氟化五边形石墨烯的拉伸性能

Tensile Properties of Fluorinated Penta-Graphene

用分子动力学方法研究了以碳五元环为结构基元的氟化五边形石墨烯的拉伸性能和变形破坏机制,以及氟化率对其力学参数的影响。结果表明:氟化能改变五边形石墨烯的变形破坏机制。低氟化率的五边形石墨烯在拉伸载荷作用下发生从碳五元环到碳多元环的转变,而完全氟化的五边形石墨烯没有发生明显的碳环转变。随着氟化率的提高五边形石墨烯的杨氏模量、断裂应力和应变呈先减小后增大的趋势。低氟化率(<15%)的五边形石墨烯,其力学性能参数均随氟化率的提高明显降低。完全氟化能提高五边形石墨烯的杨氏模量(约为29.56%),并大幅度降低其断裂应变,而其断裂应力与五边形石墨烯相当。

The tensile mechanical properties and failure mechanism of fluorinated penta-graphene,as well as the effect of different ratio of fluorinated area on the mechanical property of fluorinated pentagraphene were studied by means of molecular dynamics simulations. The results show that fluorination can change the failure mechanism of penta-graphene. The penta-graphene with low ratio of fluorinated area undergoes structural transformation from pentagon to polygon by external load. However, the fully fluorinated penta-graphene does not undergo structural transformation under tension. The Young’s modulus, fracture stress and strain of penta-graphene decrease first and then increased with the increase of the ratio of fluorinated area. When the ratio of fluorinated area is low(<15%), the mechanical parameters are significantly reduced with rising ratio of fluorinated area. Fully fluorination can increase the Young’s modulus of penta-graphene by about 29.56%, and greatly reduce the fracture strain, while the fracture stress is equivalent to that of pristine penta-graphene. These results can provide a theoretical basis for effectively adjusting the mechanical properties of two-dimensional nanomaterials such as penta-graphene.