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Carbon Nanotube Films Stronger Than Kevlar (acs.org)
ckwu writes: Carbon nanotubes are exceptionally strong and stretchy. But so far, films made out of them have come nowhere close to having the mechanical strength of individual nanotubes. Researchers now report a simple fabrication method to make carbon nanotube films that are five times as strong as those made before—and stronger than films made from Kevlar or carbon fiber. The films had an average tensile strength of 9.6 gigapascals. By comparison, Kevlar fibers and commercially used carbon fibers are around 3.7 and 7 GPa, respectively. The films are also four times as pliable as conventional carbon fibers, able to elongate 8% on average.
Yah! We can start talking about space elevator again!
Elok
I'm not buying into obsolete technology. I'll wait and see what Graphene can do.
Hi.
Sheets and other shapes of carbon nanomolecules are known to have sharp edges that can tear up biological structures (cell membranes, for one). It is not clear if or how these carbon nanomolecules interact with biochemistry, or into what compounds the nanomolecules degrade (by nature or human effort) and what effect those breakdown products have on life chemistry.
Where do we stand with testing the biological safety of these potentially magnificent compounds BEFORE we poison ourselves again by mistake, as we did with organometallics (dioxins, PCBs), synthetic estrogens (plastics), heavy metal pollution (pthalates, mercury), etc., etc.)?
Signed,
A Biologist
PS Your best defense is a solid-block carbon water filter. You're welcome.
Is there anything they can't do?
Other than make it to commercial production that is.
Let's hear it for inanimate carbon tube!
the preceding comment is my own and in no way reflects the opinion of the Joint Chiefs of Staff
And the Oscar goes to.... Carbon nanotube films!
-- Make America hate again!
Because when my wife lets the end of the roll slip back into the box, she will have to mail it back to the company to get it unraveled, rather than just waiting until I get home so I can do it.
so this is great news:
... able to elongate 8% on average.
http://azcomp.us/media.html
This is an amazing published paper on the feasibility of a space elevator.
http://keithcu.com/wiki/images...
The big take-aways:
* Decreasing the x-sectional surface area by an exponential function as altitude decreases theoretically allows any material to be used, though the volumes required would be prohibitive for any but the strongest materials, and too steep an exponential function makes the geometries also not practically possible
* A yield strength of 46.5 GPa only requires a max-to-min cross-sectional area ratio ("taper ratio") of 10. A lower yield strength would require a larger taper ratio.
The material in this article has a yield strength of 9.6 GPa which is about 7.2% of the maximum strength of graphene and 20% of the way to 46.5 GPa, and I believe stronger than any bulk material previously manufactured. Reaching 46.5 GPa only requires 36% of the 130 GPa maximum strength of graphene, leaving lots of room for falling short on the actual average yield strength of manufactured product, and also including the required engineering safety factor in the design. And if we still fall short, we have some room to raise the taper ratio.
This TEDx video describes spinning carbon nanotubes to give them more than enough strength, which is basically what these people in this article have done! It also addressed the other concerns of the Gizmodo article. Since this manufacturing is firmly in the realm of engineering, now, I would expect to see a regular rate of increasing strengths in produced materials, as the processes improve. http://spaceref.com/space-elev...
TD;DR - Space elevator is entirely possible.