Thermodynamic geometry for binary mixtures: A constrained approach

Abstract

Thermodynamic geometry for binary mixtures is explored in a constrained version. In order to have an insight into the interpretation of the scalar curvature (R) for mixtures, we develop and discuss the thermodynamic geometry for binary mixtures of hard spheres and van der Waals fluids with a restriction in the total particle number. For the case of hard spheres we have an interaction which is exclusively repulsive and van der Waals fluids account for repulsive and attractive interactions, which is a more realistic model. From our analysis, it is seen that the physical interpretation of R given for monocomponent systems, is no longer satisfied for the case of mixture of ideal gases and hard spheres. For the constrained version of the mixture of van der Waals fluids, we have that the scalar curvature nicely reproduces the behavior observed for the monocomponent fluid, including the interpretation of R as an indicator of repulsive or attractive intermolecular interactions and phase transitions.