Innovative fabrication of CNT/SiC composite fibers via impregnation-wet twisting-pyrolysis: Advancements in strength, conductivity, and EMI shielding

Abstract

Floating catalyst chemical vapor deposition (FCCVD) is a key method for synthesizing high-strength, electrically conductive carbon nanotube (CNT) fibers. However, the high porosity of FCCVD CNT fibers limits the full utilization of the intrinsic performance of CNTs. It remains a challenge to assemble and continuous fabricate high-performance CNT fibers. Herein, this study proposed an impregnation-wet twisting-pyrolysis process to fabricate continuous CNT/SiC composite fibers to enhance the mechanical and electrical properties by reducing pore sizes and improving the interaction between CNTs. The resulting compact structure and enhanced interfacial interactions of the CNT/SiC fibers exhibited both high strength (2015.27 MPa) and high electrical conductivity (7.2 × 10⁵ S/m), representing increases of 130.8 % and 69.9 % compared to pristine CNT fibers. The unidirectional laminates assembled by continuous CNT/SiC fibers demonstrated high electromagnetic interference (EMI) shielding effectiveness of 66.33 dB. This innovative continuous process holds significant potential for the industrial utilization of CNT/SiC fibers.