H. Varela, S. L. A. Maranhão, Regina M. Q. Mello
Jun 1, 2001
Citations
1
Influential Citations
50
Citations
Journal
Synthetic Metals
Abstract
Abstract This work describes comparisons between the redox behavior of electrochemically formed polyaniline (PANI) and two chemically obtained self-doped polyanilines: sulfonated polyaniline (SPAN) and poly-(aniline-co-N-propanesulfonic acid-aniline) (PAPSAH). The charge compensation processes in HCl and camphorsulfonic acid (HCSA) aqueous solutions were studied using simultaneous cyclic voltammetry and electrochemical quartz crystal microbalance techniques. Film electroactivity decreases in the PANI⪢SPAN>PAPSAH sequence in HCl solution. Charge compensation is carried out mainly with proton participation in SPAN modified electrode in both HCl and HCSA solutions. In contrast, for PANI and PAPSAH, the participation of anions also occurs, with a contribution strongly dependent on anion size. These results were analyzed in terms of the acid/base equilibrium of the polymer chains.