Effect of CNT on the Mechanical Property of Graphene/Epoxy Composite by Molecular Dynamics Simulations

Molecular dynamics simulations were adopted to explore the effect of carbon nanotube (CNT) on the mechanical property of graphene/epoxy composite. Emphasis was laid on investigating the variation of CNT length and relative distance between CNT and graphene on the composite property. The stress-strain curves and Young's moduli of the composite along axial and radial directions of CNT were obtained, which indicate that the existence of CNT, as well as the increase of CNT length and CNT-graphene separation within a limited distance, can enhance the mechanical property of the composite. This is mainly attributed to the formation of an interfacial adsorption layer of epoxy segments near CNT and graphene surfaces, as well as the p-p interaction between benzene rings. Interaction energy variation between graphene and CNT/epoxy (or CNT) versus CNT length, and morphological fracturing process of the composite, further highlight the significance of the interfacial adsorption region on improving the mechanical property of the composite on both axial and radial directions of CNT.