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Science Technology

World's Lightest Solid 65

Posted by timothy from the hull-foam dept.
Erazmus writes: "NASA's Jet Propulsion Laboratory has manufactured the world's lightest solid. At only 3 milligrams per cubic centimeter, it's close to the density of air (1.2 milligrams per cubic centimeter). Spaceflight Now has the article. The article points to JPL's site, along with some amazing pictures."
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World's Lightest Solid More

World's Lightest Solid

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  • Old news .... (Score:2, Informative)

    by psergiu ( 67614 )
    The aerogel is so old (1932) that this isn't even funny ...
    Info Here [virginia.edu]

    • Re:Old news .... (Score:4, Informative)

      by b_pretender ( 105284 ) on Wednesday May 08, 2002 @08:09AM (#3483817)
      "Aerogels had been largely forgotten when, in the late 1970s, the French government approached Stanislaus Teichner at Universite Claud Bernard, Lyon seeking a method for storing oxygen and rocket fuels in porous materials. There is a legend passed on between researchers in the aerogel community concerning what happened next. Teichner assigned one of his graduate students the task of preparing and studying aerogels for this application. However, using Kistler's method, which included two time-consuming and laborious solvent exchange steps, their first aerogel took weeks to prepare. Teichner then informed his student that a large number of aerogel samples would be needed for him to complete his dissertation. Realizing that this would take many, many years to accomplish, the student left Teichner's lab with a nervous breakdown. Upon returning after a brief rest, he was strongly motivated to find a better synthetic process. This directly lead to one of the major advances in aerogel science, namely the application of sol-gel chemistry to silica aerogel preparation. This process replaced the sodium silicate used by Kistler with an alkoxysilane, (tetramethyorthosilicate, TMOS). Hydrolyzing TMOS in a solution of methanol produced a gel in one step (called an "alcogel"). This eliminated two of the drawbacks in Kistler's procedure, namely, the water-to-alcohol exchange step and the presence of inorganic salts in the gel. Drying these alcogels under supercritical alcohol conditions produced high-quality silica aerogels. In subsequent years, Teichner's group, and others extended this approach to prepare aerogels of a wide variety of metal oxide aerogels. "

      Poor graduate student. I can relate to him, although my ZTP-Al2O3 shortcuts didn't revolutionize anything, and I ended up leaving prior to finishing my thesis. I did, however, still graduate MS.

  • good recipe: (Score:5, Interesting)

    by b_pretender ( 105284 ) on Wednesday May 08, 2002 @08:01AM (#3483777)
    quote: "It's probably not possible to make aerogel any lighter than this because then it wouldn't gel""

    That's just a challenge to the Materials Science Engineers. Maybe that can make He-gel or H2-gel and get the *solid* material to be lighter than air... at least until gas-diffusion takes over and replaces all of the H2/He with O2. A thin membrane around the outside might even prevent this from happening! I can't wait for (air)floating surfboards and cloud-cities.

    take a look at the aerogel photogallery [nasa.gov].

    • "I can't wait for (air)floating surfboards and cloud-cities."

      Uh, lighter-than-air doesn't mean anti-gravity.

      • Re:good recipe: (Score:3, Informative)

        by MindStalker ( 22827 )
        Yes, but if the total weight of you plus what your contained in is less than the weight of air, simple priciples of boyancy state that you will float up in air. If your weight is controllable (through a system of inflatable bellows for instance, like a submarine does) you can control your altitute and everything. Kinda like a blimb, only without the huge airbag.

      • Re:good recipe: (Score:3, Informative)

        by Bullschmidt ( 69408 )
        But you forget bouyancy. Just like things that are less dense than water float at the surface, things with a lower density than air (lighter-than-air) would float a certain distance up. This is just like helium ballons. A helium ballon is lighter than air. It wouldn't float in a vacuum, but it does in our atmosphere, at least until the density of the baloon equalizes with the density of air. Now, to have an air-surfboard, the stuff would have to be either pretty darn bouyant, or pretty big.

        • Re:good recipe: (Score:3, Informative)

          by Captain Nitpick ( 16515 )
          Now, to have an air-surfboard, the stuff would have to be either pretty darn bouyant, or pretty big.

          Actually, it's just going to have to be pretty big. I can't find the density of the human body at the moment, but it's reasonably close to that of water, so let's use that number, 1000 kg/m^3 (this also happens to be a nice round number, easy to work with). Air at sea level has a density of roughly 1.2 kg/m^3. In order to float, you need to get the average density of person+board down to that of air (actually you need to be below it, but neutral bouyancy is interesting enough).

          So, assuming a 100kg person, for ease of math, and assuming a massless board with a density of zero, the board would have to have a volume of over 83 cubic meters. (assuming I did my math correctly) For the metric-declined, this works out to a cube about 14 feet on a side.

    • Re:good recipe: (Score:2, Interesting)

      by Myco ( 473173 )
      What if the gel were manufactured in a partial vacuum? Might it still gel with a lower air density, and still retain its rigidity when brought into a regular atmosphere? After all, it's supposed to be very rigid so assuming it would gel at all, it should be strong enough to hold when pressurized.
    • The Aerogel In Hand has some odd, green, leaf-like things floating around. I wonder what those are.
    • Maybe that can make He-gel or H2-gel and get the *solid* material to be lighter than air...

      If the aerogel has a density of 3 milligrams per cubic centimemeter, and air has a 1.2 milligrams per cubic centimer, then replacing all of the air in this aerogel with an imaginary massless gas would result in a density of 1.8 milligrams per cubic centimeter, still heavier than air.

      However, with further engineering, perhaps someone will invent a solid lighter than air. At that point, I the floating cities that you imagine would probably become as common as floating cities made of blimps are today.

  • Insulation (Score:4, Informative)

    by DeadSea ( 69598 ) on Wednesday May 08, 2002 @08:03AM (#3483787) Homepage Journal
    This stuff was used on Mars missions to capture particles so I thought it would be really expensive stuff. No way that you would ever be able to afford enough of it to actually insulate your house, even though it is 39 times better at it than the best fiberglass insulation.

    Upon seaching Google for the cost of this stuff I ran across Aerogel Super-Insulation [aspensystems.com] made by Aspen Aerogels [aerogel.com]. They don't have prices on their sites but it looks like somebody is trying to make an insulation product out of it. It says they are trying to break into the 20 billion dollar insulation market and that mass adoption of the product would greatly reduce fossil fuel use around the world.

    • What about heat loss through windows? I believe they are still the greatest factor of heat loss in a building. If they make it more see-through, I guess maybe it'd work. :-)
      • It'd be much easier to just double or triple glaze all of your windows (since its the air pocket that does the insulating)

      • Re:Insulation (Score:3, Interesting)

        by spike hay ( 534165 )
        Actually, one of the things they are working on with this aerogel is to make it more transparent for window use. 20 times less thermal conductivity! Also, now they are selling warm aerogel jackets for large sums of money. Now, we always here about firemen getting killed in fires. Why don't we equip firemen with aerogel suits. Aerogel would keep them insulated better than Nomex. Also aerogel resists heat better than Nomex. If my memory serves me right, nomex (special plastic) can withstand 800 degrees. I believe aerogel can withstand about 2,000.
    • Insulation is a bigger market than you may think. All I can say is that whoever does do it and does it successfully will be making a crap-load of $$$ (and of course greatly reduce fosill fuel use around the world :)

  • The big question: (Score:5, Funny)

    by Goronguer ( 223202 ) on Wednesday May 08, 2002 @08:08AM (#3483810)
    Where can I get my hands on some of this stuff?

    Seriously, how expensive is it to manufacture this stuff? If it were relatively inexpensive (or if it would be if produced in sufficiently large quantities) I could think of thousands of uses for it. Or rather, I could do thousands of useless things with it. At the very least, it would be neat to build a PC case out of it.

    Anybody know?
    • Do you really want to build a PC case out of a material that's 39 times more insulating than fiberglass? You're going to need a good cooling system to handle that.

      • Re:The big question: (Score:1, Informative)

        by Anonymous Coward
        Insulation characteristics of the PC case material are quite irrelevant. PCs are cooled by forced convection (air picking up heat and leaving the case with it), not heat conduction.
    • I think it is not as solid as you think.
      One of the pictures in the picture gallery shows a brick on it and it looks like an advertisement of the strength of the material. So it probably is not very strong one and a computer case will be a challenge for the material, maybe.
      But I would like to buy some of it also :)

    • Re:The big question: (Score:3, Informative)

      by bgins ( 446545 )
      A quick look suggests it might be a bitch to clean (the surface chemistry [lbl.gov] page says it is hygroscopic); and although it appears to be strong (as in the picture of it supporting a brick), it is also a bit fragile [lbl.gov] (which also looks like a good tip in case you do actually get your hands on some).

      I wasn't able to figure out whether it would build up static electricity, and, not being an engineer or even knowing/remembering what Young's modulus, among other things in the physical specs [lbl.gov] is, I am of course only guessing, but I think it might be a better sound insulator (like a lining inside the case) than structural load-bearer (like a PC case).

      If you want to waste some time on it, why don't you read through the info [lbl.gov] and brainstorm some more uses for it? I'd love to hear what you come up with. Interesting stuff.

      • Simply heating the material to 100-120 degrees C will completely dry the material in about an hour (or longer, depending on thickness).

        Sounds perfect for making Athlon waterblocks :)

    • Re:The big question: (Score:2, Informative)

      by T-Punkt ( 90023 )
      Great idea - if you accidently drop a coin on your pc case it will most likely shatter the case, maybe it gets stuck in the aerogel or simply falls through.

      And before you attemp making your case of aerogel, please read How Do You Work With Silica Aerogel Without Breaking It? [lbl.gov].

    • Re:The big question: (Score:3, Informative)

      by kaszeta ( 322161 )
      Where can I get my hands on some of this stuff?

      Here [mkt-intl.com], for one place.

  • Another article with more info (Score:1, Funny)

    by Anonymous Coward
    I just found another article [12.36.78.51] about this aerogel. It's not too long, but it does have some worthwhile information. Check it out.

  • Lighter-than-air idea (Score:4, Interesting)

    by crow ( 16139 ) on Wednesday May 08, 2002 @08:44AM (#3484050) Homepage Journal
    What if you made a hollow sphere of aerogel? How large could you make it and still be structurally sound while containing a vacuum? Or perhaps fill it with Helium? Either way, you could make blocks that are lighter than air.

    The engineering possibilities...

  • hmmm (Score:2, Funny)

    by oyenstikker ( 536040 )
    Natelie Porman petrified in aerogel?
  • What I find remarkable about this substance is not so much its density as the fact that it's strong, too.

    There's a great image [nasa.gov] of a block of this stuff supporting a brick 1,000 times its mass.

    That strength is all compression; I don't know how it responds to shear, or tension, or if it's flexible.

    • Re:Strength (Score:2, Informative)

      by kaszeta ( 322161 )
      What I find remarkable about this substance is not so much its density as the fact that it's strong, too.

      Strong for it's weight, yes, but still very fragile and hard to work with. If you squeeze it, it shatters into lots of invisibly small dustlike particles that disappear into your carpet (remember, it *is* glass). If you try and machine it, it tends to fracture and shard.

      It also attracts dirt and moisture like you wouldn't believe.

      But it is neat to mess around with.

      (Yes, I know what I'm talking about. I've got a bag of approximately 10 ~1 cm^3 chunks here on my desk. It's a shame I don't have a digital camera handy. From here [mkt-intl.com] if anyone is interested)

      • Well, it's certainly not cheap. Random chunks are $75 for 20 grams.

        Thanks for the description of it as a glass. I'd imagined that it had a texture more along the lines of a block of Jell-O (since it's a gel). Not something I'd want to put in my eyes (I'd read years ago about the possibility of making very-long-term contact lenses out of the stuff, since it could let so much oxygen through.)
  • Well...this is a ridiculously old story and don't know why it came up, but since we're talking about it...here is the home page [nasa.gov] for the stuff at NASA [nasa.gov]. The stuff can stand incredible amounts of pressure, but be sure not to try to tear it...it will. And to see the stuff is just cool. I mean this solid just looks like it floats on you. Oh, and it's a rather expensive manufacturing process, which is why it hasn't found use in your home yet...

  • Antimatter? (Score:2, Insightful)

    by rikennedy ( 150056 )
    <p>In two places, the article claims aerogel to have a density "1000 times less" than that of glass. If that's true, then that means it has <i>negative</i> density.</p>
    <p>Consider this: What would be the density of something 0 times less dense than glass? (The same as that of glass, of course.) How about something 1 time less dense than glass? (Multiply the density of glass by 1 and subtract: It has 0 density.) So anything beyond 1 multiple means <i>it isn't there</i>.</p>
  • At 600 to 1000 m^s/g of surface area it wouldn't take much H2 adhesion to make this a relatively good h2 storage medium. Coating the surface with a monoatomic layer of Ni would seem quite a feat, however. On the other hand if we looked around hard enough we might find a hemoglobin like analogue for hydrogen.
  • This stuff has some bizarre properties-- mostly air but a great thermal insulator, ridiculously fragile, water soluble, translucent...

    If someone figures out how to make this stuff cheaply and in a form that Joe Sixpack the general contractor can slap into building walls without any special care as a thermal (and acoustic? The article mentioned something about 'low sound speed') insulation material, that person will get ultra rich.

    Either that, or find a way to make the stuff transparent enough to be used for windows. Hell, if they can toughen it up somehow, it looks see-through enough now to make a nice skylight that won't leak heat like a sieve in the wintertime.

    ~Philly

  • Pre-World War II (Score:3, Funny)

    by Wonko42 ( 29194 ) <ryan+slashdot@@@wonko...com> on Wednesday May 08, 2002 @02:28PM (#3486332) Homepage
    In other news, there's been an astonishing breakthrough in the aerospace industry -- jet-powered aeroplanes! These new jet-planes promise to unite the world as travel times are cut in half across the globe. Stay tuned for more breaking news!
  • I'd buy some setup to look good on my desk.

  • Cool! (Score:1)

    by mrdogi ( 82975 )
    OK, I was looking at the JPL site, and I must say that this [nasa.gov] picture is just amazing. The brick is 2.5 Kg, and the aerogel holding it up is 2 g. Just completely amazing, even if the basic technology is years old. Actually, especially because it is so old.
  • Geez I find it hard to believe this is the first mention of aerogel on slashdot. This shit is old, anybody who reads Popular Mechanics has read all sorts of stuff about aerogels. For those wondering about the expense of aerogels in production, lab techniques for producing them are pretty costly. IIRC you make them with various metal oxides reacting to form what's called an alcogel which has a 3D lattice of silica molecules with water suspended in the cells of the lattice. The water is forced out of the gel by soaking it in pure alcohol. The new gel is called an alcogel which is then dried supercritically. This forces the alcohol out of the gel leaving only the silica structure left. This process it pretty costly and slow which makes aerogel production sort of unsuitable (for now) in massive scales. There's lots of work being done to find shortcuts in this process, the most promising I recall reading about was to do the supercritical drying in vacuum molding chambers like used in regular plastic molding.

    Even cooler than aerogels are hydrogels which instead of being 99.8% air they are like 99% water with a silica lattice structure. There's a bit of work researching hydrogels for use in medicine. Hydrogel strips could be used as bandaids for internal oragans and some other stuff I don't rightly recall at the moment. Aerogels rock.
  • That girl holding up a sample... if it is lighter than air, why doesn't it float? Or why didn't they take the picture without woman's hand?
    Air pressure must have been low that day... rain...

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