期刊
ADVANCED FUNCTIONAL MATERIALS
卷 29, 期 19, 页码 -出版社
WILEY-V C H VERLAG GMBH
DOI: 10.1002/adfm.201900311
关键词
3D assembly; graphene; in situ electron microscopy; mechanical properties; nanoindentation; size effects
类别
资金
- JSPS KAKENHI [25820336]
- National Natural Science Foundation of China [51522210]
- State Key Research and Development Program of MOST of China [2016YFB0700403]
- Hundred Talents Program of CAS
- International Center for Young Scientists (ICYS)
- World Premier International (WPI) Center for Materials Nanoarchitectonics (MANA)
- National Science Fund for Distinguished Young Scholars, China [51525204]
- Australian Research Council (ARC) [FL 160100089]
- QUT project [322170-0355/51]
- Shanghai Municipal Science and Technology Commission [16ZR1443100]
- Shanghai Supercomputer Center
- Grants-in-Aid for Scientific Research [25820336] Funding Source: KAKEN
It is essential to understand the size scaling effects on the mechanical properties of graphene networks to realize the potential mechanical applications of graphene assemblies. Here, a highly dense-yet-nanoporous graphene monolith (HPGM) is used as a model material of graphene networks to investigate the dependence of mechanical properties on the intrinsic interplanar interactions and the extrinsic specimen size effects. The interactions between graphene sheets could be enhanced by heat treatment and the plastic HPGM is transformed into a highly elastic network. A strong size effect is revealed by in situ compression of micro- and nanopillars inside electron microscopes. Both the modulus and strength are drastically increased as the specimen size reduces to approximate to 100 nm, because of the reduced weak links in a small volume. Molecular dynamics simulations reveal the deformation mechanism involving slip-stick sliding, bending, buckling of graphene sheets, collapsing, and densification of graphene cells. In addition, a size-dependent brittle-to-ductile transition of the HPGM nanopillars is discovered and understood by the competition between volumetric deformation energy and critical dilation energy.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据