Molecular dynamics of ionic transport and electrokinetic effects in realistic silica channels

TitleMolecular dynamics of ionic transport and electrokinetic effects in realistic silica channels
Publication TypeJournal Article
Year of Publication2008
AuthorsLorenz CD, Crozier PS, Anderson JA, Travesset A
Journal TitleJournal of Physical Chemistry C
Volume112
Pages10222-10232
Date PublishedJul
Type of ArticleArticle
ISBN Number1932-7447
Accession NumberISI:000257335300041
Keywordsadsorption, CHARGE, CRYSTAL VIOLET, ELECTROLYTE-SOLUTIONS, FORCE-FIELD, POISEUILLE FLOW, SILANOL GROUPS, simulation, surfaces, WATER INTERFACE
Abstract

Silica is one of the most widely used inorganic materials in experiments and applications involving aqueous solutions of biomolecules, nanoparticles, etc. In this paper, we construct a detailed atomistic model of a silica interface that captures the essential experimentally known properties of a silica interface. We then perform all-atom molecular dynamics simulations of a silica nanochannel subjected to either an external pressure or an electric field and provide an atomistic description of ionic transport and both electro-osmotic flow and strean-tin- currents for a solution of monovalent (0.4 M NaCl) as well as divalent (0.2 and 1.0 M CaCl (2)) salts. Our results allow a detailed investigation of zeta-potentials, Stern layer conductance, charge inversion, ionic mobilities, as well as continuum theories and Onsager relations. We con clude with a discussion on the implications of our results for silica nanopore experiments and micro- and nanofluidic devices.

DOI10.1021/jp711510k
Alternate JournalJ. Phys. Chem. C