Effect of hydrogen functionalization on interfacial behavior of defective-graphene/polymer nanocomposites

The interfacial debonding between the graphene sheet and the polymer matrix plays a vital role in determining the performance of graphene/polymer nanocomposites. This paper investigates the influence of hydrogen functionalization on interfacial sliding of polymer nanocomposites reinforced by graphene containing defects using molecular dynamics simulations. Results show that the surface-hydrogenated graphene/epoxy system significantly outperformed the edge-hydrogenated case in terms of the shear strength due to better interfacial bonding between graphene sheet and epoxy matrix. The presence of defects decreases the shear strength in both surface- and edge-hydrogenated graphene/epoxy nanocomposites. It is also found that increasing the functionalization degree and temperature improves the interfacial shear properties for all tested nanocomposites. The mechanisms of functionalization underlying the interfacial sliding of graphene/epoxy nanocomposites are explored at the nanoscale, indicating that functionalization is an effective way to achieve improved interfacial properties for graphene reinforced nanocomposites.