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Technology magazine honors College of Engineering faculty member |
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Jim Winkler |
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Dec 5, 2007 |
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Good things come in very, very, very small packages.
Just ask Dr. Abdul-Majeed Azad, winner of 2007 Nano50 Award from Nanotech Briefs, an industry magazine, who has developed a new, nanotechnology-derived process to make hydrogen fuel from a byproduct of steel production.
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| Doctoral student Sathees Kesavan dropped sodium borohydride solution into the iron precursor as Dr. Abdul-Majeed Azad watched the black nanoscale iron particles that formed instantaneously. |
The associate professor of chemical and environmental engineering was recognized at the NASA Tech Briefs National Nano Engineering Conference in Boston Nov. 14, and his research featured in the magazine’s November issue. Nanotechnology is a fast-emerging science that concerns itself with the engineering of materials at the level of individual atoms and molecules.
The method relies on some well-established scientific principles. When steam passes over a hot iron surface, the metal reacts by soaking up the oxygen in the steam to form iron oxide and releasing hydrogen. While it is certainly a clean way to produce hydrogen compared to fossil-fuel combustion, it would not produce enough of the gas for use in cars, in industry and at home to cover production costs.
But increasing the surface area of the iron makes the process, known as metal-steam reforming, easier and more effective.
That’s where nanotechnology — and hundreds of thousands of tons of iron oxide annually dumped into landfills by steel manufacturers, providing a readily available, cheap supply of the metal — enter the picture.
To make nanoscale iron powder, Azad relies on a process known as solvothermal reaction, which doesn’t use water as a solvent. He dissolves waste iron oxide in a mineral acid, adds hydrazine, a compound found in rocket fuel, and then ethanol as a solvent. The mixture is taken to about 100 degrees Celius in a stainless steel jacket and kept for four hours under a pressure equivalent of five atmospheres.
This causes the iron oxide to transform into very tiny, sugar cube-shaped grains of iron that are magnetic, have a large surface area, and can’t be seen with the naked eye because they are about five billionth of a meter in size. The method produces iron nanoparticles in a more environmentally benign way and at a cost lower than more traditional reactions using either hydrogen or carbon at very high temperatures.
The particles not only can be used to produce hydrogen gas for use in fuel cells, but also have the ability to neutralize contaminants such as perchlorate, arsenic and hexavalent chromium, which have been identified as health hazards.
According to Azad, nanoscale iron particles are 10 to 1,000 times more reactive than conventional iron powders — already used in some traditional waste-water treatment processes — because the nanoparticles’ smaller size collectively gives them a much larger surface area.
The technology holds promise as a way to clean up a pervasive problem of unhealthy levels of perchlorate and arsenic in drinking water supplies that plague many parts of the world.
Perchlorate, a chemical used in rocket fuel, has been found in the drinking water of more than 11 million Americans nationwide. It keeps iodide from being absorbed by the body, has been found to damage fetuses and infants, and could lessen brain development and lead to Attention Deficit Disorder.
“Nanoscale iron appears to act like a sponge for perchlorate and arsenic,” Azad said, noting that particles can bind up to 100 times as much arsenic as the larger iron particles currently used in filters.
Azad has worked with colleagues at California’s Lawrence Berkeley National Laboratory to assess the efficacy of nanoscale iron in removing arsenic from drinking water. His research has been funded by the Department of Energy through an Edison Materials Technology Center grant to support his PhD student, Sathees Kesavan, who graduates this semester.
Collaborating with Main and Health Science campus researchers, Azad also plans to study how nanoscale iron and iron oxide particles can be used to improve magnetic resonance imaging.
According to Nanotech Briefs’ Web site, the Nano50 Awards recognize the “top 50 technologies, products and innovators that have significantly impacted, or are expected to impact, the state of the art in nanotechnology. The winners of the Nano50 Awards are the best of the best — the innovative people and technologies that will continue to move nanotechnology to key mainstream markets.” A panel of nanotechnology experts judged the nominations, with technologies, products and innovators receiving the 50 highest scores named as award winners.
Other institutions represented by the winners were Stanford, Princeton, Rice and Old Dominion universities; universities of Texas, Virginia, Florida and Missouri; Massachusetts Institute of Technology; Harvard Medical School; Xerox, Oak Ridge, Lawrence Livermore and Idaho National laboratories; NASA Langley Research Center; and the National Institute of Standards and Technology.
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