DEGRADATION AND ITS PREVENTION, AND THE DEACTIVATION AND REACTIVATION OF ELECTROACTIVE POLYTHIOPHENE FILMS DURING OXIDATION REDUCTION CYCLES

A polythiophene film prepared on a Pt electrode was degraded and deactivated by repeating the potential scan in electrolytic solutions including nucleophiles and bulky cations, respectively. In the cases of the degradation and the deactivation, the anodic peak current and potential of the cyclic voltammogram decreased and shifted positively, respectively. The degradation could be prevented by keeping nucleophilic species out of the solutions and by adding strong acids, sterically hindered phenols or methoxylated benzenes, while the deactivation was also prevented by using alkali metal salt supporting electrolytes and by adding ferricinium or tritylium salt. Once deactivated the film could also be reactivated by polarizing at a highly positive potential. The mechanisms of the degradation, deactivation and reactivation are also discussed.