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..."

Comments

Re:Actual strength?

[barawn]

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.

Technical data on Space Elevator

[marcus]

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

Nanotubes are sticky

[jgardn]

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.