Potentiostatic Oxidation of Polyaniline under Conformational Relaxation Control:  Experimental and Theoretical Study

• Published in: The journal of physical chemistry. B Vol. 107; no. 18; pp. 4269 - 4276
• Main Authors: Otero, T. F, Boyano, I
• Format: Journal Article
• Language: English
• Published: American Chemical Society 08.05.2003
• ISSN: 1520-6106; 1520-5207
• DOI: 10.1021/jp0225222

Electrogenerated films of polyaniline were studied by potential steps in acetonitrile solutions to check for the presence of compaction, relaxation, and diffusion processes giving like-nucleation chronoamperograms such as those described by the electrochemically stimulated conformational relaxation (ESCR) model. This solvent was used to avoid both proton discharge during cathodic compaction of the film at high cathodic potentials and proton exchange during redox processes. Chronoamperograms obtained from different cathodic potentials to different anodic potentials under different concentrations of electrolyte or at different temperatures indicate the presence of compaction, relaxation, nucleation, and diffusion processes under electrochemical stimulation. The ESCR model, developed to describe the electrochemical behavior of polypyrrole films by the quantification of these processes, was used to determine if it can be applied to simulate the chronoamperometric responses of the polyaniline and the influence of the different variables on the experimental chronoamperograms. Constants required to simulate the chronoamperograms were obtained from experimental results:  the same model indicates the required experimental conditions. Good agreement was obtained between simulated and experimental results.