I don’t know the porosity of aerogel but Mylar balloons retain helium for a week or more AND it’s a whole lot tougher than aerogels.

Of course, one COULD use H2 for your lifting gas if it could pass FAA safety rules.

I saw some calculations that indicated a geodesic dome a half mile in diameter could be self lifting from the hot air created by sunlight shining thru the panels. Its volume increases far faster than the weight of the construction material.

GAry 7

Aerogels are made by a sol gel process, which means that the components start out in liquid form and then the react to form the solid. If you pour the sol into a mold it takes the shape of the mold as it gels. The resulting piece isn’t flexible but it is in the shape of the mold.

You can make any arbitrary shape that you want as long as you can get it out of the mold. Of course, if you get it too thick you’ll have a hard time getting it processed. Liquids don’t flow through the gel so washing the unused reactants out is done by immersing the gel in solvent and allowing diffusion to pull stuff out of the gel. If you make too thick of a piece it takes forever to wash.

“It is a really good thermal insulator but it is hard to use as insulation because it is so fragile.”

You could use smaller chunks of aerogel placed in a soft er (and fuzzy) material in order to obtain a good insulator.

Remember that this stuff is about 95% void volume – that is, only about 5% of the volume is silica – the rest is empty space, typically filled with air. It is an open-cell material so you can remove the air and it becomes an even better insulator.

It is a really good thermal insulator but it is hard to use as insulation because it is so fragile. There are people at NASA Glenn (where I’m from) and the University of Missouri that have developed a much stronger version. As usual, there is no free lunch, so you sacrifice some of the desirable properties a little to get the strength increase, although in this case you gain strength much faster than you increase density.

Quite right. Pay attention, all you who are clamouring to acquire aerogel. Silicosis is not at all funny – it resembles a form of lung cancer, so you really don’t want to inhale silicon (di)oxide fibres.

When you said “A cubic meter of water weighs a ton, by the way.”, didn’t you mean “tonne”…?

Also searching ebay found some hifi speakers with “aerogel cores”, not sure if its the same stuff or not but a if it is a good example of practical spin off technology, although not exactly save the planet stuff.

The sound you are trying to describe, Phil, is like a “scree”. The closest anaogy I can come up with is the sound of a piece of room-temperature metal being dragged across a block of dry ice.

If you’re ever in the San Francisco Bay Area, and can manage a trip to Livermore, the Lab’s Visitors’ Center has some small chunks they’ll give you if you ask. You have to ask, though, and they won’t give you any if you’re part of a large group (say more than a half dozen) since they don’t have very much of it.

To answer some of the other questions, yes, it will crumble back to silicon powder with the slightest squeeze. And yes, Dee Jay, the density is close enough to air at STP that, supposedly, if you heat it up it will float in air (I have yet to confirm this, though).

Here’s a link to the JPL site that talks about it: http://t2stardust.jpl.nasa.r3h.net/tech/aerogel.html

I noticed that they’ve updated the text a little. It used to give the impression that JPL invented aerogel. I’m sure someone must have complained becuase it now says it was “prepared and flight qualified at JPL”, although there’s still no mention of Livermore Lab.

- Jack

anyway, how chep is “relatively” cheap. I’m just wondering if there are any commercial use for the aerogel. I want to insulate my house with this stuff . On the other hand reading of all those splinters in the skin and lungs sounds like not very consumer-friendly product.

Rob

I’d love to help with the research, but chemistry is not my forte

I’m not sure what I would need Aerogel for, I still want some.

Aerogel is cool!

Only 10 days until TAM4!

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!!

I want some…