Fiber, monolithic fiber and twisted fiber structures: efficient microwave absorption via surface-modified carbon nanotube buckypaper/silicon carbide-based self-sealing layered composites†
Abstract
The design of laminated structures is important for tuning the performance of microwave absorbing materials with integrated structures and functions, but still faces great challenges. Herein, a self-sealing layered structure that integrates a laminated structure and a self-sealing structure is proposed. In this work, CNT buckypaper (BP) was first helically convolved to obtain a three-dimensional (3D) self-sealing layered fiber. Subsequently, 3D CNT BP/silicon carbide (CNT BP/SiC) self-sealing layered (CSSL) substrates, i.e., fiber, monolithic fiber and twisted fiber structures, were prepared by changing the self-sealing layered fiber arrangement methods. Meanwhile, the impedance matching of the CSSL substrates was improved by using the SiC nanowire (SiCnw) porous film as a cladding layer. The synergistic effect of good impedance matching and the self-sealing layered structure endowed the CSSL substrates clad with SiCnw porous film (CSSLS) composites with excellent microwave attenuation properties. The minimum reflection loss values for the CSSLS with fiber, monolithic fiber and twisted fiber structures were −49.35, −50.77 and −55.02 dB respectively, and the corresponding maximum effective absorption bandwidths were 3.50, 3.50 and 3.99 GHz, respectively, in the X-band. The twisted fiber structure, which had the most complex structure, had the best microwave absorption properties.