Study of thermodynamical anomalies in mixtures

Abstract

Water-alcohol mixtures can exhibit anomalies in excess quantities. In this work, we attempt to describe these anomalies with a simple model for the water-solute mixture. The system is studied with an exact one-dimensional approach, as well as with threedimensional simulations. The interactions between particles in the mixture are represented by core-softened potentials and we compute the thermodynamic quantities of interest at constant pressure, temperature, and number of particles. The excess of the temperature of maximum density at small dilutions, the excess of volume, and excess of enthalpy are computed in the one dimensional analysis and in the simulations. The behavior of these quantities is compared with the water-alcohol experimental results.