MSE Seminar - Professor Matthew Tirrell, Univ. of Chicago and Argonne National Laboratory
Title: Polyelectrolytes in Multivalent Ionic Media: New Physics and New Materials
Abstract: Multi-valent interactions in systems of polyelectrolytes can exhibit dramatic, non-monotonic effects, for example, switching forces from repulsive to attractive and back to repulsive again, in some cases. We have been studying these patterns of behavior with the surface forces apparatus (SFA) and with electrochemical methods, such as cyclic voltametry, which enables the quantitative determination of the number of multi-valent ions residing in thin layers of charged polymers. At fixed ionic strength, all cause strong shrinkage and condensation of poly(styrene sulfonate) brushes over a narrow range of ratio multi-valent to mono-valent ions. When the multi-valent ion is an oppositely charged polymer, new fluid phases can form. Charged blocks in copolymers leads to materials with new types of ordered phases. Effects of these multi-valent interactions on supermolecular and biomolecular assembly will be discussed. There are many possibilities for the creation of new materials based on electrostatic assembly involving mutli-valent interactions.
Bio: Matthew Tirrell is the founding Pritzker Director of the Institute for Molecular Engineering at the University of Chicago, and a Senior Scientist at Argonne National Laboratory. He specializes in polymer surface properties, adsorption, adhesion, surface treatment, friction, lubrication, biocompatibility and self-assembly.
In 2009, Prof. Tirrell became the Arnold and Barbara Silverman Professor and Chair of Bioengineering at the University of California, Berkeley, with additional appointments in chemical engineering and materials science & engineering, and as a Faculty Scientist at the Lawrence Berkeley National Laboratory. He served in these capacities until taking his current appointment in 2011.
From 1977 to 1999, Tirrell was a member of the Chemical Engineering and Materials Science faculty at the University of Minnesota, where he served as department head from 1995 to 1999. From 1999 to 2009, Tirrell was Dean of Engineering and Professor of Chemical Engineering and Materials at the University of California, Santa Barbara.
Tirrell has co-authored approximately 300 papers and one book during his career. He has supervised approximately 80 Ph.D. students and 40 postdocs.
Tirrell’s honors include membership in the National Academy of Engineering, the American Academy of Arts & Sciences and the Indian National Academy of Engineering. He also has been a Sloan and a Guggenheim Fellow, a Camille and Henry Dreyfus Teacher-Scholar, and a fellow of the American Institute of Medical and Biological Engineers, of the American Association for the Advancement of Science and of the American Physical Society.
From the American Institute of Chemical Engineers Prof. Tirrell has received the Allan P. Colburn Award, the Charles Stine Award, the William H. Walker Award, and the Professional Progress Awards. He was the Institute Lecturer in 2001.
Additionally, Tirrell has served as a member of the Boards of Directors of the Santa Barbara Cottage Hospital System and of the Camille and Henry Dreyfus Foundation.
Tirrell received a B.S. in Chemical Engineering at Northwestern University and a Ph.D. in 1977 in Polymer Science from the University of Massachusetts.
Reception at 3:30 in MARC Atrium