Polyaniline layer for iron protection in sulfate medium

Polyaniline has been potentiostatically electrodeposited on iron in acidic medium to protect the electrode from corrosion. Two acids have been tested : oxalic and phosphoric acids to look for the influence of the passive layer on the system behavior. Influence of additives in the deposition have been examined together with temperature. Careful control of temperature deposition is necessary due to the high activation energy of the process. Metanilic and camphorsulfonic acids act as plasticisers for the polymer layer but also have beneficial effects on electrodeposition by lowering the passive potential and active currents.