Department of Mathematics Colloquium

University of Idaho

Fall 2013

Thursday,  October 10, 3:30-4:20 pm, room TLC 145

Refreshments in Brink 305 at 3:00 pm

Coupling Fluid and Molecular Mechanics for Nanoscale
Simulations of Soft Matter


Nikolaos K. Voulgarakis

Department of Mathematics

Washington State University, Tri-Cities


Structure and dynamics of soft matter are governed by molecular interactions and hydrodynamic fluctuations. As the molecular and hydrodynamic aspects are coupled, computer simulations of soft matter must confront this multiscale challenge. While molecular dynamics (MD) simulations can provide mechanistic insight at the atomistic level, the range of accessible length- and time-scales is severely limited. Field-theoretic models, such as fluctuating hydrodynamics (FHD), overcome such limitations by replacing molecular details with emergent conservation and scaling laws, but ignore key structural properties of soft matter. In this talk, I will present a new scale-consistent simulation framework that combines MD and FHD to enable multiscale modeling of complex systems. This method allows resolution of solute-solvent interfaces and realization of excluded volumes of particles in the presence of hydrodynamic coupling. In this approach, structures and fluctuating fields are coupled directly through excluded volume effects and hydrodynamic forces without introducing boundary conditions. Simulation results show that the hybrid FHD/MD method can reproduce the solvation free energies and scaling laws of particles dynamics for hydrophobes of difference sizes. Simulations of spatiotemporal dynamics of nanoscale objects and self-assembly of hydrophobic particles will also be presented.