Aerogeelit

Aerogeelit, or aerogels, are a class of highly porous, low‑density solid materials formed by replacing the liquid in a gel with gas without collapsing the solid network. This preservation of the gel’s nanostructure yields materials with extremely low mass, very high porosity, and often a translucent to transparent appearance.

Most aerogeelit are based on silica, but variants exist using alumina, carbon, metal oxides, or organic polymers. The silica form typically consists of a three‑dimensional silica network with pores in the nanometer range and porosity of about 95% or higher. Densities commonly range from roughly 0.001 to 0.5 g/cm3. Production involves creating a wet gel from silicon precursors and then drying under supercritical conditions or via ambient-pressure drying with surface modifications that prevent network collapse.

Key properties include exceptionally low thermal conductivity, making aerogeelit among the best thermal insulators available. Values for optimized silica aerogels are around 0.013–0.020 W/mK at room temperature. They also offer high surface area and low refractive indices, but are typically brittle. Reinforcement through fibers, composites, or coatings is a common approach to improve mechanical performance, and hydrophobic surface treatments help reduce moisture uptake.

Applications span architectural insulation, skylights and windows, spacecraft and space missions, catalyst supports, oil spill cleanup, and energy storage devices. The development of aerogeelit dates to the 1930s, with Samuel S. Kistler credited for the foundational discovery. Safety considerations focus on silica dust hazards, so handling usually requires appropriate containment and protective equipment. See also aerogel, silica aerogel, and supercritical drying.