Slashdot Mirror
The Amazing Properties of Aerogel
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.
Very good Aerogel FAQ.
--
For news, status, updates, scientific info, images, video, and more, check out:
(AXCH) 2004 Mars Exploration Rovers - News, Status, Technical Info, History.
*sigh*
I should check my links first.
Linky linky
Buy some aerogels, made in Germany. We know that they have great insulating properties, but is it insulating per unit weight? If that is the case, it is probably because they weigh so little and therefore they don't allow any convective cooling. All the cooling has to be by temperature conduction, which is not efficient in air.
This informative comment was lifted from a comment made the last time aerogels were discussed on slashdot (see the original comment here).
Clothing insulated with aerogel is available now: GRADO ZERO ESPACE
Check it out - this auction on Ebay is selling a 4-6 Cubic inch chunk of Aerogel with a "Buy it Now" price of $160. Considering the auction says it costs about $200 per cubic inch to make, thats a deal. I'm guessing some /.'er with deep pockets will be buying this pretty soon!
Looking for hardware (Currently need: Large Etch-a-Sketch) Have one? See my journal!
you can buy this stuff from MarkeTech for the rock bottom price of $975 a 4x8x0.5" piece.
I'll let someone else figure out how expensive an entire house would be to insulate.
Note that this isn't even the really good stuff (the average density of the commercial stuff is only 99.9% air, while the hi-tech versions used by NASA can be as high as 99.99% air or more)
good fiberglass is about R5 per inch, this stuff being 39 times better would be about R-195 per inch.
Well art is art isn't it, but then again water is water; and east is east; and west is west; and if you take cranberries
It's interesting that Aerogel is always mentioned as being the insulator on the mars Sojourner Rover (and current mars rovers) but it's almost never mentioned that the heat source inside the insulated electronics boxes is not merely waste resistive heating from the electronic components themselves, but from Plutonium Radioisotope Heater Units of a couple ounces each. Maybe it's a good thing they're kept low profile, the clueless luddites would have a field day.
- "Hear that?! The percolations are imminent! Cease your ingress!"
the jacket alone costs 2500 custom made, I think I'll pass on it for insulating my home...
1888 Franklin St.
Try these guys (no, I don't have anything to do with them).
/Styx
The pictures are amazing. Wow. http://stardust.jpl.nasa.gov/photo/aerogel.html
"You could take a two or three bedroom house, insulate it with aerogel, and you could heat the house with a candle."
Well, sure, anybody can point out the obvious "if you have a crack in your house" stuff, but the idea is still valid. So, don't go pulling out pivnert from 10th grade chemistry and using that as your basis for second-guessing an illustrative statement.
However, your house would STILL get too hot, even using PV = nRT. V here is constant. R, of course, is the Rieberg constant, the value of which I don't know off-hand. As long as no air leaks out, then as T goes up, P goes up accordingly. But T is on an absolute scale. Kelvins, here. 293.15 K is room temperature, 20 degrees C, and if you heat that up to 30 degrees C, 303.15 K is, in terms of proportionality, not too much of an increase, but hotter than is comfortable, i.e. too hot. Then particles, due to the pressure differential between outside and inside, want to leak out that crack. And what's happened? THE TEMPERATURE HASN'T DECREASED. n in PV = nRT has gone down in order to bring P down to atmospheric pressure outside. Oh, dear, T is higher, and nothing's leaking out! This, silly head, is why it's possible to heat a house in the first place. By your reasoning, a house could never be a different temperature than outside! Which, thank goodness, isn't the case.
And then, of course, "as a matter of fact," the air is exactly what keeps it hot, and any other thermally insulative materials, i.e. fiberglass or aerogel. When you heat up a house, you run air into a furnace, heat it up, and then pump it through the rest of the house. A candle would heat up the air immediately above it (rising products from chemical reaction) and that air diffuses throughout the house, heating it up. Just like your furnace. True, there's radiative heating from the candle as well, but compare the difference in heat when you stick your finger an inch above a candle vs. an inch to the side of it. Radiative heating is universally dispersive. Convective goes straight up. BIG difference between the two there. Oh, well, it looks like a candle COULD heat up the house insulated with aerogel.
Yes, I am a physicist.
The stuff is usually made from silica, same stuff glass is made from, but in a different configuration. So, in theory, it'll hold up to light and IR just as long as the window panes around it. And, as an added benefit, it wont suddenly implode if you look at it funny like a true vacuum would.
Your logic is ridiculous. It's like saying a campfire doesn't heat up it's surroundings because air can escape.
I was curious about the prices, too.
At What's an aerogel?, there is this:
"Air molecules don't have room to vibrate"? In other words, their temperature magically drops to 0 Kelvin? What I think he is trying to say is they don't have room to convect. Molecules vibrate as a function of temperature. Even if the air molecule were chemically bonded to something, it would still vibrate as a function of temperature.
This is a picture from an experiment using "a special air gun, particles are shot into aerogel at high velocities. Closeup of particles that have been captured in aerogel are shown here. The particles leave a carrot-shaped trail in the aerogel". (source)
Vacuum is *not* actually the perfect insulator. It is true that no heat is conducted trough vacuum, but on the other hand vacuum is near perfect in letting heat *radiate*. Now, if you combine vacuum with one or more reflective films to reflect back most of the radiated heat then you have eh, uhm, invented the termos-bottle.
Some awesome pictures;
"The Flower"
"Six Aerogel Nanocomposites"
"Magnetic Aerogel"
"Photoluminescent Silicon on Silica"
"Carbon Nanostructure in Aerogel"
General Info / Main
I think we can keep recursing like this until someone returns 1
Silicon dioxide is actually very common. Actually it's a form of quartz. Unless I am mistaken it's the same stuff they put in the little white packet that comes with your hard disk to keep condensation from forming in the antistatic bag...
Regardless, the cost of Aerogel is in its manufacture, not its ingredients. Aerogel is actually just a crystalline structure that forms when SiO2 molecules are suspended in ethanol. The trick is figuring out how to get the ethanol out and replace it with air after the lattices form. This process is called supercritical drying and involves pushing liquid CO2 though the structure at very high pressures. Actually the entire process of how to make the stuff can be found here. It's suprisingly simple. Besides the supercritical drying bit, it seems almost like something you could make yourself.
-R
Anyvbody with some industry knowledge care to comment on the chances of the prices coming down? This material sounds like it would be phenomonal to help with insulation in industrial and domestic applications, do a world of good to sort out global warming. The byline about a candle heating a house seems a bit of hyperbole but if it's even in the same ballpark as this then imagine the savings people would make on heating / air conditioning.
Realistically, is it likely to become affordable? like teflon went from space product to saucepans? or is it like space travel (by the 1970s we'll all be travelling to the moon on our holidays for no more than the price of a holiday in Florida...)?
That's what I said: vacuum does nothing at all to stop *radiative* heat-transfer. Which scales by the 4th power of the surface-temperature of the radiator by the way, which is why it's the dominating heat-transfer for high-temperature stuff like the surface of the sun, and rather insignificant for low-temperature stuff like window glass.
One company I heard of was pretty sure they could foam diamond, but were looking for a customer to foot the bill.
I've found a "Silica aerogel photo gallery"
http://eande.lbl.gov/ECS/aerogels/saphoto.htm
Some of the pics are really amazing. Cool stuff!!!
~~~Please pass the salt, I hate unsalted MD5s
Aerogel is also used within particle physics for telling different types of particles apart in Cherenkov detectors.
In any transparent material particles will emit light in a cone around their trajectory when they are travelling faster than the speed of light in that material (analogous to sonic boom produced by plane going faster than speed of sound). From measuring the angle the light is emitted at we can work out the velocity. The range of velocities we are sensitive to depends on the refractive index of the material which is where aerogel comes into the game. We have gasses with refractive indices very close to one (n = 1.0005 for CF4) or glass with large refractive index (n=1.47 for quartz) but no normal material in between. Aerogel with a refractive index around 1.03 gives us new possibilities.
Within a particle physics experiment we can use a magnetic field to determine the momentum of a particle from the curvature of its trajectory. If we put this together with the measurement of its velocity from the Cherenkov detector we can work out the mass. This allows us to distinguish pions and kaons in an experiment like LHCb which is currently under construction. Here CF4 (gas), C4F10 (heavier gas) and aerogel are used to give coverage of a wide velocity range.
The short answer is that yes it could, but only temporarily.
I believe Aerogel is an open celled matrix, meaning that the eventually the hydrogen (especially hydrogen) would leak out causing a block of the stuff to return to the ground.
I suppose it would be possible to seal a block of aerogel in some sort of polymer making for a structurally solid balloon.
..of ships and shoes and sealing wax, of cabbages and kings.
Yes, but current houses are far more leaky than they need to be
Untrue. We're having to build leaks into the houses now since the house wraps, spray-in foam insulation, and other technologies are essentially impermeable (the house wraps are actually intentionally permeated for instance). That's why a lot of new homes have major mold problems. Older homes are another issue, but you're not going to use aerogel insulation on them without a major reconstruction project anyway.
Even if we had it in the walls, the windows probably leak enough to provide sufficient ventilation.
If you leave them open, sure. Modern triple paned windows with vinyl sashes don't leak much. Nor do properly insulated doors.
It's really just silica atoms, with great spaces between. It is a solid, and so could never be lighter than air, unless filled with a lighter-than-air gas, as the previous poster said.
Campaign finance reform is national security.
Here is a picture of wires in aerogels.
http://mrmac.mr.aps.anl.gov/~jterry/nano.html
Aerogel is cool stuff. I've recently been experimenting with aerogel capacitors. These suckers can hold a huge amount of energy. Right in front of me I have two 2.5V 50-farad (yes farads, not microfarads) capacitors.
Fun for robotic projects and such. Many common devices are using super-capacitors like these. Those tiny remote control cars and those battery-free flashlights are a couple examples.
The ratio of people to cake is too big
You can already get windows (and transparent walls) from Kalwall that provide up to R-20 insulation. They use a form of aerogel called Nanogel , which is manufactured in Germany by Cabot (not like the cheese). The granular aerogel is packed between two translucent panes to form a structural panel.
The newsletter I work for wrote an article about it a couple of years ago. The article explains the insulation properties this way:
Some other fun facts:So, how much did this vial of air cost?
$35 on eBay.
That's not entirely true. Apparently there's been some success in using more exotic materials such as plastics. NASA actually has a website on the subject.
Javascript + Nintendo DSi = DSiCade
A nasty incesticide that is illegal in the US. May include deltamethrin (neurotoxic in mammals -death by seizures) but no one is really sure. Definately not chalk. Don't use it, especially if you have kids or pets.
6 A. html
http://www.pestlaw.com/x/press/2003/NYS-2003121
ant chalk or "Chinese Chalk" is a nasty incesticide that is illegal in the US. May include deltamethrin (neurotoxic in mammals -death by seizures) but no one is really sure. Definately not diatomaceous earth, borax, or aerogel. Don't use it, especially if you have kids or pets.
6 A. html
http://www.pestlaw.com/x/press/2003/NYS-2003121