Electroactive ion exchange polymers

Abstract

Electroactive ion exchange polymers contain both electroactive and ion exchange functionalities. This paper describes electroactive cation exchange polymers based on styrene, styrenesulfonate and vinylferrocene. Polymer film-modified electrodes were used to study these terpolymers. The electrochemical characteristics of these polymers are rather unusual in that the number of ferrocene/ferrocinium (Fc/Fc +)cyclic voltammetric waves seen depends on the quantity of -SO 3 − groups incorporated into the polymer film. This suggests that the chemical microenvironment around a fraction of the Fc groups changes when -SO 3 −is incorporated. The ion exchange characteristics of these polymers can be modulated electrochemically. When the Fc/Fc + in the film is quantitatively reduced, these terpolymers are cation exchangers and can incorporate electroactive cations from a contacting solution phase. When Fc is then quantitatively oxidized, the Fc + produced becomes the counterion for the -SO 3 − groups and the counterion initially present is expelled from the film. Thus, these are electroreleasing polymers; possible applications of these polymers are discussed.