arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1105.0138cond-mat.mtrl-scicond-mat.mes-hall
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石墨烯纸的力学性能

Mechanical Properties of Graphene Papers

Yilun Liu, Bo Xie, Zhong Zhang, Quanshui Zheng, Zhiping Xu

摘要:

石墨烯基纸张由于其优异的性能而引起了人们的特别兴趣,其关键是它们具有类似于骨、牙齿和珍珠层等生物材料的逐层分级结构,结合了层内强sp2键和层间交联以实现有效的负载转移。在这里,我们首先通过第一性原理计算研究各种层间和层内交联的力学性能,然后对石墨烯基纸张的整体力学性能进行连续介质模型分析。我们发现存在一个特征长度尺度l_{0},定义为\Sqrt{Dh_{0}/4G},其中D是石墨烯片的刚度,h_{0}和G分别是层间交联的高度和剪切模量。当石墨烯片的尺寸超过3 l_{0}时,广泛用于纳米复合材料的拉伸-剪切(TS)链模型不能预测石墨烯基纸的总体机械性能。相反,我们在这里提出了一个可变形的拉伸-剪切(拉伸-剪切)模型,通过考虑石墨烯片的弹性形变,以及层间和层内交联。然后将该模型应用于石墨烯基纸材料在拉伸载荷下的力学预测。根据所得结果,为设计具有高刚度、高强度和高韧性的石墨烯纸提供了优化设计策略。

英文摘要:

Graphene-based papers attract particular interests recently owing to their outstanding properties, the key of which is their layer-by-layer hierarchical structures similar to the biomaterials such as bone, teeth and nacre, combining intralayer strong sp2 bonds and interlayer crosslinks for efficient load transfer. Here we firstly study the mechanical properties of various interlayer and intralayer crosslinks via first-principles calculations and then perform continuum model analysis for the overall mechanical properties of graphene-based papers. We find that there is a characteristic length scale l_{0}, defined as \Sqrt{Dh_{0}/4G}, where D is the stiffness of the graphene sheet, h_{0} and G are the height of interlayer crosslink and shear modulus respectively. When the size of the graphene sheets exceeds 3l_{0}, the tension-shear (TS) chain model that are widely used for nanocomposites fails to predict the overall mechanical properties of the graphene-based papers. Instead we proposed here a deformable tension-shear (DTS) model by considering the elastic deformation of the graphene sheets, also the interlayer and intralayer crosslinks. The DTS is then applied to predict the mechanics of graphene-based paper materials under tensile loading. According to the results we thus obtain, optimal design strategies are provided for designing graphene papers with ultrahigh stiffness, strength and toughness.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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