Frozen smoke: a world changing discovery?
Aerogel, one of the world’s lightest solids, is strong enough to not succumb a direct blast of 1kg of dynamite and protect against heat from a blowtorch at more than 1,300C.
Scientists are trying to discover new applications for the substance, ranging from the next generation of tennis rackets to super-insulated space suits for a manned mission to Mars.
It is expected to rank alongside wonder products from previous generations such as Bakelite in the 1930s, carbon fibre in the 1980s and silicone in the last decade.
Mercouri Kanatzidis, a chemistry professor at Northwestern University in Evanston, Illinois, said: “It is an amazing material. It has the lowest density of any product known to man, yet at the same time it can do so much. I can see aerogel being used for everything from filtering polluted water to insulating against extreme temperatures and even for jewellery.”
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 end result is a substance that is capable of insulating against extreme temperatures and of absorbing pollutants such as crude oil, The British Times reported.
It was invented by an American chemist for a bet in 1931, but early formulas 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 founded 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 and absorb oil spillages.
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.
----------------
Listening to: Hema Sardesai - Badal Pe Paon Hai
via FoxyTunes
No comments:
Post a Comment