Thermodynamic anomalies in a lattice model of water: Solvation properties
Abstract
We investigate a lattice-fluid model of water, defined on a three-dimensional body-centered-cubic lattice. Model molecules possess a tetrahedral symmetry, with four equivalent bonding arms. The model is similar to the one proposed by Roberts and Debenedetti [J. Chem. Phys. 105, 658 (1996)], simplified by removing distinction between "donors" and "acceptors." We focus on the solvation properties, mainly as far as an ideally inert (hydrophobic) solute is concerned. As in our previous analysis, devoted to neat water [J. Chem. Phys. 121, 11856 (2004)], we make use of a generalized first-order approximation on a tetrahedral cluster. We show that the model exhibits quite a coherent picture of water thermodynamics, reproducing qualitatively several anomalous properties observed both in pure water and in solutions of hydrophobic solutes. As far as supercooled liquid water is concerned, the model is consistent with the second critical-point scenario.
- Publication:
-
Journal of Chemical Physics
- Pub Date:
- July 2005
- DOI:
- 10.1063/1.1950628
- arXiv:
- arXiv:cond-mat/0504194
- Bibcode:
- 2005JChPh.123b4506P
- Keywords:
-
- 82.30.Nr;
- 64.75.+g;
- 65.20.+w;
- 05.50.+q;
- 05.70.Jk;
- Association addition insertion cluster formation;
- Solubility segregation and mixing;
- phase separation;
- Thermal properties of liquids: heat capacity thermal expansion etc.;
- Lattice theory and statistics;
- Critical point phenomena;
- Condensed Matter - Soft Condensed Matter;
- Condensed Matter - Statistical Mechanics
- E-Print:
- 12 pages, 9 figures, 1 table