Electrochemistry of Conductive Polymers. XXVI. Effects of Electrolytes and Growth Methods on Polyaniline Morphology

Abstract

Effects of counterions and growth methods on polyaniline growth have been studied using the electrochemical quartz crystal microbalance and other related techniques. The results indicate that the polymer growth rates and the morphology of polymer surfaces are very different depending on the electrolytes and growth methods used. During the first cycle of the potentiodynamic growth, the weight increase is observed with a low coulombic efficiency. However, the number of electrons required for the deposition of one aniline unit quickly approaches 2.0 beginning from the second cycle, and the current efficiency becomes higher as the number of cycles increases. As the film grows, the anion insertion and deinsertion become increasingly important. For a thick polymer film in the H2SO4H2SO4 solution, the doping/dedoping process is not reversible, although it is reversible in HClO4HClO4 solutions. During the potentiostatic and galvanostatic polymerization, relatively low charge efficiencies were observed due to the degradation reactions. These results were consistent with the scanning electron microscope images. © 2002 The Electrochemical Society. All rights reserved.