ELECTROCHEMICAL QUARTZ-CRYSTAL MICROBALANCE INVESTIGATION OF A POLY(PYRROLE) SULFATED POLY(BETA-HYDROXYETHER) COMPOSITE FILM

The poly(pyrrole)/sulfated poly(beta-hydroxyether) (PPy/S-PHE) composi te film was prepared by galvanostatic electropolymerization of pyrrole in the presence of a persulfated poly(beta-hydroxyether). The redox p roperties of the PPy/S-PHE film were investigated with an in situ elec trochemical quartz crystal microbalance technique in propylene carbona te solutions of 0.5 mol/liter tetrabutylammonium perchlorate (TBA-P) a nd 0.5 mol/liter LiClO4. It was found that the PPy/S-PHE film contains higher amounts of solvent in the reduced state than in the oxidized s tate. A potential step measurement proved that the charge propagation is faster in the TBA-P electrolyte than in the LiClO4 electrolyte. The slower charge propagation in the LiClO4 electrolyte was considered to be a consequence of the lithium S-PHE salt generated in the film duri ng the reduction having poorer solubility in propylene carbonate.