Microgravimetric study of the influence of the solvent on the redox properties of polypyrrol modified electrodes

The redox behavior of the polypyrrole films in the presence of LiClO4 salt in different solvents like propylene carbonate (PC), N,N-dimetilformamide ( DMF), methanol (MetOH), ethanol (EtOH), acetonitrile (ACN) and water was in vestigated using simultaneous electrochemical quartz crystal microbalance a nd cyclic voltammetry experiments. Both charge and mass changes during redo x processes were rationalized in terms of multiple regression considering s ome solvent parameters and ionic transport characteristics. The electroacti vity of PPY modified electrodes increase in the sequence PC<DMF<EtOH<MetOH< ACN<water. Also the mass gains in the sequence PC<water<EtOH<DMF<MetOH<ACN, showing clearly the influence of the solvent physico-chemical nature on th e electroactivity and electroneutralization processes. (C) 2001 Elsevier Sc ience B.V. All rights reserved.