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UMSL Center for Nanoscience promises great progress in small packages

This article first appeared in the St. Louis Beacon: October 1, 2008 - Nano-this and nano-that. Recently, anyone who follows science news is seeing the prefix "nano" everywhere -- nano(ro)bots, nanotubes, nanotechnology. We are told that nanoscience holds great promise for the future, and that the future is beginning now.

First, "nano" is not to be confused with "Nanu." Fans of old sitcoms will remember Robin Williams as Mork from Ork ending each program with the phrase "Nanu. Nanu." Those born after 1982, please ignore this paragraph.

"Nano" refers to size -- very, very small size. A meter is about 36 inches. A millimeter is a one thousandth of a meter, or .036 inches. We can see a millimeter, which is about the size of a pinhead. A micrometer or micron is one thousandth of a millimeter, or .000036 inches. We cannot see a micrometer without instrumentation. And a nanometer is one thousandth of a micrometer, or .000000036 inches. Small molecules are measured in nanometers. Atoms are measured in Angstroms, one tenth of a nanometer.

Today, special microscopes can visualize structures a nanometer in diameter, so that we can actually see molecular structure. Some extremely powerful microscopes can see the atoms in these molecules.

The excitement surrounding nanoscience stems from the fact that many materials change their properties or behavior as their size gets smaller. When particles get very small, they can show changes in magnetic, optical, chemical, and electrical properties. So nanoscience represents qualitative change.

And although chemists have been working with molecules for a long time, nanotechnology aims to build its structures with complete uniformity in shape and composition and with 100% yield. It is technology more like building cars on an assembly line than like cooking up a reactive mixture in a chemist's flask.

Nanotechnology has already found applications in extending the life of batteries, in catalyzing chemical reactions on an industrial scale, and in making supercapacitors that store large quantities of electrical charge.

Perhaps the easiest way to begin to understand the nano business is to examine some of the current projects at the Center for Nanoscience at the University of Missouri - St. Louis.

UMSL's Center for Nanoscience

About two years ago, the university hired Jingyue (Jimmy) Liu, Ph.D., as director and George Gokel, Ph.D., as associate director of what was then the Center for Molecular Electronics. This center housed together researchers from various science departments, especially chemistry and physics, in a well-equipped science facility.

The two directors decided to make the center a true Center for Nanoscience and changed the name accordingly. They wanted to make it an interactive center -- a nexus of scholarly excellence. Faculty members within the center would collaborate with each other, and would reach out to the St. Louis area for other collaborations. They would pursue technology transfer and look for patentable ideas and products.

Accordingly the center offers for a fee the use of their powerful equipment and expert personnel to companies and researchers from other universities. A company could look at its products on a nanoscale level with a scanning electron microscope, a transmission electron microscope, or an atomic force microscope, and analyze them with other hi-tech equipment such as nuclear magnetic resonance machines or X-ray crystallography. Dan Zhou, Ph.D., who came from Monsanto with Liu would be available to help researchers use the equipment, or to do the analyses for them.

Professor Liu is leading one of the major initiatives at the Center for Nanoscience. It involves the production of better chemical catalysts. A catalyst is a substance that increases the rate of a chemical reaction without itself becoming changed. A catalyst, for instance, is needed for hydrogen fuel cells to work.

Of course, there is another sort of catalyst - and that's economic.

"One of the roles that a state university can play is to enhance industrial development locally," Gokel said. "People tend to think of us as providing an educated labor pool, but if we enhance the economic vitality of the community, we improve employment prospects for that labor pool."

A number of local companies, large and small, are already using the Center for Nanoscience. Among them:

Monsanto

Pana Charumilind, Ph. D. is continuing a long-term collaboration with Professor Liu on the development of improved catalysts. Monsanto doesn't have a lot of the high-resolution equipment on site, and it is very convenient to drive just a few miles to get the necessary information. One type of technical problem he studies is that catalysts may lose their efficiency after multiple uses. Microscopy on the nano scale allows a visual inspection of the catalyst when it is first used, after a few cycles, and after many uses. He can actually see whether the surface has been fouled by chemicals that stick, or whether the metal atoms in an alloy have moved within their crystalline structure.

Crosslink USA

Access to powerful equipment opens possibilities for a much smaller local company, Crosslink USA. Crosslink makes materials for supercapacitors, which are energy storage devices, used in U.S. Army munitions. Conventional capacitors store electricity by physical separation of charges distributed on metal plates. They discharge very quickly, but can't store a high density of electricity like a battery. So they are often used along with batteries for a quick burst of power and subsequent recharging by the battery.

Supercapacitors still release power quickly, but can store lots more electricity because of the materials used in making them. Crosslink's supercapacitor material is made of a plastic, polyaniline, that can be made conductive. As the polyaniline is formed into nanostructures, such as extremely thin tubes, their capacity for storing electricity is greatly increased because surface area is greatly increased. Their molecular structure can vary according to which agents called "dopants" are used in their manufacture. The scanning and transmission electron microscopes are able to examine the structure -- to show if a batch has opened up more surface, and conversely to show the molecular structure of a batch that has improved energy storage capacity.

Pat Kinlen, Ph. D. of Crosslink predicts that these plastic-based supercapacitors will be routinely used in hybrid cars.

Solae

Solae, a leading supplier of soy ingredients for food, uses special techniques developed by Liu and Zhou for ultramicroscopy on delicate food proteins. Solae can learn about the fine structure and detailed surface properties of its soy protein products with these gentle techniques.

Carbon nanotubes exemplify nanotechnology

No article on nanoscience is complete without a section on carbon nanotubes. Google the words "carbon nanotubes" and eight companies appear on the commercial righthand side of the page, including one that offers 5 grams of nanotubes for $100. If you notice that your car battery or nickel/cadmium batteries are working longer, it is because they contain carbon nanotubes acting as life-extending catalysts.

Thomas George, Ph. D., chancellor of UMSL and professor of chemistry and physics, is an expert on carbon nanotubes and other nanomolecules of pure carbon.

Carbon nanotubes seem to have nearly limitless potential applications, from ultra-strong fabrics to computer chips to flat panel displays and even to hydrogen fuel cells. They are lighter than steel but about 100 times stronger. They can conduct electricity and heat, and can emit light under the proper conditions. They are flexible and self repairing.

As George explains, the structure of carbon nanotubes is the same as that of graphite, the 'lead' in pencils. Graphite consists of two-dimensional sheets of carbon atoms arranged hexagonally in a honeycomb-like structure. These sheets are stacked on top of each other in pencil lead, but in nanotubes a single sheet can be rolled up. Many nanotubes are multiwalled and thus more rigid.

Other Applications of Nanotechnology

The future of nanotechnology seems nearly limitless, although the technical problems with each new material are daunting.

Many advances will probably come in medicine. George Gokel, for example, makes and studies organic molecules that act as gateways in biological membranes for charged elements such as sodium and potassium ions to enter or leave cells. These molecules can be thought of as model antibiotics. Thomas George has been researching destroying cancer cells using nanoparticles of gold attached to tumor-specific antibodies. Once the antibodies bind to the tumor cells, laser pulses heat the gold nanoparticles so quickly and extremely that they become little nanobombs.

In short, nanotechonology offers a whole new kind of science where great progress can come in very small packages.

Jo Seltzer is a freelance writer. 

Jo Seltzer