Conducting polymer films of cross-linked structure and their QCM analysis

The authors investigated polypyrrole (PPy) films for the purpose of obtaining microporous structures for high power-density supercapacitor applications. The PPy films were formed with dopants based on a naphthalene ring substituted with multiple sulfonate groups, viz. mono, di, and trisulfonates. Using the quartz crystal microbalance (QCM) method, we obtained in situ and semi-quantitative data for these PPy films during their electropolymerization and charge-discharge (doping-undoping) processes. The electropolymerization process of the PPy films in the presence of the multisulfonates (disulfonates and/or trisulfonates) involves an electrostatic cross-link, which is considered to produce microporous structures. AC impedance analysis indicated that the PPy/trisulfonate film had a higher diffusivity and a higher capacitance than the PPy/disulfonate and PPy/monosulfonate films. (C) 2000 Elsevier Science Ltd. All rights reserved.