Department of Physics


Department of Physics Apple - Gravity

Phone (701) 231-8974, fax (701) 231-7088


Seminar Abstract

January 26, 2004

"Mesoscale Modeling of Soft Condensed Matter: Application to Complex Fluids and Membranes"

Dr. Daniel M. Kroll
Supercomputing Institute for Digital Simulation and Advanced Computation
University of Minnesota

Complex fluids, such as amphiphilic mixtures, colloidal suspensions, and polymer solutions, mixtures, and melts, are characterized by structure on mesoscopic length-scales -- ranging from nano- to micrometers -- and energy scales comparable to the thermal energy. The meso-scale structures of these systems endow them with many interesting and unique features, and they are widely used in the processing, chemical, and energy industries.

Complex fluids present a challenge for conventional methods of simulation due to the presence of disparate time scales in their dynamics. The unique problems associated with the modeling and analysis of the behavior of these systems have created the need for new simulation techniques that overcome some of the difficulties associated with the use of atomistic molecular dynamics simulations and macroscopic approaches based on the numerical solution of continuum equations. The modeling of these systems requires the use of "coarse-grained" or mesoscopic approaches that mimic the behavior of atomistic systems on the length scales of interest. The goal is to incorporate the essential features of the microscopic and mesoscopic physics in models that are computationally efficient and are easily implemented in complex geometries and on parallel computers.

In this lecture, recent research involving the development and application of a range of mesoscale simulation techniques will be summarized. Work involving the use of coarse-grained, dynamically triangulated surface models of membranes to study the budding of crystalline (clathrin-coated pits) in fluid membranes and the phase behavior and structure of microemulsions -- membranes of fluctuating topology -- will be described, and a recently developed particle-based mesoscopic simulation technique for fluid flow will be discussed. Some future research involving extensions of these techniques to model the dynamics and rheology of complex mixtures will be outlined.