engleski

A Molecular Dynamics study of micro-heterogeneity in water-alcohol mixtures

Molecular Dynamics study of water-alcohol mixtures show considerable micro-heterogeneity, almost independently of the underlying models. We report results for several alcohols such as methanol, ethanol, n-propanol, terbutanol and butoxyethanol. Thermodynamical, dynamical and structural properties are compared with experimental ones. We analyze the correspondence between the micro-structure and the concentration fluctuations of the different models. The importance of system size and equilibration and production times are particularly emphasized. The analysis of the concentration fluctuation is made through the Kirkwood-Buff integrals, and particular attention is paid to the dependence of these quantities on the force field parametrization of the alcohol. The influence of the water model is equally analyzed in some particular cases. This allows an indirect test of the type of micro-structure that is privileged in the real system.

micro-heterogeneity; water-alcohol mixtures; Kirkwood-Buff integral

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