Mechanical Properties and Fracture Behavior of Graphene and Graphene Allotropes
讲座名称：
Mechanical Properties and Fracture Behavior of Graphene and Graphene Allotropes
讲座时间：
2014-04-25
讲座人：
裴清祥
形式：
校区：
兴庆校区
实践学分：
讲座内容：
报告人：裴清祥博士 A*STAR, Singapore
报告题目: Mechanical Properties and Fracture Behavior of Graphene and Graphene Allotropes
时间：2014年4月25日（星期五） 10:30-11:30
地点：教一楼南二层第二会议室
报告主持：刘子顺教授
Mechanical Properties and Fracture Behavior of Graphene and Graphene Allotropes
Dr PEI Qing-Xiang
Institute of High Performance Computing, A*STAR, Singapore
In recent years, two-dimensional materials, such as graphene and graphene allotropes, have attracted a great interest. Using molecular dynamics simulation, we study the mechanical properties and fracture behavior of graphene and graphene allotropes (α, β, γ, and 6,6,12 graphynes). We find that the Young’s modulus, fracture strength and strain of graphynes are much lower than that of graphene. We show that the acetylenic linkages in the graphyne structures have a strong effect on the mechanical properties and fracture behaviors of graphynes. The higher the percentage of the linkages in graphynes, the lower is the Young’s modulus and fracture stress, which is attributed to both the lower atoms density in graphynes and the weak single bonds in the acetylenic linkages. The crack of the graphynes is found to be initiated at the single bond of the acetylenic linkages in the structures. We also investigated the effect of hydrogenation on the mechanical properties and fracture behavior. It is found that hydrogenation can greatly deteriorate the mechanical properties of graphene and the graphene allotropes, depending on the hydrogenation coverage, location, and distribution. The hydrogenation-induced reduction in mechanical properties is due to the formation of weakened out-of-plane C-C bonds, which leads to earlier breaking of those bonds and subsequent fracture of graphene and the graphene allotropes.
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