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New Microscope Shows Nano-Fibre Formation
Freshly Exhumed writes "An article, with mpeg and avi movies, in Chemical and Engineering News describes how researchers from Danish high-tech firm Haldor Topsoe and the Danish Technical University have made a groundbreaking discovery in the field of nano-research. With the help of a specially designed microscope, researchers can now directly observe carbon nano-fibre formation. This is a prelude to actually controlling the growth of the fibres, which up until now has been very problematic. The new microscope's impact is expected to have tremendous significance for the development of future electronic components, energy extraction, and environmental technology."
I've found growing carbon nanofibers by decomposing hydrocarbon gases on solid catalysts very intriguing. The main problem that they have faced is that it has been very difficult to probe the fundamental steps that drive the growth, in part because of the high temperature and pressure required to sustain the reaction.
It looks like they have somehow found a way around this problem.
[bigbrother-mode] Forget RFID, what if in say 50 years, every baby gets a little nano-computer implanted that is fed by bio-electricity ? This is some scary shit even though it could have some practical uses. A biomonitor that will give you a signal (on your mobile with wireless technology), location tracing (for if you get lost as a child) [/bigbrother-mode] Still cool tech though :)
This is the sig that says NI (again)
Are the costs really hideous? Given the potential it could be a viable business given a longer range business plan.
This type of scanning electron microscopy is fairly new (~10-15 yrs), but it's not a Danish invention... a lot of places make and sell these microscopes. Traditional SEM requires sputter coating your subject with gold or osmium, something really electron dense to get a good conduction and bounceback. You "shine" electrons at your subject, they bounce back, you detect them. All well and good, but the coating process meant some artifacts were introduced, and you killed your subject. The detection had be done under high vacuum, and it had to be dry, so water and air wouldn't scatter the electrons and ruin your imaging.
o scopes/esem/): "When the electron beam (primary electrons) ejects secondary electrons from the surface of the sample, the secondary electrons collide with water molecules, which in turn function as a cascade amplifier, delivering the secondary electron signal to the positively biased gaseous secondary electron detector (GSED). Because they've lost electrons in this exchange, the water molecules are positively ionized, and thus they are forced/attracted toward the specimen (which may be nonconductive and uncoated), serving to neutralize the negative charge produced by the primary electron beam."
Environmental SEM (or "variable pressure" SEM) puts the subject in a chamber that's isolated from the electron emitter/detector by a thin membrane. The separation allows for different pressures and atmospheres around the detector and the subject. From an informative website(http://www.itg.uiuc.edu/ms/equipment/micr
You can take live action shots of wee beasties or watch crystals grow, live, rather than having to take snapshots of stopped processes.
Very cool.
The man who does not read good books has no advantage over the man who cannot read them. - Mark Twain
This is the size at which quantum effects dominate, and according to string theorists, is the size you start to see many more dimensions that the usual 4 (I've heard from 6 to 10 dimensions exist at this scale).
"Somebody has to do something. It's just incredibly pathetic it has to be us."
--- Jerry Garcia
That is correct, A Danish is actually from Austria and is called, the more appropriate "Wienerbrod", translates in English to "Bread from Vienna"
If you mod me down, I *will* introduce you to my sister!
Agreed, getting an HV TEM to get carbon lattice images at 500 C and with gasses being fed into the column is pretty damned impressive. One has to wonder, however, about the effect of the electron beam flux on the nanotube formation.
I used to work with a guy doing extremely low-loss EELS (plasmon edge stuff) and he found that he had to drop the accelerating voltage to 100kV to prevent nanotube deterioration. Though, he was working on small single-wall tubes, not the big, multi-walled behemoths you see in these images. At 200kV, he believed that he was actually seeing enough knock-on energy to produce electron-postitron pairs.
(It still never ceases to amaze me that I can use the work 'big' to describe something that's probably 100nm in diameter)