Atomistic Simulation of Interface Effects in Hybrid Carbon Fiber Reinforced Polymer Composites Incorporating ZnO Nanowires

This paper reports a molecular dynamics (MD) simulation study for evaluating the interfacial properties of ZnO nanowire (NW)/carbon fiber reinforced polymer (CFRP) hybrid composites. Molecular structures of the hybrid composite components, including cross-linked epoxy, graphene sheet representing carbon fiber surface, and ZnO NW are simulated. A representative volume element (RVE) is modeled at the nanoscale containing a ZnO NW vertically aligned on the carbon fiber surface and embedded in the epoxy matrix. Normal displacement load is applied to the carbon fiber sheet to separate it from the ZnO NW perpendicular to the fiber sheet. The traction-separation properties of the interface between fiber and the enhanced matrix are evaluated. The cohesive parameters, including the interfacial strength and the cohesive energy in the ZnO NW hybrid model, are compared with the bare model (fiber and epoxy). The MD simulation results show a 98% improvement in the cohesive energy and 130% improvement in interfacial strength of the hybrid CFRP composites. This study demonstrates the promising effect of aligning ZnO on the fibers for enhancing fiber-matrix adhesion.