Issue Date: January 14, 2013
ACS Award In Applied Polymer Science
Sponsored by Eastman Chemical
When Mitchell A. Winnik of the University of Toronto meets with scientists in industry, he likes to listen to their problems. Throughout his career, he’s taken these puzzles back to his lab to study their fundamental underlying science. In doing so, Winnik has helped these scientists overcome hurdles as they invent new technologies or improve existing ones.
“He has been able to bring rigorous science to bear on topics in applied material science that are of extreme importance in modern life,” says Robert H. Grubbs, an organic chemist at California Institute of Technology who has known Winnik since graduate school.
Winnik’s best-known work came from his collaborations with companies that produce coatings, including ICI Paints, Union Carbide, and Rohm and Haas. The coatings industry wanted to formulate environmentally friendly paints by minimizing the use of solvents. Manufacturers add these volatile organic compounds to latex paints to help the paints dry into stable, strong films. Unfortunately, these chemicals contribute to smog formation.
To help companies find effective paint formulations that require less solvent, Winnik developed a method to observe latex paints at the molecular level while they dry.
A latex paint starts as a water-based suspension of pigment molecules and polymer nanoparticles. As the paint dries, the nanoparticles press together and polymer molecules inside each particle diffuse across the interface between particles, stitching them together and forming a film that holds the paint’s pigments in place.
Winnik’s technique uses fluorescence resonance energy transfer, a tool popular with biologists, to measure the distance between fluorescent dyes attached to the polymers in the paint particles. As the paint dries, the distance between dye molecules drops, leading to a change in fluorescence. Using this method, Winnik monitored how changing particle polymers or tweaking paint additives—two ways to reduce solvent use in latex paints—affected the film-formation process. Many of the environmentally friendly paints found in stores today benefited from this coatings research, Winnik says.
Winnik’s research has extended beyond coatings. He worked with instrument maker Applied Biosystems to develop gel-forming polymers for DNA sequencing. More recently, he has designed polymers that chelate lanthanide ions for use in a proteomics technique called mass cytometry. And with Ian Manners of the University of Bristol, in England, he has studied a family of block copolymers made from polyferrocenylsilane that self-assemble through a mechanism similar to that of amyloid fibrils. They’re the first synthetic polymers that grow like natural fibers do.
“Simply put, Mitch Winnik is the most gifted applied polymer chemist in the history of our department,” says Robert H. Morris, chair of the Toronto chemistry department.
Winnik, 69, earned a B.A. in chemistry from Yale University in 1965 and a Ph.D. in organic chemistry from Columbia University in 1969. He worked as a postdoctoral fellow at Caltech before joining the chemistry faculty at Toronto in 1970. In 1981, he became a full professor of chemistry, and in 1998 was named university professor, the university’s highest honor for scholarly achievement.
Over his career, Winnik has published more than 600 papers and produced 23 patents. In 1999, he won the Roy W. Tess Award in Coatings from the ACS Division of Polymeric Materials: Science & Engineering.
Winnik will present the award address before the ACS Division of Polymeric Materials.
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