Theoretical prediction of corrosion inhibition by ionic liquid derivatives: a DFT and molecular dynamics approach

Ionic liquids (ILs) have recently attracted significant attention in many domains, particularly as potential corrosion inhibitors owing to their outstanding properties, including low vapor pressure, high thermal and chemical stability, and the ability to be tailored for specific applications. Their effectiveness results mainly from their ability to strongly interact with metal surfaces, often via electrostatic and chemical interactions, thereby forming a protective barrier against corrosion. This study investigated three ionic liquids (ILs), namely, 3-(5-ethoxy-5-oxopentyl)-1-phenethyl-1H-imidazol-3-ium bromide ([5E5O-Imid] Br), 3-(6-ethoxy-6-oxohexyl)-1-phenethyl-1H-imidazol-3-ium bromide ([6E6O-Imid] Br), and 3-(4-acetoxybutyl)-1-phenethyl-1H-imidazol-3-ium bromide ([4AB-Imid] Br). This study aimed to assess the ILs' ability and efficiency to prevent mineral corrosion to understand the underlying mechanisms, as well as to identify the appropriate materials and timing prior to their experimental application. Density functional theory (DFT) was used to predict the electronic properties and reactivity of the molecules under investigation. Furthermore, molecular dynamics (MD) simulations were used to model the atomic-scale interactions between the ILs and metallic surfaces, offering in-depth insights into the adsorption mechanisms and interactions responsible for corrosion inhibitions.