Graphene Aerogel Takes World's Lightest Material Crown

cylonlover writes "Not even a year after it claimed the title of the world's lightest material, aerographite has been knocked off its crown by a new aerogel made from graphene. Created by a research team from China's Zhejiang University in the Department of Polymer Science and Engineering lab headed by Professor Gao Chao, the ultra-light aerogel has a density of just 0.16 mg/cm3, which is lower than that of helium and just twice that of hydrogen."

Density calculation?

[fuzzyfuzzyfungus]

I'm assuming that the 'density' figure given is a 'weight of graphene in a given volume' one, rather than one that includes the gasses occupying the pores/cells of the material?

It would be quite shocking indeed if something largely saturated in nitrogen and oxygen were less dense than helium...

Density

[Phanatic1a]

" the ultra-light aerogel has a density of just 0.16 mg/cm3, which is lower than that of helium and just twice that of hydrogen."

Picture in the article shows a chunk of the stuff being supported by a blade of grass. If the density's lower than that of helium, why isn't it floating away instead of sitting there like a thing that's denser than the atmosphere around it?

I don't quite get it

[wonkey_monkey]

What makes this so different from, say, creating a hollow cube with some very fine polymer for the vertices, with the faces and interior remaining empty? If something's full of holes, is its density still measurable in a meaningful way? A battleship is less dense than water in this sense, but the material it's made from isn't.

Re:Aerogel vs. M&Ms

[fuzzyfuzzyfungus]

Given that all aerogels are extremely tenuous foams, I would strongly suspect that all of them are pretty good insulators(even if one were made of a very good conductor of heat, like silver, there is just so little solid and so much trapped-gas-pocket that good insulation is to be suspected). However, if the aerogel is made of a material that burns in oxygen, the same combination of a tiny amount of solid with plenty of gas probably results in a very swift burn once you get it started.

I'd suspect that a carbon aerogel would be only slightly worse as an insulator than a silica one; but I wouldn't try taking a blowtorch to it(except to see what happens...)

Re:I'd believe it if you added the word "solid"

[Lorens]

Well, it should be possible to make it less squishy (carbon makes diamonds, after all). Cover it with some other graphene variant in low pressure, and one just might manage to make a lighter-than-air solid. I'd avoid the torch, though.