STUDY OF POLYPYRROLE FILMS MODIFIED WITH COPPER AND SILVER MICROPARTICLES BY ELECTROCHEMICAL CEMENTATION PROCESS

Electroactive polypyrrole (PPy) films obtained under potentiostatic electropolimerization from aqueous solutions of pyrrole doped with sulfate (SO 4 2-) anions were modified by incorporation of copper (Cu) and silver (Ag) microparticles using electrochemical cementation process. The electrochemically deposited and dissolving processes metals (Cu and Ag) onto and from polypyrrole were investigated. The PPy-Cu and PPy-Ag electrodes were characterized by electrochemical techniques and scanning electron microscopy (SEM) analysis and the electrochemical response of these modified electrodes was compared to that of the unmodified polypyrrole electrode. The results indicate that two forms of metal, valence and elemental ones, can be formed on polypyrrole at a constant cathodic potential. However, only the valence metal can be left on polypyrrole at the anodic potential. The copper and silver particles interact with polypyrrole films involving a strong complex formation affecting its electrochemical behavior. Scanning electron microscopy measurements show that dendritic-like metal aggregates are formed on the film surface. The electrochemical experiments reveal that metal deposition on conducting polymer can be envisaged as an attractive method for the electrodes fabrication