AFM studies of the adhesion properties of surfactant corrosion inhibitor films

Abstract

The properties of an adsorbed corrosion inhibitor - Tall Oil Fatty Acid (TOFA) imidazolium chloride, on mica, gold and X65 steel were studied using in-situ atomic force microscopy (AFM). Topography images and thickness measurements show that the structure of inhibitor film changes from monolayer to bi-layer as inhibitor concentration exceeds its Critical Micelle Concentration (CMC). Further kinetic study indicates that the developing of a full film takes about 6 hours. Quantitative force measurements were performed to evaluate the mechanical and adhesion properties of inhibitor films. Results show that the stress, needed to physically remove adsorbed inhibitor molecules is of the order of MPa. © 2013 by NACE International.