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Sunday, 19 August 2007

Frozen Smoke…Cool!

Filed under: Geek Stuff |


Now here’s an amazing substance which can help insulate astronauts’ EVA suits for manned missions to Mars...for absorbing kinetic energy from bomb blasts...and for transmission of greater force in tennis rackets! These are just a few of the already-discovered properties of aerogel, invented in 1931 and now being looked at for 21st-Century solutions to 21st-Century problems. Here’s how it’s produced:

Silica aerogel is made by drying a hydrogel composed of colloidal silica in an extreme environment. Specifically, the process starts with a liquid alcohol like ethanol which is mixed with a silicon alkoxide precursor to form a silicon dioxide sol gel (silica gel). Then, through a process called supercritical drying, the alcohol is removed from the gel. This is typically done by exchanging the ethanol for liquid acetone, allowing a better miscibility gradient, and then onto liquid carbon dioxide and then bringing the carbon dioxide above its critical point. A variant on this process involves the direct injection of supercritical carbon dioxide into the pressure vessel containing the aerogel. The end result removes all liquid from the gel and replaces it with gas, without allowing the gel structure to collapse or lose volume.

There, I hope I didn’t blow your mind with that. Now, let’s see the other side come up with stuff like this. They can’t...and they never will; they’ll just blame it on the JOOOOOOs.
Meanwhile, Western Civilization marches on.

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