Structural and transport properties of an SPC/E electrolyte in a nanopore

Yuk Wai Tang, Kwong Yu Chan, I. Szalai

Research output: Contribution to journalArticle

40 Citations (Scopus)

Abstract

Equilibrium (HMD) and nonequilibrium molecular dynamics (NEMD) simulations were conducted to investigate the effects of confinement on the structural and transport properties of an electrolyte in a nanopore. The extended simple point charge (SPC/E) model was used to model water molecules in a 0.5 M KCl electrolyte. The cylindrical nanopore was smooth, structureless, and hydrophobic with a radius that varied from 4.75 to 15.8 A. Changes in energies and structures were observed as the nanopore radius varied. The ion-ion, ion-water, and water-water interaction energies, the ion-ion and ion-water pair distribution functions, the density profiles of H and O atoms, and the water orientation about the vertical axis and around an ion were calculated in the simulations. Because of confinement in the radial direction in a narrow pore, there was incomplete solvation of ions, evidenced by less negative ion-water energy and less alignment of water molecules with the field of the ion. With a stronger confinement, H-bonding decreased, whereas the external field had a stronger influence on the orientation of the water molecules. Both EMD and NEMD results showed a decrease of ionic conductivity with decreasing pore radius, but there was an appreciable discrepancy between the conductivities obtained by the two methods for the cases of smaller pore diameters.

Original languageEnglish
Pages (from-to)18204-18213
Number of pages10
JournalJournal of Physical Chemistry B
Volume108
Issue number47
DOIs
Publication statusPublished - Nov 25 2004

Fingerprint

Nanopores
Transport properties
Electrolytes
Structural properties
transport properties
electrolytes
Ions
Water
water
ions
porosity
Molecules
radii
Molecular dynamics
Helmet mounted displays
molecular dynamics
helmet mounted displays
molecules
Solvation
Ionic conductivity

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Structural and transport properties of an SPC/E electrolyte in a nanopore. / Tang, Yuk Wai; Chan, Kwong Yu; Szalai, I.

In: Journal of Physical Chemistry B, Vol. 108, No. 47, 25.11.2004, p. 18204-18213.

Research output: Contribution to journalArticle

Tang, Yuk Wai ; Chan, Kwong Yu ; Szalai, I. / Structural and transport properties of an SPC/E electrolyte in a nanopore. In: Journal of Physical Chemistry B. 2004 ; Vol. 108, No. 47. pp. 18204-18213.
@article{dc68417d3fbb4f96bde6e4468e80ad24,
title = "Structural and transport properties of an SPC/E electrolyte in a nanopore",
abstract = "Equilibrium (HMD) and nonequilibrium molecular dynamics (NEMD) simulations were conducted to investigate the effects of confinement on the structural and transport properties of an electrolyte in a nanopore. The extended simple point charge (SPC/E) model was used to model water molecules in a 0.5 M KCl electrolyte. The cylindrical nanopore was smooth, structureless, and hydrophobic with a radius that varied from 4.75 to 15.8 A. Changes in energies and structures were observed as the nanopore radius varied. The ion-ion, ion-water, and water-water interaction energies, the ion-ion and ion-water pair distribution functions, the density profiles of H and O atoms, and the water orientation about the vertical axis and around an ion were calculated in the simulations. Because of confinement in the radial direction in a narrow pore, there was incomplete solvation of ions, evidenced by less negative ion-water energy and less alignment of water molecules with the field of the ion. With a stronger confinement, H-bonding decreased, whereas the external field had a stronger influence on the orientation of the water molecules. Both EMD and NEMD results showed a decrease of ionic conductivity with decreasing pore radius, but there was an appreciable discrepancy between the conductivities obtained by the two methods for the cases of smaller pore diameters.",
author = "Tang, {Yuk Wai} and Chan, {Kwong Yu} and I. Szalai",
year = "2004",
month = "11",
day = "25",
doi = "10.1021/jp0465985",
language = "English",
volume = "108",
pages = "18204--18213",
journal = "Journal of Physical Chemistry B Materials",
issn = "1520-6106",
publisher = "American Chemical Society",
number = "47",

}

TY - JOUR

T1 - Structural and transport properties of an SPC/E electrolyte in a nanopore

AU - Tang, Yuk Wai

AU - Chan, Kwong Yu

AU - Szalai, I.

PY - 2004/11/25

Y1 - 2004/11/25

N2 - Equilibrium (HMD) and nonequilibrium molecular dynamics (NEMD) simulations were conducted to investigate the effects of confinement on the structural and transport properties of an electrolyte in a nanopore. The extended simple point charge (SPC/E) model was used to model water molecules in a 0.5 M KCl electrolyte. The cylindrical nanopore was smooth, structureless, and hydrophobic with a radius that varied from 4.75 to 15.8 A. Changes in energies and structures were observed as the nanopore radius varied. The ion-ion, ion-water, and water-water interaction energies, the ion-ion and ion-water pair distribution functions, the density profiles of H and O atoms, and the water orientation about the vertical axis and around an ion were calculated in the simulations. Because of confinement in the radial direction in a narrow pore, there was incomplete solvation of ions, evidenced by less negative ion-water energy and less alignment of water molecules with the field of the ion. With a stronger confinement, H-bonding decreased, whereas the external field had a stronger influence on the orientation of the water molecules. Both EMD and NEMD results showed a decrease of ionic conductivity with decreasing pore radius, but there was an appreciable discrepancy between the conductivities obtained by the two methods for the cases of smaller pore diameters.

AB - Equilibrium (HMD) and nonequilibrium molecular dynamics (NEMD) simulations were conducted to investigate the effects of confinement on the structural and transport properties of an electrolyte in a nanopore. The extended simple point charge (SPC/E) model was used to model water molecules in a 0.5 M KCl electrolyte. The cylindrical nanopore was smooth, structureless, and hydrophobic with a radius that varied from 4.75 to 15.8 A. Changes in energies and structures were observed as the nanopore radius varied. The ion-ion, ion-water, and water-water interaction energies, the ion-ion and ion-water pair distribution functions, the density profiles of H and O atoms, and the water orientation about the vertical axis and around an ion were calculated in the simulations. Because of confinement in the radial direction in a narrow pore, there was incomplete solvation of ions, evidenced by less negative ion-water energy and less alignment of water molecules with the field of the ion. With a stronger confinement, H-bonding decreased, whereas the external field had a stronger influence on the orientation of the water molecules. Both EMD and NEMD results showed a decrease of ionic conductivity with decreasing pore radius, but there was an appreciable discrepancy between the conductivities obtained by the two methods for the cases of smaller pore diameters.

UR - http://www.scopus.com/inward/record.url?scp=10044231823&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=10044231823&partnerID=8YFLogxK

U2 - 10.1021/jp0465985

DO - 10.1021/jp0465985

M3 - Article

VL - 108

SP - 18204

EP - 18213

JO - Journal of Physical Chemistry B Materials

JF - Journal of Physical Chemistry B Materials

SN - 1520-6106

IS - 47

ER -