Molecular dynamics study of electrolyte‐filled pores

Abstract

The structure and dynamics of aqueous electrolyte solutions in cylindrical pores with pore radii of 11.1 Å have been investigated by molecular dynamics simulations. The pores serve as models for porous polymer membranes that have recently been produced. Polar functionalized pores were modeled by positive and negative surface charges on the cylinder surface. The observed correlation between ion mobility and the extent of contact ion pair formation with the surface charges provides a possible explanation for the experimentally observed ion selectivity in these pores.

Model Channel Ion Currents in NaCl-Extended Simple Point Charge Water Solution with Applied-Field Molecular Dynamics

“…The equilibrium properties of ions in channels have also been studied with statistical mechanics and simulation approaches using simplified channel models (Vlachy and McQuarrie, 1986;Sorensen and Sloth, 1992;Lozada-Cassou et al, 1996;Lynden-Bell and Rasaiah, 1996;Hartnig et al, 1998;Lo et al, 1998;Roux, 1999;Tang et al, In press). For instance, based on the mean spherical approximation, the excess chemical potential for binding divalent ions relative to monovalent ions in a confined space with constrained charges helps explain the selectivity of a voltage-gated calcium channel for Ca ++ over Na + (Nonner et al, 2000).…”

Study of ion partitioning in nanoporous materials by analytical approach and molecular modeling

“…The current understanding of ionic transport across nanopores based on macroscopic (Donnan) and mesoscopic (Primitive model using GCMC and PB) fluid physics is only partial. This paper presents a molecular simulation study [12][13][14][15][16][17] of the ions behavior at the water/nanopore interface, focusing on the effect of a neutral atomic surface from hydrophobic to hydrophilic case. The behavior of ions at the interface is characterized by determining the density distribution and the coefficient of partition.…”