Electropolymerization of pyrrole in aqueous solvent mixtures studied by in situ conductimetry

The dependence of in situ conductance of polypyrrole (PPy) at several water contents was systematically investigated using four different counter anions with acetonitrile (ACN) or propylene carbonate (PC) as solvent. The water content was found to affect profoundly the properties of these materials, as, e.g., PPy/tosylate films prepared in some mixtures of ACN and water were very poor conductors. The influence of solvent was greatest for PPy/ClO4 films. Although the preferential solvent for electropolymerization has been generally ACN +1% H2O, this report shows that at least in the presence of ClO4−, PF6− and BF4 dry PC gives superior results.