Molecular Dynamics, Monte-Carlo Simulations and Atomic Force Microscopy to Study the Interfacial Adsorption Behaviour of Some Triazepine Carboxylate Compounds as Corrosion Inhibitors in Acid Medium

Abstract

Molecular dynamic, Monte-Carlo simulation approach and electrochemical methods were used to study the temperature effects on mild steel (MS) corrosion in 1.0 M of HCl in the absence and presence of triazepine carboxylate compounds. The inhibition action of all triazepine carboxylates compound studied was performed via adsorption on MS surface. Comparison between several adsorption isotherms reveals that the adsorption was spontaneous and followed Langmuir isotherm in HCl for all inhibitors and at all studied temperatures. Furthermore, selection is founded on the correlation coefficient is known nearly linear and value close to one. Kinetic and thermodynamic parameters for all inhibitors led to suggest the occurrence of chemical mechanism and also the spontaneity of the adsorption process on mild steel surface. The corrosion inhibition mechanism was discussed with the light of some triazepine carboxylate compounds constituents. The effect of molecular structure on the inhibition efficiency has been explored by quantum chemical computations and obvious correlations were observed. The binding energies of tested triazepine carboxylate compounds on Fe (110) surfaces were calculated using molecular dynamics simulation. Very good agreement was obtained with the experimental data. In addition, Atomic force microscopy (AFM) indicated that Cl–Me–CN molecules contributed to a protective layer formation by their adsorption on the steel surface. AFM parameters, such as root mean square roughness (Rq), average roughness (Ra), and ten-point height (Sz), revealed that a smoother surface of inhibited mild steel was obtained, compared to uninhibited steel surface.