Huang Yujia, Yasuda Kouichi, Wan Chunlei
State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China.
Department of Materials Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute of Technology, Tokyo 152-8552, Japan.
ACS Appl Mater Interfaces. 2020 Dec 9;12(49):55148-55156. doi: 10.1021/acsami.0c15193. Epub 2020 Nov 30.
There is a critical need to develop lightweight and mechanically reliable materials for electromagnetic interference (EMI) shielding applications in the harsh environment. In this study, we propose a low-density (∼2.2 g/cm) reduced graphene oxide (rGO)/silica ceramic with multilayer rGO sheets parallelly aligned inside the silica matrix through a new intercalation strategy. The parallel rGO sheets lead to outstanding EMI shielding effectiveness values of 29-33 dB in the X-band, owing to the interlayer multiple reflections of the electromagnetic wave. Meanwhile, the parallel rGO sheets elevate the flexural strength by 110-130% and improve the fracture toughness by 100-130% compared with the monolithic silica by capturing and deflecting the propagating cracks. The nanolaminated structure constructed by the intercalation approach can effectively break the trade-off between mechanical properties and EMI shielding performances in the graphene/ceramic composites, thus opening up new opportunities in the lightweight and mechanically reliable EMI applications.
在恶劣环境下的电磁干扰（EMI）屏蔽应用中，迫切需要开发轻质且机械性能可靠的材料。在本研究中，我们通过一种新的插层策略，提出了一种低密度（约2.2 g/cm）的还原氧化石墨烯（rGO）/二氧化硅陶瓷，其中多层rGO片在二氧化硅基质内平行排列。由于电磁波的层间多次反射，平行的rGO片在X波段导致了29 - 33 dB的出色EMI屏蔽效能值。同时，与整体二氧化硅相比，平行的rGO片通过捕获和偏转扩展裂纹，使弯曲强度提高了110 - 130%，并使断裂韧性提高了100 - 130%。通过插层方法构建的纳米层状结构可以有效打破石墨烯/陶瓷复合材料中机械性能和EMI屏蔽性能之间的权衡，从而为轻质且机械性能可靠的EMI应用开辟新的机遇。
