Corrosion inhibition and adsorption of imidazolium based ionic liquid over P110 steel surface in 15% HCl under static and dynamic conditions: Experimental, surface and theoretical analysis

The present paper deals with the corrosion inhibition evaluation of imidazoline based ionic liquid, namely 1-Decyl-3-methylimidazolium chloride (DMIC) on P110 steel in 15% HCl under static and dynamic conditions. The influence of KI addition was also examined over the inhibition performance (ɳ%). EIS results reveal that R_ct increase with increases in DMIC concentration. PDP suggests that the inhibition action of DMIC is a mixed type inhibitor. The inhibitive performance of DMIC is less, and its maximum inhibition efficiency is 68.61% at 400 mg/L. Addition of KI (0.5 mM) + DMIC (400 mg/L) enhanced the corrosion inhibition efficiency to 90.15%. The performance of DMIC and DMIC+KI decreases with an increase in temperature. The adsorption of DMIC obeys the El-Awady isotherm. The performance of DMIC is better under hydrodynamic conditions as compared to static conditions. The performance of DMIC decreases when the rotation speed is higher than 1500 rpm. Density functional theory (DFT) suggests that both anionic/cationic parts help in the DMIC adsorption. Molecular dynamic simulation (MD) reveals that neutral DMIC adsorbed flatly over P110 steel while protonated adsorbed in a twisted manner.