Research and Application of Silica Aerogel Insulation Materials in Different Fields
2017-12-27 15:34:15 From: Tradematt-Aerogel
As a thermal insulation material. The slender nano-network structure of silica aerogel effectively limits the propagation of localized thermal excitation with a solid state thermal conductivity 2-3 orders of magnitude lower than the corresponding glassy material. Nanopores inhibit the contribution of gas molecules to heat conduction. Silica aerogel refractive index close to l, and the infrared and visible light annihilation coefficient ratio of 100 or more, can effectively penetrate the sun, and prevent the ambient temperature of the infrared heat radiation, become an ideal transparent Thermal materials have been used in solar energy and building energy savings. By means of doping, the radiative heat conduction of the silica aerogel can be further reduced, and the thermal conductivity of the carbon aerogel can be as low as 0.013 w / m · K at room temperature and normal pressure, which is the lowest current thermal conductivity Solid material, is expected to replace polyurethane foam to become a new type of refrigerator insulation. The incorporation of titanium dioxide can make silicon aerogels a new type of high temperature thermal insulation materials. The thermal conductivity at 800K is only 0.03w / m · K, which will be further developed as a new material for military products.
It is also an ideal acoustic delay or high-temperature sound-proofing material due to the low sound velocity properties of silica aerogel. The acoustic impedance of this material is larger (103-107 kg / m2 · s), which is an ideal acoustic impedance coupling material of ultrasonic detector.The preliminary experimental results show that the density of acoustic impedance is about 300 kg / m3 Silicon oxide aerogels as a coupling material, can make the sound intensity increased by 30 dB, if using a density gradient silica aerogel, is expected to get a higher sound gain.
In environmental protection and chemical industry. Nanostructured silica aerogel can also be used as a new type of gas filtration, and other materials is different from the uniform pore size distribution, porosity is a high efficiency gas filtration material. Due to the material is particularly large than the plot. Aerogel as a new catalyst or catalyst carrier side also has broad application prospects.
As a new type of nanoporous material, in addition to the silica aerogel, other units, binary or multiple oxide aerogel, organic aerogel and carbon aerogel have been developed. As a unique material preparation method, the relevant technology has been widely used in the development of other new materials, such as the preparation of porous silicon with very high porosity, metal-aerogel hybrid material for high performance catalyst, high temperature superconducting material, Ultrafine ceramic powder and so on.