Inverse Nacre-like Epoxy-Graphene Layered Nanocomposites with Integration of High Toughness and Self-Monitoring

Epoxy nanocomposites have many promising applications in the fields of aerospace and aeronautics, as well as many others. Achieving tough epoxy nanocomposites remains a great challenge, however. One inspiration for improving the mechanical properties of epoxy nanocomposites is nacre, which has remarkable fracture toughness for its layered brick-and-mortar'' architecture. Inspired by this, we fabricated a lamellar graphene scaffold by the freeze-casting technique. An alternating-layered epoxy-graphene nanocomposite was made by infiltrating epoxy into this graphene scaffold. As our epoxy-graphene nanocomposite consists of similar to 99 wt % organic epoxy, in contrast to nacre containing similar to 96 wt % inorganic aragonite, we call it an inverse nacre-like'' epoxy-graphene layered nanocomposite. It exhibits exceptional fracture toughness, 3.61 times that of pure epoxy, and demonstrates anisotropic conductivity due to the anisotropic graphene scaffold, which can be used to detect cracks. Our bioinspired strategy provides a promising approach to combine excellent mechanical properties with functional properties to fabricate high-performance nanocomposites.