▎ 摘　　要

Continuous graphene fibers (GFs) and graphene/SiC fibers (G/SiCFs) are fabricated from silicon carbide (SiC) fibers through vacuum annealing. The transformation gradually happens from the surface to the core of the fiber until complete conversion. Graphene sheets are in-situ formed after Si sublimation of 3C-SiC grains in the SiC fiber. Although porous structure is formed inevitably, the fiber shape is well maintained with circular cross section. The continuous GFs exhibit low density (1.63 g/cm(3)), excellent electric conductivity (53,900 S/m), high tensile strength (0.22 GPa) and elastic modulus (23 GPa, gauge length: 25 mm). Good properties can be probably attributed to interconnected graphene sheets. GFs have great electromagnetic interference shielding effectiveness of 62.8 dB, while G/SiCFs have outstanding microwave absorption properties. The minimum reflection loss (RL) value of -54.86 dB is achieved with sample thickness of 2.1 mm. When sample thickness is 1.4 mm, the effective absorption bandwidth of G/ SiCFs can reach 4.4 GHz. Excellent flexibility is also possessed by a bundle of 1000 graphene filaments. Taking advantages of the facile conversion of silicon carbide fibers, the method demonstrated in this work can be further extended to prepare metal-containing GFs (Ti, Al, Zr, et.) and achieve large-scale production. (C) 2021 Elsevier Ltd. All rights reserved.