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

The authors investigated polypyrrole (PPy) films for the purpose of obtaini ng microporous structures for high power-density supercapacitor application s. The PPy films were formed with dopants based on a naphthalene ring subst ituted with multiple sulfonate groups, viz. mono, di, and trisulfonates. Us ing the quartz crystal microbalance (QCM) method, we obtained in situ and s emi-quantitative data for these PPy films during their electropolymerizatio n and charge-discharge (doping-undoping) processes. The electropolymerizati on process of the PPy films in the presence of the multisulfonates (disulfo nates and/or trisulfonates) involves an electrostatic cross-link, which is considered to produce microporous structures. AC impedance analysis indicat ed that the PPy/trisulfonate film had a higher diffusivity and a higher cap acitance than the PPy/disulfonate and PPy/monosulfonate films. (C) 2000 Els evier Science Ltd. All rights reserved.