Improvement of adhesion and continuity of polypyrrole thin films through surface modification of hydrophobic substrates

Conducting polymer polypyrrole is reported to have a poor adhesion to substrate which limits its applicability as thin films. In this article, we report synthesis of well-formed and continuous film of polypyrrole through treatment of hydrophobic substrates. However, in place of the widely used organosilanes, the substrates were simply treated with surfactant cetyl trimethylammonium bromide (CTAB) prior to vapor phase polymerization under controlled environment. Polypyrrole films formed on CTAB pretreated substrates were found to have improved adhesion and continuity compared to the films formed on untreated substrates. The improved adhesion results in better electronic properties as seen during Electron field emission studies. Based on contact angle analysis, we propose that CTAB molecules act as anchoring agents for the oxidant layer on the substrate and hence assist in the deposition of a more continuous polypyrrole film. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39771.