Molecular dynamics simulation of corrosive species diffusion in imidazoline inhibitor films with different alkyl chain length

Diffusion performances of corrosive species in imidazoline derivative film with different alkyl chain length are investigated by molecular dynamics simulation method. The diffusion coefficient is used to evaluate the inhibition efficiency. Calculated results indicate that the diffusion coefficient decreases with the increasing alkyl chain length, and the inferred inhibition efficiency increases with the increasing alkyl chain length, which is well in accordance with reported experimental results. Furthermore, the diffusion process of corrosive species is discussed in detail, and four factors, fractional free volume, interaction energy, displacement period and self-diffusion coefficient, are proposed to illustrate the microscopic diffusion mechanism.