Slashdot Mirror


First Pure Nanotube Fibers Made

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..."

8 of 97 comments (clear)

  1. Heh by smoondog · · Score: 4, Funny

    The Space Elevator can't be far away now...

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

    -Sean

  2. How about a "moon leash"?... by kommakazi · · Score: 4, Funny

    Well since I've just recently been told that the moon actually is moving away from the earth (see this 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....

  3. Actual strength? by IANAL(BIAILS) · · Score: 4, Insightful

    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)?

    1. Re:Actual strength? by barawn · · Score: 4, Informative

      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.

  4. Re:so a space elevator isn't next... by A55M0NKEY · · Score: 4, Funny

    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.

    --

    Eat at Joe's.

  5. Technical data on Space Elevator by marcus · · Score: 4, Informative

    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

    and here is a design study for a space elevator:

    Space Elevator Phase 1
    Space Elevator Phase 2

    --
    Good judgement comes from experience, and experience comes from bad judgement.
    - W. Wriston, former Citibank CEO
  6. Nanotubes are sticky by jgardn · · Score: 4, Informative

    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 radical sect of Islam would either see you dead or "reverted" to Islam.
  7. the real deal by Goldsmith · · Score: 4, Interesting

    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.