Sedit
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Metallic Nano Clusters
Due to a recent threed that was tainted from the start with philosophy ,religion and charlatans I have decided to create a threed that takes on a more
scientific approach into the generation of metallic nano clusters.
Below are some of the refrences I have found thus far that talk about these materials.
This is of the discovery of natural gold nano particals that appears in salty ground waters in Australia proving that nanoclusters can exist in nature
without having to be man made.
| Quote: |
Nature's Own Nano Gold Found
Larry O'Hanlon, Discovery News e-mail share bookmark print
Nature's Own: July 17, 2008
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Miniscule triangular and hexagonal plates of gold less than 20 nanometers thin and identical to those manufactured by humans have been found occurring
naturally in salty groundwaters of Western Australia.........
Refrence:http://dsc.discovery.com/news/2008/07/17/nano-gold-nature.html
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It goes on to state how these have been previously over looked due to there small sizes ect...
Here is a decent little paper on the catalytic abilities of gold nano clusters and its capabilitys for conversion of CO to CO2.
I cant help but think that this may inturn do away with palladium some time in the near future for use in catylatic converters for automobiles in the
near future.Gold albeit expensive is nothing in compared to palladium and the likes.
| Quote: |
Scientists in Japan discovered 10 years ago that gold displays fantastic catalytic abilities when it is shrunk to 3 to 5 nm in size. If the gold
particles are any bigger or smaller than this, the element resumes its inertness.
One such reaction is the conversion of carbon-monoxide (CO) to carbon-dioxide (CO2). Nanogold catalyzes this at room temperature and with 100-percent
efficiency. A potential application is to aid firefighters, who now wear protective masks containing copper-manganese-oxide. That material's
effectiveness at getting rid of CO, however, lasts only 15 minutes, while nanogold protects for several hours.
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Refrence:http://www.sciencedaily.com/releases/2004/04/040428062059.htm
A small artical on Nano gold catalyst.
Refrence:http://chemicalsabbatical.blogspot.com/2008/09/nano-gold-catalysts.html
Synthesis, structure and properties of metal nanoclusters
| Quote: | Metal nanoclusters have physical properties differing significantly from their bulk counterparts.
Metallic properties such as delocalization of electrons in bulk metals which imbue them with high
electrical and thermal conductivity, light reflectivity and mechanical ductility may be wholly or
partially absent in metal nanoclusters, while new properties develop. We review modern synthetic
methods used to form metal nanoclusters. The focus of this critical review is solution based
chemical synthesis methods which produce fully dispersed clusters. Control of cluster size and
surface chemistry using inverse micelles is emphasized. Two classes of metals are discussed,
transition metals such as Au and Pt, and base metals such as Co, Fe and Ni. The optical and
catalytic properties of the former are discussed and the magnetic properties of the latter are given
as examples of unexpected new size-dependent properties of nanoclusters. We show how classical
surface science methods of characterization augmented by chemical analysis methods such as
liquid chromatography can be used to provide feedback for improvements in synthetic protocols.
Characterization of metal clusters by their optical, catalytic, or magnetic behavior also provides
insights leading to improvements in synthetic methods. The collective physical properties of
closely interacting clusters are reviewed followed by speculation on future technical applications
of clusters.
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Refrence:http://www.rsc.org/delivery/_ArticleLinking/DisplayArticleForFree.cfm?doi=b517312b&JournalCode=CS
This by far seems as though it is going to show the full potential of nano clusters due to the fact that using two disimular metals one can achieve a
stable 'alloy' of sorts which could never be formed other wise.Very well written paper with decent amount of data to go off of.
Refrence:http://h2.ipcf.cnr.it/alex/72.pdf
Something for our Biochemistry freinds is an artical talking about gold nanostructures basicly made from gold salts and Tofu.
Soybeans strike nanogold
Refrence:http://www.rsc.org/chemistryworld/News/2007/November/06110702.asp
The use of nanoclusters as a catalysts is probly by far is greatest use for us amature chemist due to its ability to create a high surface area
platinum catalyst. The best part of all is that its created using a bacteria which seems well within the range of an amature.
Bacteria base nanoclusters
http://www.physorg.com/news75131830.html
http://www.newscientist.com/article/dn9821-bacteria-skin-hel...
And last but not least a refrence sent in from Nicodem Showing that gold nano clusters have chiral properties which I find strange for a substance I
have always incorrectly assumed was a sphere.
Refrence:http://www.ingentaconnect.com/content/ben/cnano/2008/00000004/00000001/art00010?crawler=true
These are just a few references of the wealth of information out there on the subject and I posted them just to get the ball rolling and see what
others think of the subject of metal nanoclusters
~Sedit
[edit]
Also there is this PDF that I forgot to link of the magnetic propertys of Iron nano clusters
Is there any way for me to upload more then one file at a time?
[Edited on 10-2-2009 by Sedit]
[Edited on 10-2-2009 by Sedit]
Attachment: Nanoclusters.pdf (126kB)
This file has been downloaded 562 times
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Sauron
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@sedit
The 2007 short puff piece in Chemical World on soy based gold nanoclusters identies Khattesh Kitti and says his company has a patent.
The USPTO database says otherwise.
Even an application for patent should have shown up in the intervening two years.
A Google search on Khattesh Katti comes up null
A Google search on "soybean gold nanocluster" comes up with much puffery of the same sort as you posted. That is science news, not science.
No peer reviewed journal articles by Khattesh Katti?
Where's the patent? What is the number? What priority date and where was it filed? Cite it or post the full text plrase.
So far all I have seen is self promotional publicity. That is P.T.Barnum not science.
Let's see some SCIENCE.
BTW DMF is used in great quantities in the production of numerous pharmaceutical peptides. The Chemical World, or Khattesh Katti, overstaed the
problems of such reagents in pharm industry. Keeping in mind that Katti and colleagues are trying to hawk their own product-to-be, that is
understandable, but marketeering is not science. Let's stick yo science.
I am not disputing the existance of nanoparticles or nanoclusters. I am not even disputing that amateurs might prepare metal nanoclusters, though I
must say, I doubt any ability to characterize them once produced. I am not even sure what instrumentation is required. Mass spec? AA? SEM? Few have
these at hand.
At least we have gotten well away from Au91) and forcefields emenating from beakers of aqua regia.
So Scotty, put the transporter on standby. I will wait and see if there's any intelligent life here, before I tell you to beam me up.
[Edited on 11-2-2009 by Sauron]
Sic gorgeamus a los subjectatus nunc.
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Nicodem
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| Quote: | Originally posted by Sedit
Soybeans strike nanogold
Refrence:http://www.rsc.org/chemistryworld/News/2007/November/06110702.asp |
The paper referenced there is attached for those who do not access:
V. Kattumuri et al, Small, 3 (2007) 333. DOI: 10.1002/smll.200600427
Attachment: Gum Arabic for the Stabilization of Gold Nanoparticles.pdf (697kB)
This file has been downloaded 791 times
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Sauron
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Thanks, Nicodem. That work out of U.Neb. was not in question except by analogy.
The question is, in view of all the PR flak from Khattesh Kitti, there is a derth of hard information to back it up, in the journals, or in the patent
lit. This is in spite of his (Kitti's) claim to a patent.
Seems like a lot of drum beating but no music, doesn' it?
Sic gorgeamus a los subjectatus nunc.
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Nicodem
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This author has 140 publications and only a part of it is in the nanochemistry field, the rest being catalysis, synthesis, biochemistry, etc. so I'm
not sure which one you are looking for. His latest is a 42 pages patent related to the paper I posted above, so maybe you are looking for this:
WO2009005752 : Stabilized gold nanoparticle and contrast agent
His newest paper in Small is also related:
Soybeans as a Phytochemical Reservoir for the Production and Stabilization of Biocompatible Gold Nanoparticles
Katti, Kattesh V. et al
Small, 4 (2008) 1425-1436. (find attached)
[Edited on 11/2/2009 by Nicodem]
Attachment: Soybeans as a Phytochemical Reservoir for the Production and Stabilization of Biocompatible Gold Nanoparticles.pdf (772kB)
This file has been downloaded 771 times
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Nicodem
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And here is another one:
Nanocompatible Chemistry toward Fabrication of Target-Specific Gold Nanoparticles.
Katti, Kattesh V. et al
Journal of the American Chemical Society, 128 (2006) 11342-11343.
But keep in mind that his gold nanoclusters are not even that small. They are ~15nm or Au198, but they are coated in such way as to make them stable
in vivo which makes them actually useful for imaging and such. Otherwise much smaller gold nanoclusters are also possible.
Attachment: Nanocompatible Chemistry toward Fabrication of Target-Specific Gold Nanoparticles.pdf (219kB)
This file has been downloaded 771 times
…there is a human touch of the cultist “believer” in every theorist that he must struggle against as being
unworthy of the scientist. Some of the greatest men of science have publicly repudiated a theory which earlier they hotly defended. In this lies their
scientific temper, not in the scientific defense of the theory. - Weston La Barre (Ghost Dance, 1972)
Read the The ScienceMadness Guidelines!
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Sauron
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That;s more like it.
JACS is prestigious enough and more.
Sic gorgeamus a los subjectatus nunc.
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not_important
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| Quote: | | And last but not least a refrence sent in from Nicodem Showing that gold nano clusters have chiral properties which I find strange for a substance I
have always incorrectly assumed was a sphere. |
For less than about 16 atoms, gold clusters are certainly not spherical, the smaller ones are basically flat. Even above that size the shape need
note be spherical, pyramidal shapes are common and flat nanoparticles still are formed on the surface of other substances. I believe on of the links I
gave in the other thread discussed that a bit,.
http://www.sciencedaily.com/releases/2007/01/070116131214.ht...
http://www.sciencemag.org/cgi/content/abstract/281/5383/1647
http://nanotechwire.com/news.asp?nid=1601&ntid=122&p...
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watson.fawkes
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| Quote: | Originally posted by Sauron
The 2007 short puff piece in Chemical World on soy based gold nanoclusters identies Khattesh Kitti and says his company has a patent. [...] The USPTO
database says otherwise. [...] Even an application for patent should have shown up in the intervening two years. |
Patent applications to the USPTO are kept private for the first year after filing. Only after that are they published. The
justification, as I recall, is that it assists the clarity of evidence in interference proceedings.
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Sauron
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Yes, I know that since I own US, EU and other patents. But the statement was made in 2007 that the patent existed, and this is 2009 so the normal
period for confidentiality is long over. The USG can slap a secrecy order on an application when it sees fit and continue that as long as it likes. I
do not think that likely in this case. I suspect that, like my Google search, using the spelling from Chemical World was a bad idea. The man's name is
Kattesh not Khattesh, middle initial V. Katti, and a patent search under that name may well give better results.
Now that Nicodem has posted a JACS paper by Katti on this work as well as other papers there is no longer any reason to suspect chicanery. So maybe
there's a patent issued, maybe there's an application in progress.
Sic gorgeamus a los subjectatus nunc.
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Sedit
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Heres something for you.
Its a link to Dr. Katti research interest and at the bottom of the page he runs a list of his patents with there numbers to go along with it.
Refrence:http://web.missouri.edu/~kattik/katti/katres.html
Ah just found this and it explains why the soybean patent hasn't been found yet and if so it would be very recent considering this artical is from
October 2008
| Quote: |
The (patent pending) method Katti has invented eliminates synthetic chemicals involved in the production of gold nano-particles. That means that the
production process is entirely environmentally friendly.
GreenNano submerses gold salts in water and then adds soybeans. A complex but wholly natural process leads to the creation of gold nano-particles.
Sounds almost too good to be true, but more curious things have known to have occurred in the nano-business (including the growth of cell phones on
plants). |
Link :http://www.globalwarmingisreal.com/blog/2008/10/10/green-nano-technology-is-ready-to-come-of-age/
[Edited on 11-2-2009 by Sedit]
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Sedit
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This possibly deserves its own place in techno chemistry but since I only have one source for it at the moment.
This method shows a home built cell that is used to synthesis Ni/Pd nano clusters with an average size of 4.9 nm
using tetraoctyl ammonium bromide(a surfactant to stop the clusters from coagulating into larger structures) in a Dimethylformide(which increased the
stability lifetime to over 4 weaks compared to other solvents used such as MeCN)
Interesting to note that the use of the Ni/Pd clusters out performed plain on Pd nano clusters which makes me think it could possibly be due to better
use made from the avalible Pd. These test runs that they performed with the catalyst proved almost quantitive yeilds in most of the synthesis they
performed using it.
Questions : Does anyone think it would be possible to perform these test in other solvents such as DMSO which I have on hand and also
what is the price range of PdCl and the likes? I was going to try to attempt Cu nanoclusters due to buget issues and such but after further study I
realise that this is just no practical because non nobel metals are way to prone to oxidation at such small scales.
Attachment: electronano.pdf (775kB)
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