Stephen E. Webbercmsew@mail.utexas.edu
William H. Wade Endowed Professorship in Chemistry
AB, Washington University - St Louis, 1962
PhD, University of Chicago, 1965
NSF Predoctoral Fellow University of Chicago 1965
Visiting Professor, U. de Paris - Sud, 1986
Visiting Professor, Ecole Polytechnique Federale de Lausanne, Switzerland, 1983
Polymer photophysics and self-assembling polymers
My research interests include photophysical processes in polymers and polymer self-assembly. Students in my group typically are involved in polymer synthesis and characterization in additional to photophysical studies and the development of theoretical models.
Photophysical processes in polymers can involve a complex interplay of effects. For example, attaching a small number of fluorophores to a polyelectrolyte permits one to study the ability of an ionic species to approach the polyelectrolyte chain and quench the excited state. If there are a large number of chromophores on the polymer chain then energy transfer along the chain can occur, analogous to "photon harvesting" in the photosynthetic reaction center.
Polymers can be synthesized from very difference monomers such that different blocks of the polymer can be selectively solvated. Depending on the molecular weight of the polymer and the choice of solvents the polymers may self-organize into various structures such as "polymer micelles". These are analogous to surfactant micelles but with much larger molecular weight and size (typically 107 daltons and 50 nm diameter) and a long, flexible corona region. These structures can be used to effect solubilization of hydrophobes or can be used to create arrays on surfaces.
C. Ted Lee, Jr., Won Ryoo, P. Griffin Smith, Jr., Jose Arellano, Daniel R. Mitchell, Richard J. Lagow, Stephen E. Webber, Keith P. Johnston "Carbon Dioxide-in-Water Microemulsions" J. Am. Chem. Soc. 125 (2003): 3181-3189.
Hahn, J; Webber, S. E. "Graphoepitaxy Control of the Deposition of Cationic Polymer Micelles on SiO2 Surfaces" Langmuir 19 (2003): 3098-3102.
C. Simmons, S. E. Webber, E. B. Zhulina "Association of Ionized Polymer Micelles with Oppositely Charged Polyelectrolytes" Macromolecules 34 (2001): 5053-5066.
R. M. Talingting, Y. Ma, C. Simmons, S. E. Webber "Cationic Polymer Micelles on Polyelectrolyte-Modified Surfaces" Langmuir 16 (2000): 862-865.