Compressive deformation mechanism of honeycomb-like graphene aerogels
Compressive deformation mechanism of honeycomb-like graphene aerogels
复制标题
蜂窝状石墨烯气凝胶的压缩变形机制
DOI：
10.1016/j.carbon.2018.04.013
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发表时间：
2018-08-01
期刊：
影响因子：
10.9
通讯作者：
Wang, Chao
中科院分区：
文献类型：
--
作者：
Shang, Jun-Jun;Yang, Qing-Sheng;Wang, Chao
石墨烯气凝胶（GAs）是一种先进的石墨烯组装体，具有很好的弹性，压缩后可以很容易地恢复其原始形态。GAs的宏观压缩行为是石墨烯片的微观结构演化的结果。本文采用粗粒分子动力学（CGMD）方法研究了蜂窝状GA的微观结构压缩响应。基于单层石墨烯的粗粒度（CG）模型，可以构建蜂窝状结构并逐层排列以形成完整的GA模型。在这项工作中提出的CGMD模拟是用TersoffCG势进行的，该势是专门为单层石墨烯开发的。研究了石墨烯片层数、尺寸以及层间重叠方式对石墨烯压缩行为的影响。此外，在压缩过程中的GAs的石墨烯网络中的应力分布进行了分析。在不同网络结构的遗传算法中，发现了不同的微尺度应变集中和应力局部化现象。此外，在一定的压缩应变范围内的模型的负泊松比被发现，这与微观结构的安排和石墨烯片的变形。(C)2018爱思唯尔有限公司版权所有
Graphene aerogels (GAs) are a kind of advanced graphene assemblies, which are quite elastic and can easily restore their original form after compression. The macroscale compression behavior of the GAs is the result of microstructural evolution of the graphene sheets. In this paper, the microstructural compression response of honeycomb-like GAs is investigated via coarse-grained molecular dynamics (CGMD) method. Based on the coarse-grained (CG) model of a single-layer graphene, honeycomb-like structures can be built and arranged layer-by-layer to form the complete GA model. CGMD simulations presented in this work are carried out with a TersoffCG potential, which was developed specifically for single-layer graphene. The effects of layer number, size of the graphene sheets and the interlaminar overlap pattern on the compressive behavior of the GAs are studied. Moreover, the stress distribution in graphene networks of the GAs during the compression process is analyzed. Different microscale strain concentrations and stress localizations are discovered in the GAs with different network patterns. Furthermore, a negative Poisson's ratio of the models within a certain range of compressive strain is found, which is related to both the microstructural arrangement and the deformation of graphene sheet. (C) 2018 Elsevier Ltd. All rights reserved.