Conductivity of polypyrroles

Two independent groups have reported that polypyrrole can be formed within a swollen film of poly(vinyl chloride) attached to an electrode surface 296 297). Niwa etal. 298 299) have described the properties of these composites, which, they claim, can combine the toughness of PVC with the conductivity of polypyrrole. 

Glatzhofer et al.1281 describe the reduction of conductivity of polypyrrole films, doped with poly(styrene-p-sulfonate), as increasing concentrations of dioxane are added to the aqueous electrolyte. They claim that the solvent induces a conformational change in the counterion, which modifies the film morphology. 

Duffitt GL, Pickup PG (1992) Enhanced ionic conductivity of polypyrrole due to incorporation of excess electrolyte during potential cycling. J Chem Soc Faraday Trans 88 1417-23... 

Effect of the Counterion on the Tensile Strength and Conductivity of Polypyrrole (PPy) Films... 

Samuelson and Druy [100] reported that the counterion has an important role in the decay of electrical conductivity of polypyrrole. For polypyrrole with p-toluenesulphonate counter-ion, the decay in electrical conductivity with time in air showed first-order kinetics... 

Table 16.3. Conductivity of polypyrrole/toluenesulphonate, polypyrrole/ tetrafluoroborate and polypyrrole/perchlorate before and after heating in nitrogen for 900 minutes. Adapted from Macromolecules 19, 824 (1986), with permission of the American Chemical Society...

K. West, L. Bay, M.M. Nielsen, Y. Velmumgu, and S. Skaarup, Electronic conductivity of polypyrrole-dodecyl benzene sulfonate complexes, J. Phys. Chem. B, 108(39), 15001-15008 (2004). 

Wang, PC., Z. Huang, and A. MacDiarmid. 1999. Critical dependency of the conductivity of polypyrrole and polyaniline films on the hydrophobicity/hydrophilicity of the substrate surface. Synth Met 101 852. 

Yamaura, T, T. Hagiwara, and K. Iwata. 1988. Enhancement of electrical conductivity of polypyrrole film by stretching Counter ion effect Synth Met 26 209. 

Zotti, G., S. Zecchin, G. Schiavon, B. Vercelli, A. Berlin, and E. Dalcanale. 2003. Potential-driven conductivity of polypyrroles, poly-JV-alkylpyrroles, and polythiophenes Role of the pyrrole NH moiety in the doping-charge dependence of conductivity. Chem Mater 15 4642-4650. 

Eftekhari, A. 2004. Enhanced stability and conductivity of polypyrrole film prepared electrochemically in the presence of centrifugal forces. Synth Met 142 305. 

AguUar-Hemandez, J. and K. Potje-Kamloth (2001). Evaluation of the electrical conductivity of polypyrrole polymer composites. 7. Phys. D Appl. Phys. 34,1700-1711. 

Boxall, D. L. and Osteryormg, R. A. (2004). Switching potentials and conductivity of polypyrrole films prepared in the ionic liquid l-butyl-3-methylimidazolium hexailuorophosphate. Journal of The Electrochemical Society 151, 2, pp. E41-E45. 

Mao, H. and Pickup, P. (1990). In situ measurement of the conductivity of polypyrrole and poly[l-methyl-3-(pyrrol-l-ylmethyl)pyridinium]+ as a function of potential by mediated voltammetry, redox conduction or electronic conduction Journal of American Chemical Society 112, pp. 1776-1782. 

Table 5.2 Results of elemental analysis and dry conductivity of polypyrrole films . (Reproduced from Journal of Applied Polymer Science, 2004, 93, 526. Reprinted with permission of John Wiley Sons, Inc.)...

The electrolyte concentration employed during synthesis also influences the conductivity of polypyrrole. This has been observed for polypyrrole films electrogenerated on aluminum electrodes, where the conductivity varies from 100 to 320 S cm when the electrolyte concentration (/-butylammonium p-toluenesulfonate salt) increases from 0.05 to 0.3 M [37]. Similar results have been obtained by Satoh et al. [51] using ITO glass electrodes. These higher conductivities should be associated with the higher dopant concentration or the influence of the electrolyte concentration on the polymerization rate. 

The electrical conductivity of polypyrrole is known to be a strong function of its oxidation state and hence of the applied potential the oxidized polymer is highly conductive (10 to 10 S cm ) and the reduced form is semiconductive or nearly insulating to 10" S cm ). Quantitative conductivities of dry polypyrrole... 

The electrical conductivity of polypyrrole depends not on the kind of dopant but on its concentration. Sun and Sun [155] observed that H2SO4, KI, and others. 

It is well known that the electrical conductivity of polypyrrole has a significant effect on transmission, reflection, and absorption of microwaves. Heavily doped conducting films are highly reflective, whereas lightly doped semiconducting films have a very high transmittance [190] and are therefore of interest for both the control and improvement of the polymer conductivity prior to the design of such applications. 

Rodrfguez, J., Otero, T. F., Grande, H., Moliton, J. R, Moliton, A., and Trigaud, T., Optimization of the electrical conductivity of polypyrrole films electrogenerated on aluminum electrodes, Synth. Metals, 76, 301-305 (1996). 

Yamaura, M., Sato, K., and Hagiwara, T., Effect of counter anion exchange on electrical conductivity of polypyrrole films, Synth. Met., 39, 43-60 (1990). 

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