The corrosion performance of polyaniline film modified on nickel plated copper in aqueous p-toluenesulfonic acid solution

Abstract

Polyaniline (PANI) coatings were synthesised on 1 μm Ni plated on copper (Cu/Ni). Polyaniline films were achieved under cyclic voltammetric conditions in 0.1 M aniline containing p-toluenesulfonic acid solution. Polyaniline coatings which indicated that the p-toluenesulfonic acid solution was a suitable medium for the formation and deposition of polyaniline on a Cu/Ni substrate. Electrochemical polymerization of polyaniline resulted in the deposition of uniform, compact and strongly adherent PANI coatings on Cu/Ni . Their corrosion protection performance in 3.5% NaCl was investigated by using the AC impedance spectroscopy (EIS) technique and anodic polarization curves, which showed that polyaniline coating exhibited a significant physical barrier property against the attack of corrosive products on nickel plated copper, for longer periods and drastically reduced the corrosion rate of copper. It was found out that the barrier properties of the polyaniline coating was improved by its catalytic behaviour on formation of freshly produced nickel oxide layers and the reduction of polymer film at metal/polymer interface.