Introduction to Aerogel

In Volume 250 of the world-renowned authoritative academic journal Science, ten new materials that could change the world were listed. Among them, one material claiming multiple world records ranks first on the list. Only slightly heavier than an equal volume of air, it can withstand high temperatures up to 1400°C, higher than the melting point of most metals. Scientists worldwide are fascinated by its unique properties — this material is aerogel.

Aerogel is a highly dispersed solid material featuring a nanoporous network formed by agglomerated colloidal particles, with gaseous media filling the pores. It boasts low thermal conductivity, low density, low dielectric constant, low acoustic impedance, high porosity and high specific surface area. Exhibiting outstanding performance in thermal, electrical, acoustic, mechanical and optical fields, it enjoys broad and tremendous application prospects in aerospace, transportation, petroleum, communications, district heating & cooling, construction, metallurgy, electronics, environmental protection and other industries.

Silica aerogel is the commercially produced material with the best thermal insulation performance to date. Featuring low density and low thermal conductivity, SiO₂ aerogel effectively suppresses heat conduction. Its average pore size of 50 nm is smaller than the mean free path of air molecules, restraining convective heat transfer of air. Furthermore, countless pore walls inside silica aerogel act as reflective and refractive surfaces for thermal radiation. Combined with special reflective additives, thermal radiation can be minimized. In summary, silica aerogel simultaneously inhibits heat conduction, convection and radiation, nearly blocking all pathways of heat transfer. It is a thermal insulation material with immense application value.