aerogel
Sign in to saveright|thumb|A block of silica aerogel in a hand.
AI overview
Aerogel is an extremely lightweight, porous solid material made by removing liquid from a gel while preserving its structure, leaving behind a substance that is mostly air. It matters because its combination of low weight, low density, and insulating properties makes it useful for applications ranging from spacecraft insulation to scientific research.
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Article
23 sectionsContents
- History
- Properties
- Structure
- Porosity of aerogel
- Knudsen effect
- Waterproofing
- Production
- Gelation
- Drying
- Supercritical drying
- Freeze-drying
- Preparation of non-silica aerogels
- Materials
- Silica aerogel
- Carbon
- Metal oxide
- Other
- Applications
- Safety
- See also
- References
- Sources
- External links
right|thumb|A block of silica aerogel in a hand.
Aerogels are a class of synthetic porous ultralight material derived from a gel, in which the liquid component for the gel has been replaced with a gas, without significant collapse of the gel structure. The result is a solid with extremely low density and extremely low thermal conductivity. Aerogels can be made from a variety of chemical compounds. Silica aerogels feel like fragile styrofoam to the touch, while some polymer-based aerogels feel like rigid foams. thumb|Aerogel crystals produced in ScCO2 drying Aerogels are produced by extracting the liquid component of a gel through supercritical drying or freeze-drying. This allows the liquid to be slowly dried off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia, and tin dioxide. Carbon aerogels were first developed in the late 1980s.