Tensile property enhancement of defective graphene/epoxy nanocomposite by hydrogen functionalization

The performance of graphene/epoxy nanocomposites strongly depends on the interfacial interaction between the graphene and polymer as well as the structural defects of materials. This paper investigates the effect of hydrogen functionalized graphene on tensile properties of polymer nanocomposites by using molecular dynamics simulations. The pristine graphene sheet is functionalized by adding hydrogen atoms on its edge or surface. Results show that compared with those reinforced by pristine graphene, the nanocomposites reinforced with functionalized graphene exhibit considerably improved tensile modulus, ultimate strength and strain due to improved interfacial bonding between the functionalized graphene sheet and epoxy matrix which provides much better load transfer capability. It is also found that an increase in temperature decreases the tensile modulus and ultimate strength but increases the ultimate strain in both armchair and zigzag directions. The mechanisms of functionalization underlying the tensile behaviors of graphene/epoxy nanocomposites are explored at the nanoscale, suggesting that the application of functionalization is an effective way to achieve improved modulus and strength for graphene reinforced nanocomposites.