Dual-functional graphene/carbon nanotubes thick film: Bidirectional thermal dissipation and electromagnetic shielding

Spacecraft materials are a key limiting factor for the rapid development of the aerospace exploration field. In an advanced spacecraft, superior multi-functional material with thermal management and electromagnetic shielding can ensure the normal operation of its equipment in space. Currently, graphene thin film can't satisfy a high heat flux and excellent through-plane thermal conduction. In this contribution, a full-carbon dual-functional graphene/carbon nanotubes (CNTs) thick film with high heat flux was successfully prepared, and the structure and composition evolution was investigated after hot-pressing carbonization and graphitization of 2800 degrees C, which indicates the existence of a compact defectsfree and high crystalline carbon structure. Molecular dynamics simulations further confirm the formation of C-C covalent bonds between graphene sheets and CNTs after 2800 degrees C graphitization, enhancing the phonons transfer in through-plane. Simultaneously, the axially adjacent graphene sheets are connected by the CNTs, which endow excellent thermal conductive properties. The in-plane and through-plane thermal diffusivity are as high as 1188.2 mm(2)/s and 8.0 mm(2)/s, respectively. Moreover, the electrical conductivity up to 1819.17 S/cm and EMI SE reach 75 dB in Ku-band. The results provide a bright prospect for spacecraft materials preparation and application. (C) 2020 Elsevier Ltd. All rights reserved.