In-situ electrochemical studies on the redox properties of polypyrrole in aqueous solutions

Two electropolymerization techniques have been used in preliminary research on polypyrrole, such as potential cycling and galvanostatic modes. The cyc lic voltammograms and chronopotentiograms can describe the proceeding of th e growth of polypyrrole from various aqueous solutions. The cyclic voltamme try of a polypyrrole film in an electrolyte solution can further characteri ze the polypyrrole films electrochemically. Some evidence has been shown of doping with cations. Polypyrrole differs with respect to the extent of oxi dation, doping anions, and also reduction, doping cations. Such properties can be switched dynamically between anion and cation coupling or hopping th rough electrochemical oxidation and reduction of the polypyrrole backbone. (C) 1999 Elsevier Science Ltd. All rights reserved.