Molecular dynamics simulation of inhibition mechanism of 3,5-dibromo salicylaldehyde Schiff's base

Molecular dynamics simulation method was adopted to investigate the absorption behavior, inhibition mechanisms on Fe (100) surface in aqueous solution and the diffusion behavior of H3O+, Cl- and H2O in three of 3,5-dibromo salicylaldehyde Schiff base inhibitor films, including 3,5-dibromo salicylaldehyde-2-pyridinecarboxylic acid hydrazide (L1), 3,5-dibromo salicylaldehyde-2-thiol-phenecarboxylic acid hydrazide (L2), 3,5-dibromo salicylaldehyde-2-aminobenzothiazole (L3). The effects of the interaction energy, radial distribution function and the self-diffusion coefficient were studied accompanying with density functional theory (DFT) study. The results demonstrated that the order of adsorption energy is E (L2) > E (L1) > E (L3), absorption manner is a multi-center chemical adsorption for three inhibitor films; for different inhibitor films, the diffusion coefficients followed the order of D (L3) > D (L1) > D (L2) for the Cl- corrosive particles, the diffusion coefficients followed the order of D (L3) > D (L1) > D (L2) for the H3O+ corrosive particles. For the three inhibitor films, the diffusion coefficients of the three corrosive particles all followed the order of D (H2O) > D (H3O+) > D (Cl-). The inhibition efficiency order was obtained from the diffusion coefficient which is agreed well with the experimental results as EI (L2) > EI (L1) > EI (L3). Three kinds of inhibitor films have good corrosion inhibition efficiency in aqueous solution. (C) 2015 Elsevier B.V. All rights reserved.