Corrosion protection of stainless steel by electropolymerised pani coating

Polyaniline coatings have been obtained on stainless steel electrochemically from sulphuric acid medium under cyclic voltammetric, galvanostatic and potentiostatic conditions. The corrosion performance of the coating has been evaluated by EIS and polarization methods in 1 M H2SO4, 1 M HCl, and 1 M NaCl solutions. The polyaniline coating has been found to offer more than 90% protection in acid medium. However, the polyaniline coating is not protective in NaCl media. Besides, it is observed that polyaniline coating is much more stable in sulphuric acid than in hydrochloric acid.