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

Journal Article · Sat Jan 01 04:00:00 EST 2011 · Journal of Physical Chemistry A

DOI:https://doi.org/10.1021/jp110318n· OSTI ID:1021987

Chialvo, Ariel A ^[1]; Cummings, Peter T ^[1]

---

1. ORNL

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.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1021987
• Journal Information: Journal of Physical Chemistry A, Journal Name: Journal of Physical Chemistry A Journal Issue: 23 Vol. 115; ISSN 1089-5639
• Country of Publication: United States
• Language: English

Related Subjects

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