One perplexing problem that has faced scientists in the modern, petroleum-fueled age, is how to clean up oil spills that make their way into water sources. A nanotechnology project at
Michigan Technological University may have some suggestions on that.
Tech scientists Yoke Khin Yap, an associate professor in the physics department, and Jaroslaw Drelich, an associate professor of materials science and engineering, have built a tiny filter that separates oil and water quickly and cleanly, using carbon nanotubes as a coating over a very fine stainless steel mesh. The carbon nanotubes let oil through, but not water.
"They have a super-honeycomb structure that repels water," says Yap. "But they like organic stuff, like oil."
In testing, the pair poured a mixture of water and gasoline through the filter, which produced the desired result; all the gas dripped through, with about 20 percent of the water going through along with it, but 80 percent of the water stayed put.
Right now, the filter is just about the size of a quarter, so no oil spills are going to be filtered by it any time soon. Still, Yap and Drelich say it has real-world possibilities, with some tinkering. For instance, applied electricity could heat the filter, making oil run through faster or evaporating the water for more efficient filtering. A vacuum system sucking the oil away on the other side of the filter also might aid the process.
"But the attractive thing is that it's so simple," Yap says. "It runs by gravitation."
Simple is good when it comes to manufacturing and using the technology, which may have applications for a multitude of industries using oil products. It might help purify oil from Canadian tar sands, or recover oil from ocean-going vessels' waste discharges, or even scrub the oil inside an automotive engine.
The project was published in the journal Carbon earlier this year, and is funded by the National Science Foundation.
Writer: Sam EgglestonSource: Yoke Khin Yap, Michigan Technological University
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