Electrochemistry of Polythiophene and Polybithiophene Films in Ambient Temperature Molten Salts

Abstract

Polythiophene and polybithiophene polymer films were deposited on platinum, tungsten, and glassy carbon electrodes by anodic oxidation of the monomer in ambient temperature molten salts, consisting of a mixture of aluminum chloride and 1‐methyl‐3‐ethyl‐imidazolium chloride. The formation reaction of polythiophene and polybithiophene is totally irreversible. The polymer films are conductive in the oxidized state and nonconductive when reduced as indicated by the shape of cyclic voltammetric curves for the polymers and for ferrocene oxidation on electrodes covered by different thicknesses of polymer. Results of ferrocene oxidation on electrodes coated by polythiophene suggest that these polymer films are porous. The films obtained in these molten salts are more stable and their electrochemical behavior appears to be less complicated than that of films prepared in acetonitrile solutions.