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Science Technology

First Pure Nanotube Fibers Made 97

Posted by timothy
from the now-make-a-parka-from-them dept.
TheSync writes "Researchers at Rice have announced the discovery of how to create continuous fibers from single-wall carbon nanotubes (SWNT). The breakthrough was based on the ability to dissolve a large amount of SWNTs in sulfuric acid, up to 10% SWNTs in solution. At high concentrations, the SWNTs form tightly packed liquid crystals that can be processed into pure fibers. The Space Elevator can't be far away now..."
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First Pure Nanotube Fibers Made

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  • Heh (Score:5, Funny)

    by smoondog (85133) on Tuesday December 09, 2003 @08:42PM (#7675335)
    The Space Elevator can't be far away now...

    Unfortunately, it needs to be on average 35,000 Km away to work.

    -Sean
    • Unfortunately, it needs to be on average 35,000 Km away to work.

      Something of a misconception. In actual fact an elevator cable has to be attached to the elevator car for the system to work correctly.

  • by kommakazi (610098) on Tuesday December 09, 2003 @08:45PM (#7675370)
    Well since I've just recently been told that the moon actually is moving away from the earth (see this [slashdot.org] thread) we really ought to leash the moon to the Earth to prevent this. I like the moon where it is. I suppose it could double as an elevator....
  • Actual strength? (Score:5, Insightful)

    by IANAL(BIAILS) (726712) on Tuesday December 09, 2003 @09:08PM (#7675576) Homepage Journal
    The Space Elevator can't be far away now..."

    I think that's more than a little bit premature. Sure, it seems like we can make them a little easier now in the lab... but as an earlier poster mentioned, we're going to need some pretty long lengths to streach into orbit. Nowhere have I heard how exactly the little fibres that are grown in the lab will be joined together *at the usual nanotube strength* over and over again to make these long lengths.

    Won't the 'joints' between individual fibres be a weak point in the system, and since we're joining thousands (if not millions) of little tube lengths in the lab, won't that have a rather large impact on the actual strength of the tube (vs if it was actually one long continuous length)?
    • Nah, they'll probably use some super glue and Camel Books ;-)
    • Re:Actual strength? (Score:5, Informative)

      by barawn (25691) on Tuesday December 09, 2003 @09:54PM (#7675909) Homepage
      I think that's more than a little bit premature. Sure, it seems like we can make them a little easier now in the lab... but as an earlier poster mentioned, we're going to need some pretty long lengths to streach into orbit. Nowhere have I heard how exactly the little fibres that are grown in the lab will be joined together *at the usual nanotube strength* over and over again to make these long lengths.


      Wow, that's surprising, considering that Slashdot has had plenty of explanations as to how you do it. :)

      Nanotube strength is more than you need. Much more. Pure carbon nanotube strands are strong enough to make a completely untapered elevator, all by themselves. (300 GPa tensile strength).

      For a space elevator, you're not building one continuous nanotube to orbit. That'd be insane. What you do is you build a composite fiber, just like you have fiberglass, or Kevlar fibers - you dope some composite with nanotubes to increase their strength.

      Now, you may say "so what? they still have to build them!". They have. Kilometer-long doped CNT fibers have already been produced. No, they're not as strong as you need. Yes, that's being worked on, and yes, it's an engineering problem, not a fundamental flaw. Once you've got kilometer-long length, it's not much more of a step to be thousands of km long (believe it or not). At *absolute worst* you could build a system to join segments of the elevator together. There have already been presentations and ideas on this theory, and it's perfectly sound.

      There is nothing fundamental preventing the space elevator from being built. It's just a matter of time, and this is one (very large) step along the way. But it's important to remember that it's just engineering problems - big, but tractable.
      • Re:Actual strength? (Score:4, Informative)

        by WolfWithoutAClause (162946) on Tuesday December 09, 2003 @10:48PM (#7676357) Homepage
        Nanotube strength is more than you need. Much more. Pure carbon nanotube strands are strong enough to make a completely untapered elevator, all by themselves. (300 GPa tensile strength).

        Nope. That's a theoretical maximum strength; but the theory is probably wrong. Current experimental strength of short fibers is about 120 GPa, and that's only just what you'd need to do this (about 60 GPa is needed, plus a safety factor of say 2).

        What you do is you build a composite fiber, just like you have fiberglass, or Kevlar fibers - you dope some composite with nanotubes to increase their strength.

        Not quite. If you dope a plastic with nanotubes you'd end up with a material whose strength and weight were dominated by the polymer. That would be wayyyy too heavy and weak. The idea is that you have to use an absolute bare minimum of glue to stick the nanotubes fibers together. Trouble is no-one knows how to do this right now with adequate strength; nanotubes are slippery and particularly hard to glue; and as noted, we don't have a great deal of strength to play with- we need a safety factor for practical reasons.

        Kilometer-long doped CNT fibers have already been produced. No, they're not as strong as you need. Yes, that's being worked on, and yes, it's an engineering problem, not a fundamental flaw.

        Those fibers aren't even as strong as Kevlar. So, no, it's still a research problem. The engineering begins when we have a cable even a few feet long; of the right strength/weight ratio. Until then- engineers and financiers must hang fire.

        • Nanotubes are sticky (Score:5, Informative)

          by jgardn (539054) <jgardn@alumni.washington.edu> on Wednesday December 10, 2003 @02:55AM (#7677862) Homepage Journal
          The nanotubes are sticky and bond well with themselves. Read the article.

          The process they describe here is a way of storing the nanotubes for transport, so that they can be assembled later.

          Creating nanotubes is dead-on easy. I've actually seen a nanotube creation lab in the Physics department in the University of Washington. I think it is on the third or fourth floor. Go visit there if you get a chance.

          After the nanotubes are created, they have to be seperated. They come in a hairball and need to be seperated individually. Next they are stored in a liquid type suspension. When they want to form their nanotube rope, they need a way to squeeze them back together again and extract all of the liquid. The liquid described in the article is beneficial because it helps organize the nanotubes so that they can be easily extracted. You will end up with 100% pure nanotube rope or cable at the end of the process.

          Now you are probably speculating that it can't be that simple. It is. Sheep hair (wool), cotton fiber, polyester, and such all work in the same way.
          • The nanotubes are sticky and bond well with themselves. Read the article.

            While this is true, for a sufficiently strong composite material we will also need the nanotubes to bond well to the substrate polymer. Although CNTs are attracted to each other, they tend to have featureless, smooth surfaces that don't bond well with other materials. The likely solution to this problem is a process called 'functionalization' which adds features -- small appendages -- to the CNTs so that there is more traction wi

          • The nanotubes are sticky and bond well with themselves.

            Absolutely. But the fur-balls haven't previously achieved anything like their full strength potential.

            Creating nanotubes is dead-on easy.

            Yup. But the problem is creating 120GPa nanotube cable- nobody has ever done that so far.

            You will end up with 100% pure nanotube rope or cable at the end of the process.

            True, but that doesn't make it strong. Furballs have not massive strength. The microstructure of the 100% rope is completely critical. The nano

        • it's still a research problem. The engineering begins when we have a cable even a few feet long

          I've been reading this thread with great interest, and I agree with points made by both sides. However, IAAE (I Am An Engineer), and I wish to point out that there's a fuzzy line between Physics and Engineering. When Roebling [greatbuildings.com] invented wire rope, was he a Physicist or an Engineer? At what point did his work transition from Research to Engineering? If you asked him, he'd say he was an Engineer and all his work wa

          • The headline (you did RTFS, right?) says it all: "Rice engineers make first pure nanotube fibers"

            Yeah, I did, and I've read most of the NACA research papers on space elevators too. Please tell me where, when you RTFS, where it says that the material they made had a strength/weight ratio sufficient to make a Space Elevator. Until that has been demonstrated it's material science; which is really very much more basics physics research than engineering.

            • Ah, but the Rice engineers weren't working on space elevators, they were working on nanotube fibers. To the space elevator engineers perhaps this is still physics research, but to the nanotube cable makers (with applications beyond space elevators) this is engineering.

              I said it was a fuzzy line...

              • It's not engineering, it's research. It so happens that the researchers here are engineers and chemists, but it's still research.
                • ALL good engineering is research, by that definition, because they're doing something that hasn't been done before. When engineers design a new fiber-optic network that's faster than any other network in the world, that'd be research? When engineers design *anything* that's better than what's been done before, that's research?

                  The difference between "evolutionary" progress in science and "revolutionary" progress in science are pretty well understood. You can speed up "evolutionary" progress by throwing mone
        • Nope. That's a theoretical maximum strength; but the theory is probably wrong. Current experimental strength of short fibers is about 120 GPa, and that's only just what you'd need to do this (about 60 GPa is needed, plus a safety factor of say 2).

          Early experimental strength is 1/3 to 1/2 of what theory predicts, and the theory is probably wrong? The theory is for pure nanotube fibers, based on carbon-carbon bond strength. Considering early experiments are so close to the theory, it's probably correct.

          And
    • Re:Actual strength? (Score:3, Interesting)

      by nanobug (446693)
      "Won't the 'joints' between individual fibres be a weak point in the system...".

      Not necessarily, it depends on how you join them. You need to ensure that the joints are totally seamless so there are no weak points.

      See nanodiamond.info [nanodiamond.info] for an example of how to join them which increases the overall strength (or strength to weight ratio) rather than weakens them. The trick involved actually lets you use them for buildings and bridges under compression as well as cables under tension. Warning: shameless plug
    • I'm not thinking of the strength, I trust in the durability and strength. I'm more concerned about all that "flak" in form of broken dead satellites out there.
      It's like trying to avoid a gunshot, only this time it's rotating, and in size of a fist...

      How come noone talked about that yet?
  • Awesome, we've made one more step towards a Space Elevator! Unfortunately, we've still got about 100,000 more to go... but hey, progress is progress.
  • by WolfWithoutAClause (162946) on Tuesday December 09, 2003 @09:11PM (#7675602) Homepage
    Just because something is made of nanotubes doesn't make it strong, it depends on how they are laid out. The press release sounds good, but until they publish the measured strength/weight ratio of a few feet of their manufactured cable. (The data might be in the paper, but I haven't bought it. Anyone?)
  • So why concentrated sulfuric acid I wonder. Would a concentrated solution of a different strong acid work as well? If it's just acidity to get increased solubility, why not a superacid like HF-SbF5? Any organic chemistists out there?
    • They said it was basically the same process used to make Kevlar. If you were a chemist that knew how to make Kevlar it seems fairly logical to try and apply that technique to carbon nanotubes.
  • Why not use the nanotubes for high temperature super conductors?

    A.K.A. Fast @ss processors with minimal heat.

    Or for more scientific and broader uses, much much much much better inductors (another boost to computers), solenoids (yea yea, same thing), electromagnets (umm, sort of different) for magnetic levitation used in maglev trains, etc...

    Good times await.
    • Are the nanotubes, then, superconductive by nature? fun stuff, if they are.
    • Some of this research has already been done. I know isolating metal ions and atoms inside C60 and fusing the resulting C60 into a tube (or bonding them close to each other) does not display superconductive properties.

      I would suspect fullerines have similar conductance to graphite

      Plus, a previous slashdot story indicated that fullerines undergo total disentegration under some conditions [slashdot.org]

      Nanotubes as transistors [slashdot.org]

      NAnotubes extend battery life [slashdot.org]
    • Nanotubes' 20 K critical temperature (T_c) does not come close to a high temperature superconductor.

      High T_c is usually defined as above the boiling point of liquid nitrogen, a good, cheap, plentiful, environmentally-friendly coolant, which is 77 K. This implies that liquid nitrogen can be used to keep the material superconducting, a property which drops costs and engineering challenges dramatically. Nanotubes' more popular and practical properties are its tensile strength (i.e. space elevator), and it
  • This would be a dupe [slashdot.org], if it weren't for the two different (nearby) universities.
  • ... is Duct Tape. That's where the money of the future is and you heard it here first on /.

    And that will allow the Canadian government to keep it's existing military equipment flying and floating well into the 22nd century.

  • ... but what about molecular monofilament fibers?

    or bulletproof clothing? Seems like a fabric made of this stuff could make a mighty fine lightweight aircraft skin, or a parachute that folds up into a money belt, or....???
    • by A55M0NKEY (554964) on Tuesday December 09, 2003 @10:59PM (#7676454) Homepage Journal

      Year: 2009

      Place: Wal*Mart

      Blotter: A bearded armed thug wearing a stylish black blouse was killed while trying to hi-jack the daily armored car. The purp was struck with a .357 caliber round which entered his chest and left his back.

      Witnesses report that upon falling to the ground the woman's blouse was missing. Apparently, the robber thought the high tensile strength of Jaquline Smith's new line of clothes would protect him from any bullets. What he didn't consider was that the nylon stitches that held it together would tear and that the round would pull the entire blouse off his back, taking it in through the bullet hole and out a grapefruit sized hole in his back eventually ending up imbedded in the door of an Oldsmobile in the parking lot.

      Police finding the round still wrapped in the pretty - if bloodsoaked, blouse, impounded it as evidence.

  • Reading about this really seems to me to be an important break-thru, it started me to think if we are on the border of moving away from a metal/plastic based manufacturing economy toward a carbon based one. For many many everyday uses replacing metal/ plastic. beverage containers can openers and so on. The question i suppose is, does this needs to be recycled ?
  • by marcus (1916) on Wednesday December 10, 2003 @01:11AM (#7677294) Journal
    I don't know how many are interested and yet don't know about these pages but here is some good stuff for dreamers to read...

    Institute for Advanced Concepts [usra.edu]

    and here is a design study for a space elevator:

    Space Elevator Phase 1 [usra.edu]
    Space Elevator Phase 2 [usra.edu]

    • I'm glad to see so many space elevator stories on Slashdot lately. I think the actual feasibility of this idea is important to impress upon people. SE research has a considerable amount of NASA funding, the fruits of which where the Phase I & II NIAC reports mentioned in the parent post.

      LiftWatch.org [liftwatch.org] is a news/portal site dedicated to following this and other developments in space elevators and related technologies. Besides the main front page news, here are some handy links for the SE afficianado

  • That is pretty much it, having a one meter nanotube or better yet a woven bunch of nanotubes and you need the length trimmed to i/2 meter? Lazers, plasma torch, sharp pair of sissors, acid?Actually I only skimmed read the article so if the answer is there, take it easy.
  • One of the dangers of long nanotubes is that they are extremely strong compared to their thickness. This makes them ideal for cutting purposes. I guess one of the dangers of long nanotubes might be that people can be cut. Imagine (accidently) cutting someones throat with a fiber thinner than a hair, which is almost invible to the eye.
  • the real deal (Score:5, Interesting)

    by Goldsmith (561202) on Wednesday December 10, 2003 @01:18PM (#7681206)
    This is actually what we've been looking for.

    A way to self-assemble nanotubes into ropes which can be used macroscopically. Whether or not it's strong enough to use in a space elevator remains to be seen, but we can actually talk about trying that now!

    The nanotubes which were used here are electronics grade tubes, that means that most likely they were single or double walled (single walled being the strongest possible), and had a very low defect density. This is obviously important to the mechanical strength.

    I work in a nanotechnology lab, and part of my job is to grow nanotubes. They naturally come in ropes which are around 1 to 10 nanometers in diameter and a few microns to a centimeter in length. The tubes are held together in solution due to van der Waals forces (basically friction) which are absurdly high for nanotubes. We've been separating tubes from eachother in solution from years, but efforts to re-align them have focused on the air-water interface. All they have done is found a solution which will solvate more tubes, to the point that the tubes have no room to run "against the grain" and so become aligned. This is done all the time with polymers. In retrospect it seems obvious and easy (it wasn't).

    I remember a week ago Smalley was being bashed here about his conflicting views with Drexler on the future of nanotechnology and molecular assemblers (versus self-assembly). If you'll notice, Smalley is on this paper. This is why he has a Nobel prize, and why he disagrees with Drexler, self-assembled nanotechnology is already here, and it's only going to get better.
  • The space elevator wont happen as it is hard to secure from people who what to pressure or embarrass the people that built it.

    Consider how easily a cessna or some other flying craft filled with delusional muslims, white power supremacists, 7th day adventists or some other crackpot-du-jour, can be flown into it and cause major embarrassment to the spineless politicians that declared it perfectly safe.

    On the other hand the politicians might be able to blame it on the autoprompter, in which case it's all due
    • The only place to put the space elevator is at the equator. The best place to put it is over the ocean. The area for quite some distance around the space elevator can be a no-fly zone (at least, barring those aircraft whose destination is the elevator) and anything which violates its airspace can be warned and then blown out of the sky.

      The only thing with a real chance to damage the space elevator will hence be a stealth aircraft or a cruise missile.

  • Did anyone else notice the date in the corner of the image? It's Febuary 2002. I guess it takes a long time for this kind of reasearch to go from the lab to the media.

    The other way of doing it is basically the cold fusion method (call a press conference immediately). Pros and cons. :)
  • Everybody's getting excited about the tensile strength of buckytubes: 600x that of steel, by mass. Space elevators, drug delivery, yadda yadda yadda. What about shigawire [technovelgy.com], an essential technology proposed by Frank Herbert in his epochal _Dune_ novels? Similar to Larry Niven's monomolecular filaments, these prefigures of long buckytube strands are used for vast data storage, and for slicing through any material, even "plasteel", like a knife through butter on their monomolecular "edge". Where's the 100m buck

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