Document Type
Article
Original Publication Date
2018
Journal/Book/Conference Title
Physical Chemistry Chemical Physics
Volume
20
First Page
27838
Last Page
27848
DOI of Original Publication
10.1039/c8cp03791d
Date of Submission
October 2019
Abstract
We study the pressure-driven flow of aqueous NaCl in amorphous silica nanotubes using nonequilibrium molecular dynamics simulations featuring both polarizable and non-polarizable molecular models. Different pressures, electrolyte concentrations and pore sizes are examined. Our results indicate a flow that deviates considerably from the predictions of Poiseuille fluid mechanics. Due to preferential adsorption of the different ionic species by surface SiO! or SiOH groups, we find that a significant electric current is generated, but with opposite polarities using polarizable vs. fixed charge models for water and ions, emphasizing the need for careful parameterization in such complex systems. We also examine the influence of partial deprotonation of the silica surface, and we find that much more current is generated in a dehydrogenated nanopore, even though the overall efficiency remains low. These findings indicate that different methods of nanopore preparation, which can produce a range of surface properties, should be examined more closely in the related experimental methods to generate electrokinetic current.
Rights
© the Owner Societies 2018
Is Part Of
VCU Chemistry Publications
Comments
This article is the postprint version of the article published in October 2018 at https://doi.org/10.1039/c8cp03791d.