Impact energy absorption behavior of graphene aerogels prepared by different drying methods

Materials & Design

Lulu Niu¹  Pengwan Chen²  Yang Qiao³  Daniel Rittel⁴  Jing Xie⁵ 

[1] Advanced Technology Research Institute, Beijing Institute of Technology, Jinan 250307, China;Corresponding authors at: State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.;Explosion Protection and Emergency Disposal Technology Engineering Research Center of the Ministry of Education, Beijing 100081, China;;CNNC No.7 Research &State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China;

关键词: Graphene aerogel;    Dynamic compression;    Energy absorption;    Porous structure;   

DOI  :  

来源: DOAJ

【 摘 要 】

The experimental investigation of the dynamic mechanical behavior of graphene aerogel is still lacking due to its low impendence. The present work, therefore, reports on the preliminary experimental characterization of the energy absorption characteristics of graphene aerogel by using the split Hopkinson pressure bar emphasis on the influence of the drying method. The graphene aerogels were synthesized by the sol-gel method and dried, either by supercritical CO2 drying (SD) or by freeze-drying methods (FD). It was observed that under dynamic uniaxial compression, the SD samples exhibited a negative Poisson's ratio throughout gradual compression. However, FD samples failed by radial shattering without this auxetic behavior. The energy dissipation ratios of SD samples increased from 41% to 73% as expected with the specimen thickness increasing from 3 mm to 12 mm, being overall higher in comparison with FD samples which rises from 35% to 43%. SD graphene aerogels have a large number of random pores (∼50 nm), which is beneficial for absorbing the kinetic energy through plastic deformation and pore walls’ collapse. By contrast, the FD graphene aerogels’ pore walls buckle readily under the impact, and fail due to their ordered porous structure at the micron scale (∼1μm), which impairs their energy absorption capability.

【 授权许可】

Unknown