Non-Equilibrium Molecular Dynamics Simulation of a Spherical Solute in a Nanopore: Coupled Continuum/Atomistic Simulation

Tod Pascal, California Institute of Technology

Scaling down fluid flows from millimeter-sized capillaries to micrometer-sized fluidic channels is a popular method for miniaturization of a wide variety of important analytic and bioseparation devices. Sub-micron miniaturization has led to qualitatively new physical phenomena. At these length scales a number of important dimensions (electric double layer thickness, size of biomolecular analytes) become of the same order as the channel width. Overlapping of the electric double layers within the channel has an important impact on the electro-osmotic flow and distribution of charged analytes, and therefore could be used as a tool for flow control and manipulation as well as molecular separation.

We present an investigation of the factors affecting the electrophoretic mobility of a large solute in a charged nanopore. Factors, including charge, mass and radii of the solute, are shown to influence the mobility of the solute in a way not predicted by current continuum theories. Such effects will have to be accounted for when designing similar systems at the nanoscale.

Abstract Author(s): Tod Pascal(1), Dr. Aidan P. Thompson(2)<br />(1) - MSC, California Institute of Technology, Pasadena, CA<br />(2) - Computational Materials and Molecular Biology Dept., Sandia National Laboratories, Albuquerque, New Mexico