Abstract
As a model system of adsorption process of anti-corrosion additives on the metal surface, molecular dynamics simulation of benzotriazole (BTA) molecules with copper slabs has done. As a force field, we used ReaxFF (Reactive Force-Field) interatomic potential to simulate adsorption dynamics and the charge transfer on the solid surface. In order to investigate the selective adsorption, the physical adsorption and the chemical adsorption on the surface, we made hybrid slab model which have both a copper (Cu) area and a copper (I) oxide (Cu2O) area. The number of BTA molecules adsorbed on the Cu area is 5 times larger than that on the Cu2O area. BTA molecules made adsorbed layer in parallel to the copper (I) oxide (Cu2O) surface, and aggregation of the molecules due to the surface diffusion is found. On the other hand, BTA molecules made adsorbed layer in vertical to the copper (Cu) surface. Detailed dynamics focused on charge transfer shows surface diffusion and enhancement of polarization due to charge transfer from the metal surface caused the selective adsorption. In real phenomena, the reason why a few anti-corrosion additives are able to protect metal surface thought that it is from this selective nature of adsorption onto newly formed metal surface.
