The Amazing Properties of Aerogel

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The Amazing Properties of Aerogel

Posted by michael on Tuesday January 20, 2004 @06:39PM from the it-slices-it-dices dept.

RideMax writes "We all know NASA is using a substance called 'aerogel' in the Stardust spacecraft to catch pieces of the Wild-2 comet. The NYT is running an article about some other amazing aerogel properties. My favorite quote: 'It's the lowest density of any solid, and it has the highest thermoinsulation properties. Though it would be very expensive, you could take a two- or three-bedroom house, insulate it with aerogel, and you could heat the house with a candle. But eventually the house would become too hot.'" We've looked at Aerogel before.

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Aerogel Facts and a Picture by dekashizl · 2004-01-20 18:45 · Score: 5, Interesting
Some facts, from JPL Aerogel site:
- It is 99.8% Air
- Provides 39 times more insulating than the best fiberglass insulation
- Is 1,000 times less dense than glass
- Was used on the Mars Pathfinder rover
And a cool picture of aerogel in somebody's hand.

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balsa wood in the right structure can do as much.. by Anonymous Coward · 2004-01-20 18:46 · Score: 5, Interesting

It also has incredible compressive strength. "It can take 2,000 times its body weight without damage," Dr. Tsou said. NASA's Web site shows a 2-gram cube of aerogel (less than 0.1 ounce) supporting a 2.5-kilogram brick (about 5.5 pounds).

That particular example doesn't seem that impressive, I used to build balsa wood structures that would hold over 600 lbs(~270kg), with only 15 grams of balsa wood and glue, with strict rules on how it could be built. The world record is somewhere in the 1500 lb mark with a similar weight of wood.
Re:R-factor? by dekashizl · 2004-01-20 18:55 · Score: 5, Interesting

Not sure if all Aerogels are created equally, but this is from 1999 NASA article on Aerogel:
"A single one-inch thick windowpane of silica aerogel is equivalent to the insulation provided by 20 windowpanes of glass (R-20 insulation factor)."

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For news, status, updates, scientific info, images, video, and more, check out:
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my god... by ruebarb · 2004-01-20 18:56 · Score: 5, Interesting

let me get this straight....virtually unbelieveable insulation at the coldest of temperatures...creating super greenhouses/habitats and so forth...

improves the desalination of seawater plants a thousand fold...

my god....all we have to do is find a cheap or easier way to produce (like we do with virtually everything in the world in the free enterprise system) and we can offer virtually energy free habitats (excess heat can be channelled into electronics and solar can pick up the rest) - as well as a cheap water supply for the world...

christ...someone get me some chemists and a few venture capitalists.....this is incredible... - and it's real and now...not like those carbon nanofibers people want to use to create space elevators...

pax
RB

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1. Re:my god... by Znork · 2004-01-20 22:07 · Score: 5, Interesting
  
  "Imagine if your house were perfectly insulated, then you would only need to suck out the heat added by the things inside it (200W per person, another 200W per computer)."
  
  Well, and the CO2. And the water vapour. And whatever toxics that leak in miniscule amounts from materials inside.
  
  You dont have to imagine it, it's been tried. It was found to profoundly suck, as people got sick and the houses molded or rotted.
  
  The technology for building houses with perfect insulation has been here for a long time. Unfortunately, the problem isnt the insulation anymore, the problem is the ventilation. But come up with a highly efficient and cheap heat exchanger system and you could solve that too :).
2. Re:my god... by Indras · 2004-01-21 01:08 · Score: 4, Interesting
  
  all we have to do is find a cheap or easier way to produce
  
  A friend of mine said that the reason aerogel has the light bluish tint to it is that the crystal structure does not form perfectly due to earth's gravity. Aerogel made in zero-G should, in theory, be completely clear.
  
  Now, if we added a module to the ISS to make transparent aerogel, the ISS would fund itself! I mean, think about it... with how much it costs per cubic inch of the tinted stuff, and the fact that the ISS would have a monopoly on all transparent aerogel produced, you could charge practically whatever you wanted, and sell it to governments around the world.
  
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It is subject to shattering, catasrophically by dstone · 2004-01-20 18:59 · Score: 4, Interesting

The article doesn't touch on it, but the NASA FAQ mentions this unique property...

Q: What happens if I touch it?

A: Silica aerogel is semi-elastic because it returns to its original form if slightly deformed. If further deformed, a dimple will be created. However, if the elastic limit is exceeded, it will shatter catastrophically, like glass.
1. Re:It is subject to shattering, catasrophically by fo0bar · 2004-01-20 21:02 · Score: 4, Interesting
  
  I ordered a vile of aerogel fragments on ebay, and it arrived yesterday. And I can tell you this: yes, it shatters easily, but it all has to do with size ratios. Aerogel can support up to 1000 times its own weight. When you're dealing with a 6x6x1" piece, it can certainly hold up a brick like in the photos you see. But when you're dealing with a fragment the size of a grain of rice, the force of a set of tweezers claming too hard is definitely more than 1000 times its weight. The result is, well, shattering.
Re:balsa wood in the right structure can do as muc by Quixote · 2004-01-20 18:59 · Score: 5, Interesting

Here is brick-on-aerogel picture. Looks quite cool.
Photos by Anonymous Coward · 2004-01-20 19:01 · Score: 5, Interesting

Some cool shots.
What people don't know about aerogel by state*less · 2004-01-20 19:07 · Score: 5, Interesting

Here's a nerdy factiod about aerogel that might help your processor speed.

There has been some close research into using substances like aerogel to improve processor speeds. Apparently the substances can be used as very efficient insulators between traces and components. This is because aerogel and substances like it are mostly made of air, which has a very high dielectric constant so aerogel itself is a very good insulator.

It's better described here
more on aerogel by movefaster · 2004-01-20 19:15 · Score: 5, Interesting

I have a friend who works on this. Here is a NASA newspaper article on her work; here is her website, showing aerogel in many different configurations. If you want to know more about it, you could always drop her a line.
While I'm sure aerogel has many pracitcal uses (trying not to fall asleep here), the "cool" factor is also very high. I've seen some of her samples, and everything the article says is correct. It's so light it feels like the wind could take it; in fact, if you drop it in water, I think it dissolves. Since the material is so expensive, it's obviously something you don't want to do, since every last piece is precious.
As you might imagine, a material that's ultra-light and 'holographic' has artistic applications, too. The "brain" image made it onto the cover of Nature neuroscience, and wouldn't look out of place in a design magazine. When you see it up close, the image seems to be 'embedded' in the material, even though it's so light you could easily crush it with your hand. The airiness and delicacy of the material makes the image that much more striking.
While we're all attuned to the utilitarian value of materials like this, it's always neat to see what people outside of engineering can do with them.
More miracle heating/cooling by arrianus · 2004-01-20 19:30 · Score: 4, Interesting

For those of you who like stupid science tricks/supercheap climate control, here's a trick for how to heat and cool a house without using any energy (outside of what's free from the Sun):

First, some background on black body radiation. All matter radiates some light, based on its temperature. By basic thermodynamics, the amount of radiation that a color of matter absorbs in a given frequency range (as opposed to reflects) is directly proportional to how much it radiates (as compared to a perfect black body of the same temperature).

The sun only radiates on a fairly small set of frequencies, and that set is very different from the frequencies at which a black body at room temperature radiates. If you build a panel of a material that is perfectly absorbent in the frequencies on which the Sun radiates (perfect black body), but reflects in the remaining frequencies (perfectly white on the blackbody frequencies of room temperature), it will lose very little heat to radiation, but absorb a lot from the sun, and it'll get very hot. If you take a body that reflects radiation in the colors the sun emits (white), but absorbs/radiates elsewhere (black), it'll get very, very cool, even in bright sunlight. You can get pretty close to the full 1000W/m^2 of heating (level of Sun's radiation hitting the earth). In cooling, you get pretty close to the ideal from Stefan's Law (http://www.egglescliffe.org.uk/physics/astronomy/ blackbody/bbody.html), which gives 300-500W/m^2 at typical Earth temperatures (over 400W/m^2 heat loss at typical room temperature).

This means that you can theoretically heat or cool a house with just a painted square on the roof a few square meters in area, if you could just create a material of the right color.

Problem is the guy who came up with this (and showed it to me) was a physicist and not a chemist, and had no idea how one would go about creating a material whose color was that well controlled.

Still a nifty concept, eh? If you could make this, it would save a ton of energy, since you'd no longer need to burn gas to heat and use electricity to cool -- just flip a panel on your roof, and the temperature changes (although for heating, the house would need to be well enough insulated to last the night).
Zero-G manufacturing? by phr1 · 2004-01-20 19:30 · Score: 4, Interesting

Along with perfect ballbearings and other ideas that didn't work out, one of the more interesting suggestions for zero-g (actually microgravity) manufacture was metal foams. The idea is to shoot gas bubbles into molten metal. With no gravity to make the bubbles rise to the top, they'd stay where they were, and cooling down the mix would result in metal foam, sort of like foam rubber except with metal instead of rubber. I wonder if aerogel amounts to the same thing and could be made the same way?
Ref: The Third Industrial Revolution by G. Harry Stine.
Practical Application by aiken_d · 2004-01-20 19:36 · Score: 5, Interesting

See CDT Water for one practical, functional application of aerogel.

In short, they push contaminated water through aerogel and use electrodes to pull ionic molecules apart. The ions get caught in the aerogel mesh, and the purified water flows through. At least, that's my layman's understanding of it.

Cheers
-b

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Very expensive? by Daetrin · 2004-01-20 19:39 · Score: 4, Interesting

Though it would be very expensive, you could take a two- or three-bedroom house, insulate it with aerogel, and you could heat the house with a candle.
Maybe I'm missing something, but elsewhere they said "But, Dr. Tsou said, the material was not used much, except in powdered form as a nontoxic anti-caking agent for food."
If it's so expensive, what kind of food exactly were they using it on? Caviar?

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Re:Really? by AKAImBatman · 2004-01-21 04:44 · Score: 4, Interesting

On a more serious note, I wonder if this stuff has any radiation shielding properties? When they fired particles into the gel, they were very quickly stopped. And placing the gel against a bunsen burner doesn't even phase it. If it protects against radiation just as well, its light weight may make it the perfect space ship shielding material.

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