very offtopic - making Aerogel at home

I came across this article today [adzoe.8m.com] which contains a fairly well documented way to make aerogel. Basically its one of the lightest known building compounds known to man as its 99% empty space (hence why its used in space).

I just thought it was very cool :-)

Maybe someone here will pick up the challenge to make a reprap capable of being made of, and making, this.

They invented this stuff at Lund's University back in Sweden where I used to work at the beginning of the 1980's. The original lab blew up and burned down when that high pressure alcohol gambit that you have to do went bad on them one day.

Alter Schwede! - as we say in Germany. :-)

I just looked around a bit and found that there are materials with even friendlier critical temperatures and pressures. E.g. Chlorine at 417 K and 8.14 bar. Yes, I would do these experiments outside wearing a mask... CnH2n+2 are also interesting. They are inflammable (explosive at pressure under consideration) but not toxic. However, increasing n means lower critical pressure but higher critical temperature...

Very offtopic? Very interesting anyway!

Howie

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Airspace V - international hangar flying!
[www.airspace-v.com] for tools and toys

IN that article, it talks about them reducing the temperature required to just about room temperature

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Jay

> IN that article, it talks about them reducing the
> temperature required to just about room
> temperature

Right. He also writes about 1,000 psi which is more than 70 bar. [www.flexwareinc.com] tells for CO2 a critical temperatur of 304.4 K and critical pressure of 73.8 bar. In summer, CO2 can be made supercritical at room temperature...

However, I am also concerned about the pressure. 73.8 bar seem quite a lot to me. Yes, I know that standard equipment from your hardware store can handle that. However, if I would build something on my own I would search for a ruin somewhere outside and sit on the other side of a wall when applying pressure and hope that it holds the parts of my device which have been catapulted with a thrust of several thousand Newtan.

Howie

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Airspace V - international hangar flying!
[www.airspace-v.com] for tools and toys

Good idea. Makes sense. 'Nuff said.

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Jay

I'd like to get some of this stuff to put in my walls... Maybe in my windows too...

That said, I think I'll refrain from pressurizing flammables. I don't know what alcohol will do, but I've heard horror stories, (or rather interesting anecdotes, the teller had all his fingers,) about oil and air compressors.