An XPS study of the adsorption of organic inhibitors on mild steel surfaces

Adsorption of organic inhibitors on mild steel at different electrochemical conditions was studied using X-Ray Photoelectron Spectroscopy (XPS). To en able a quantification of the XPS data, the inhibitors were labelled with a Br atom. The new inhibitor molecule was compared to conventional ones in el ectrochemical experiments to ascertain compatibility between results. From XPS analysis, it was concluded that potentials in the active potential regi on, when compared to passive, gave higher amounts of adsorbed inhibitor on the surface. The results proved to be consistent with a previously publishe d model, suggesting a competitive adsorption mechansim between the inhibito r anions and other electrolyte anions, e.g. SO42- and Cl-. (C) 2000 Elsevie r Science Ltd. All rights reserved.