Ultra-Long Carbon Nanotubes Could Serve as Future Transmission Lines
November 10, 2009 by Lisa Zyga
Carbon nanotube fibers hundreds of meters long could be fabricated by being processed in a superacid. Image credit: Rice University.
(PhysOrg.com) -- When it comes to carbon nanotubes, the majority of research so far has focused on small-scale applications. But now, a team of researchers from Rice University has created carbon nanotubes that are hundreds of meters long, yet just 50 micrometers thick. The researchers say there is no limit to how long the nanotubes can be made, which opens the doors to large-scale applications including using nanotubes as electrical transmission lines and as the basis of structural materials.
The Rice project began in 2001, led by the late Nobel laureate Richard Smalley. After years of research investigating solution-processing techniques, the scientists found that a superacid called chlorosulphonic acid could spontaneously dissolve carbon nanotubes at concentrations 1,000 times greater than any other solvent. The method can produce well-aligned carbon nanotubes on a large scale, in which nanotubes can be shot out of a nozzle similar to a shower head. The researchers have published the details of the acid-processing technique in a recent issue of Nature Nanotechnology.
Since carbon nanotubes are highly conductive, the researchers are currently working on a project for making electrical transmission lines. "Metallic nanotubes conduct electricity better than copper, they're lighter, and they fail less often," said Rice chemical engineering professor Matteo Pasquali.
To make transmission lines, the researchers will need extremely large amounts of metallic nanotubes. Currently, there aren't any good methods that can make large batches of nanotubes that contain all metallic nanotubes without any semiconducting nanotubes. But some recent research in this area has been promising, and the researchers predict that a breakthrough could occur in the near future.
More information: True solutions of single-walled carbon nanotubes for assembly into macroscopic materials, Nature Nanotechnology, Published online: 1 November 2009; doi:10.1038/nnano.2009.302
via: Technology Review
© 2009 PhysOrg.com
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I say ditch the transmission lines idea and push for superconducting transmission lines. yeah it costs a bit to cool but if we are really moving toward a green and effecient power generating grid then when its 4oclock in Cali - solar power could help out Mississipi where it is 7pm
When they say it conducts better than copper, some reports I see show it conducting 1000X better so superconductors may not be better and for sure will be more machine intensive with long runs of LN2 lines which have to be insulated.
It would be really good for the space elevator if the nanotubes were conductive, for one thing it would be a very long cable in a magnetic field and as such could generate electricity directly. The thing is making 160,000 Km lengths that are about 100X stronger than steel. It is an exciting time for sure in the nanotube world.
How are you going to improve efficiency of something which get already around 90% 100 times ? Electric motor which makes 90 kW mechanic work with 1 kW of electric power ? Impossible . Tesla 2010 Roadster's electric motor has average efficiency of 92% and Large Utility Generators can have up to 98% efficiency
I'm not sure why the article focuses on transmission lines. In my mind, it's far more important that such conductors would revolutionize electric motors and make magnetic energy storage practical.
Sonhouse:
1000X copper's conductivity? Do you have a reference for that? I thought cnt would give something like 3-5X; which would still be revolutionary.
Yes increasing efficiency by 100X is impossible.
But, even at 90% efficiency, motor/generator losses are important. Efficiency is everything in electric cars. If the efficiency could be improved to say 99%, then the car will go 10% farther on a charge. On top of that one would get 10% more energy recovery from regenerative braking. Even more importantly, the motor size and weight could be reduced drastically which would also increase efficiency. Such motors might even be small enough to incorporate into the wheels without adding too much unsprung weight. All in all, it's conceivable that an electric car's range might be doubled compared to using copper.
On the one hand, there may not be that much usable power there, if the ionosphere doesn't recharge fast enough, or if the cable isn't moving with respect to the magnetic field
On the other hand, if there's lots of power available, could we control it, or would we have the world's largest lighting bolt?
A thousand HP motor takes a thousand hp of energy even if it is 100% efficient. Making motors out of nanotubes that conduct 1000X more than copper mean LIGHTER not less energy since existing motors are already way past 90% efficient already. With nanotubes or room temp superconductors which it looks like pure nanotubes approach already, motors would be a lot smaller in diameter and be a lot lighter for one thing because carbon is pound for pound :) lighter than copper. So you use less windings and so the motor may end up being say, only twice the diameter of the shaft or better and a lot lighter. Don't read less energy, it won't save much, a few percent only but they would for sure be a lot smaller for the same power.
Here is one link: A wiki piece, scroll down to 'electrical properties' http://en.wikiped...nanotube
"Structurally it doesn't matter what kind off nanotubes you use for a space elevator. Conductive ones would make it a generating station, but what would the results be of drawing power from the ionosphere and magnetic fields?"
It is expected that conductivity to some degree should be there to dissipate building of charge but not so conductive that it becomes a lightning rod.
Also, can we expect this method to produce sheets?
What year can I pull up a you-tube video of a thread holding up a three hundred pound man?