CHARACTERISTICS OF WATER IN POLYPYRROLE FILMS

Polypyrrole films containing different dopant ions were electrochemica lly synthesized and the interaction between polypyrrole and water was evaluated by means of sorption isotherm, cluster function and d.s.c. I t was found that the water sorbed in the polypyrrole behaved as a non- freezing bound water which was rather isolated and prevented from clus tering over the whole experimental range of the relative water vapour pressure from 0.1 to 0.95. This might be associated with the nature of the conductive polymers having a pi-conjugated system where the deloc alization of carbonium charges would lower the ionic polarity and hydr ophilicity of the polymeric chains. (C) 1998 Elsevier Science Ltd. All rights reserved.