Polypyrrole electrogeneration in acetonitrile / water mixtures

Summary form only given. The effort devoted on the study of the mechanism of electrochemical polymerization of pyrrole has been orientated to determine the best conditions of synthesis for the growth of films with optimal properties. One of the points of interest has been the study of the positive effect of the addition of low amounts of water to the organic electrolytic medium of synthesis (e.g.acetonitrile). It is assumed that the acetonitrile + 1% of water mixture is an optimal medium for the obtention of high conducting films. However, the comparative study of polypyrrole electrogeneration in other acetonitrile/water relationships has received not much attention. In this work the polypyrrole electrogeneration in acetonitrile solutions having high water contents (20%<[H/sub 2/O]< 50%) onto a rotating disk electrode has been studied. When polypyrrole is generated on a stooped electrode, high conducting films were obtained. On the contrary, when the electrode was rotated, the obtained polymer films showed a very poor conductivity. Those results have been explained in terms of the intervention of solvent on the polymerization mechanism, as consequence of specific acetonitrile/water interactions.