Lightweight and high EMI shielding performed ZrB2-SiC/CF@Epoxy-Fe3O4 composites with carbonated cotton fibers

Fast development of information science and electronic technology, as well as the use of related equipment have been inducing unavoidable electromagnetic wave (EMW) pollution. High performed electromagnetic interference (EMI) shielding composites are required for weakening or resolving such problems. In this study, we aimed to prepare lightweight and porous composites with high EMI effectiveness, especially under relatively high service temperature condition. Silicon carbide (SiC) and zirconium diboride (ZrB₂) were compounded with cotton fibers (CFs) to prepare ZrB₂-SiC/CF compounds, cooperated with high-temperature sintering technique at 800 °C–1200 °C. Furthermore, epoxy resin dipping was applied to improve the mechanical property, combining with Fe₃O₄ nanoparticle’ coating on their surface to enhance the EMI shielding performance. Average EMI shielding efficiency of the ZrB₂-SiC/60CF@Epoxy-Fe₃O₄ with a thickness of 1.54 mm was as high as 58.93 dB, at a frequency range of 18-26 GHz. High dielectric loss induced by carbonated CFs, magnetic loss from Fe₃O₄ nanoparticles, as well as the porous structure contributed to this high EMI shielding performance. The MATLAB software was used to further exam the SEM pictures before and after sintering and helped to explain the change in composite’s porosity and morphology, as well as their influence on the EMI shielding performance.