▎ 摘　　要

Nanofiller reinforced carbon-matrix nanocomposites (Nanofiller/Cs) have great potential for aerospace military applications, owing to their lightweight, high specific strength and capable of shielding electromagnetic interference (EMI) at extreme temperature conditions. Motivated by this, many researchers focus on infiltrating pyrocarbon into carbon nanotube (CNT) assemblies to fabricate CNT/Cs. Despite attractive results, Nanofiller/Cs with combination of excellent mechanical and EMI shielding properties have not been realized so far. Herein, a 3D core-shell nanofiller of CNT@graphene (CNT@G) is incorporated into pyrocarbon system to fabricate novel cellular CNT@G/Cs. The core-shell CNT@G induces notably crack-tip blunting and crack deflection during fracture, giving CNT@G/Cs significantly increased mechanical properties at optimized G layers: 43.2% in flexural strength and 102.7% in fracture toughness, compared to the porous neat carbon. Moreover, introduction of CNT@G enhances EMI shielding effectiveness (SE) in X-band from 26.6 to 45.3 dB, resulting in high specific SE of 43.1 dB cm(3)/g with ultralow density of 1.05 g/cm(3). The excellent shielding capability mainly stems from remarkably enhanced absorption loss caused by conductive G skeleton, special G-CNT junction interfaces and unique cellular structures. This work provides a promising methodology to prepare ultralight high-performance Nanofiller/Cs by combining reinforcement and functionality of CNT@G and toughening effect of core shell structures. (c) 2020 Elsevier Ltd. All rights reserved.