Study of Polyaniline Oxidation Kinetics and Conformational Relaxation in Aqueous Acidic Solutions

The oxidation kinetics of the polyaniline was investigated in aqueous solutions by potential steps for different values of the experimental variables. The chronoamperometric responses present a maximum, as described by the Electrochemically Stimulated Conformational Relaxation (ESCR) model. The empirical reaction kinetics R = k[ClO4−]α[pAn*(qH+)]β[H+]−γwas corroborated from the experimental results. The kinetic magnitudes: rate coefficients, reaction orders or activation energy were obtained. The value of each of those kinetic magnitudes change as a function of the initial reduced and packed state used for the subsequent oxidation: they include quantitative structural information about the structural conformational packing state of the chains in the initial state of the material The fractional reaction order indicates, as expected, the existence of a complex mechanism for the oxidation reaction.