When the gel removes most of the solvent, making the gel much less liquid than the solid content, or the gel's spatial mesh structure is filled with a gas, the appearance is solid, this is the dry gel, also known as aerogel.The aerogel has the effect of expansion, the effect of touch and change, the effect of dispulation.
In the 1990s, a new space adiabatic reflective porcelain layer (Therma-Cover) was developed by researchers at the National Aeronautics and Space Administration (NADA) to solve the problem of heat transfer control of spacecraft. The material is suspended by some inertia. It is composed of tiny ceramic particles in latex, which has high thermal conductivity, high emissivity, low thermal conductivity, low heat storage coefficient and other thermal properties, and has excellent heat insulation and reflection function. This high-tech material has been promoted and applied abroad by the aerospace industry, used in construction and industrial facilities.
Also in the 1990s, NASA developed a new material aerogel to solve the problem of high and low temperature isolation of spacesuits. This material is called a silica aerogel. It is the lowest density solid material currently known and the best insulation material to date. The minimum density can reach 3kg/m3, and the thermal conductivity is as low as 0.013W/(m·K) at normal temperature. This kind of nano-high-tech materials has been promoted to the military and civilian fields in the aerospace industry, and its price has also been reduced to the price point that civilians can bear. So far, the technology for producing silica aerogel insulation felt for domestic industrial use has been relatively complete.