Large-Scale Molecular Dynamics Elucidates the Mechanics of Reinforcement in Graphene-Based Composites

Using very large-scale classical molecular dynamics, the mechanics of nano-reinforcement of graphene-based nanocomposites are examined. Simulations show that significant quantities of large, defect-free, and predominantly flat graphene flakes are required for successful enhancement of materials properties in excellent agreement with experimental and proposed continuum shear-lag theories. The critical lengths for enhancement are approximately 500 nm for graphene and 300 nm and for graphene oxide (GO). The reduction of Young's modulus in GO results in a much smaller enhancement of the composite's Young's modulus. The simulations reveal that the flakes should be aligned and planar for optimal reinforcement. Undulations substantially degrade the enhancement of materials properties.

Automated summary

Using large-scale classical molecular dynamics simulations, the mechanics of nano-reinforcement of graphene-based nanocomposites are investigated. The simulations show that a significant amount of defect-free, predominantly flat graphene flakes is necessary to enhance the materials properties. The results are in excellent agreement with experimental and proposed continuum shear-lag theories. The optimal critical lengths for enhancement are approximately 500 nm for graphene and 300 nm for graphene oxide (GO). The simulations also suggest that aligned and planar flakes are crucial for optimal reinforcement, as undulations degrade the enhancement of materials properties.