Mechanical mutability of polycrystalline graphene from atomistic simulations

Elastic responses in the direction across the graphene grain boundary are investigated with four different combinations of defect polarities by using molecular dynamics simulations. It is found that Young’s modulus of the grain boundary changes from 238.3 to 693.3 GPa with varying the polarity combination. The phenomenon of defect inversion is observed for one particular polarity combination. Moreover, the Kapitza conductances have 54.9% and 4.8% differences among the different polarity combinations at 1 and 300 K, respectively. These findings suggest that polycrystalline graphene is amenable to the concept of mechanical mutability at room temperatures without sacrificing its thermal conductance.