Electropolymerization mechanism and electrochemical properties of polypyrrole film doped with a large anion

Using the galvanostatic method the polypyrrole films doped with common low molecular weight inorganic anions and with the large surfactant anions were obtained. The electrochemical behaviour of polypyrrole films electrosynthesised in the presence of 1,2 dihydroxybenzenedisulfonic (3,5) acid disodium salt (1,2 DHBSAS) was investigated by cyclic voltammetry. The study has been focused on the evaluation of the effects of electrosynthesis conditions on the electroresponse of the PPY films as well as on the role of the nature of the electrolyte on the doping process and on the interface properties of the polymer electrode. The results indicate that the kinetics of the redox process are mainly governed by diffusion of the cations and anions of the supporting electrolyte ( cycling electrolyte), while the large anions remain immobilized in the polymer structure. Therefore, the kinetics of the process can be monitored by changing the nature of the electrolyte and this may allow modulation of the electrical and optical properties of PPY/1,2 DHBSAS film.