A detailed electronic-scale DFT modeling/MD simulation, electrochemical and surface morphological explorations of imidazolium-based ionic liquids as sustainable and non-toxic corrosion inhibitors for mild steel in 1 M HCl

Three new eco-friendly imidazolium-based ionic liquid derivatives with different chain lengths: [Eth-IM thorn , Br-], [Met-IM thorn , Br-] and [Prop-IM thorn , Br-] on mild steel in 1 M HCl was investigated. Electrochemical Impedance Spectroscopy, Potentiodynamic polarization techniques were used as experimental studies. Theoretical calcu-lations using DFT (Density Functional Theory) and molecular dynamics (MD) simulations were performed to demonstrate the reactivity behavior and the reactive sites of three molecules. The results revealed that these synthesized ionic liquids exhibited good corrosion inhibiting property >90 %. Electrochemical measurements showed that these organic compounds are mixed-type inhibitors. SEM and EDX examinations proved the for-mation of a protective layer of adsorbed inhibitors at the steel surface. The computational findings are in good agreement with inductive effects of methyl, Ethyl and Propyl functional groups.