[FoRK] The Age of Alchemy

Stephen D. Williams sdw at lig.net
Thu Jan 7 14:24:24 PST 2010


Inert Aluminum? Where's my transparent aluminum??

http://www.thenational.ae/apps/pbcs.dll/article?AID=/20100104/FRONTIERS/701039920/1036/NEWS
http://www.pnas.org/content/103/28/10577.abstract?ck=nck&cited-by=yes&legid=pnas;103/28/10577
> Return of the alchemists
>
> Robert Matthews
>
> * Last Updated: January 03. 2010 7:58PM UAE / January 3. 2010 3:58PM GMT
>
> The practical aspect of alchemy generated the basics of modern 
> chemistry. Photolibrary
>
> With its associations with wizards, spells and magic, alchemy is not a 
> term you expect to come across in a prestigious research journal. Like 
> astrology and divination, the idea of transforming ho-hum materials 
> into wondrous ones at the wave of a wand has long been dismissed by 
> scientists. Yet last week, the US National Academy of Sciences 
> published a paper that not only begins with that taboo word, but even 
> claims to explain how to bring about such transformations.
>
> The implications are certainly startling. According to the authors of 
> the paper, it is possible to mimic certain properties of precious 
> metals as platinum and palladium using combinations of far more 
> mundane materials. And that opens up the prospect of replacing 
> expensive strategic metals in many industrial applications by much 
> cheaper alternatives.
>
> The origins of the breakthrough lie in a curious discovery made by 
> chemists around 40 years ago. A number of research teams in Europe and 
> America reported that when carbon atoms were added to atoms of 
> tungsten, the resulting material – tungsten carbide – seemed to 
> possess some of the properties of the far more costly metal platinum. 
> In particular, it mimicked the ability of platinum to act as a 
> catalyst, boosting the efficiency of chemical reactions. Somehow the 
> combination of atoms of two different elements were behaving like a 
> single “superatom” of an entirely different atom.
>
> During the 1980s, more examples of the superatom phenomenon emerged. 
> Researchers at the California Institute of Technology discovered that 
> combinations of aluminium atoms had some of the properties of the far 
> rarer metal ruthenium, used as a catalyst by the chemical industry.
>
> In the search for explanations, attention focused on the key players 
> in chemical reactions: electrons. The properties of every atom are 
> dictated by the arrangement of these subatomic particles in so-called 
> “shells” surrounding the central nucleus of their host atoms.
>
> The link between these arrangement and chemical properties is famously 
> demonstrated by the Periodic Table, the block-like diagram that graces 
> the walls of every chemistry lab. Atoms with similar configurations of 
> electrons and thus similar properties, such as alkali metals or inert 
> gases, end up close to each other.
>
> The fact that superatoms mimic the behaviour of individual atoms 
> suggests that both have similar electron arrangements. That, in turn, 
> suggests that new types of superatom could be predicted by using the 
> Periodic Table.
>
> Now a team of researchers at Pennsylvania State University led by Prof 
> Welford Castleman has confirmed this, opening the way to a whole new 
> branch of chemistry.
>
> The team’s discovery stems from its work on a superatom constructed 
> from 13 aluminium atoms, which studies revealed had properties similar 
> to a single atom of iodine. On the Periodic Table, iodine sits in the 
> column of so-called halogen elements, which are just one electron 
> short of becoming inert gases. That suggests adding one more electron 
> to the iodine-like cluster of 13 aluminium atoms would make them 
> chemically inert – which is just what the team found.
>
> Emboldened by this, the team has now used the Periodic Table to 
> predict that a superatom made from atoms of titanium and oxygen should 
> behave like a single atom of nickel. Their reasoning can be understood 
> with basic arithmetic: titanium and oxygen have four and six outermost 
> electrons respectively, while nickel has 10 such electrons. The same 
> idea has led them to predict that zirconium plus oxygen should act 
> like palladium, which – like platinum – is a widely-used but pricey 
> industrial catalyst.
>
> In research published last week in the online early edition of 
> Proceedings of the National Academy of Sciences, the team has now 
> confirmed these predictions – along with the 40-year-old connection 
> between tungsten carbide and platinum. But they have gone further, 
> using spectroscopic studies to show that the root cause really is the 
> similarity in the electron structures of the superatoms and the atoms 
> they mimic.
>
> Now the team is working its way across the big central block of the 
> Periodic Table, consisting of so-called transition metals from 
> scandium – used in aerospace alloys – to gold. Their aim is to 
> discover other superatoms, and to gauge the extent of their 
> similarities to standard atoms.
>
> Not surprisingly in view of the commercial implications of success, 
> the Penn State team is not alone in its quest. Researchers at Virginia 
> Commonwealth University recently announced that a cluster of eight 
> caesium atoms plus a vanadium atom mimic the magnetic strength of 
> manganese. The research team has also predicted that superatoms of 
> gold and manganese will be magnetic while not conducting electricity – 
> a combination making them useful in some biomedical applications.
>
> Such discoveries suggest we are witnessing the birth of a whole new 
> branch of chemistry, and one that could not have arrived at a better 
> time – for many critical technologies are crying out for a 
> breakthrough in material science.
>
> An example is nuclear fusion power, in which the energy source of the 
> sun and stars is harnessed in giant reactors known as tokamaks. The 
> walls of such reactors are blasted by intense radiation in the form of 
> fast moving neutrons, and the resulting damage and replacement 
> threatens to make nuclear fusion uneconomic. Reactor walls made of 
> superatomic metals may be the answer. The economics of many other 
> technologies, from superconducting power cabling to fuel cells, might 
> also be transformed by the discovery of low-cost superatomic equivalents.
>
> Before it fell into disrepute, alchemy had many distinguished 
> adherents – among them Sir Isaac Newton. Their 21st century 
> successors, armed with a book of spells in the form of the Periodic 
> Table, may soon be achieving feats of magic that will astound us all.
>
> Robert Matthews is Visiting Reader in Science at Aston University, 
> Birmingham, England
sdw






More information about the FoRK mailing list