Wednesday, 9 March 11:00am – 12:00pm

This seminar will be delivered in Online Zoom Please email chemistry.researchsupport@sydney.edu.au for zoom link and password.

Speaker: Prof Lynn Walker; Department of Chemical Engineering, Carnegie Mellon University, USA

Host: A/Prof. Markus Muellner

Title: Relationship between nanoscale structure and transport properties of block copolymer solutions

Abstract: At high polymer concentrations, solvent-selective block copolymer molecules self-assemble into concentrated micellar solutions that form highly-ordered, nanostructured, soft solids.   Controlling the solvent quality allows for high densities of deformable (soft) particles to be achieved. Solvent stable nanoparticles dispersed in these soft solids will sample the solvent-swollen continuous structure providing a method to template, store, and define the environment of nanoparticulate material.   Dispersed phase materials including metal oxide nanoparticles and globular proteins have been studied, providing composite systems in two interesting limits; hard particles dispersed in a dense dispersion of soft particles and a dense dispersion of soft particles with a bimodal level of softness. We characterize the transport of nanoparticles on the local micelle packing and overall structure of the soft solid.  These materials have rich phase behavior offering considerable potential in templating, transport properties and nanostructure control through both molecular design and processing; we are specifically interested in the potential of these soft nanostructured matrices for protection and storage of proteins.

Biography: Lynn M. Walker is a Professor of Chemical Engineering and both Chemistry (by courtesy) and Materials Science & Engineering (by courtesy) at Carnegie Mellon University. She holds a B.S. degree from the University of New Hampshire and a Ph.D. from the University of Delaware, both in chemical engineering.  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, and in 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.  Current research focuses in two directions: quantifying the influence of flow on self-assembled nanostructures and controlling transport to complex fluid-fluid interfaces. She has twice been recognized for teaching by receiving the Kun Li Award for Excellence in Education from the Department of Chemical Engineering at CMU, is the 2016 recipient of the Lazarus Award for Mentoring from CMU and the 2015 WIC Mentorship Excellence Award from AIChE.  She recently took the role of Perspectives Editor for AIChE Journal, she is stepping down as Editor-in-Chief of Rheologica Acta and serves on the editorial boards of the Journal of Rheology, Journal of Non-Newtonian Fluid Mechanics, and Langmuir.  She is a fellow of both the American Institute of Chemical Engineers and the Society of Rheology.