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Carbon Nanotubes Harder Than Diamond
purduephotog writes "CDAC has announced the formation of a new form of hexagonal packed carbon similiar to diamond. Carbon nanotubes are compressed at 75 GPa and quenched. The new material is conclusively different via Raman Spectroscopy and both cracked and indented the diamond anvil used in its creation. CDAC is also known to have created via CVD the hardest diamond to date."
Does it go to 11?
The key difference between a Programmer and a Senior Programmer is that one of them is Mexican.
I've never done a spectroscopic analysis of ramen before - I usually just ate it
to spell out Chemical Vapor Deposition?
Overuse of acronyms degrade language, you know.
I cant see them becoming a girls best friend though
Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
What truth?
There is no dupe
Raman Spectroscopy
Dude, they're always tough until you boil them for 3 minutes. This is nothing new.
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This might be good for new machining tools?
I wonder what the optical properties are, and what the maximum size of these is?
And thus, the student overtakes the master.
Ut Tensio, Sic Vis
These are the types of advances we need to make the space elevator a reality. Either using nanotubes like this in a matrix, or more mind-boggingly, create wires of them.
Going up!
...or maybe not.
Raman, the technology and dietary staple of millions of college students makes carbon nanotubes harder than diamonds, (but still not harder than the $.25 cent Raman noodles themselves)
I realize you are kidding... here is what Raman really is... (give or take a few details ;p)
Spectroscopy: study of quantities of light at various wavelengths (or frequencies). Useful because matter interacts with light, so by measuring light passing through unknown matter, you figure out what its passing through.
Raman spectroscopy, is a branch where one looks at the wavelength shift occurring as light passes through a sample. A bit like doppler radar involves a shift of frequency (although it's not a shift due to the movement of molecues, but rather due to energy differences in orbitals as they move/distort).
The cool thing about Raman is that you just need a single wavelength of excitation, meaning you can build a spectrometer with a single laser diode. Then you filter off the laser line, and presto, the only light left will be the spectrum of interest.
Caveats: low intensity, frequency shift is very small, you still need a monochromator. Advantages: you get information that isn't available in standard IR & UV-vis spectra, the spectra are excitation freuency independant (not entirely true), by taking advantage of resonances it's possible to get REALLY intense spectra (resonance Raman and SERS).
Damn... Just when I get my +5 sword diamond bladed, they make a better diamond... or rather, carbon thingy
Only the purest of souls seek enlightenment. Everyone else just wants power.
The 2001 edition of the annual review of materials research, http://www.annualreviews.org/, has a nice review of the field of super hard materials. the authors point out that scratching a diamond is not, in intself, much evidence of anything; in the real world lots of soft scratch hard examples can be found. The authors of this article also point out that one of the few flaws of diamond is that it reacts with iron, so you can't diamond coat cutting tools; instead, you have to use much softer things like boron nitride or TiN. Nanotubes could have a major commercial future if they are harder then TiN, non reactive to iron, but softer then diamond.
full citation SYNTHESIS AND DESIGN OF SUPERHARD MATERIALS; J Haines, JM Léger, G Bocquillon
Annual Review of Materials Research, Vol. 31: 1-23
How can this possibly be modded as informative? Refering to Superman as evidence and then posting a link that only talks about diamond finds around the great lakes does not convince me of the posters veracity.
"Prefiero morir de pie que vivir siempre arrodillado!"
...and enough with the nanotube ring jokes. That's not what I'm talking about.
You see, nowadays, when you want to facet a gemstone into the shapes most people have come to expect in jewelry, one has to use abrasives to put the faces in the stone. Usually Silicon Carbide grit (9.5 hardness, usually for softer stones) or diamond (10 hardness, for harder stuff) on a spinning disk to grind into the stone. But this doesn't work for all gemstones, notably diamond. Trying to facet a diamond with diamond grit on a lap (the disk) will just cut gouges into your lap. They are not cheap.
So diamonds still have to be done the hard way: roughly shaping the stone by cleaving, then using 2 diamonds, one of poor quality, to rub the faces into the good diamond. If this stuff can be synthesized in different grits (particle sizes) for fairly cheap, then it can be used to facet diamonds with machinery rather than by hand. Much of a diamonds (and most other stones) value is actually from the labor put into faceting it. This is especially so for smaller stones. How cheap? Well, currently lapidaries are paying for synthetic diamond grit...
Any sufficiently advanced influence is indistinguishable from control.
What? They compress African peasants to make diamonds? The bastards!
For humans, J. Storrs-Hall (of sci.nanotech fame) proposed a space railway that could be built sooner and more cheaply than a space elevator. It's a linear induction motor laid along a 300km-long track, 100km above the ground, where the atmosphere is thin enough to take a few orbits to decay your orbit. You drive your spaceship up a ramp to one end, and the motor accelerates you along the railway at about 10G for about 90 seconds, putting you in a slightly elliptical orbit with an apogee on the other side of the Earth. When you hit apogee, you do a burn to get into a higher orbit.
Relatively little radiation because you cross the Van Allen belts much faster. You get to LEO without burning any of your own fuel, which is a big energy win. The railway is low enough that orbits still decay slowly, so there's no space junk to worry about at that altitude.
The structure is a collection of A-frames, built like a radio tower. Like the space elevator, only a tiny fraction of the height is subjected to significant weather. The structure is under compression, not tension, which widens the choice of materials. According to Storrs-Hall, existing synthetic diamond would be suitable.
WWJD for a Klondike Bar?
Keep in mind the compressive strength of a material is not the same as the strenth in tension. Not only that material like this has pretty much no elastic properties. ie, thats why you can easily shatter a diamond even though it's so strong
I'm expecting 2 more dupes of this article.
We've got a lot of problems right here on earth, folks- and I'd much rather you all put that brainpower to them.
There are lots of down to earth problems involving high loads and other stressors on cables. How do you make the SF bay area bridge safer against earthquakes? (or against sabotage?). How do we scale up the design of that suspension bridge to get multi-mile spans in the Florida keys or elsewhere? Is it possible to build such a bridge across the Gibraltar istmus?
Can we make a cable that's strong and waterproof enough to safety retrofit earthenware dams all around the mouth of the Mississippi region, and do it cheaply? Is there something that could help stabilize really tall free standing radio masts in central Russia, and is thermally less expansive than steel cable, or better yet electrically non-conductive? What design changes could have kept the WTC standing for at least a few additional hours, and what sort of materials would they require?
The thing is, if we get good answers to even some of these questions, they are likely in this case to point us towards towards space program uses as well. The problems you cite will apply to every use, not just a space elevator. Someone will be looking into using these fibers for zeppelin fabric to build really large gasbags and set up a major freight hauling system across the Mediterranian sea, and someone else will raise the issues of safety, location or insurance just like you have here.
Half the reason so many engineers want to build really big projects like space elevators is to show all the people who toss out bullet comments just like yours for every new project, space or earth, military or peaceful, that big things can still be done. You're doing it about space. Someone else will do it about any new idea that could alleviate poverty, or clean up the environment, or somehow improve someone's quality of life. So nothing will change. Thank goodness its all perfect now.
Who is John Cabal?