Molecular dynamics and density functional theory study on relationship between structure of imidazoline derivatives and inhibition performance

The inhibition performance of two imidazoline derivatives, 3-ethylamino-2-undecyl imidazoline (EUI) and chloride-3-ethylamino-3-(2,3-two hydroxyl) propyl-2-undecyl imidazoline sodium phosphate(CEPIP), for Q235 steel in CO2 saturated solution at 298 K have been tested by weight loss experiment and electrochemical techniques. The adsorption behavior of the two inhibitors on Fe surface has been studied using molecular dynamics (MD) method and density functional theory. The results indicated that the two imidazoline derivatives could both adsorb on the Fe surface firmly through the imidazoline ring and heteroatoms, the two inhibitors both have excellent corrosion inhibition performance.