Computer simulation of diffusion of corrosive particle in corrosion inhibitor membrane

Molecular dynamics (MD) simulation method was adopted to investigate the diffusion behavior of H3O+, H2O and Cl− in three decylamides of a-amino acids inhibitor membranes, including 2-amino-N-decyl-3-(4-hydroxyphenyl) propionamide (A), 2-amino-N-decylacetamide (B), and 2-amino-N-decylpropionamide (C). The effects of the fractional free volume (FFV), the self-diffusion coefficient and the interaction energy on the diffusion coefficient were studied. The results demonstrated that the diffusion coefficient was determined by the combined effect of the three factors. For the same corrosive particle, the diffusion coefficients in the three corrosion inhibitor membranes followed the order of D(A) < D(B) < D(C). For the same inhibitor membrane, the diffusion coefficients of the three corrosive particles followed the order of D(H2O) > D(Cl−) > D(H3O+). The inhibition efficiency order obtained from the diffusion coefficient agreed well with the experimental results.