June Meeting Notice

Thursday, June 16, 2011

Kim R. Williams: Field-Flow Fractionation: Dealing with the Big Stuff

Kim R. Williams

Department of Chemistry and Geochemistry
Colorado School of Mines
Golden, CO 80401

Abstract:

Nanoscience and nanotechnology have contributed to the formation of a new frontier for separations scientists. The synthesis of novel polymers and nanoparticles and their widespread use in areas as diverse as medicine, coatings, and household laundry have progressed more rapidly than the development of techniques to analyze them. Unlike molecular species, these nanomaterials usually possess distributions in molecular weight/size, chemistry, charge, etc. The range of these distributions can vary from batch-to-batch leading to different observed performances and, even, conflicting results. Separations can play a key role in understanding variations in results and in producing the uniform fractions essential to correlating physicochemical properties with observed behavior and performance.

Field-flow fractionation (FFF) is a family of techniques that was created specifically for separating and characterizing macromolecules, nanoparticles, and micron-sized particles. The separation process takes place in an open channel devoid of packing material and the retention time for each analyte species depends on its diffusion coefficient and interaction with an applied field. In practice, this translates to a wide size range of analytes that can be injected into a single FFF channel, low shear rates, and the ability to analyze samples without the need to prefilter. These advantages will be demonstrated with applications to microgel analysis and protein reassociation-dissociation studies. Various types of fields, e.g., centrifugal, electrical, crossflow, temperature gradient, etc., can be implemented and give rise to different FFF techniques with different capabilities. This presentation will address FFF basics and advances particularly with respect to insights that can be gained from polymer and nanoparticle analyses.

References:

1. S. K. R. Williams, J. R. Runyon, A. A. Ashames, Anal. Chem., 83, 634-642 (2011).

2. Anal. Chem. Feb 1, 2011 feature podcast http://pubs.acs.org/doi/abs/10.1021/ac101759z

About the Speaker:

Kim Williams received her B.Sc. from McGill University, Canada and a PhD from Michigan State University working with Professor Stanley Crouch. A chance meeting led her to a postdoc with the late Professor J. Calvin Giddings at the University of Utah. She subsequently became the Assistant Director of the Field-Flow Fractionation Research Center, and an Adjunct Assistant Professor in the Chemistry Department at the University of Utah. She not only learned about FFF, polymers, and nanoparticles but also took to skiing, river running, and mountain biking. All these skills continue to serve her well in her current position as an Associate Professor of Chemistry at the Colorado School of Mines. Her research interests in developing new separation capabilities for nanoscale materials are encompassed by diverse projects such as FFF and LC of polymers and nanoparticles, FFF-single particle counting to detect low levels of outliers (or aggregates) in CMP slurries and biotherapeutics, investigating new drug delivery pathways, and fabricating nanostructures for filtration and next generation photovoltaics.

She is highly involved with Outreach activities such as working with middle school teachers to develop lectures and inexpensive experiments using common household items and teaching FFF workshops in the US and abroad. From 1995-2005, she was an instructor for a two-day ACS short course on particle sizing techniques. She remains actively involved with faculty at universities in Thailand, the country where she was born and raised. She has twice been selected by chemistry graduate students as the Professor of the Year.

Details:

Location:	D'ignazio's Towne House
Times:	5:00 PM Executive Committee Meeting 5:45 PM Social "Hour" 6:30 PM Dinner 7:30 PM Presentation
Cost:	$30
Dinner Choices:	Tilapia Sirloin Steak Eggplant Parmesan

NOTICE TO STUDENTS AND FACULTY: Full-time students with valid ID may attend dinner meetings at half-price. Faculty members at colleges and universities are urged to bring one or more students to the meeting. If they do, they also can attend at half-price.