Water-Methanol Mixtures with non-Lorentz-Berthelot Combining Rules: A Feasibility Study

0368356 - ÚCHP 2012 RIV NL eng J - Journal Article
Moučka, F. - Nezbeda, Ivo
Water-Methanol Mixtures with non-Lorentz-Berthelot Combining Rules: A Feasibility Study.
Journal of Molecular Liquids. Roč. 159, 1 Sp.I:Sl (2011), s. 47-51. ISSN 0167-7322. E-ISSN 1873-3166
Institutional research plan: CEZ:AV0Z40720504
Keywords : water-alcohol mixtures * non-Lorentz-Berthelot rules * excess mixing properties
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 1.580, year: 2011

To examine a possibility to predict qualitatively correctly the properties of water-alcohol mixtures using pure fluid non-polarizable interaction potential models, a family of non-Lorentz-Berthelot combing rules was used in simulations on the water-methanol mixtures defined by the standard TIP4P (water) and OPLS (methanol) interaction models. A certain strategy to locate the region of the cross parameters yielding, potentially, a minimum in the partial molar volume of methanol has been adopted to reduce complexity of the problem and CPU time. It is found that a small deviation from the Lorentz rule along with a larger change in the Berthelot cross energy gives rise to a concavity of the excess volume at low methanol concentrations and hence to a minimum in the partial molar volume which is otherwise missing if the Lorentz-Berthelot rules are used. Nonetheless, it does not seem that non-Lorentz-Berthelot rules alone will be able to bring the results to a full quantitative agreement with experiment.
Permanent Link: http://hdl.handle.net/11104/0202726