e.g. a polymeric copper phenanthroline complex that can be reversibly de- and re-metallated because it retains the pseudotetrahedral environment after decomple-xation, A very diversified electrochemistry is displayed by polypyrrole films containing electron donor as well as electron acceptor redox centers in the same film... [Pg.82]


See other pages where Polymeric polypyrroles is mentioned: [Pg.104]    [Pg.541]    [Pg.274]    [Pg.301]    [Pg.996]    [Pg.91]    [Pg.265]    [Pg.104]    [Pg.541]    [Pg.274]    [Pg.301]    [Pg.996]    [Pg.91]    [Pg.265]    [Pg.207]    [Pg.39]    [Pg.45]    [Pg.387]    [Pg.173]    [Pg.319]    [Pg.326]    [Pg.331]    [Pg.334]    [Pg.336]    [Pg.344]    [Pg.361]    [Pg.567]    [Pg.588]    [Pg.1036]    [Pg.16]    [Pg.58]    [Pg.82]    [Pg.285]    [Pg.338]    [Pg.41]   
See also in sourсe #XX -- [ Pg.93 ]




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