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Buckyballs Polymerized Into Buckywires
KentuckyFC writes "Scientists have found a way to join buckyballs together so that they form buckywires. The wires form when buckyballs are dissolved in an aromatic hydrocarbon called 1,2,4-trimethylbenzene. The solvent links the balls together to make wires shaped like a string of pearls, which then precipitate out. This relatively simple procedure opens the door to industrial-scale manufacture. Buckywires ought to be efficient light harvesters because of their great surface area and the way they can conduct photon-liberated electrons. But perhaps the area of greatest interest is drug delivery. The researchers suggest that buckywires ought to be safer than carbon nanotubes because the production method is entirely metal-free. This contrasts with the production of nanotubes, which are formed in a reaction catalyzed by metallic nanoparticles."
Aromatic hydrocarbon, my ass. Those damn kids have been into my Scotch again.
"That's not jewlery she's talkin bout. It really don't cost that much."
Probably depends on the tensile properties. From what I gather, nanotubes and buckywires could have different characteristics there, since they don't really share the same structure. Without knowing any details, I wonder if the difference would make them more elastic... That would have a mix of effects on ballistics, I suppose.
From: (PDF warning) http://www.davis-floyd.com/USERIMAGES/File/Bucky%20balls%20Fullereness%20and%20the%20future.pdf
being the strong, macroscopic person that you are, you get a hold of this, and you stretch it and stretch it and stretch it, and before it breaks you can stretch it to 20 or 30 percent longer than it was to begin with. The tensile strength is very high.
The indication is that when it finally does break, it doesn't break brittly but pulls out a little chain of carbon atoms the break is a plastic failure, not a brittle failure. One thing that we do know from actual tubes that have been made and distorted, is that you can take this tube and you can bend it. You can bend it so much that it buckles like a soda straw and then when you let go, it just snaps right back it does not break.
So, any tube, like the soda straw, as you begin to bend it, the material of the soda straw at the top of the bend has to stretch and underneath, on the inside of the bend, so that the bending stiffness of it depends on just how hard it is to stretch that material and this is the hardest material in the universe to stretch, so the stiffness of this little nanotube will be higher than any other object you can build out of the tinker toy set, forever and anon.
Benzene boiling point 80 degrees C at STP
Iron boiling point 2860 degrees C at STP
It would seem much easier to vacuum distill benzene out of the buckywire product than iron, because of the difference in boiling points. If 80 degrees C is still too hot for buckywires, then vacuum distillation will work at a lower temperature. So the technology to separate the good from the bad is much easier with the benzene process so it'll probably be done better.
Benzene traps are simple cheap and easy to use (well, relatively anyway), whereas nanoparticle "traps" are basically expensive filters that may or may not work and or be maintained, so just blowing filtered N2 thru the product and cleaning the contaminated N2 stream would probably work pretty well. Recycling benzene is simple, but I think all you can do with nanoparticles is bury them or maybe dissolve the whole filter in a super strong acid. So, trapping / recycling bad stuff using the benzene process is much simpler and easier to do, so it'll probably be done better.
Finally monitoring benzene levels (to verify your containment is working, detect when it fails) is pretty trivial, but monitoring nanoparticle contamination levels is pretty much a mystery or at least not standardized. And when you have a spill, the fire department and EPA know exactly what to do with spilled benzene but would be mystified by nanoparticles. So, when the bad stuff inevitably gets released into the environment, "we" know exactly how to handle the benzene process, but not the nanoparticle process.
Making eco-judgements about a chemistry topic, when all you can base it on is sloganeering like benzene is bad, is not going to result in useful judgments.
Benzene and many derivatives, are just as toxic (if not more so) than a lot of metals.
That's about as vague of a "statement" as can be made, but if you really believe it is true, we can set up a little wager and I'll wash my hands in a bucket of pure benzene if you'll agree to wash your hands or any other appendage with a mercury organometallic and we'll see who ends up healthier. Or if you don't like mercury organometallics, I'll let you chose any soluble lead compound. Or, how about a tasty ionic Uranium compound?
"Science flies us to the moon. Religion flies us into buildings." - Victor Stenger
Maybe because "buckyballs" is a "pop sci" term and you look funny using it. They are more often called fullerenes.
Example of use: http://en.wikipedia.org/wiki/Rhondite
Fullerenes have little current practical use (they are rather expensive) but a lot of interesting potential uses, because you can trap things inside them: a lot of exotic materials can be made with them. There is even a purely organic compund (a mixed crystal of fullerene and a small organic compound) which exhibits ferromagnetic properties.
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Apparently, buckyballs can be toxic: http://nanotechweb.org/cws/article/tech/20355
According to the image in the article, the individual buckyballs are linked by SP3 carbons (@-CH2-Phi-CH2-@) from the solvent. This means, there is no pi electron system, and therefore no electrical connectivity, between the buckyball entities. The physical characteristics of this material are vastly different from nanotubes, which are a single extended pi system. I highly doubt that this stuff can be a replacement for any application which requires long-distance electron flow, such as light harvesting, microelectronics, etc.
The bonding is controlled by both the thermodynamics of the multi-bonded fullerenes, as well as the kinetics involved in multiple crosslinkings, forcing fullerenes next to each other. If you read the actual article, the evidence suggests that the fullerenes are slowly polymerizing, and crosslinking - an NMR spectrum after several months implies that it actually is one, big, horrible mess (or not fullerenes anymore, depending on how skeptical you are of this).
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