Preparation of lightweight, honeycomb-like, wideband microwave absorbing SiC/C aerogels via carbothermal reduction

Based on the micro-nano scale designs for absorbing materials, analyzing the influence of microstructures on absorbing properties is a feasible strategy to achieve efficient lightweight broadband electromagnetic wave absorbers. In this work, the silicon-containing arylacetylene resin, serving as a ceramic polymer precursor, is employed to coat SiO 2 gel. Subsequently, the PSA/SiO 2 aerogel underwent carbothermal reduction and the polymer-derived ceramics process, transforming it into a SiC/C aerogel. This SiC/C aerogel exhibits a low density of 0.2 g/cm³ and a high porosity of 68 %. The rich morphology of SiC/C aerogel is conducive to both interfacial polarization and multiple scattering, resulting in excellent impedance matching and attenuation. With a reflection loss of −52.6 dB and an effective absorption bandwidth of 6 GHz, SiC/C aerogels also achieve effective absorption in both the X and Ku bands. These results may thus be of great significance in guiding the design and mechanism investigation of high-performance.