Inhibition Effect and Adsorption Behavior of Two Imidazolium- based Ionic Liquids on X70 Steel in Sulfuric Acid Solution

摘要

In this work, two imidazolium-based ionic liquids with different chain lengths namely 1-allyl-3-ethylimidazolium bromide ([AEIM]Br) and 1-allyl-3-hexylimidazolium bromide ([AHIM]Br)respectively, were researched on corrosion of X70 steel in 0.5 M sulphuric acid. The corrosionresistance ability was tested by electrochemical methods including the electrochemical impedancespectroscopy (EIS) and potentiodynamic polarization measurement. Results showed that [AHIM]Brhave a better inhibition ability than [AEIM]Br. Scanning electron microscope (SEM) was utilized tofurther analysis the appearance of steel surface. Furthermore, the inhibition mechanism of twoinhibitors was analyzed by adsorption isotherm study and molecular dynamics (MD) simulation. Theexperimental and theoretical results are consistent and the adsorption of the two inhibitors on steelsurface belongs to mixed type of chemisorption and physisorption.