The nanoscale particles and pores of Si02 aerogel, as well as the continuous spatial network structure, make it have very low thermal conductivity. The heat conduction of the material is mainly realized through convection, radiation and heat conduction, so it is necessary to reduce its thermal conductivity from the heat transfer path of the material.
Convection: When the diameter of the porosity in the aerogel material is less than 70nm, the air molecules in the porosity lose the ability to flow freely, and are relatively attached to the porosity wall, then the material is in an approximate vacuum state, and it is impossible to carry out thermal convection.
Radiation: Because the pores in the material are nanoscale pores and the material itself is very low volume density, so that the material internal stomata wall tends to be "infinite" for a few days, for every one of the stomata wall has the role of shielding hot plate, thus producing an effect close to "infinite shielding hot plate", so that the thermal radiation is minimized.
Heat conduction: The density of aerogel is very low, larger than the surface and the volume skeleton is loose, due to the existence of nearly infinite nanopore, heat flow in the solid can only be transmitted along the pore wall, and the nearly infinite pore wall constitutes the "infinite path" effect, making the ability of solid heat conduction drop to close to the minimum limit.