Acridine as Bioinspired Corrosion Inhibitors

Mild steel has been considerably exploited in various manufacturing and commercial fields due to its tremendous mechanical performance. However, mild steel's high susceptibility to corrosion under acidic conditions leads to vast economic losses and environmental consequences. Inhibitors used for steel corrosion in the acidic medium are ordinarily polar heteroaromatic molecules with electronegative atoms. Acridines are one type of inhibitor with several advantages, such as heteroatoms, functional groups and their polarity, double bond conjugation, and importantly efficient and non-hazardous synthetic routes. The polar moieties of such inhibitors are considered to augment their adsorption on steel surface, thus creating a shielding to inhibit steel corrosion. Acridine analogs are N-heterocyclic organic compounds that can be easily produced owing to impeccable inhibition capacity. The current review discusses the chemistry, synthesis, corrosion inhibition mechanism, and properties of acridines and their derivatives.