Scientists hail ‘frozen smoke’ as material that will change world:
Aerogel is nicknamed “frozen smoke” and is made by extracting water from a silica gel, then replacing it with gas such as carbon dioxide. The result is a substance that is capable of insulating against extreme temperatures and of absorbing pollutants such as crude oil.It was invented by an American chemist for a bet in 1931, but early versions were so brittle and costly that it was largely consigned to laboratories. It was not until a decade ago that Nasa started taking an interest in the substance and putting it to a more practical use.
In 1999 the space agency fitted its Stardust space probe with a mitt packed full of aerogel to catch the dust from a comet’s tail. It returned with a rich collection of samples last year.
In 2002 Aspen Aerogel, a company created by Nasa, produced a stronger and more flexible version of the gel. It is now being used to develop an insulated lining in space suits for the first manned mission to Mars, scheduled for 2018.
Mark Krajewski, a senior scientist at the company, believes that an 18mm layer of aerogel will be sufficient to protect astronauts from temperatures as low as -130C. “It is the greatest insulator we’ve ever seen,” he said.
Aerogel is also being tested for future bombproof housing and armour for military vehicles. In the laboratory, a metal plate coated in 6mm of aerogel was left almost unscathed by a direct dynamite blast.
It also has green credentials. Aerogel is described by scientists as the “ultimate sponge”, with millions of tiny pores on its surface making it ideal for absorbing pollutants in water.
Kanatzidis has created a new version of aerogel designed to mop up lead and mercury from water. Other versions are designed to absorb oil spills.
He is optimistic that it could be used to deal with environmental catastrophes such as the Sea Empress spillage in 1996, when 72,000 tons of crude oil were released off the coast of Milford Haven in Pembrokeshire.
Aerogel is also being used for everyday applications. Dunlop, the sports equipment company, has developed a range of squash and tennis rackets strengthened with aerogel, which are said to deliver more power.
Earlier this year Bob Stoker, 66, from Nottingham, became the first Briton to have his property insulated with aerogel. “The heating has improved significantly. I turned the thermostat down five degrees. It’s been a remarkable transformation,” he said.
Mountain climbers are also converts. Last year Anne Parmenter, a British mountaineer, climbed Everest using boots that had aerogel insoles, as well as sleeping bags padded with the material. She said at the time: “The only problem I had was that my feet were too hot, which is a great problem to have as a mountaineer.”
However, it has failed to convince the fashion world. Hugo Boss created a line of winter jackets out of the material but had to withdraw them after complaints that they were too hot.
Although aerogel is classed as a solid, 99% of the substance is made up of gas, which gives it a cloudy appearance.
(By the way, the British home-owner cited doesn’t seem to understand how a thermostat works.)