Layer-by-layer assembly of a novel biomimetic fish scale structure onto carbon fiber surface via thiol-ene click chemistry to enhance high-temperature resistance and functionality of carbon fiber/ epoxy composites

This work developed functional, high-temperature-resistant CF/epoxy composites using compression molding by sequentially grafting graphene oxide (GO) and carbon nanotubes (CNTs) onto the surface of carbon fibers (CF) via thiol-ene click chemistry, creating a bioinspired fish-scale structure with varying thicknesses. At 180 degrees C, the CF-(GO-CNTs)2 composites exhibited increases in IFSS, ILSS, flexural strength, and modulus by 182.7 %, 73.1 %, 240.6 %, and 404.0 %, respectively, compared to commercial CF composites. These enhancements were ascribed to considerable improvements in the chemical interactions and entanglement between the CF and matrix, which resulted from the incorporation of GO and CNTs. Moreover, they possessed strong carbon-carbon bonds and inherent high-temperature structural stability. Remarkably, the electrical conductivity and thermal conductivity increased by 383.3 % and 227.9 %, respectively. At 9.6 GHz, the CF-(GO-CNTs)3 composite achieved an SET value of up to 30.8 dB. This was mainly because the modified GO and CNTs, when combined with epoxy resin to form composites, provided abundant interface polarization centers and carrier availability. The interfacial enhancement mechanisms and electromagnetic shielding mechanisms of the modified CF composites were investigated. This work offered a new strategy for developing high-temperature-resistant CF composites with functional properties.