Partial Molar Volume of Methanol in Water: Effect of Polarizability

0324985 - ÚCHP 2009 RIV CZ eng J - Journal Article
Moučka, F. - Nezbeda, Ivo
Partial Molar Volume of Methanol in Water: Effect of Polarizability.
[Parciální molární objem metanolu ve vodě: Vliv polarizovatelnosti.]
Collection of Czechoslovak Chemical Communications. Roč. 74, č. 4 (2009), s. 559-563. ISSN 0010-0765
R&D Projects: GA AV ČR IAA400720802
Institutional research plan: CEZ:AV0Z40720504
Keywords : water–methanol mixtures * partial molar volume * polarizability
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 0.856, year: 2009

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.

Dosud používané párové potenciály nejsou schopny vystihnout nejzákladnější vlastnost směsi voda-metanol, minimum parciálního molárního objemu. Jako pokus odchýlit se od obvyklých kombinačních pravidel byl uvažován polarizovatelný model vody. Ukazuje se, že zahrnutí polarizibility je schopno kvalitativně změnit chování směsi a dosáhnout shody s experimentem
Permanent Link: http://hdl.handle.net/11104/0172553