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How Aerogels Work


Everyday Aerogel Uses
The crayons on top of the aerogel are protected from the flame underneath. Similar silica aerogels were used to insulate the Mars rover.
The crayons on top of the aerogel are protected from the flame underneath. Similar silica aerogels were used to insulate the Mars rover.
NASA/JPL-Caltech

In their earliest days, aerogels were marketed as thickening agents and used in everything from makeup and paint to napalm. They were also used as cigarette filters and insulation for freezers. Monsanto was the first company to market aerogel's commercial applications. However, Kistler's supercritical drying method, though effective, was also dangerous, time-consuming and expensive. After 30 years of production, all these factors led Monsanto to discontinue its focus on aerogels in the 1970s.

However, this wasn't the end of aerogel. Not long after it was abandoned by Monsanto, scientists developed a process that made the production of aerogels less toxic by using a safer alkoxide compound. They also made it less dangerous by replacing supercritical alcohol with supercritical carbon dioxide in the drying process. These developments reduced the time spent drying the aerogels and reduced the hazardous and flammable nature of their production. Such advances made aerogel a bit more commercially viable again, and scientists grew intrigued by the product's possibilities. [source: Hunt and Ayers, History]

As aerogel's production was made less complicated and dangerous, its unique properties have made aerogel popular with a range of industries. Silicon manufacturers, homebuilding materials manufacturers and space agencies have all put aerogel to use. Its popularity has only been hindered by cost, though there is an increasingly successful push to create aerogels that are cost-efficient. In the meantime, aerogels can be found in a range of products:

[source: Aerogel.org, Modern History]

Because of aerogel's unique structure, its use as an insulator a no-brainer. The super-insulating air pockets with the aerogel's structure almost entirely counteract the three methods of heat transfer: convection, conduction and radiation [source: Cabot Corporation]. Even though aerogel is still quite expensive, the good news is that studies have shown that aerogel insulation used in wall framing and hard-to-insulate areas such as window flashing can save a homeowner up to $750 per year. In addition to helping homeowners save money, aerogel insulation can significantly reduce your carbon footprint. [source: Aspen Aerogels, New Spaceloft]. Companies are racing to find a way to bring costs down, but for now, aerogels are more affordable for NASA than the general public. Still, aerogels are put to use by construction companies, power plants and refineries. Perhaps when it's more affordable, aerogel will achieve that A-list status.

From Earth to space, aerogels undoubtedly have a place in our future. Read on to learn about recent aerogel advancements and how you, too, can experiment with aerogel.


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