Theoretical prediction and electrochemical evaluation of vinylimidazole and allylimidazole as corrosion inhibitors for mild steel in 1M HCl

Corrosion inhibition potentials of two imidazole derivatives namely, vinylimidazole (VI) and allylimidazole (AI) for carbon steel in 1M HCl at 25°C were predicted theoretically using quantum chemical calculations and molecular dynamics (MD) simulations. DFT calculations indicated that VI is more reactive towards steel surface than AI. Equilibruim adsorption behaviour of VI and AI molecules on Fe2O3 (010) surface was investigated using molecular dynamics (MD) simulations. The equilibrium adsorption energy followed the order: VI>AI. Theoretical conclusions were subsequently validated experimentally using potentiodynamic polarization, linear polarization resistance, electrochemical impedance spectroscopy, and surface analytical techniques (SEM and AFM).