Inspired by the highly interlocked structures of bird nests, vanadia-based structures which form a more highly entangled worm-like nanostructure were made. Photo via Chemical Science.

Aerogels are typically made from pearl necklace-like strings of silica nanoparticles, and can be strengthened with a polymer coating, so that the strands form crosslinks wherever they meet. But inspired by the highly interlocked structures of bird nests, Leventis switched to vanadia-based structures, which form a more highly entangled worm-like nanostructure.

'Both crosslinked silica and vanadia are very strong materials. But crosslinked vanadia aerogels never fail under compression, and can absorb at least four times the kinetic energy of the silicon carbide ceramics used for armour,' said Leventis. 'Killer applications will be in areas where we can take advantage of the multifunctional character of these materials - strength in combination with acoustic and thermal insulation - such as lightweight structural materials for buildings, and the automotive and airplane industries.'

This is not the first time Leventis has gained notice for his work with nanomaterials. Last June, the chemistry professor made Nanotech Briefs' Nano 50 list of top researchers in the field. Leventis made the list for his previous work with aerogels.

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That's how UMR chemist Nicholas Leventis describes his invention: cross-linked aerogels. The extremely lightweight and sturdy composite material is four to five times stronger than material currently used in military armor. This week he was named to Nanotech Briefs list of Nano 50 for his work.

Aerogels are nothing new. They've been around since the 1930s, but they were highly brittle and of little practical use. By chemically bonding -- or cross-linking -- strings of tiny glass particles with polymers like polystyrene, polyurethane and epoxy, Leventis created aerogels that are 100 times more resistant to breakage and totally resistant to moisture.

Leventis sees possible uses in military armor, lightweight thermal insulation, fuel transport systems, tiny, but sturdy, drug-delivery vehicles and lighter, more efficient aircraft and spacecraft frames.

Want to see something cool? These videos show the difference between conventional armor-grade material and a cross-linked areogel when they're hit with an impact that is eight times that of a .45 mm bullet. It's pretty impressive.

First, the conventional material:

Now, here's the aerogel:

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Visions bloggers would like to extend their congratulations to UMR's own Jay Switzer, the Donald L. Castleman Distinguished Professor of Chemistry, for receiving the Presidential Award for Research and Creativity from the University of Missouri.

The award was presented last night during an ceremony hosted by interim University of Missouri President Gordon H. Lamb and his wife, Nancy, in Columbia.

Switzer is an international leader in materials synthesis by electrodeposition, an area at the interface between chemistry, electrochemistry, materials science and solid-state physics. Since joining UMR in 1990, he has produced numerous patents and journal articles, including four Science papers and a Nature paper.

It's a well deserved award. Congratulations, Jay!

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As a kid, Jay Switzer made everything from fireworks to tear gas in his parents' Ohio basement. Today, he is just as intriqued by experimentation and discovery. In October, the American Chemical Society will honor his work with it's Midwest Award.

Switzer, the Donald L. Castleman Distinguished Professor of Chemistry at the University of Missouri-Rolla and a senior investigator in the UMR Materials Research Center, is known for his research into the chirality, or "handedness," of drugs. Most important drugs on the market today are chiral -- they exist as either right-handed or left-handed molecules. While one "hand" is useful as a drug, the other can be toxic.

Last summer, Switzer began a project to determine if a chemical used by water districts to disinfect the water supply (monochloramine) actually raised lead levels in the water -- it does.

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One year after Hurricane Katrina struck the Gulf Coast, UMR civil engineer Jianmin Wang will present findings from research he conducted in the Big Easy to the American Chemical Society's National Meeting and Exposition Sept. 10-14 in San Francisco.

Wang and colleagues collected 238 soil and sediment samples one month after Katrina hit and analyzed them for pesticides and heavy metals. The pesticide levels were "generally not of great concern," but as many as 50 percent of the samples contained arsenic and 30 percent in their leachaets had lead equal to or above maximum level of those metals allowed in drinking water.

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As part of her annual Farm Tour, U.S. Representative Jo Ann Emerson (pictured) visited campus today to meet with a pair of UMR chemical engineers who've devised a way to make ethanol using things like corn stalks, rice hulls and various types of wood - like the leaves and branches typically left over by the forestry industry.

Missouri recently made the switch to E10 to replace straight gasoline. We'll need 13 billion gallons of ethanol per year to keep up with demand. If we go with E85, we'd need 123 billion gallons of the stuff. If 100 percent of the state's corn grain were used for ethanol production, it would only yield 30 billion gallons. Considering some of that grain also has to go to the food market for people and animals, it doesn't take a rocket scientist to see that an alternative fuel source is needed.

Enter Neil Book and Olliver Sitton.

Continue reading "Wood you use ethanol?" »

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UMR professors Charles C. Chusuei and Yangchuan Xing, with graduate students Robert V. Hull and Liang Li, recently reported success with characterizing the surfaces of carbon nanotube fuel cell catalysts. The National Synchroton Light Source, a scientific facility that is funded by the U.S. Department of Energy, recently reported on the team's research, which appeared in the April 6 issue of the journal Chemistry of Materials.

From the NSLS story:

Characterizing the surface structure of catalyst materials is important for the improvement of current fuel cell technology, which promises to deliver an environmentally benign means of energy production. Using x-rays produced at the National Synchrotron Light Source (NSLS), researchers at the University of Missouri-Rolla (UMR) were able to detect the presence of PtOx at the outer-most perimeters of a potential catalyst: platinum nanoparticles tethered to carbon nanotubes. At the same time, they determined that its bulk composition was predominantly metallic.

Fuel cells are devices capable of generating electrical energy directly without involving a thermal cycle that typically release greenhouse gases, such as CO and NOx, into the atmosphere. Today, burning coal is still the primary and most efficient (with regard to power density) means of electrical energy production in the United States. New information obtained from a study performed at the NSLS may help catalyst researchers design improved fuel cell devices that can compete with current fossil fuel technology.

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I don't remember a world without AIDS.

I was 4 years old when the first cases were reported. The disease, and the unknown, terrorized people and stigmatized the afflicted.

Twenty five years later, we know a lot more about how the disease is spread. And although we don't have a cure, scientists are pushing to develop ways to help those suffering. Nuran Ercal is one of those scientists. Working with William Banks, professor of geriatric medicine at Saint Louis University, Ercal has found that a newly redesigned antioxidant may play a critical role in preventing HIV-1-associated dementia, a condition that a third of the adults and half of the children with AIDS develop.

Their research will be published in an upcoming issue of the journal Experimental Neurology.

Now if only the golden anniversary could bring with it a cure.

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A couple of years ago, a Scientific American reader, no doubt in need of some conversation starters for a Fourth of July picnic, wanted to know what physical and chemical changes occur when fireworks are set off. The reader submitted the question to SciAm's "Ask the Experts" forum, and SciAm in turn asked UMR's resident pyrotechnics expert, Paul Worsey. Now, Worsey's original response will be published in an upcoming issue of the magazine.

And what, exactly, does happen when a firework gets lit? Here's a condensed version of Worsey's response:

Continue reading "How fireworks work" »

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