Polypyrroles, properties conductivity

Otero, T.E, E. Angulo, J. Rodriguez, and C. Santamaria. 1992. Electrochemomechanical properties from a bilayer Polypyrrole/non-conducting and flexible material. Artificial muscle. J Electroanal Chem 341 369. 

Polypyrrole can also be synthesized with substituents on the nitrogen. However, these substitutions can dramatically alter the properties of the films and have deleterious effects on their conductivities. For example, although poly- V-methylpyrrole has an appearance and level of doping similar to those of polypyrrole, the conductivity is diminished to 10 S cm" [4]. PoIy-A -methylpyrrole has an oxidation potential of 0.45 V (versus SCE), a positive shift of 0.65 V compared with polypyrrole. In general, N-substituted polypyrroles are more difficult to oxidize and correspondingly less air sensitive than the parent polymer [119]. Substituted pyrroles with ethyl, propyl, or butyl groups attached to the nitrogen can also... 

A wide variety of solvents has been used for polymerization. In most cases polypyrrole is prepared from electrolyte solutions employing aprotic organic solvents, but since the initial work of Diaz etal. [4] much work has been done on polymerization reaction in aqueous solutions [50,111-12], achieving films with properties similar to those produced from organic solutions. For example, high-quality polypyrrole films (conductivities higher than 500 S cm ) in aqueous solution ofp-toluensulphonate have been obtained [116]. 

M Omastova, S Kosina, J Pionteck, A Janke, J Pavlinec. Electrical properties and stabihty of polypyrrole containing conducting polymer composites. Synth Met 1996 81 49-57. 

Tat yana VV, Oleg NE. Polypyrrole a conducting polymer its synthesis, properties and applications. Russ ChemRevl997 66(5) 443. 

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

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... 

This reverse electrochemical control of the gel composition and volume is the basis for the singular electrochemical properties and the concomitant applications of conducting polymers. Reactions and properties based on polypyrrole films can be summarized as shown in Table 5 and below ... 

Besides synthesis, current basic research on conducting polymers is concentrated on structural analysis. Structural parameters — e.g. regularity and homogeneity of chain structures, but also chain length — play an important role in our understanding of the properties of such materials. Research on electropolymerized polymers has concentrated on polypyrrole and polythiophene in particular and, more recently, on polyaniline as well, while of the chemically produced materials polyacetylene stih attracts greatest interest. Spectroscopic methods have proved particularly suitable for characterizing structural properties These comprise surface techniques such as XPS, AES or ATR, on the one hand, and the usual methods of structural analysis, such as NMR, ESR and X-ray diffraction techniques, on the other hand. 

There are several reports of Ag nanocomposites with conducting polymers like polyaniline [38] and polypyrrole [39]. However, electrical conducting properties of green metal - starch... 

As might be expected, the properties of polythiophene show many similarities with those of polypyrrole. As with polypyrrole, polythiophene can be prepared via other routes than electrochemical oxidation both as the neutral material [390-392] or in the p-doped form [393]. This material is produced as an infusible black powder which is insoluble in common solvents (and stable in air up to 360°C), with conductivities ranging from approximately 10 11 Scm-1 in the neutral form [390] to 102 Scm-1 when doped [19, 393, 394]. Early work on thiophene polymers showed that the p-doped material is air-sensitive in that the conductivity decreases on exposure to the atmosphere [20, 395] although no evidence of oxygen-containing species was seen in XPS measurements [19],... 

Electronically conducting polymers (ECPs) such as polyaniline (PANI), polypyrrole (PPy) and po 1 y(3.4-cthy 1 cncdi oxyth iophcnc) (PEDOT) have been applied in supercapacitors, due to their excellent electrochemical properties and lower cost than other ECPs. We demonstrated that multi-walled carbon nanotubes (CNTs) prepared by catalytic decomposition of acetylene in a solid solution are very effective conductivity additives in composite materials based on ECPs. In this paper, we show that a successful application of ECPs in supercapacitor technologies could be possible only in an asymmetric configuration, i.e. with electrodes of different nature. 

Dynamic properties. On the basis of cyclic voltammetry, Diaz et al. (1981) showed that thin films of polypyrrole on an electrode immersed in acetonitrile could be repeatedly driven between the conducting and insulating states, as shown by the stability of the cyclic voltammograms of the films (see Figure 3.73). 

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