Anomalies in supercooled NaCl aqueous solutions

A microscopic perspective

M. Paula Longinotti, Marcelo Carignano, Igal Szleifer, Horacio R. Corti

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

In this work we studied the effect of NaCl on the thermodynamic and dynamic properties of supercooled water, for salt concentrations between 0.19 and 1.33mol kg-1, using molecular dynamic simulations for TIP5PE water model and ion parameters specially designed to be used in combination with this potential. We studied the isobaric heat capacity (Cp) temperature dependence and observed a maximum in Cp, occurring at Tm, that moves to lower temperature values with increasing salt concentration. Many characteristic changes were observed at scaled temperature TTm ∼ 0.96, namely a minimum in the density of the system, a reduction of the slope of the number of hydrogen bonds vs. temperature, and a crossover from Vogel-Tamman-Fulcher to Arrhenius dynamics. Finally, at low temperatures we observed that water dynamics become heterogeneous with an apparently common relationship between the fraction of immobile molecules and T/Tm for all studied systems.

Original languageEnglish
Article number244510
JournalJournal of Chemical Physics
Volume134
Issue number24
DOIs
Publication statusPublished - 28 Jun 2011
Externally publishedYes

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anomalies
aqueous solutions
Temperature
water
salts
Water
dynamic characteristics
Salts
crossovers
thermodynamic properties
specific heat
hydrogen bonds
slopes
molecular dynamics
Molecular Dynamics Simulation
temperature dependence
Thermodynamics
temperature
Specific heat
Molecular dynamics

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry
  • Medicine(all)

Cite this

Anomalies in supercooled NaCl aqueous solutions : A microscopic perspective. / Longinotti, M. Paula; Carignano, Marcelo; Szleifer, Igal; Corti, Horacio R.

In: Journal of Chemical Physics, Vol. 134, No. 24, 244510, 28.06.2011.

Research output: Contribution to journalArticle

Longinotti, M. Paula ; Carignano, Marcelo ; Szleifer, Igal ; Corti, Horacio R. / Anomalies in supercooled NaCl aqueous solutions : A microscopic perspective. In: Journal of Chemical Physics. 2011 ; Vol. 134, No. 24.
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