Molecular dynamics simulation study on adsorption of imidazoline and quinoline derivatives on Fe (001) surface

Corrosion inhibitors are an effective method for preventing and controlling metal corrosion. This study investigates the adsorption characteristic of four corrosion inhibitors, 2-Oleyl-3-Amine-ethylimidazoline (OAI), 2Oleyl-3-[N-(2-Aminoethyl)-N-(2-Carboxyethyl)amino]imidazoline (OAAI), Oleyl chlorinated quinoline (OQC) and benzyl quinoline chloride (BQC), on the Fe(001) surface employed molecular dynamics simulation. The results indicate that, compared to quaternized imidazoline groups, quinoline groups interact more effectively with non-polar groups to promote molecular adsorption on the Fe(001) surface, exhibiting a stronger tendency for parallel adsorption. The polar groups of quinoline derivatives achieve a more uniform coverage on the Fe (001) surface. The polar functional groups of all four inhibitors are capable of penetrating the hydration layer on the Fe(001) surface, making direct contact with the metal, thus preventing water from interacting with the metal surface. Quinoline derivatives exhibit superior water molecule displacement capabilities compared to imidazoline derivatives, while imidazoline rings possess a greater ability to penetrate the hydration layer. The radial distribution function analysis reveals significant differences in the spatial arrangement and local structure of atoms within the adsorption layers of the four corrosion inhibitors on the Fe(001) surface.