Excess properties of aqueous solutions: hard spheres versus pseudo-hard bodies

Abstract

The effect of repulsive interactions (geometrical packing of molecules) on mixing properties is examined considering hard sphere solutes of different diameters in the hard sphere and pseudo-hard body solvents. It is shown that the fluid of pseudo-hard bodies, representing repulsive interactions in water, captures, without any parameter adjustment, the experimentally observed decrease of the partial molar volume of nonpolar solutes (hard spheres) at their low concentrations when compared to that in a nonpolar (hard sphere) solvent.

Keywords:

• aqueous solutions
• primitive models
• pseudo-hard bodies
• excess volume
• partial molar volume

Acknowledgement

This work was supported by the Grand Agency of the Academy of Sciences of the Czech Republic (Grant No. IAA400720802).