Scrith?

[swestrup]

Every once in a while I go looking for works on the theoretical ultimate strengths of materials. This is difficult because material science is still more experimentation than theory and because phrases like 'ultimate strength' have technical meanings in material science which make other uses of the terms hard to impossible to google for.

Yesterday though, I found a doozy of a statement. In an article about strengths of materials, that reported a theoretical carbon substance that was 8 orders of magnitude stronger than carbon nanotubes!. Now, I *KNOW* that sounds incredible, and I've already emailed the guy and asked him for further information. Unfortunately, he replied that he got the information from a materials scientist who came across it in an obscure materials journal and noted down the numbers, but hasn't ever been able to find the article again.

Frankly, I suspect that the numbers were written down wrong and the substance isn't that much better than nanotubes. On the other hand, I can do enough of the math in my head to know it WOULD be better than nanotubes, and that alone should be worth reporting. For those who don't want to read the article, the secret is to make benzene-like rings with double-carbon bonds and then link them together like chainmail, but in a 3D mesh, not just 2D. The results means that the individual carbon bonds are not only stronger than those in carbon nanotubes, but that the inter-ring repulsion forces increase the stiffness and strength of the material. 8 orders of magnitude seems really high, but I can imaging the results being one or two higher than 'traditional' nanotubes, and that could prove useful indeed!

Still, if the numbers are accurate, it means that we could someday make something that might even be strong enough to build a ringworld or dyson sphere out of.

Comments

[auriam.livejournal.com]

Yet, how in the name of Blarg do you "interlink" carbon rings?.. for one, they might be too "thick" to link (not enough space in the middle).. and for another, I can't think of any conceivable chemical or physical process that could tangle benzene rings up in each other.. you'd have to assemble the mesh individually, and AFAIK, that's currently impossible.. but maybe someday, that might make quite a nice material.

[swestrup]

Well, yeah, that is the 64 gigadollar question, isn't it? Then again, new exotic assembly systems are invented all the time. _sps_ suggested it might just <hand-waving-mode>require an atomically sculped rigid block on monocrystaline diamond, into which carefully prepared feedstocks are inserted with great force. The idea is to build something like the closer on a zipper, but instead of linking hooks, it links carbon rings.</hand-waving-mod>

As for spacing, the article didn't say if these were 6-carbon rings, or if they were larger. For any given interlink mesh-pattern for the rings there would be a best size for the rings... It just occured to me that all this time I was assuming the rings were of uniform size. If they aren't, you can have a structure with extra very-large rings threaded through distant rings, and adding an extra level of structural integrity, I think.

Dang! I sure wish I knew enough molecular modelling to try and work this out myself!