'Solid smoke' material aerogel gets added strength
Recent improvements to a type of material known as aerogel could lead to a new generation of highly insulating clothing, a major conference has heard.
Aerogels have been around for a long time, and have been described as "solid smoke" because they are so light.
But these traditional types - made from silica - are fragile and brittle.
By altering the composition and structure of these materials, scientists have now produced aerogels that are hundreds of times stronger.
The advances were described at the 244th National Meeting of the American Chemical Society in Philadelphia.
Traditional aerogels developed decades ago and made from the silica that is found in beach sand are brittle, and break and crumble easily.
The new varieties are made by altering the innermost architecture of traditional silica aerogels.
Scientists use polymers, a plastic-like material, to reinforce the networks of silica that extend throughout an aerogel's structure.
Another way is to make them from polyimide, an incredibly strong and heat-resistant polymer, then insert brace-like cross-links to add further strength to the structure.
"The new aerogels are up to 500 times stronger than their silica counterparts," said Mary Ann Meador from Nasa's Glenn Research Center in Ohio, US.
"A thick piece actually can support the weight of a car. And they can be produced in a thin form, a film so flexible that a wide variety of commercial and industrial uses are possible."
She said the new types of aerogel could yield highly insulating clothing that would keep people warm with less bulk than traditional "thermal" garments.
It could also potentially be used in the walls of fridges and freezers, reducing their thickness and increasing storage space.
The Nasa Glenn scientist also said the space agency was exploring use of a heat shield made from flexible aerogel that would inflate like a balloon when spacecraft enter a planetary atmosphere.
The material might also be suitable for insulating spacesuits. However, it is probably not be suitable for clothing used by firefighters, which requires protection beyond the 302C (575F) limits of this substance.