Dynamics, Microviscosity, and Length Scales in Aqueous Polymer Solutions

In this project funded by the Experimental Physical Chemistry Program of the Chemistry Division, Castner will investigate friction in polymer and polymer-based complex fluids experimentally using time-dependent optical techniques. In these experiments a simple hypothesis relating the microviscosity of a polymer solution to the microviscosity of the monomer will be tested, and related behavior in triblock co-polymers will be explored. Optical-heterodyne detected Raman-induced Kerr effect spectroscopy will be used to measure the microviscosities. Recent advances in femtosecond spectroscopic techniques will help improve the measurements. The widely variable shear viscosity of these triblock co-polymer gels system will allow incisive tests of the microviscosity hypothesis. A second set of experiments will explore dynamics in thermoreversible hydrophilic polymer gels.

Results of these experiments will lead to better understanding of aqueous polymer solutions and are of relevance to the design of improved polymer gels for drug delivery and other applications. This research will be be conducted in collaboration with theorist Robert Cave of Harvey Mudd College, an undergraduate institution. The PI also mentors first-year women students from Douglass College in an Introduction to Scientific Research course. As a result, undergraduates from Rutgers University, Douglass College, and Harvey Mudd College can obtain experience in this forefront research area.