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Title: Aqua Ions-Graphene Interfacial and Confinement Behavior: Insights from isobaric-isothermal molecular dynamics

We carry out a systematic micro-structural characterization of the solidfluid interface (SFI) of water and simple metal chloride aqueous solutions in contact with a free standing plate or with two such plates separated by an inter-plate distance 0 ! h( ) ! 30 at ambient conditions via isothermalisobaric molecular dynamics. With this characterization we target the interrogation of the system in search for answers to fundamental questions regarding the structure of the external and internal (confined) SFI s, the effect of the differential hydration behavior among species and its link to species expulsion from confinement. For water at ambient conditions we found that the structure of the external SFI s is independent of the interplate distance h in the range 0 ! h( ) ! 30 , i.e., the absence of wallmediated correlation effects between external and internal SFI s, and that for h < 9 the slit-pores de-wet. Moreover, we observed a selective expulsion of ions caused by the differential hydration between the anion and the cations with a consequent charging of the slit-pore. All these observations were interpreted in terms of the axial profiles for precisely defined order parameters including tetrahedral configuration, hydrogen bonding, and species coordination numbers.
Authors:
 [1] ;  [1]
  1. ORNL
Publication Date:
OSTI Identifier:
1021987
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Physical Chemistry A; Journal Volume: 115; Journal Issue: 23
Research Org:
Oak Ridge National Laboratory (ORNL)
Sponsoring Org:
SC USDOE - Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; ANIONS; AQUEOUS SOLUTIONS; BEHAVIOR; BONDING; CATIONS; CHLORIDES; CONFIGURATION; CONFINEMENT; COORDINATION NUMBER; CORRELATIONS; DISTANCE; DYNAMICS; HYDRATION; HYDROGEN; INTERFACES; IONS; METALS; MICROSTRUCTURE; MOLECULAR DYNAMICS METHOD; ORDER PARAMETERS; PLATES; RANGE; TARGETS; WATER