Combined impedance and Raman analysis in the study of corrosion protectionof iron by polyaniline

Chemically prepared Polyaniline coatings on iron electrodes were tested in chloride or sulphate solutions at neutral or slightly acidic pH for which o nly the emeraldine base moiety exists. However, the Raman results indicate the presence of polarons and the impedance diagrams were explained by the p resence of a faradaic reaction evolving on an electronically conducting por ous medium.