Graphene origami reinforced polyethylene nanocomposite under ballistic impact

• Graphene origami (GOri) is used to reinforcePE nanocomposites. • The fracture strength and specific penetration resistance of nanocomposites is improved significantly. • Further improvement can be achieved by increasing the roughness of GOri. Polymeric nanocomposites reinforced with two-dimensional (2D) nanosheet fillers, such as graphene, exhibit excellent mechanical properties for impact-resistant applications. However, the reinforcement effectiveness is greatly limited by graphene’s intrinsic brittleness and weak interfacial load transfer rate between graphene and polymer matrix. Herein we design and employ graphene origami (GOri) to overcome these limitations. In the origami format, GOri possesses high surface roughness and flexibility without a cost of mechanical strength. By using molecular dynamics simulations, we investigate the fracture mechanisms and penetration behavior of GOri/polyethylene (PE) nanocomposites under nanoindentation and ballistic impact loading. The results reveal that GOri can significantly enhance fracture strength and specific penetration resistance of the nanocomposites due to the strengthening effect induced by the rough surface of GOri. This roughness-induced improvement over conventional graphene can be further tuned by increasing the roughness of GOri. Our findings highlight the potential of GOri/PE nanocomposites as lightweight, high-performance protective materials and provide key insights into the nanoscale mechanisms governing impact resistance in polymer-based systems.