Green corrosion inhibitors based on biomacromolecules and macrocycles: A review

Biodegradable biological molecules, including macrocycles and naturally occurring biopolymers, are well-known for their various biological activities and pharmaceutical applications. These bio-molecules are reported for their environmentally benign nature and considerable corrosion inhi-bition efficiency in aggressive aqueous media. The sizeable molecular framework with plenty of available metal-inhibitor interaction sites facilitates effective surface adsorption. Further, to achieve improvement in corrosion inhibition performance, different chemical functionalization methods have been explored. Consequently, the application of macrocycles and large biomole-cules is an attractive topic of research in the area of green corrosion inhibitors. This review pre-sents recent advancements in macrocycles and natural biopolymers as green corrosion inhibitors. In addition, related reports on biopolymer nanoparticles and various nanocomposites are pre-sented. The importance of molecular structure and chemical functionalization in the inhibition is debated. The results of computational and theoretical studies are discussed.