Aerogel
Description
Any synthetic, open-celled solid foam that is composed of a network of interconnected nanostructures. Aerogels are derived from gels in which the liquid has been replaced with gas while retaining the structure of the solid framework. The first document example of an aerogel was created the Samuel Kistler in 1931 with a silica gel (patented 1937). Kistler later made aerogels with alumina, chromia and tin dioxide., The unique properties of aerogels are due to its high surface area and open porous structure that provides extremely low density, thermal conductivity, and sound conductivity. Although they may feel fragile to the touch, they have strong structural integrity. They have been used in solar cells, fuel cells, batteries, supercapacitors as well as more mundane things, such as paints, cosmetics, coats, rugs, pipes, spill-clean-up kits and insulation. Of particular interest for museums is its usefulness in fire protection blankets (Praestegaard 2023).
Aerogels were first, and most commonly made from silica (see aerogel, silica), but they ave also been made from:
- Natural polymers: Cellulose, Agar (SEAgel), gelatin, pectin,
- Synthetic polymers: phenol-formaldehyde, Polyacrylate, Polystyrene, Polyurethane, Epoxy, Polyimide (AeroZero)
- Metal oxides: iron oxide, Tin oxide, lanthanide, actinide
- Carbon: carbon nanotubes
- Metals: gold, copper
Synonyms and Related Terms
frozen smoke; blue smoke; solid air; solid cloud
Product names: Santocel; Santocel-C; Santocel-Z; Pyrogel; AeroZero
Applications
- Fire protection
- Thermal and sound insulation
- Thickening agent
Risks
- Structurally strong but can shatter like glass
- Will dissolve in water unless chemically treated
Physical and Chemical Properties
- Particle size averages 2-5 nm
- Pore size is usually 100nm
- Porosity greater than 50% with examples of 99%
- Density - 0.2 - 0.2 g/ml
- Very lightweight
Working Properties
Resources and Citations
- Praestegaard L., G. Sorig Thomsen, K. Woer 'Before the Fire: Experiments on Fire-Protecting Cover Materials', Studies in Conservation, Vol. 68 (1), pp. 1-8, 2023.
- Alwin, S., Sahaya Shajan, X. Aerogels: promising nanostructured materials for energy conversion and storage applications. Mater Renew Sustain Energy 9, 7 (2020).
- Skanacid A/S: www.skanacid.dk
- Supedium: The Incredible Aerogel
- Wikipedia: https://en.wikipedia.org/wiki/Aerogel
- Aerogel: What is Aeogel?