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World Record: Four-Centimeter-Long Carbon Nanotube
colonist writes "University of California scientists at Los Alamos National Laboratory and chemists from Duke University have recently grown a four-centimeter-long, single-wall carbon nanotube (SWNT): a new world record. Previous SWNTs were a few millimeters long. Yuntian Zhu and his colleagues used a process called 'catalytic chemical vapor deposition' from ethanol (alcohol) vapor. From their abstract: 'Our results suggest the possibility of growing SWNTs continuously without any apparent length limitation.' Zhu: 'although this discovery is really only a beginning, the continued development of longer length carbon nanotubes could result in nearly endless applications. Actually, the potential uses for long carbon nanotubes are probably limited only by our imagination.'"
Space elevator, here we come!
they'd have 13 inches already, without all that expensive equiptment!
Wonderous stuff, if only to know that the most brilliant uses for this haven't been thought of yet.
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I was going to post something about "could we spin these in space and spool them through the atmosphere for a space elevator, then I saw the growth rate:
11 micrometres a second!
Unless I've flubbed my math, that's over 4 days to grow the short length - not saying that's not a damned good thing, as we _need_ material if we're to get Out cheaply, but production speed is almost as important as strand length.
Negativity aside (sorry, it's my nature); good work guys, keep on growing/going.
the potential uses for long carbon nanotubes are probably limited only by our imagination
....
:)
If it can't be used as a medium for pornography, it's not a proper invention!
the first animated gifs I ever saw was porn
the first avi I ever saw was porn
the first mpeg movie I ever saw was porn
the first DivX movie I saw was porn
unzips flies waiting for the nanotube in the post
I hope it says more about porn than it says about me
There are places where the networks are not touching,and there are places where they are-Boeing's Lori Gunter
Out cheaply, but production speed is almost as important as strand length.
..
yeah. used to take them whole weeks to make a car, once upon a time. something about 'industrialization' changed all that, though
; -- the corruption of government starts with its secrets. a truly free people keep no secrets. --
Geostationary orbital radius 38,785 km.
Growth rate 11x10^-6 m/s
elapsed time = 38,785,000 / 11x10^-6 = 3.526x10^12 s ~= 112,113 Years.
It going to be a long time till we have a swnt all the way at this rate.
PS yes I know that we don't have to have a single tube all the way there. We are going to have to ramp up the growth rate considerably though.
-- The morphemes of your disquisition are ascertainable, but they have eschewed an ambit of transpicuous exposition.
Answering my own question here, but it appears the article is correct. Metallic in this case is refering to the crystaline structure that the carbon forms. This gives the nanotube certain properties that are 'metallic' - High tensile strength, ductile, flexible, etc.
In Science News, June 14, 2003, Baughman's team of Univ of Texas made a single-walled carbon nanotube fiber composite that's the width of a human hair, and 100 to 200 meters long. The nanotubes are spun with polyvinyl alcohol, and are 4 times tougher than spider silk (the previous record-holder) as well as stronger (can hold more weight).
100-200 meters, that's a length you can do useful stuff. One weird thing is, they weave it in with ordinary cloth to make supercapacitors in clothing (for built-in antenna,s tiny batteries, et cetera). The field is called 'electronic textiles'!
A.
Hydrocoptic marselvanes here we come! What's next, prefamulated amulite?
Attention deficit disorder is a complicated issue, spanning several major... HEY LET'S GO RIDE BIKES!
Heh heh heh heh....
"Times have not become more violent. They have just become more televised."
-Marilyn Manson
I have to disagree. The electrical, thermal and strength properties of this material make its applications limitless.
I'll bet it becomes as important a material as doped silicon.
You can mod me down, but you cannot call me a coward.
One thing that concerns me with nanotechnology is that the creation of all kinds of weird molecules that nature has no time to adapt to may leave us with some remarkably odd (and possibly pervasive) toxicity problems.
What if CNT's get widely adopted into clothing, tupperware, etc, and then 30 years down the line we find that the little fibers that inevitably break off when you handle such material get lodged in the lungs and induce cancer (like asbestos and other kinds of fibers do)?
I've heard of all kinds of interesting possible applications of CNT's (super strong fabrics and cables, conductive fabrics, electro-kinetic fabrics (generates electricity for your ipod just from you moving around)). But is anyone looking seriously into governing and exploring toxicity issues with these new synthetic molecules and materials?
bif
wag more
bark less
Can we build it yet? huh? huh? Can we can we can we?
Can you tell I'm really excited by this?
Time to go enter a ribbon climbing robot contest!
-- I'm not a pessimist, I'm a realist. It's not my fault that life sucks so much. --
Because, as discussed above, this is not a solid tube. Your own quote says:
Baughman's team spins fibers made of carbon nanotubes and.
The greater the length of nanotube, the less epoxy needed to hold the woven elevator ribbon together. Since the epoxy weighs a lot more than the nanotube, this is a good thing and reduces load on the ribbon from its own weight
- Sig
Yuntian Zhu and his colleagues used a process called 'catalytic chemical vapor deposition' from ethanol (alcohol) vapor.
So in other words, they're having a few beers in the lab one night, and one of them spills it into the testing appratus.
Scientist #1:"Dude? What have you done?"
Scientist #2: (Frenzied running in circles) "Oh my God!! Oh my God!! Oh my God!! Oh my God!! Oh my God!! Oh my God!! Oh my God!!"
Scientist #3: "Uhhh, guys, something's happening..."
I seem to recall that, some two years ago, an article (slashdot or not, I wasn't able to find it) quoted an engineer who was looking at the effects of individual nanotube lengths on the tensile strength of a nanotube composite.
The quote I'm remembering was that, if they could reliably build single-walled nanotubes at least an inch long and use that composite design, the tensile strength would be enough to build the elevator.
4 cm / 2.54 = orbit?
Pavlov's Dog ate the bell, and now he's barking at Schroedinger's cat all the time... -Me
Okay, so we can make them. Say that nanotubes become commonplace. Say that somebody discoveres they cause brain disease in fish and lung cancer.
How would we clean up the mess? Do they combust? Will they eventually oxidize to CO2? How do you destroy a carbon nanotube? Or will they just go through the food cycle causing damage for millenia?
Following up to your own reply, a carbon nanotube has properties which are either metallic or semiconductive, depending on the chirality of the tube. Each tube is essentially a rolled-up piece of graphene (single layer of graphite), which has a hexagonal crystal lattice. If you imagine taking a sheet of that hexagonal structure and rolling it into a tube, there will clearly be a line along which the two opposite edges join, kinda like the line that runs up the back of the stocking.. :-) If you roll the sheet up perpendicularly to the axis of the nanotube, you get (basically) a bunch of rings of hexagons. If there's a bit of twist, you get spirals of hexagons. These two structures would have different chirality - the number of hexagons around the circumference of the tube matters, too.
To make a long story short (too late), by controlling the amount of twist in the nanotube you can determine whether that particular nanotube will be a metal or a semiconductor, and (I believe) can control the bandgap as well. Now, if we can just learn to control the chirality easily and cheaply...
Anyone with more experience in carbon nanotubes, please chime in. I'm only a few weeks into a graduate class in nanotubes, and may have missed a subtlety or two.
Ce n'est pas un vrai mouvement de robot!