Composite Polymeric Films on Electrodes: Incorporation of Poly(4‐Vinylpyridine) into Base‐Hydrolyzed Cellulose Acetate Coating

A new composite polymer electrode coating based on a mixture of cellulose acetate and polyvinyl pyridine is described. The incorporation of the ion exchanging polymer to the cellulose acetate domain allows the binding of counterionic reactants in acidic media, while maintaining the size exclusion discriminative properties of cellulose acetate. Different permeabilities are obtainable by a controlled hydrolysis of the coating in alkaline media. The transport and loading characteristics are explored using cyclic voltammetry and rotating disk measurements. Parameters affecting the film electrochemistry are investigated. The resulting composite coating exhibits properties superior to those of the two components alone, resulting in several potential electroanalytical and electrocatalytic applications. Countenonic reactants are retained for extended periods compared to pure polyvinyl pyridine coatings. Effective discrimination against surface‐active organic materials is illustrated. Similar protection can be achieved using a bilayer electrode coating.