Can we construct a solid material that will float in air?

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newtonian

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A spin-off from my other thread where I asked what is the lightest solid currently manufactured.<br /><br />Can we construct a solid structural material that is lighter than air - say a very light solid with vacuum holes within it?<br /><br />If we could, then we could have 'permanent' manned (or robotic) monitoring above current baloon height monitoring [for weather, etc.]<br /><br />What is the lightest multiple pane glass with vacuum layers?
 
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vogon13

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Seems like I saw a photo of a chunk of helium suffused aerogel floating on a cup of CO2 once.<br /><br />But I am not super sure about this . . . . .<br /><br /><br /> <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>
 
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newtonian

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vogon13 - Hi! Do you have any links on aerogel - what is it exactly?
 
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newtonian

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derekmcd - Excellent - similar to what I had in mind! The link states concerning one type of aerogel:<br /><br />"JPL also produced aerogel for the Mars Pathfinder and Stardust missions, which possesses well-controlled properties and purity. This particular JPL-made silica aerogel approaches the density of air. It is strong and easily survives launch and space environments"<br /><br />OK, glass is also silica based and aeorogel is semi-transparent - how does it do at high temperature?<br /><br />Almost the density of air. OK, have we got past that and produced a type of aerogel or other solid that is lighter than air?
 
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kmarinas86

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It's possible to create solids that float in air. Your skin creates flakes that becomes dust.
 
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dragon04

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Aerogel is an incredible insulator. It is oblivious to convective, conductive and radiated heat at temperatures of up to 3,000 degrees F in the right configuration and thickness.<br /><br />It can support 2000 times its weight. It is highly dessicant.<br /><br />It's made out of silicon dioxide (glass) yet it's somewhat flexible. There are a ton of links to aerogel. The downside right now is that it's expensive.<br /><br />Another interesting product is CFOAM.. It was invented right here n my home town. It's a strong, lightweight carbon product derived from coal.<br /><br />In certain applications, it can insulate against temperatures up to 3,000 degrees Celsius.<br /><br />CFOAM is pretty cool stuff.. Read about it here :<br /><br />http://www.cfoam.com/index.htm<br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>
 
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plutocrass

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If this process for making aerogel is right, then you could just mix in whatever ratio of liquid helium/hydrogen with the liquid carbon dioxide when you flush out the alcohol. You could make a flying carpet this way!<br /><br /><font color="yellow">From scratch, Hunt's aerogel process begins with the mixing of TEOS and water. To allow these two immiscible fluids to loosen up and mix, alcohol is added. The water breaks apart the TEOS, attacking the silicon bonds, and creating an intermediate ester that condenses into pure silica particles. With the assist of a catalyst, ammonium fluoride, and a solution of ammonium hydroxide to control the pH, the silica particles grow and link, forming an alcogel. A clear gel, the alcogel is sufficiently strong so that when a bottle is half filled with it and turned upside down, it will not flow. <br /><br />The gel is then inserted into a pressure vessel where liquid carbon dioxide flushes out and replaces the alcohol in the gel, reducing potential fire risks in the process. Pressure is increased, the carbon dioxide becomes supercritical, and as it is slowly vented, the alcogel dries into an aerogel. </font><br /><br />
 
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nexium

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The flying carpet would have approximently zero weight in air because of boyancy, But a few grams of payload would cause it to decend. Neil
 
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kmarinas86

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Umm. You have to make something less dense than air to make it float. If the helium does not increase the size of the aerogel, then aerogel will not float. If you want floating solids, there are plenty, mylar can float if you add helium. You could make it look solid by making it shaped like a brick, or an elephant.<br /><br />One time I made a balloon that was neutral buoyant in three axes, I could hang it upside, sideways, etc, without going into orbit. Trim the edges of the balloon or cut part of the string to make it float longer. <img src="/images/icons/smile.gif" /><br /><br />I let it go in my bedroom with the ceiling fan on, it survived, and it made dozens upon dozens of circulations, like reverse gravity! On that day, I saw UFO outside my window and later went to project prom. That was a fun May 7th 2004.<br /><br />http://uplink.space.com/showthreaded.php?Cat=&Board=seti&Number=107981
 
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plutocrass

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Hi to Both, Thanks for responding. <br /><br />I think the key is the pocket size within the aerogel. It was changed to a smaller pocket size in order to improve appearance. But this also increased its density.<br /><br />From what I understand, the aerogel is composed of solid walls filled with a liquid, which is then gutted out and replaced with C02, under high temps/pressure (which blends the distinction between liquid and solid so that you don't get surface collapse.) It is 98.8 percent air (CO2) with 0.2 percent SiO2. <br /><br />This process is an improvement in the old aerogel which had very large pockets of 3000 angstroms. The new process has uniform pockets where all pockets above 400 angstroms are removed, providing a density just three times that of air.<br /><br />What would happen to the density of this substance if the pockets were increased in size from 400angstroms to 3000angstroms, and the CO2 in the center was replaced with Helium? because, I'm thinking, Magic Carpet Ride!<br /><br /><br />http://www.lbl.gov/Science-Articles/Archive/aerogel-insulation.html<br /><br />http://www.unitednuclear.com/aerogel.htm<br />
 
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kmarinas86

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Why not make it a vacuum inside? that would be neat. Riding the vacuum <img src="/images/icons/tongue.gif" /><br /><br />Imagine what kind of boogie boards you could make out of steel reinforced aerogel <img src="/images/icons/smile.gif" />
 
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newtonian

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plutocrass - OK, I haven't researched it yet - thank you all for the info and links. What is TEOS?<br /><br />Can the aerogel pockets be made into a vacuum, or is it too flexible for that?
 
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newtonian

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Dragon04 - Insulates to 3,000 F? How well does it insulate over time exposure?<br /><br />Sounds of interest to my survival on earth during red giant phase - as we expect earth surface temperatures considerably less than 3,000 F.<br /><br />I look forward to reading about CFOAM - thanks for the link.<br /><br />Can aeorogel survive on Venus? I know glass is resistant to sulfuric acid and heat.
 
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plutocrass

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Kmar*, Newt*: <br /><br />From what I could understand, there is a substance that is formed from a chemical reaction, that makes alcogel. This alcogel is the same gel as aerogel, but with the pockets filled with alcohol. It's the first stage in the process.<br /><br />The process to remove the alcohol will collapse the walls and the alcogel will become powderized if there is nothing in the pockets.<br /><br />So they heat it up under intense pressure and blast in the liquid CO2, then the alcohol blasts out of the walls without causing them to collapse. This is because the definition between liquid and solid is blurred under such extreme conditions. <br /><br />The CO2 replaces the alcohol in the pocket, from what I can understand. It seems you need some kind of gas to provide partial pressure in order to keep the walls from collapsing. <br /><br />And they improved the process by making smaller, uniform pockets in order to provide clarity. I don't know how they do this, but it seems possible that they could create larger pockets of uniform sized, which would decrease the density of the magic carpet. <br /><br />If you could lay a Persian Tapestry on top of it, that would be most excellent! I would also need to keep a live cobra in a basket on the front of the rug, in lieu of decorative dice.<br /><br />
 
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rogerinnh

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One problem that you encounter whenever you use helium inside something like a baloon or the cells of aerogel is that, since the helium atoms are so small, they will migrate right through the walls of the enclosure. That's why, when you buy a rubber baloon with helium in it, by the next day the baloon is lying on the floor, somewhat deflated, instead of floating around the room. Mylar baloons are a bit better, because the mylar is not quite as porous as rubber, but they, too, will leak helium. I'd guess that the silica of the aerogels will have the same problem.<br /><br />As for having a vacuum inside the cells of the aerogel you then have the problem of air molcules migrating INTO the cells. You'd have to come up with one heck of a strong and impervious cell structure in order to maintain the vacuum.<br /><br />An article I read many decades ago posed the question, What would be the interesting feature of a one mile diameter sphere constructed from several-inch-thick walls of steel and containing a vacuum inside? The answer, it would float just like a helium baloon. So, maybe the answer isn't in creating a solid than can float in air, but rather creating a "structure" that can float in air. Make it big enough and you could have the desired high-altitude floating observatory.
 
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plutocrass

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Hi Roger: I'm not sure about that leaking idea with helium. This is because it is such a good insulator, and I wonder if this property would help us determine the probability of helium leaking out.<br /> <br />aerogel_insulator<br />
 
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TheShadow

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Your photo cannot be displayed, because it contains errors. <div class="Discussion_UserSignature"> <p> </p><p> </p><p> </p><p> </p><p><font size="1" color="#808080">Who knows what evil lurks in the hearts of men, the Shadow knows. </font></p> </div>
 
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dragon04

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I've not been able to find any data that suggests the duration of aerogel's insulative properties over time, although I would make the dangerous assumption that if it ignores all forms of heat transferrance, it ostensibly insulates as long as you wish it to.<br /><br />If it does ablate over time, I would further assume that by simply replacing lost material, one could keep the insulative properties perpetual.<br /><br />No mention of its resistance to gamma, ultraviolet or x-ray radiation was noted, however. Even if one can insulate to extreme temperature, other forms of shielding would be required for EM radiation at those wavelenghts.<br /><br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>
 
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newtonian

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RogerInNH - OK, so how about the lighter aluminum instead of steel? Or some light alloy?<br /><br />Or flubber?
 
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newtonian

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Dragon04 - Insulation is rarely 100%. However, there is alway air conditioning and heat exchangers which would not work hard if insulation is good.<br /><br />I am currently researching heat exchangers such as are used in the manufacture of glass.<br /><br />One of the problems with one of my models for surviving red giant phase is the weight buildup of 20,000 levels of existence.<br /><br />I had forgotten that not only will vacuum insulate - it will also make the structure lighter!<br /><br />So far we have glass (as in themos bottles, etc. - aka vacuum flasks), aerolgel, C-foam. Any other candidates for lighter than air structures? <br /><br />Having other unique properties, such as insultion, is a plus of course.
 
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newtonian

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Dragon04 - I see CFoam is more a thermal insulator than ligher than air. I'm interested in that too! The link you provided indicates it can resist 1650 C, or 1500C or 3500 C depending on the environment - that is excellent.
 
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newtonian

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plutocrass - Thank you for the links.<br /><br />From your link:<br /><br />The graphic below shows Thermal Conductivity vs. Pressure curves obtained on VICTOR for pure single-step silica aerogel and single-step silica aerogel with 9% (wt/wt) carbon black. At ambient pressure the addition of carbon lowers the thermal conductivity from 0.017 to 0.0135 W/mK. The minimum value for the carbon composite of ~0.0042 W/mK corresponds to ~R30/inch.<br /><br />Can someone translate what this would translate to in how much heat would be transferred from 500 C to 50C per day or hour or however this is usually measured.<br /><br />Can multiple paned glass with aerogel in between be useful for structures on Venus - or a lasting probe on Venus?
 
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josh1943

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alot of this is just fast numbers and by no means is it exact.<br /><br />aerogel seems to be about 1.5 gram per liter normal air is about 1.2g/L<br /><br />aerogel can float in CO2 that has a weight of 1.75g/L<br /><br />it seems that if the co2 inside the aerogel could be replaced by some other gas such as n2 or anything lighter it would likly float in normal air. im not sure if the gell must have co2 as the replacement gas. another problem is that most lighter gasses are combustable that might cause a few problems. <br /><br />possable problems with what i have just said would be<br /><br />1 i do not know exactly what makes up aerogel. havent really researched it much so the gas may not be mostly c02.<br /><br />2the gass if it is co2 might need to be or the reactions will not take place correctly. <br /><br />and interesting ider might be to take aerogel and make a sphere and remove part of the air inside. you dont need a total vacuum all you would need to do is remove part of the air. altho im not sure how strong aerogel is it should be possable.<br />
 
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