Charges, Hydrogen Bonds and Salt
How to Design Functional Polyelectrolyte Complexes
Biomedical Engineering Graduate Seminar
Dr. Kenneth R Shull, PhD
Professor, Materials Science and Engineering
Abstract: Polyelectrolyte complexes are formed by mixing oppositely-charged polymeric molecules in the presence of water. The process is driven by the release of counterions, and the strength of the attractive interaction can be mediated and even eliminated by the addition of salt. We have developed a series of partially charged polymers where attractive hydrogen bonding interactions between molecular components also play a role. In these systems everything matters: solvent composition, solution pH (for aqueous solvent systems), charge fraction, salt concentration and identity, temperature, etc. These systems are ideally suited for fundamental studies of polyelectrolyte complex formation and property investigation, and also present a useful design space for the synthesis of functional materials. The design approach will be illustrated in our case with formation of nanoporous membranes for water purification.
Bio: Ken Shull is Professor of Materials Science and Engineering at Northwestern University. His research interests involve the interfacial properties of polymers, with a particular emphasis on adhesion, fracture and the behavior of thin films and coatings. Recent interests include the large-strain deformation and fracture behavior of ‘soft’ materials including polymer nanocomposites, the mechanical properties and phase behavior of polyelectrolyte complexes, and advanced uses of the quartz crystal microbalance.
He received B.S. and M.S. degrees in Materials Science from MIT, followed by a Ph.D. in Materials Science from Cornell University, which he received in 1990. He worked as a research staff member at the IBM Almaden Research Center for 3 years before joining Northwestern University in 1993. He is a fellow of the American Physical Society and of the Adhesion Society.
Friday, September 14, 2018 at 3:00 pm
Minerals and Materials Engineering Building (M&M), U113
1400 Townsend Drive, Houghton, MI 49931