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Compressive strength
editWhat is a typical compressive strength (before non-elastic deformation) ?
- How does the strength vary with density ? - Rod57 (talk) 11:14, 25 February 2014 (UTC)
absorption
editThe last section says: "... able to mop up 900 times its weight in oil, at a rate of 68.8 grams (2.43 oz) per second." How does this make sense without saying how much gel you use? 79.220.249.100 (talk) 21:40, 19 July 2014 (UTC)
- It doesn't. The reference does not state it, but another reference does (http://phys.org/news/2013-03-ultra-light-aerogel.html) -- "the aerogel can absorb organics at a high speed: one gram of such aerogel can absorb 68.8 grams of organics per second", so ... it can absorb more than 60 times its weight in oil in a second. I am skeptical of the claim, TBH, but that is what it says. DeepNorth (talk) 01:19, 14 August 2015 (UTC)
Graphene foam and laser-induced graphene
editShould this article be merged with graphene foam? They both seem to be foams of graphene...Also, recently "laser-induced graphene" was announced, which seems to be a different kind of graphene foam. Should it get its own article? Lfstevens (talk) 17:38, 13 December 2014 (UTC)
Thermal properties?
editWhereas the thermal conductivity of air at STP is 0.026 W/(m.K), that of silica aerogel is around 0.005 W/(m.K). The low thermal conductivity of silica helps here. Presumably graphene's specific thermal conductivity is higher than for silica, but the strength of graphene may mean that less mass is needed. So what is the thermal conductivity of aerographene? Is it more or less than that of silica aerogel? Vaughan Pratt (talk) 06:27, 30 June 2020 (UTC)
Floating
editThe text currently says "It is approximately 7.5 times less dense than air. Note that the cited density does not include the weight of the air incorporated in the structure: it does not float in air." but that makes no sense - in a given volume, a mixture of A+B, where A is less dense than B, will always be less dense than B itself (A dilutes B). Looking at the source given, the comments contain speculation that it aerographene would normally be heavier than air (because carbon is heavier than air) unless some other item less dense than carbon were incorporated - e.g. a vacuum. In other words, if the carbon nanotubes are hollow and sealed (the internal space having zero density), this could lower the density of the carbon structure itself to be less than air, and hence the overall density would also (even including air) be less than that of air. From a layman's reading of carbon nanotube it seems likely they're made in a vacuum so that might be right.
However, that still doesn't explain why it doesn't rise in air: buoyancy means that despite gravity, a less dense item would tend to rise. In extremis, a football made with a shell of graphene but a vacuum inside should rise like a helium balloon. Is it just air turbulence/resistance that prevents this with aerographene? In an enclosed tank filled with N2/O2/Ar/CO2 etc. would it rise? It would be good to see knowledgeable people improve the explanations. Ozaru (talk) 05:39, 10 July 2023 (UTC)
- This looks like marketing gone mad. Scientist weighed a piece of material in the lab, and came up with the figure of .16 mg/cm cubed. marketing man saw figure and realised that that was lighter than air, ignoring fact that that figure was obtained on a normal set of scales at normal atmospheric pressure: ie sample weighed xgramms more than the air it displaced. Marketing went crazy with lighter than air, and no one actually looked at it and said "eh!" There is no reliable independent source for "lighter than air" and no explanation how it is lighter than air, but doesn't float - all the marketing images of this show it balancing on a flower of some sort. I am removing claim that this is lighter than air until a reliable, independent source is found for this exciting development which defies the laws of physics, as Exceptional claims require exceptional sources. Moons of Io (talk) 06:56, 10 July 2023 (UTC)
- The clue is in the name: aerographene consists of air and graphene. The claim that its density is 160 g/m3 is based on ignoring the air and only counting the graphene, which is completely misleading. 86.1.129.140 (talk) 19:03, 12 July 2023 (UTC)