Theoretical study of N-thiazolyl-2-cyanoacetamide derivatives as corrosion inhibitor for aluminum in alkaline environments

A series of systematic theoretical studies on the use of N-Thiazolyl-2-cyanoacetamide derivatives as corrosion inhibitors of aluminum in alkaline environment was carried out by using density functional theory (DFT), molecular dynamics (MD) simulation and Monte-Carlo (MC) simulation. The growth characteristics of Al were obtained and discussed. Results show that the (1 1 1) face of Al is suitable as a substrate for adsorption due to its large number of adsorption sites and low surface energy. Quantum chemical calculation shows that the reactive regions of the three derivatives are located on the benzene ring and the thiazole ring. The difference in E-LUMO determines the different performances between corrosion inhibitions, whereas solvation effects mainly change the dipole moment of three inhibitors. MC simulation shows that solvation effects can change the molecular configuration of the corrosion inhibitor, there affecting the corrosion inhibition efficiency. MD simulation shows that the free volume and the self-diffusion of the film are the two key factors that affect the inhibition of the corrosion particle diffusion by the corrosion inhibitor film. The results were in good agreement with reported experiment results. This study can help understand the mechanism of similar inhibitors and develop more inhibitors for Al in alkaline environment. (C) 2018 Elsevier B.V. All rights reserved.