3D Lamellar-Structured Graphene Aerogels for Thermal Interface Composites with High Through-Plane Thermal Conductivity and Fracture Toughness

Nano-Micro Letters

Yun Ding¹  Peng Min¹  Chao Shu¹  Xiaofeng Li¹  Pengfei Liu²  Xiyuan Chang³  Zhong-Zhen Yu⁴ 

[1] Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, 100029, Beijing, People’s Republic of China;Beijing Key Laboratory of Advanced Functional Polymer Composites, Beijing University of Chemical Technology, 100029, Beijing, People’s Republic of China;State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, 100029, Beijing, People’s Republic of China;State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, 100029, Beijing, People’s Republic of China;State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, 100029, Beijing, People’s Republic of China;Beijing Advanced Innovation Center for Soft Matter Science and Engineering, Beijing University of Chemical Technology, 100029, Beijing, People’s Republic of China;

关键词: Anisotropic aerogels;    Graphene;    Thermal conductivity;    Epoxy composites;    Fracture toughness;   

DOI  :  10.1007/s40820-020-00548-5

来源: Springer

【 摘 要 】

tsLamellar-structured graphene aerogels with vertically aligned and closely stacked high-quality graphene lamellae are fabricated.The superior thermally conductive capacity of the aerogel endows epoxy with a high through-plane thermal conductivity of 20.0 W m−1 K−1 at 2.30 vol% of graphene content.The nacre-like structure endows the epoxy composite with enhanced fracture toughness.AbstractAlthough thermally conductive graphene sheets are efficient in enhancing in-plane thermal conductivities of polymers, the resulting nanocomposites usually exhibit low through-plane thermal conductivities, limiting their application as thermal interface materials. Herein, lamellar-structured polyamic acid salt/graphene oxide (PAAS/GO) hybrid aerogels are constructed by bidirectional freezing of PAAS/GO suspension followed by lyophilization. Subsequently, PAAS monomers are polymerized to polyimide (PI), while GO is converted to thermally reduced graphene oxide (RGO) during thermal annealing at 300 °C. Final graphitization at 2800 °C converts PI to graphitized carbon with the inductive effect of RGO, and simultaneously, RGO is thermally reduced and healed to high-quality graphene. Consequently, lamellar-structured graphene aerogels with superior through-plane thermal conduction capacity are fabricated for the first time, and its superior through-plane thermal conduction capacity results from its vertically aligned and closely stacked high-quality graphene lamellae. After vacuum-assisted impregnation with epoxy, the resultant epoxy composite with 2.30 vol% of graphene exhibits an outstanding through-plane thermal conductivity of as high as 20.0 W m−1 K−1, 100 times of that of epoxy, with a record-high specific thermal conductivity enhancement of 4310%. Furthermore, the lamellar-structured graphene aerogel endows epoxy with a high fracture toughness, ~ 1.71 times of that of epoxy.

【 授权许可】

CC BY