Chemical Engineers at UMass Amherst Win NSF Nanotechnology Grants Totalling $2.2 Million

AMHERST, Mass. - The latest round of funding from the National Science Foundation’s (NSF) highly competitive Nanoscale Interdisciplinary Research Teams (NIRT) program has awarded grants to two projects based at the University of Massachusetts Amherst in the Chemical Engineering Department. Research teams headed by principal investigators W. Curt Conner and James Watkins will receive a total of $2.2 million over four years.

The multidisciplinary field of nanotechnology (or "nanotech" for short) involves submicroscopic design and construction using quantities of matter so small that they can be measured in billionths of a meter, the size of molecules.

Conner’s team received $1.2 million to study "Microwave Synthesis of Nanostructured Catalysts." Specifically, they will be studying the manufacture of zeolites, key catalysts for making fuels and other chemicals. Frequently described as "molecular sieves," zeolites feature a variety of crystalline structures with the atoms arranged around pores as small as a few tenths of a nanometer, just large enough for oxygen and nitrogen molecules to get through, or with new sieve syntheses as large as 10 nanometers in diameter. The chemical properties of the pore walls give zeolites and these new sieves the ability to catalyze a variety of reactions, while their pore sizes enable them to separate unwanted substances from a mixture by trapping particular molecules in the pores and allowing others to flow through.

Because different compositions impart different desirable properties, scientists have supplemented the 30 or 40 naturally occurring zeolites with about 150 specially engineered synthetics. It is to the fabrication of these artificial zeolites and molecular sieves that Conner’s nanotech team is directing its attention.

It has been known for a few years, Conner explains, that microwave radiation can significantly improve the efficiency of making zeolites. In conventional zeolite manufacturing, carefully calibrated batches of the necessary ingredients are mixed and then "cooked" in an autoclave for up to several days. However, if instead they zap the mixture in a microwave chamber, they can achieve the same results in as little as 15 minutes. So far, nobody has been able to establish why microwaves affect the zeolite synthesis process as they do. That question will be the focus of Conner’s research.

The other members of Conner’s interdisciplinary research team include Shaw Ling Hsu, polymer science and engineering, Sigfrid Yngvesson, electrical and computer engineering, and Scott Auerbach, chemistry. They are collaborating with the University of Connecticut as well as with Dupont, Rohm & Haas, W. R. Grace and CEM and others in industry on these efforts.

Watkins’ team will use its $1 million NSF grant to make new insulating films, a nanotech challenge relating to the manufacture of computer microchips. As computer processing power increases, with more and smaller circuits crowded onto each chip, engineers face a variety of difficulties with the silica-based insulating material that surrounds a chip’s copper wiring. One effective way to make the material a better insulator is to introduce small pores, about five nanometers in diameter. In order for the material to be strong, the pores have to be in a highly ordered array.

From his previous research, Watkins is well versed in the technique of using organic polymers to design structures with precise, regular distribution of nanoscale features. The next several steps in the chip-making process involve etching the silicate insulation material with a pattern of channels for the chip’s copper components. With this NIRT grant, Watkins’ team will be developing techniques to introduce that patterning at the polymer template stage of the process before putting in the silicate. "If we can do that," Watkins says, "that’s a huge win, because you get rid of several downstream processing steps that are complicated and difficult."

Watkins is also co-director of MassNanoTech, a UMass initiative announced January 21 as a focus for nanotechnology research. Working with the industrial partners in his NIRT is one way MassNanoTech will be aiding local and national business development.

Contact W. Curt Conner at 413/545-0316 or wconner@ecs.umass.edu.

Contact James Watkins at 413/545-2569 or watkins@ecs.umass.edu.