Thermal behavior on a polyaniline electrode in zinc sulfate aqueous solution

Various kinds of conducting polymers have been synthesized and their physicochemical properties and applications have been studied actively.‘There have been several reports on electrochemical studies on polyaniline [l-7]. Anodic oxidation of polyaniline in aqueous solutions may cause not only anion doping but also proton elimination. In situ measurements of absorption spectra [6,81 and weight changes [1,7,91 of polyaniline in the anodic process have been reported. The measurement of temperature change during electrolysis may provide useful information concerning electrode reactions. We have already reported thermal behavior in the graphite intercalation process [lO,ll]. In this paper, the thermal behavior at a polyaniline electrode in ZnSO, aqueous solution was examined in order to obtain knowledge on the electrochemical doping process.