Comparative study of conducting polymers by the ESCR model

Following the hypothesis of the electrochemically stimulated conformational relaxation model (ESCRM), electrochemically generated films of poly(I-methylpyrrole), polythiophene, poly(3-methylthiophene), polyaniline, and polymethylaniline were studied by potential steps in lithium perchlorate/acetonitrile solutions. All the chronoamperograms studied by influence of different compaction potentials, or different temperatures, show a maximum, indicating the presence of conformational relaxation movements of the polymeric chains as kinetic-controlling processes of the electrochemical oxidation. Magnitudes as charge consumed to compact one mole of polymeric segments during cathodic polarization, the cathodic potential where the compaction of the polymers starts, the enthalpic increment between two stationary states defined by constant overpotentials of compaction and oxidation, and the diffusion constants stated at constant anodic overpotentials were obtained in the context pointed by the model for the studied polymers. The comparative study of the magnitudes for the different polymers, including similar magnitudes for polypyrrole and polyaniline from the literature, allows a comparative view of some structural, kinetic, and thermodynamic aspects, which can be useful for designing tailored properties, or applications, of the conducting polymers.