On February 15th, Science reported the collaboration work titled as “Double-negative-indexceramic aerogels for thermal superinsulationan” , which was jointly completed by Lanzhou University, Harbin Institute of Technology, UCLA, UC Berkeley, etc. Prof. Qiangqiang Zhang, a young scholar from College of Civil Engineering and Mechanics of Lanzhou University, was listed as the co-first author as well as Xiang Xu (UCLA, Harbin Institute of Technology) and Menglong Hao (UC Berkeley). Prof. Hui Li (Harbin Institute of Technology), Prof. Yu Huang (UCLA) and Prof. Xiangfeng Duan (UCLA) were corresponding authors. The research results were given high remarks by Manish Chhowalla, Department of Materials Science and Metallurgy, University of Cambridge, and Deep Jariwala, Department of Electrical and Systems Engineering, University of Pennsylvania at PERSPECTIVE on Science.
Ceramic aerogels are attractive candidates for thermal insulation for their low density, low thermal conductivity, and excellent fire and corrosion resistance. However, owing to their brittle nature and crystallization-induced pulverization behavior, ceramic aerogels often suffer from serious strength degradation and structural collapse under large thermal gradients or extended high-temperature exposure. Thermal insulation under extreme conditions requires exceptional stability and reliability. Therefore, robust mechanical and thermal stability are the key roadblocks to using ceramic aerogels for reliable thermal insulation under extreme conditions. The article introduced three-dimensional hBN(hexagonal boron nitride) and βSiCAGs ceramic aerogels that is ultralight, very mechanically strong, and thermally insulating with hyperbolic structures, negative thermal expansion coefficient and negative Poisson’s ratio.
(Translated by Tanbai; proofread by Zhang Yuyuan)