Ceramic aerogel is expected to become a new aviation material

Recently, researchers from universities such as Harbin Institute of Technology, Lanzhou University, University of California, Los Angeles, and University of California at Berkeley have synthesized a hyperbolic structural ceramic aerogel with a layered structure that can greatly enhance traditional ceramic aerogels. The properties of the material provide research ideas for solving the brittleness problem of ceramic ultra-light structures and the problem of thermal crystallization, and promote the application of ceramic aerogel in the fields of heat insulation, catalysis, energy, environmental treatment, aerospace and other fields.

Ceramic aerogel is very suitable for use as a thermal insulation material in the aerospace industry due to its ultra-light, fire-resistant, corrosion-resistant and high-temperature resistance. However, its brittleness, high-temperature crystallization, thermal shock and contraction seriously restrict the related research and application. The research results obtained this time are based on a five-year basic study of graphene aerogels, which was completed in two years. According to Xu Xiang, the project leader and associate professor of Harbin Institute of Technology, the basic research in the early stage of the project completed the research work on superelasticity, negative Poisson's ratio, ultralight, electrical conductivity, fluid behavior and energy consumption behavior of graphene aerogel. On this basis, the research team used the CVD technique of in-situ deposition of ceramics in graphene aerogel template, and by heating the etched template, the prepared ceramic aerogel not only has negative Poisson's ratio characteristics, but also passes through the hole. The "double-wall" substructure of the wall simultaneously achieves the negative thermal expansion characteristics of the ceramic aerogel, thereby enhancing the mechanical and thermal properties of the ceramic aerogel.

Xu Xiang said that the preparation of ceramic aerogel CVD is the key to research. In order to impart flexibility to the ceramic aerogel, control the wall thickness of the pore wall, improve the crystal aerogel crystallinity, and achieve structural design, the researchers have experienced nearly a thousand repeated experiments. In addition, the ultra-light properties of ceramic aerogels make it impossible for commercial measurement systems to test their thermal conductivity. To this end, the research team built specialized measurement equipment and conducted reliability demonstrations.

The researchers said that the study is only the beginning, and the research team will continue to develop ceramic aerogel ultra-light structures that are more flexible and can adapt to higher operating temperatures and have lower thermal conductivity to further promote ceramic aerogels. Wide range of applications.