Professor Lynn Walker

Professor Lynn Walker
Department of Chemical Engineering and Materials Science
University of Minnesota
Flier

Engineering fluid-fluid interfaces through processing and multicomponent adsorption

Systems involving deformable interfaces between immiscible fluids offer a significant challenge for materials design and processing. Static interfacial/surface tension is often the only parameter considered in the design of systems with fluid-fluid interfaces. In foams, emulsions, blends, sprays, droplet-based microfluidic devices and many other applications, the dynamic nature of surface active species and deformation of interfaces requires a more detailed characterization of the interfacial transport, dynamic interfacial properties and interfacial structure. Macroscopic properties and the ability to tune and control phenomena requires an improved understanding of the time-dependent properties of the interfacial tension and interfacial mechanics. We have developed tools and approaches to quantify the impact of surface active species, particularly polymeric species, on interfacial behavior. Surfactant-nanoparticle complexes, polymer-surfactant aggregates and proteins (sequence specific polymers) show the potential of interfacial processing in controlling interfacial properties. The use of sequential adsorption, differences in transport timescales and variability in reversibility of different species allows interfaces to be engineered. This talk will provide the motivation to use microscale interfaces for efficient analysis of complex interfacial phenomena and how that relates to the material properties of interface-dominated materials

Professor Lynn Walker

Prof. Lynn Walker received her B.S. degree from the University of New Hampshire and a Ph.D. from the University of Delaware, both in chemical engineering. Prior to joining CEMS, she was at Carnegie Mellon University in Chemical Engineering and both Chemistry (by courtesy) and Materials Science & Engineering (by courtesy). She was an NSF International Postdoctoral Fellow at the Katholieke Universiteit in Leuven, Belgium before joining CMU in 1997. She has held visiting faculty positions at the Polymer IRC in Leeds, UK, Chemical Engineering at UCSB, and held the Piercy Visiting Professorship at the University of Minnesota. Her research focuses on quantifying the coupling between flow behavior and flow-induced microstructure in complex fluids. Currently her research focuses in two directions: quantifying the influence of flow on self-assembled nanostructures and controlling transport to complex fluid-fluid interfaces. She recently took the role of Perspectives Editor for AIChE Journal, served as Editor-in-Chief of Rheologica Acta and serves on the editorial boards of the Journal of Rheology, and Journal of Non-Newtonian Fluid Mechanics. She is a fellow of the American Institute of Chemical Engineers, the Society of Rheology, and the American Physical Society (DSOFT).