Electrochemical and spectroelectrochemical studies on copolymerization of diphenylamine with 2,5-diaminobenzenesulfonic acid

Electrochemical copolymerization of diphenylamine (DPA) with 2,5-diaminobenzenesulfonic acid (DABSA) was carried out in aqueous 4 M H2SO4 by employing cyclic voltammetry (CV). Copolymer films were grown for different molar concentration ratios of DPA and DABSA. Electrochemical homopolymerization of DPA alone was also carried out under similar conditions. UV-visible spectroelectrochemical studies were performed to add evidence for copolymer formation when electropolymerization was performed with DPA and DABSA. A growth equation for the deposition of copolymer film was deduced as Q(G) = k [DPA](1.02) [DABSA](-0.69) C-n(1.2), where C-n is the number of cycles in CV, by utilizing the charge associated with film deposition. X-ray photoelectron spectroscopy was used to find the elemental composition of copolymer and changes in redox characteristics of the copolymer in comparison with poly(diphenylamine). (C) 2002 The Electrochemical Society.