Mixed cation and anion transport during redox cycling of a self-doped polyaniline derivative in nonaqueous media

This work describes a microgravimetric study of the charge compensation pro cess in different supporting electrolyte solutions of propylene carbonate o r acetonitrile for a polyaniline derivative, poly (aniline-co-N-propane sul fonic acid aniline), PAPSAH. The viscoelastic properties of thin PAPSAH fil ms were investigated using an electroacoustic impedance technique. These re sults demonstrate that the film behaves rigidly, validating the use of the Sauerbrey equation for mass measurements with the electrochemical quartz cr ystal microbalance (EQCM). Both cation and anion participation in the charg e compensation process were studied using cyclic voltammetry and EQCM measu rements. On a molar basis, the cation and anion contributions during the re dox process for thin films of this material are roughly 50% each in Li+-con taining supporting electrolytes. The cation and anion participation during the redox process increase in the following order: tetrabutylammonium < Na < Li+ and ClO4- = AsF6-, respectively. The significance of these results f or applications of self-doped polyaniline derivatives in nonaqueous media i s discussed. (C) 2000 The Electrochemical Society. S0013-4651(99)12-023-8. All rights reserved.