The characteristics of nano aerogel insulation felt is mainly determined by the characteristics of aerogel, so what are the characteristics of aerogel, here small series summarizes two points:
1. thermal conductivity of SiO2 aerogels. Aerogel is a kind of nanoporous network structure composed of colloidal particles or polymer molecules. the common SiO2 aerogel is a highly dispersed solid material composed of SiO2 network skeleton and gas filled in nanoporous pores. Has a porosity of more than 80 percent, the pore diameters of which are mesopores between 2 and 50 nm formed by interconnecting nano network frameworks, the density of which is only 30 to 100 kg / m, and the thermal conductivity of the SiO2 aerogel is only 0102 w / ( MK ) at normal temperature. Therefore, SiO2 aerogel is a typical lightweight and excellent thermal insulation material.
2. light transmission characteristics of aerogels. At high temperature, the thermal radiation energy of infrared ray with wavelength less than 8 μ m will almost pass through the aerogel, which leads to a sharp rise in the thermal conductivity of SiO2 aerogel. in order to reduce the thermal conductivity of radiation, it is necessary to combine the opacifier which can absorb or scatter infrared light in the aerogel. the common infrared opacifiers are carbon black, TiO2 and so on.