David Doetschman, professor and chair of chemistry, hopes his latest project will protect our nation from the deadly effects of chemical and biological weapons.
With the aid of his research team and funding from Science Applications International Corporation (SAIC), Doetschman is trying to create a substance that will not only absorb radiation or attract the toxins of a “dirty bomb,” but also neutralize the material into something harmless.
This potentially lifesaving material is known as aluminosilicate, a very porous combination of aluminum, silicon and oxygen. Cat owners know this substance well; it is a common ingredient in cat litter. Conservationists use aluminosilicates to clean up chemical spills; the catastrophic oil spill of the Exxon Valdez in 1989 is a notable example.
Doetschman is going a step further and learning what happens when aluminosilicates soak up light and other radiation. Working in the most controlled environment possible, a sterile vacuum box, Doetschman beams visible light, infrared light or radio waves into extremely fine particles of the aluminosilicate.
“Light comes from a source in the machine, strikes the sample, and the machine collects the light reflected off the sample,” he said. Based on the machine’s readings, Doetschman can determine how much light or radio waves have been absorbed and how their behavior changes once inside the aluminosilicate. By charting the absorption of each wavelength and carefully controlling the test environment (the vacuum box prevents dust particles, moisture, or even oxygen from tainting the results), Doetschman is able to peer into aluminosilicate’s secret internal environment: he can find out the identity of molecules inside and how they change once they’re soaked up.
“These patterns tell us a great deal about the identity of the molecule that the aluminosilicate is absorbing and what kind of motions the molecule is undergoing,” he said. “We hope that the research will reveal something new about molecules in these very tight spaces.”
Doetschman is also trying to answer some other scientific questions: how does the newly absorbed substance react to its surroundings? Are the molecules attracted to or repelled by the surface of the aluminosilicate?
Doetschman has learned the answers to these questions by merely watching how the molecule vibrates, which he said has been a more informative pursuit than studying the molecule’s rotation or reorientation.
Sometimes, he says, the simplest solution is the best.
Doetschman demonstrates use of a glove box apparatus for handling the aluminosilicate materials in the absence of oxygen and moisture. He wants these aluminosilicates to be more than just a clean-up crew for radiation. In fact, plans to transform them into a sensor by filling them with molecules or metal ions that can detect certain substances in the environment; the mere presence of the substances would automatically trigger a defensive response by the molecules inside the aluminosilicates.
His research team has also been trying to alter the aluminosilicates to be able to neutralize toxins. “We still need better ways to deal with chemical weapons,” Doetschman said, “And there’s no better substance than one that’s capable of absorbing a great deal of material.”
Eventually, Doetschman hopes to alter the inside of aluminosilicates so they’ll be very acidic or basic and thereby have the ability to “chew up” anything they soak up. “They would not be acidic or basic to the touch; they would only react to things that get absorbed inside, so they’d be remarkably safe to handle,” he said.
SAIC remains very interested in Doetschman’s work. With several homeland security and military contracts, they’re eager to see the results and put his findings to good and practical use. Perhaps the war on terror will end and such defensive measures won’t be necessary. Until then, Doetschman’s research continues.