Collect. Czech. Chem. Commun. 2009, 74, 559-563
Published online 2009-03-22 21:34:55

Partial molar volume of methanol in water: Effect of polarizability

Filip Moučkaa and Ivo Nezbedaa,b,*

a Faculty of Science, J. E. Purkinje University, 400 96 Ústí nad Labem, Czech Republic
b E. Hála Laboratory of Thermodynamics, Institute of Chemical Process Fundamentals, Academy of Sciences of the Czech Republic, v.v.i., 165 02 Prague 6-Suchdol, Czech Republic


The available pairwise additive intermolecular interaction models used so far in simulations in combination with common combining rules do not seem to be able to reproduce the most distinct feature of aqueous solutions of alcohols, the minimum of the partial molar volume at low alcohol concentrations. Nonetheless, this fundamental failure seems to have been paid little attention to, partly because of very high requirements for accuracy and, hence, CPU time of simulations. As an attempt to go beyond empirical combining rules and account in a more physical and yet simple way for the cross interactions, a feasibility study has been undertaken using a polarizable model of water in molecular simulations of the water–methanol mixture at ambient conditions. It turns out that the inclusion of polarizability may qualitatively change the behavior of the mixture bringing the result in agreement with experiment.

Keywords: Water–methanol mixtures; Partial molar volume; Polarizability.

References: 12 live references.