Our own [Eliot] dug this one up from the grave. While the recipe has been online for a while, do you know many 10 year olds who made their own Aerogel, that wonderful insulator that's essentially gelled air? [William] made some(cache) for his science project in 2002. He started with Silbond H5, a combination of ethyl alcohol and ethyl polysilicate. You can get the MSDS after a painless email registration on the Silbond website. After the gel is formed you have to soak it in an alcohol bath to make sure all water has been removed from the structure. Then the gel is placed in a drying chamber. Liquid CO2 is forced into the chamber to displace all the alcohol in the chamber and the structure. Once the the alcohol is gone the supercritical drying phase begins. The temperature is raised to 90degF and the pressure is regulated to 1050psi. At this point the liquid CO2 in the gel structure takes on gas properties (looses surface tension) and leaves the silica structure. All that remains in the chamber is your new Aerogel which is 99% empty space and 1000 times less dense than glass.
Of course, if you're lazy, you can buy some here.
21. You know, it IS possible to make Aerojello this way. I bet it has fewer calories than regular Jello!
Posted at 6:54PM on Mar 25th 2008 by Cal