Posted on 05/21/2006 7:17:16 PM PDT by PeaceBeWithYou
Scientists have uncovered a class of gold atom clusters that are the first known metallic hollow equivalents of the famous hollow carbon fullerenes known as buckyballs. The evidence for what their discoverers call hollow golden cages appeared today in the online early edition of the Proceedings of the National Academy of Sciences.The fullerene is made up of a sphere of 60 carbon (C) atoms; gold (Au) requires many fewer16, 17 and 18 atoms, in triangular configurations more gem-like than soccer ball. At more than 6 angstroms across, or roughly a ten-millionth the size of a comma, they are nonetheless roomy enough to cage a smaller atom.
This is the first time that a hollow cage made of metal has been experimentally proved, said Lai-Sheng Wang, the papers lead corresponding author.
Wang is an affiliate senior chief scientist at the Department of Energys Pacific Northwest National Laboratory and professor of physics at Washington State University. The experiments were buttressed and the clusters geometry deciphered from theoretical calculations led by Professor Xiao Cheng Zeng of the University of Nebraska and co-corresponding author.
Wang, who worked in the Richard Smalley lab that gave the world buckyballs, is part of a large cluster of researchers who have spent much of the past decade attempting to find the fullerenes kin in metal. But their search has proved difficult because of metal clusters tendency to compact or flatten.
Experiments at the PNNL-based W.R. Wiley Environmental Molecular Sciences Laboratory elicited the photoelectron spectra of clusters smaller than Au32, which had been theorized as the gold-cage analog to C60 but ruled out by Wangs group in an experiment that showed it as being a compact clump.
They instead turned their attention to clusters smaller than 20 atoms, which earlier work by Wangs group showed were 3-D, but larger than 13 atoms, known to be flat. The spectra and calculations showed that clusters of 15 atoms or fewer remained flat but that all but one possible configuration of 16, 17 and 18 atoms open in the middle. At 19 atoms, the spaces fill in again to form a near-pyramid.
Au-16 is beautiful and can be viewed as the smallest golden cage, Wang said. He pictures it as having removed the four corner atoms from our Au20 pyramid and then letting the remaining atoms relax a little, and thus opening up space in its centre.
It and its larger neighbours are stable at room temperature and are known as free-standing cages unattached to a surface or any other body, in a vacuum. When deposited on a surface, the cluster may interact with the surface and the structure may change.
Wang and his co-workers suspect that many different kinds of atoms can be trapped inside these hollow clusters, a process called doping. These doped cages may very well survive on surfaces, suggesting a method for influencing physical and chemical properties at smaller-than-nano scales, depending on the dopants.
Wangs group has not yet attempted to imprison a foreign atom in the hollow Au cages, but they plan to try.
Ben Wa balls for beneficial bacteria?
I think it has been done, but it's all nuclear physics at that point. I saw something about changing mercury to gold in the presence of a certain radio-isotope, but I can't remember the details.
Not "Shengshapes" but rather
Shenogains (ducks and runs)
(( ping )) for the science list
This could really be interesting, we know that the great
ability of ferris metalurgy lies in the entrapment of carbon atoms, a lot of promise here.
This may imply MORE uses for gold hence a jump in demand
and well, we know what that means.
How about testaora, or testaura?
"buckyballs"
Our brains deal exclusively with special-case experiences. Only our minds are able to discover the generalized principles operating without exception in each and every special-experience case which if detected and mastered will give knowledgeable advantage in all instances.
- from Operating Manual for Spaceship Earth, 1963
Others have seen so much more standing on this mans sholders.
R. Buckminster Fuller was way before his time. I wish articles like this would at least mention him beyond "buckyballs" and "fullerenes".
If you haven't read his Ops manual for Spaceship Earth - do so - even now in 2006 it will still blow your mind to new heights.
I actually had the privledge of meeting this man and shaking his hand twice - once in Switzerland at a physics conference in the early 70's and again in San Diego at a Shriners Temple where he was lecturing shortly before his passing in 1983.
We are blessed with one of his Geodesic Domes here in Oakland CA at Lakeside Park and if memory serves me it predates the one in Canada.
http://www.bfi.org/
Nice place to visit for more info on this Great Thinker and Doer.
Glenn Seaborg did it in 1980-something. But that's easy. Some of our brightest (al)chemists are working on a way to do the same thing using only chemical means, plus a few choice spells and a prayer to Termagent.
And yet we can't develop a more workable way to create energy without burning gas or oil. Boy, those oil companies must be pretty powerfult to suppress smart guys like these dudes who are working on fullerenes. (/sarcasm)
Pretty close to being the non-metallic/ormus version of the metal.
Yup, I'll ping this one too, but I'm travelling on business & won't be back home until later tonight or sometime tomorrow, so I won't have my list handy until then.
Does one dopants to a do?
A gold cage would be kind of heavy, but it would be chemically nearly inert. Somewhere in there are materials characteristics that might find useful application.
I dub thee "Gitmonium"...
PNAS abstract
http://www.pnas.org/cgi/content/abstract/0600637103v1
|
Well if you put your hard drive in one it should be safe from a EM Pulse
"Hmmm, quite interesting, but it all begs the question "What will these little gold cages actually do?"."
Well, to be fair, it's impossible to say at this point. However, buckyballs have been around for a long time, and they are manufactured and sold. They do have some uses---the problem being that they are incredibly expensive---which makes their applications extremely limited.
Offhand, it seems like a gold version would be more expensive but I'm not sure how much more. I have a feeling the labor will be the main expense.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.