Polypyrrole, as a conducting polymer

Synthesis, properties, and applications of polypyrrole as a conducting polymer 97UK489. 

Kara S, Zama T, Takashima W, Kaneto K (2006) Tris(trifluoromethylsulfonyl)methide-doped polypyrrole as a conducting polymer actuator with large electrochemical strain. Synth Met 156 351... 

Figure 15.10 SEM images PPy films doped with TFSI anions and prepared on (A) a glassy carbon electrode and (B) on a Pt electrode. The electrode side (with a macroporous morphology on Pt) is shown on the left in each case, and the solution side on the right. (Reprinted with permission from Synthetic Metals, Tris(trifluoromethylsulfonyl)methide-doped polypyrrole as a conducting polymer actuator with large electrochemical strain by S. Hara, T. Zama, W. Takashima and K. Kaneto 156, 2-4, 351-355. Copyright (2006) Elsevier Ltd)...

Conductive polymers, such as polyacetylene, polythiophene, polypyrrole, polyisothianaphthene, polyethylene dioxythiophene, polyaniUne, and so on, have interesting properties that make them suitable for use in PEMFCs (Heeger, 2001 Shirakawa, 2001). Their electroconductivity and noncarbon functionalities allow some of them to perform effectively as alternative carbon catalysts or with carbon supports to enhance their catalytic effects. Huang et al. utilized polypyrrole as a conductive polymer support for a platinum catalyst active for the ORR (Huang et al., 2009). Their results show significant resistance to carbon corrosion and improved conductivity over traditional Pt/C catalysts. They report that the platinum on polypyrrole catalyst (Pt/Ppy) has well-dispersed platinum particles of about 3.6 nm in diameter. CV scans up to 1.8 V revealed that there was httle carbon support corrosion on the Pt/Ppy and a twofold increase in activity than Pt black at 0.9 V. 

Transition metal compounds, such as organic macrocycles, are known to be good electrocatalysts for oxygen reduction. Furthermore, they are inactive for alcohol oxidation. Different phthalocyanines and porphyrins of iron and cobalt were thus dispersed in an electron-conducting polymer (polyaniline, polypyrrole) acting as a conducting matrix, either in the form of a tetrasulfonated counter anion or linked to... 

In recent years the electrochemistry of the enzyme membrane has been a subject of great interest due to its significance in both theories and practical applications to biosensors (i-5). Since the enzyme electrode was first proposed and prepared by Clark et al. (6) and Updike et al. (7), enzyme-based biosensors have become a widely interested research field. Research efforts have been directed toward improved designs of the electrode and the necessary membrane materials required for the proper operation of sensors. Different methods have been developed for immobilizing the enzyme on the electrode surface, such as covalent and adsorptive couplings (8-12) of the enzymes to the electrode surface, entrapment of the enzymes in the carbon paste mixture (13 etc. The entrapment of the enzyme into a conducting polymer has become an attractive method (14-22) because of the conducting nature of the polymer matrix and of the easy preparation procedure of the enzyme electrode. The entrapment of enzymes in the polypyrrole film provides a simple way of enzyme immobilization for the construction of a biosensor. It is known that the PPy-... 

Alzawa et al. have extended the Idea that the electrically stimulated release of neurotransmitters may be accomplished with the electrochemical undoping of a conductive polymer membrane. They have also demonstrated the timed release of neurotransmitter amino acids such as glutamic acid with a polypyrrole membrane (140). 

As mentioned previously a hybridization of an insulating PED film and a conductive polymer layer is quite attractive when they are applied to an electric device. In this case a hybridized multi-layered structure is expected to be fabricated, and the throwing power of the PED film can conveniently be utilized for this purpose. Additionally the photoelectrochemical area-selective doping and/or undoping of a polypyrrole film as dascrivec. earlier in this section encourage us to pursue this objective. The key problem in the fabrication of a hybridized multi-layered structure is hov to control the deposition of a PED overcoat onto polypyrrole layer and. vice versa. Figure 5 shows... 

Aizawa has studied an enzyme (metal) electrode based on immobilized GOD, which is a redox enzyme [66]. Interfacing in this type of biosensor requires facilitation of electron transfer from the active site of the enzyme protein to the metal electrode. Various methods have been used, such as electron mediators, electron promoters, and molecular wires, to accomplish this purpose. For example, a conducting polymer, polypyrrole, formed by electropolymerization on the electrode surface, was used to form electron wires which can facilitate electron transfers to and from the metal electrode. 

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