Molecular mechanisms causing anomalously high thermal expansion of nanoconfined water

Steve Garofalini, Thiruvilla S. Mahadevan, Shuangyan Xu, George W. Scherer

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

Anomalously high thermal expansion is measured in water confined in nanoscale pores in amorphous silica and the molecular mechanisms are identified by molecular dynamics (MD) simulations using an accurate dissociative water potential. The experimentally measured coefficient of thermal expansion (CTE) of nanoconfined water increases as pore dimension decreases. The simulations match this behavior for water confined in 30 Å and 70 Å pores in silica. The cause of the high expansion is associated with the structure and increased CTE of a region of water ∼6 Å thick adjacent to the silica. The structure of water in the first 3 7 of this interface is templated by the atomically rough silica surface, while the water in the second 3 7 just beyond the atomically rough silica surface sits in an asymmetric potential well and displays a high density, with a structure comparable to bulk water at higher pressure.

Original languageEnglish
Pages (from-to)1997-2001
Number of pages5
JournalChemPhysChem
Volume9
Issue number14
DOIs
Publication statusPublished - Oct 6 2008

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Thermal expansion
thermal expansion
Silicon Dioxide
Water
water
silicon dioxide
porosity
coefficients
Molecular dynamics
simulation
molecular dynamics
expansion
causes
Computer simulation

Keywords

  • Glass
  • Interfaces
  • Molecular dynamics
  • Nanomaterials
  • Water

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Atomic and Molecular Physics, and Optics

Cite this

Molecular mechanisms causing anomalously high thermal expansion of nanoconfined water. / Garofalini, Steve; Mahadevan, Thiruvilla S.; Xu, Shuangyan; Scherer, George W.

In: ChemPhysChem, Vol. 9, No. 14, 06.10.2008, p. 1997-2001.

Research output: Contribution to journalArticle

Garofalini, Steve ; Mahadevan, Thiruvilla S. ; Xu, Shuangyan ; Scherer, George W. / Molecular mechanisms causing anomalously high thermal expansion of nanoconfined water. In: ChemPhysChem. 2008 ; Vol. 9, No. 14. pp. 1997-2001.
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