Stabilization of polyaniline films by Surface attachment of oxidizable Substrates

Abstract

Cyclic Voltammetry was used to study the Electrochemical properties of PAminophenol on a Polyaniline modified carbon electrode surface. The resilts reveal reversible redox waves. The quinone derivatives formed frop P-Aminophenol(PAP) oxidation seem to depress the rate of degradation of Polyaniline at positive potentials. The electrochemical properties of Phenol on a polyaniline modified electrode were also investigated. The results showed that phenol also stabilises the polyaniline film at positive potentials above 0.70 V (SCE). The effect of solution pH on the rate of degradation of the polyaniline film was also investigated. It was observed that lowering of the solution PH slows down to some extent the rate of degradation of the polyaniline film. From the degradation data an expression for calculating the pK of the polyanilne film was derived using Kinetics. Cyclic Voltammetric analysis of the degradation of metal modified polyaniline show that Lead deposition in polyaniline suppresses the latter's electrochemical degradation at positive potentials above 0.70 V (SCE). Tin modified polyaniline appears to show improved conductivity. Modification of polyaniline by deposition of silver does not result in a substantial change in the polyaniline electrochemical characteristics. Cyclic Voltammetry will be used as a diagnostic tool to assess film behavior in different environments.