Simple preparation and characteristics of stabilized, protonated poly-4-vinylpyridine films containing electroactive anions on glassy carbon electrode surfaces

Abstract

Stable, cross-linked, polyelectrolyte coatings were prepared directly on glassy carbon electrode surfaces by reacting poly-4-vinylpyridine with alkyl dihalides in the solid phase. The electrochemical properties of hexachloroiridate(III/IV) and hexacyanoferrate(II/III) couples incorporated in these films are summarised. The analysis of limiting current data from rotating disc electrode experiments provided values for the rate constant for oxidation of Fe 2+ substrate by polymer-bound IrCl 2− 6 under conditions where reaction was confined to the coating/solution interface. Differences between these values and those pertaining to homogeneous solutions and to the interior of the polymer phase are briefly discussed in terms of the diffusion-controlled encounters of the reacting species prior to charge transfer. In these kinetic studies, high substrate concentrations produced limiting currents which did not conform with the predictions of relevant theory. The causes of these discrepancies could not be specified.