Penetrative fracture behavior of monolayer graphene oxide: nanoscale experiment and molecular dynamics simulation

Abstract Graphene, a two-dimensional material, is expected to be employed as a next-generation component for structural and functional applications because of its light weight and excellent mechanical properties. For applications requiring lightness and impact resistance, preventing penetrative damage upon particle impact is critical for applications in mechanical protection. However, graphene is known to have high defect sensitivity. Graphene oxide (GO) may be a better candidate, as functional groups (e.g. hydroxy and epoxy groups) bonded to the C–C network in GO result in better deformability, ductility, and durability compared to graphene. For mechanical applications, it is crucial to understand the fracture behavior, especially the penetrative fracture behavior, of GO membranes. This study characterizes the penetration behavior and fracture morphology of GO membranes subjected to particle impact. Nanoscale experiments were conducted using an atomic force microscope and laser-induced particle impact test for GO. These material testing methods employ nanoscale spheres to induce particle penetration, with the former experiment conducted under quasi-static loading and the latter under dynamic loading. Additionally, molecular dynamics simulations were performed to elucidate the fracture mechanisms of GO. Finally, cyclic fatigue experiments and simulations revealed that GO’s ductility provides resistance to catastrophic failure, indicating its durability. These comprehensive investigations provide valuable insights into the fracture properties of GO membranes under impact penetration.