Virgin and chemically functionalized amino acids as green corrosion inhibitors: Influence of molecular structure through experimental and in silico studies

Amino acids are naturally occurring, biodegradable, cheap, and easily available alternatives against the conventionally used toxic corrosion inhibitors. The structural features of the different amino acids play a crucial role in the adsorption and inhibition performance. The chemical functionalization of organic molecules using single-step protocol is an important strategy for improving the corrosion inhibition performance. The different functional groups present in the amino acid structures provide the choice of chemical modification of these amino acids. A number of derivatives such as Schiff bases, ionic liquid derivatives, surfactants, polymeric amino acids, etc. have been prepared using simple functionalization methods. This article presents an overview of the correlation of the experimentally obtained results of the amino acids and their derivatives with their structural features via computational techniques. The significance of amino acids as corrosion inhibitors, the importance of chemical modification, computational studies on amino acids, and the mechanism of adsorption and corrosion inhibition by amino acids are described herein.