Variable capacitance and conductance in polyaniline : A simple model with interacting sites and a single quasi-reversible charge transfer

Abstract

This study is devoted to the comparison of Cyclic Linear Sweep Voltammetry curves obtained for an electronic conducting polymer, the polyaniline, and curves obtained from a mathematical model. Our model is based on the following assumptions : - reversible, quasi-reversible or irreversible charge transfer - electrostatic or mechanical interactions within the electroactive polymer in order to explain the abnormal width of voltammetric peak of these materials [1–3] - variable capacitance to explain the polymer's capacitive behaviour [4] - variable conductivity to explain the shape of the voltammograms of such polymer [5–7] - Steady-state hysteresis which is taken into account by different values for the formal redox potential between forward and reverse scans, together with a slight dependence of the conductivity with the current direction.