Rapid and inexpensive synthesis of liter-scale SiC aerogels
Lujia Han, Shile Chen, Honghua Li, Yanhao Dong, Chang‐An Wang, Jiangtao Li
Abstract
Ceramic aerogels are promising materials for thermal insulation and protection under harsh environments. Yet current synthesis methods fail to provide an energy-, time-, and cost-effective route for high-throughput production and large-scale applications, especially for non-oxide ceramic aerogels. Here we reported a way to synthesize SiC aerogels within seconds and over liter scale, with a demonstrated throughput of ~16 L min−1 in a typical lab experiment. The key lies in renovated combustion synthesis and a fast expansion from powder reactants to aerogel products over 1000% in volume. The synthesis process is self-sustainable and requires minimal energy input. The product is very cheap, with an estimated price of ~$0.7 L−1 (~$7 kg−1). The obtained SiC aerogels have excellent thermo-mechanical properties, including low thermal conductivity, high elasticity, and damage tolerance. Our invention not only offers a practical pathway for large-scale applications of ceramic aerogels, but also calls for rethinking of combustion synthesis in one-step conversion from raw chemicals to bulk products ready for practical applications. Damage-tolerant ceramic aerogels are valuable, yet their synthesis is time-consuming and expensive. Here we report a facile, low-cost combustion synthesis of SiC aerogels, at Liter scale. Further technological development may enable game-changer aerogels for extreme-environment applications.