Closed-cell ZrO2/SiC-based composite nanofibers with efficient electromagnetic wave absorption and thermal insulation properties

For the first time, a multiphase closed cell SiC-based composite nanofiber integrating efficient electromagnetic (EM) wave absorption, thermal insulation and high temperature resistance was designed and fabricated through electrospinning technique with zirconium as sintering aid and hollow C/SiO 2 spheres (HCSSs) as pore-forming materials. The unique multi-phase and closed cell structure not only improves the dielectric loss and facilitates the multiple reflection and absorption of EM waves, but also hinders the solid-phase heat transfer and increases the interfacial thermal resistance. Given their 10% HCSSs content, the nanofibers exhibited a minimum reflection loss of −48.6 dB at 3.5 mm thickness. Meanwhile, the samples showed ultra-low thermal conductivity (~0.026 W/m K) and excellent thermal stability (~1400 ℃). These superior properties make our nanofibers are expected to be applied for EM wave absorption and high-temperature thermal insulation under extreme conditions. • A novel strategy for developing porous absorbing material is reported. • Multiphase and closed cell structure improve the microwave absorption and thermal insulation performance simultaneously. • Close cell ZrO 2 /SiC nanofibers show great potential as microwave wave absorption devices in high-temperature.