Lightweight and flexible graphene/SiC-nanowires/poly(vinylidene fluoride) composites for electromagnetic interference shielding and thermal management

摘要

Lightweight and flexible ternary composites with graphene (Gn), silicon carbide nanowires (SiCnw), and poly (vinylidene fluoride) (PVDF) matrix were successfully fabricated via electrostatic assembly and solution casting followed by hot-pressing. The synergism of two-dimensional Gn and one-dimensional SiCnw with stacking fault structure improved the formation of conductive paths and multiple interfaces. This enhanced the dielectric properties, electromagnetic interference (EMI) shielding and thermal conduction performance of the fabricated composites. For instance, by the incorporation of 9.5 wt % Gn-SiCnw, the dielectric constant and the dielectric loss of the composites were increased by 4 orders of magnitude compared with neat PVDF. A maximum EMI shielding effectiveness (SE) of 32.5 dB was achieved for the composites at 1.2mm thickness in the frequency range 8.2-12.4 GHz. The high EMI SE of the Gn-SiCnw/PVDF can be attributed to the high electrical conductivity, dielectric constant and dielectric loss. The composites also showed a high thermal conductivity of 2.13W. m(-1). K-1, due to the formation of a thermally conductive network between Gn and SiCnw. This dual functionality of the Gn-SiCnw/PVDF composites demonstrates that they are outstanding materials with potential applications in EMI shielding and thermal management for microelectronics. (C) 2019 Elsevier Ltd. All rights reserved.