World's Lightest Solid Gets Even Lighter

They look like wisps of smoke and are so light that they have been nicknamed 'Frozen Smoke' - But make no mistake about it, the airy looking translucent Aerogels are not only the world's lightest solids, but also, amongst the strongest. Now, scientists have figured out how to make them even lighter and very very flexible!

First created in 1931, by American scientist Samuel Stephens Kistler, Aerogels, are manufactured materials that are derived from a gel in which the liquid portion has been replaced with a gas. The result is a solid so light and strong, that a block of Aerogel the size of a human being, would only weigh 455gms (about one pound), yet, be capable of supporting an object weighing half a ton.

In addition to that, they are also very effective thermal insulators, very flexible and, can withstand temperatures of up to 3,000 degrees Fahrenheit. It's therefore no wonder that the use for Aerogels ranges from home insulation to collecting Space dust!

So far, Aerogels, which also happen to be very fragile and expensive to manufacture, have been largely made from silicon dioxide (the main ingredient in sand), metal oxide and polymers.

Now scientists from University of Central Florida have announced a new breakthrough - Aerogels from carbon nanotubes - wisps of carbon so small that about 50,000 of them would fit on the width of one human hair. Dubbed the 'Multiwalled Carbon Nanotube Aerogel (MCNT), they are not only lighter than what is currently available, but also, very flexible. Lei Zhai, the lead researcher behind the project maintains that when infused with a plastic material, they can be stretched thousands of times - To give you an idea, if the nanotubes inside one-ounce carbon are unraveled and placed side-to-side, and end-to-end, they would carpet three football fields.

The researchers believe that this new nano solid can be used inside sensors to detect pollutants and toxic substances, chemical reactors and thanks to the fact that they are excellent conductors of electricity, also for electrical components.

Sources: nanotechnology.org, gizmag.com