Influence of Stone-Wales defects on elastic properties of graphene nanofilms

Molecular structural mechanics based finite element method is applied to study the influence of the two types of Stone-Wales defects on the elastic properties of monolayer and multilayer graphene nanofilms. Models with spatial frame structures are developed to simulate the graphene crystal with Stone-Wales defects based on the linkage between the inter-atomic potential energy in molecular mechanics and the strain energy in classical structural mechanics. Several possible influencing factors, including the number and types of Stone-Wales defects, the distance between two defects and the position of defects in the graphene, are taken into account to evaluate Young's moduli and Poisson's ratios of armchair and zigzag monolayer graphene nanofilms. It is shown that the Stone-Wales defects have remarkable influence on the elastic properties of monolayer graphene. In addition, the size-dependent Young's moduli and Poisson's ratios of multilayer graphene nanofilms are also investigated when the Stone-Wales defects in surface layers are taken into consideration. (C) 2012 Elsevier B.V. All rights reserved.