On the composition dependence of thermodynamic, dynamic and dielectric properties of water-methanol model mixtures. Molecular dynamics simulation results

Galicia-Andres, E. and Dominguez, H. and Pusztai, László and Pizio, O. (2015) On the composition dependence of thermodynamic, dynamic and dielectric properties of water-methanol model mixtures. Molecular dynamics simulation results. CONDENSED MATTER PHYSICS, 18 (4). ISSN 1607-324X

Preview

Text 1512.07794v1.pdf Available under License Creative Commons Attribution. Download (461kB) | Preview

Abstract

We have investigated thermodynamic and dynamic properties as well as the dielectric constant of water-metha- nol model mixtures in the entire range of composition by using constant pressure molecular dynamics simu- lations at ambient conditions. The SPC/E and TIP4P/Ew water models are used in combination with the OPLS united atom modelling for methanol. Changes of the average number of hydrogen bonds between particles of different species and of the fractions of differently bonded molecules are put in correspondence with the be- havior of excess mixing volume and enthalpy, of self-diffusion coefficients and rotational relaxation times. From the detailed analyses of the results obtained in this work, we conclude that an improvement of the description of an ample set of properties of water-methanol mixtures can possibly be reached, if a more sophisticated, carefully parameterized, e.g., all atom, model for methanol is used. Moreover, exploration of parametrization of the methanol force field, with simultaneous application of different combination rules for methanol-water cross interactions, is required.

Actions (login required)

Edit Item