Based on the previous research on the deformation and thermal insulation mechanism of elastic ceramic aerogels, the research group of Professor Wang Hongjie of the School of Materials Science and Technology of Xi’an Jiaotong University proposed and prepared a layered ceramic aerogel constructed by silicon carbide-based ceramic nanowires from the perspective of structural design. Recently, the research results were published in Nature Communications.
Ceramic aerogels have the advantages of being lightweight, chemically stable, and super insulating, but their application is limited by brittleness and low strength. In order to improve its performance, in recent years, researchers at home and abroad have successively developed a series of elastic ceramic aerogels constructed by flexible ceramic nanostructures. The aerogel overcomes the brittleness of traditional ceramic aerogel and achieves compression rebound, but its strength is low, resulting in insufficient bearing capacity. Increasing the density is an effective way to improve the strength of aerogels, but the increase of density will lead to the reduction of material deformation ability and thermal insulation performance. As a result, there is a complex correlation between the strength, deformation, and thermal insulation properties of ceramic aerogels.
The results of Professor Hongjie Wang’s research group can not only improve the deformation resistance of nanowires in the process of aerogel deformation, but also maintain the flexibility and deformability of nanowires in deformation, achieve high strength and high flexibility, and at the same time, guide the directional transmission of heat flow to ensure their good thermal insulation performance. In addition to the recoverable compressive properties, elastic-plastic tensile deformation and bending deformation ability, the obtained layered SiC-SiOx nanowire aerogel has a strength and modulus increase of up to 10 times compared with other elastic ceramic aerogels, which is a soft and strong ceramic aerogel. In addition, the aerogel exhibits good thermal stability over a wide temperature range (-196 to over 1200°C), as well as low thermal conductivity. (Source: Yan Tao, China Science News)
Soft and strong ceramic aerogel a) Macroscopic morphology b) Cross-sectional layered structure c) High cross-linking of nanowires in the layer d) Compressive resilience and high load-bearing e ) Elastoplastic tensile deformation and high tensile strength f) Recoverable flexural deformation and high flexural strength (courtesy of the research group)
Related Paper Information:https://doi.org/10.1038/s41467-023-42703-7