Tough composites inspired by nacre

Abstract

Nacre, the iridescent material that mollusks make to line their shells and coat their pearls, is exceptionally tough. Researchers have now made a composite of graphene and an epoxy resin inspired by nacre that is lightweight and crack resistant (Matter 2019, DOI: 10.1016/j.matt.2019.08.013). What's more, the new composite is conductive and might be used for self-monitoring automobile, aircraft, and wind turbine parts. The tiniest crack would disrupt the material's conductivity, a property researchers could use to build self-monitoring structural materials that sound a warning before the fractures get bigger and cause catastrophic failure. Nacre's mechanical properties arise from its structure, composed of platelets of brittle calcium carbonate held together by organic biopolymers. The layered structure thwarts cracks. Researchers have copied this structure using platelet-mimicking graphene or other particles embedded in epoxy. But graphene sheets tend to clump together, and the composite's mechanical properties are poor. Qunfeng Cheng, a chemist at