Ionic Liquids as Green Corrosion Inhibitors

Abstract

Ionic liquids (ILs) are organic salts that are liquid below 100 °C. ILs are associated with several advantages and properties, such as low toxicity, low vapour pressure, high solubility, high thermal and chemical stability and, most importantly, being environmentally benign, which make them ideal green alternatives for different industrial and biological applications. Survey of the literature suggests that numerous series of ILs, including imidazolium, pyridinium and tetra-ammonium, are extensively utilized as corrosion inhibitors for different metal/electrolyte systems. These compounds serve as effective corrosion inhibitors and they become effective by adsorbing on the metal surface following the Langmuir adsorption isotherm model. Their adsorption mode of corrosion mitigation is widely supported by SEM, AFM and EDX analyses. Computational analyses showed that they interact with the metallic surface through the charge transfer mechanism. ILs act as mixed- and interface-type corrosion inhibitors.