Conducting polymer, electron-conductive

Conducting Polymers Electronically conducting polymers (such as polypyrrole, polythiophene, and polyaniline) have attracted considerable attention due to their ability to switch reversibly between the positively charged conductive state and a neutral, essentially insulating, form and to incorporate and expel anionic species (from and to the surrounding solution), upon oxidation or reduction ... 

On the other hand, Doblhofer218 has pointed out that since conducting polymer films are solvated and contain mobile ions, the potential drop occurs primarily at the metal/polymer interface. As with a redox polymer, electrons move across the film because of concentration gradients of oxidized and reduced sites, and redox processes involving solution species occur as bimolecular reactions with polymer redox sites at the polymer/solution interface. This model was found to be consistent with data for the reduction and oxidation of a variety of species at poly(7V-methylpyrrole). This polymer has a relatively low maximum conductivity (10-6 - 10 5 S cm"1) and was only partially oxidized in the mediation experiments, which may explain why it behaved more like a redox polymer than a typical conducting polymer. 

For a fast catalytic reaction, free access of gas, electrons, protons and water is needed. This leads to a best compromise of the volume fractions of protonconducting polymer, electron-conducting carbon, active sites and void space. 

Novel hybrid materials have been realized in which fullerenes participate in composite films with 7r-conjugated-polymer electron donors such as oligothio-phenes. Established studies have already shown that the photoinduced electron transfer is rather enhanced between 7r-conjugated polymers and fullerenes, while back electron transfer is considerably slower [145,149,171,172].Electrosynthe-sized polythiophene with pendant fullerene substituents was recently obtained from the corresponding biothiophene-fulleropyrrolidine dyad [173]. The novel material described has the potential of a double-cable polymer, heavily loaded with fullerene electron-conducting moieties. 

New Engineering Thermoplastics New High Performance Thermosets Thermotropic Liquid Crystals Lyotropic Liquid Crystals Molecular Composites Advanced Composites Non-Linear Optical Polymers Electronically Conducting Polymers... 

Among the species that dope PPy and PTh and render the polymers electronically conducting are BFJ, CIOJ, CP, CF3SO3, CH3C6H4SO5, PF, and AsF Oi7,n8,i29)... 

Ormecon GmbH offers a wide range of dispersions of the organic metal polyaniUne for use in basic and applied research for polymer electronics in universities and other public research institutions. A series of dispersions is available based on water or a variety of organic solvents, covering a wide range of conductivity between 10 and 10 S/cm. 

Onoda, M., Y. Kato, H. Shonaka, and K. Tada. 2004. Artificial muscle using conducting polymers. Electron Eng Jpn 149 7. 

There is electron hopping between the redox centers (process 1), as in conventional redox polymers. Electron transfer may also occur through the polymer backbone via a metal-metal electronic interaction (process 2, superexchange pathway) or via polymer-based charge carriers (process 3, polymer mediation). The electronic interactions between the tt-system of the polymer and the metal centers usually enhance the rate of the electron transfer process. Electron transfer via polymer-based charge carriers requires the polymer to be electronically conductive at potentials close to the formal potential of the redox groups. 

Among the electroactive polymers, electronically conducting polymers such as polypyrrole and polythiophene and piezoelectric polymers such as polyvinylidine fluoride (PVDF) are the most promising with regard to tissue engineering applications. 

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