Study of Adsorption of Corrosion Inhibitor 1-(2-aminoethyl)-2-oleyl-2-imidazolinium Chloride on Carbon Steel Under CO_2 Environment by Using In-Situ AFM Measurements

摘要

The most common corrosion inhibitors used to minimize corrosion of carbon steel in the oil and gas industry contain imidazoline molecules. However, the behavior of imidazoline molecules at the interface remains poorly understood, especially with respect to the adhesive and cohesive forces of inhibitor films. The objective of this work is to understand the adsorption/desorption process of 1-(2-aminoethyl)-2-oleyl-2-imidazolinium chloride on carbon steel. In order to study adsorption of imidazolinium chloride on carbon steel, in-situ atomic force microscopy (AFM) measurements were performed in air, with and without imidazolinium chloride, in a 1 wt% NaCI solution purged with CO_2 at pH 4. In-situ electrochemical/AFM measurements confirmed the formation of an inhibitor film on carbon steel surface, resulting in a decrease in corrosion rate as determined by electrochemical measurements. Quantitative force measurements were also performed to evaluate the force required for penetration of the inhibitor film adsorbed on carbon steel.