New insight on the interfacial behavior between graphene-based membranes and protonated silicon-dioxide via molecular dynamics simulations

Graphene, with many excellent properties, is often attached to silicon dioxide substrates in practical applications. In this paper, we used the molecular dynamics method to investigate the interfacial behavior between protonated silicon-dioxide and graphene-based membranes (GBM/pSiO(2)) with the different distribution and concentration of functional groups. The binding energy, free energy and entropy effect was obtained to get a detailed insight into the adhesive mechanism. Particularly, we laid stress on the size effect of 2D-square-sheet length on the interface behavior at nanoscales. Our results indicate that the high oxygen-concentration and edge functional groups in GBM enhance the interfacial adhesion, while the small sheets are more firmly adsorbed on the substrate. The analysis of energy decomposition proves that van der Waals energy still plays a major role on the interfacial behavior in the nanoscale contact system of GBM/pSiO(2). We believe this nanoscale interfacial behavior simulation could be further extended for research on the adhesion of 2D materials to 3D materials.