Understanding Mechanical Response of Elastomeric Graphene Networks.
Understanding Mechanical Response of Elastomeric Graphene Networks.
复制标题
了解弹性石墨烯网络的机械响应。
DOI：
10.1038/srep13712
复制
发表时间：
2015-09-08
影响因子：
4.6
通讯作者：
Saiz E
中科院分区：
文献类型：
--
作者：
Ni N;Barg S;Garcia-Tunon E;Macul Perez F;Miranda M;Lu C;Mattevi C;Saiz E
基于纳米碳材料（例如石墨烯或碳纳米管）的超轻多孔网络由于其在生物工程到电化学装置等广泛领域的应用而引起了越来越多的兴趣。然而，通常很难通过控制纳米材料的机械性能将纳米材料的性能转化为大块三维网络。在这项工作中，我们通过冷冻铸造和热还原构建了具有明确结构的弹性体石墨烯多孔网络，并系统地研究了关键微观结构特征的影响。由大的还原氧化石墨烯薄片（>20μm）制成的多孔网络具有超弹性并表现出高能量吸收，与小薄片（<2μm）相比，机械性能大大增强。更好地恢复石墨性质也有相当大的效果。相比之下，微观结构差异（例如泡沫结构或泡孔尺寸）对机械响应的影响较小或可以忽略不计。可恢复性和能量吸收取决于密度，由于变形过程中壁断裂和摩擦之间的相互作用，密度呈现最小值。这些发现表明，多孔石墨烯网络机械性能的提高很大程度上取决于控制细胞壁性能的石墨烯薄片的工程设计。
Ultra-light porous networks based on nano-carbon materials (such as graphene or carbon nanotubes) have attracted increasing interest owing to their applications in wide fields from bioengineering to electrochemical devices. However, it is often difficult to translate the properties of nanomaterials to bulk three-dimensional networks with a control of their mechanical properties. In this work, we constructed elastomeric graphene porous networks with well-defined structures by freeze casting and thermal reduction, and investigated systematically the effect of key microstructural features. The porous networks made of large reduced graphene oxide flakes (>20 μm) are superelastic and exhibit high energy absorption, showing much enhanced mechanical properties than those with small flakes (<2 μm). A better restoration of the graphitic nature also has a considerable effect. In comparison, microstructural differences, such as the foam architecture or the cell size have smaller or negligible effect on the mechanical response. The recoverability and energy adsorption depend on density with the latter exhibiting a minimum due to the interplay between wall fracture and friction during deformation. These findings suggest that an improvement in the mechanical properties of porous graphene networks significantly depend on the engineering of the graphene flake that controls the property of the cell walls.