This award supports computational research on complex fluids. 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 mesoscale structures of these systems endow them with many interesting and unique features, and they are widely used in the processing, chemical and energy industries. It is therefore important to explore ways in which their properties can be modeled numerically to predict behavior, test physical theories, and provide feedback for the design and analysis of experiments and industrial applications.
These systems 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 their behavior has 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 length scales of interest. The goal is to incorporate the essential features of the microscopic and macroscopic physics in models that are computationally efficient and are easily implemented in complex geometries and on parallel computers.
The research entails the development and application of a range of mesoscale simulation techniques. In particular, previous research involving Monte Carlo simulations of dynamically triangulated random surfaces will be extended to study the structure and thermodynamics of microemulsions with a finite spontaneous curvature. Work on a recently developed particle-based mesoscopic simulation technique for fluid flow will continue, and it will be extended to model the dynamics and rheology of complex mixtures, including embedded vesicles modeled as a randomly triangulated network. This work will be a first step towards integrating simulation techniques for network models of membranes with mesoscopic solvent simulation techniques and developing the capability to model blood flows in narrow capillaries and the trafficking of blood born cells into tissue, which is crucial for the proper function of the immune system. Much of this work will be preformed in close collaboration with experiment, and previous collaborations involving the use of simulations to model and interpret fluid membrane flicker spectroscopy data - and determine the bending rigidity and spontaneous curvature of individual lipid bilayer vesicles - will continue and be extended.
Mesoscale simulation techniques have matured over the last several years to the extent that they can now be used to model specific amphiphilic mixtures and determine their phase behavior and rheology. Since simulations provide an essentially approximation-free method for studying these coarse-grained models, when performed in concert with experiment, they provide an ideal vehicle for model refinement and can be used to help engineer materials with desired properties. One of the goals of this research is to develop algorithms and disseminate software that can be used for the design and understanding of industrial and biological processes. Students will be introduced to these techniques in an interdisciplinary course. %%% This award supports computational research on complex fluids. 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 mesoscale structures of these systems endow them with many interesting and unique features, and they are widely used in the processing, chemical and energy industries. It is therefore important to explore ways in which their properties can be modeled numerically to predict behavior, test physical theories, and provide feedback for the design and analysis of experiments and industrial applications.
Mesoscale simulation techniques have matured over the last several years to the extent that they can now be used to model specific amphiphilic mixtures and determine their phase behavior and rheology. Since simulations provide an essentially approximation-free method for studying these coarse-grained models, when performed in concert with experiment, they provide an ideal vehicle for model refinement and can be used to help engineer materials with desired properties. One of the goals of this research is to develop algorithms and disseminate software that can be used for the design and understanding of industrial and biological processes. Students will be introduced to these techniques in an interdisciplinary course. ***
