ON A NOVEL POLYPYRROLE MORPHOLOGY

Electrochemically deposited polypyrrole thin-film gas sensors have bee n observed to exhibit significantly different structural and morpholog ical properties on variation of deposition conditions. The careful con trol of all deposition variables, therefore, is crucial if reproducibi lity is to be attained. This paper attempts to explain the origins of a novel morphological variant which involves the formation of a tendri llar texture on the growth face of the polymer thin film. We suggest t hat this morphological feature is the result of variations in electrol yte purity levels during electrochemical deposition. We show that the oxidation of pyrrole monomer is a significant source of electrolyte im purity. (C) 1998 Elsevier Science Ltd.