High impact resistance in graphyne

Graphyne was recently facilely synthesized with superior mechanical and electrical performance. We investigate the ballistic protection properties of alpha-, beta-, delta-, and gamma-graphyne sheets using molecular dynamics simulations in conjunction with elastic theory. The velocities of the in-plane elastic wave and out-of-plane cone wave are obtained by both membrane theory and molecular dynamics simulations. The specific penetration energies are approximately 83% that of graphene, indicating high impact resistance. gamma-Graphyne has high sound wave speeds comparable to those of graphene, and its Young's modulus is approximately 60% that of graphene. delta-Graphyne has the highest cone wave speed among the four structures, while alpha-graphyne possesses the highest penetration energy and impact resistance at most tested projectile speeds. Our results indicate that graphyne is a good protective structural material.