MSE Seminar: “Mesoscale Simulations of Multiphase Soft Matter Materials and Fluids”

Details

Paul Millett, Ph.D.

Associate Professor, Department of Mechanical Engineering

University of Arkansas

Dr. Paul Millett is an Associate Professor and holds the 21st Century Endowed Professorship Chair in the Mechanical Engineering department at the University of Arkansas.  His research and teaching interests include computational materials science, computational fluid dynamics, numerical methods, parallel computing, and materials design for energy and biomedical applications.  Dr. Millett’s research is funded by the National Science Foundation, the US Department of Energy, 3M, the Center for Advanced Surface Engineering, and the Membrane Science Engineering and Technology Center.

Abstract

The manipulation of multi-phase fluids, comprised of two or more immiscible liquids or liquid-solid suspensions, at very small length scales is an emerging avenue for materials discovery. Shaping such fluid phases into small droplets, bubbles, emulsions, or bicontinuous domains can be viewed as a precursor step towards fabricating functional material architectures. This talk will discuss how advanced computer simulations can shed light on the kinetics and metastable states within bicontinuous interfacially-jammed emulsions (bijels) that consist of two immiscible liquids stabilized with neutrally-wetting solid particles.  Particular attention will be given to the morphology of such systems in thin-film geometries under external electric fields to produce unique membranes for applications including energy production, water purification, and catalytic membranes.     

In addition, this talk will present hydrodynamical simulations of deformable liquid-filled capsule suspensions.  The rheology and microstructure of these suspensions in pressure-driven flow conditions within microfluidic channels will be examined.  Flow-induced capsule deformation results from both capsule-fluid interactions (in particular the local shear rate) as well as capsule-capsule interactions.  For relatively soft capsules, inertial focusing is observed for Re > 100 characterized by a narrowing of the capsule distribution towards the channel centerline.  The relative viscosity of the suspension (relative to the capsule-free fluid) and the principal tension within capsule membranes is analyzed for varying Reynolds number, Capillary number, and channel dimensions.