MIT Team Studies the Fracture of Imperfect Graphene Materials
Experimental results have shown that, despite significant defects at grain boundaries, the strength of polycrystalline graphene, a two-dimensional carbon material discovered recently, is comparable to that of the pristine defect-free material, although it is widespread knowledge in civil engineering that defects typically weaken a material’s strength. To explore this concept, an MIT team that included Professor Markus Buehler, Dr. Zhao Qin PhD ’13 and CEE graduate student Gang Seob Jung studied the enhanced mechanism of fracture toughness of polycrystalline graphene by utilizing a novel algorithm to generate well-stitched polycrystalline graphene models and focusing on their fracture under loading. Their results conclude that the polycrystalline graphene releases up to 50 percent more energy under fracture than the pristine graphene, suggesting that out-of-plane deformation of polycrystalline graphene and enhanced dissipation mechanisms governs the fracture pathway and leads to the higher toughness. These results suggest an approach of adding two-dimensional materials into new types of composites, for use for example as construction materials that have a greater capacity to mitigate extreme environmental conditions. Read their paper published in Extreme Mechanics Letters.