Institute of Chemical Physics, University of Latvia, Raina bulvāris 19, LV-1586 Rīga, Latvia.
Laboratory of Bio-Inspired &Graphene Nanomechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, via Mesiano 77, I-38123 Trento, Italy.
Nat Commun. 2017 Apr 12;8:14982. doi: 10.1038/ncomms14982.
Carbon-based three-dimensional aerographite networks, built from interconnected hollow tubular tetrapods of multilayer graphene, are ultra-lightweight materials recently discovered and ideal for advanced multifunctional applications. In order to predict the bulk mechanical behaviour of networks it is very important to understand the mechanics of their individual building blocks. Here we characterize the mechanical response of single aerographite tetrapods via in situ scanning electron and atomic force microscopy measurements. To understand the acquired results, which show that the overall behaviour of the tetrapod is governed by the buckling of the central joint, a mechanical nonlinear model was developed, introducing the concept of the buckling hinge. Finite element method simulations elucidate the governing buckling phenomena. The results are then generalized for tetrapods of different size-scales and shapes. These basic findings will permit better understanding of the mechanical response of the related networks and the design of similar aerogels based on graphene and other two-dimensional materials.
基于碳的三维气凝胶网络由相互连接的多层石墨烯中空管状四角锥构成，是最近发现的超轻材料，非常适合先进的多功能应用。为了预测网络的整体力学性能，了解其单个构建块的力学性能非常重要。在这里，我们通过原位扫描电子显微镜和原子力显微镜测量来表征单个气凝胶四角锥的力学响应。为了理解所获得的结果，即四角锥的整体行为受中心接头的屈曲控制，我们开发了一个机械非线性模型，引入了屈曲铰链的概念。有限元法模拟阐明了主导屈曲现象。然后将结果推广到不同尺寸和形状的四角锥。这些基本发现将有助于更好地理解相关网络的力学响应，并设计基于石墨烯和其他二维材料的类似气凝胶。
