Corrosion protection of steel by polyaniline (PANI) pigmented paint coating

The corrosion performance of polyaniline (PANI) pigmented coating on steel has been studied by electrochemical impedance spectroscopy (EIS) in 3% NaCl and 0.1N HCl solutions. Initially, the impedance values were found to decrease due to the corrosion of steel in pin holes of the coating. However, on increased exposure time, the impedance values were found to increase due to the formation of passive film on the exposed steel in pin holes. These studies have shown that the polyaniline pigmented coatings are able to protect the steel both in acid and neutral media.