Interfacial adhesion of polycarbonate to graphene and silicon oxide: A comparative molecular dynamics analysis

In this study, molecular dynamics was used to evaluate the adsorption-free energy of polycarbonate on a solid wall surface that represented a fiber material. Three solid surfaces were used: clean graphene without functional groups to represent surface-treated carbon materials, graphene with OH groups without surface treatment, and SiO2 to represent glass fiber. The results showed that the adsorption free energy per unit area for clean graphene was greater than the adsorption free energy per unit area for the other two solid wall surfaces, which is different from the experimental results where the surface treated carbon fiber had a smaller adsorption free energy. The structure of benzene rings was analyzed, and it was found that benzene rings are deposited almost parallel to the solid wall on all solid walls and that the density of benzene rings with SiO2 and OH groups is the smallest on Graphene with the smallest angle and closest to the solid wall, resulting in smaller adsorption energy. This suggests that the π-π interaction between the benzene ring and the solid surface may account for a large proportion of the adsorption energy. It also suggests that chemical reactions between the solid surface and the polymer, which were not considered in this study, may have a significant effect on the adsorption energy.