Solvophobic interaction in a simple associated fluid

We apply Wertheim's theory on the associated fluid (1984, J. stat. Phys., 35, 19) to the study of the solvophobic effect in the simplest associated fluid where the dimer and the monomer molecules are in equilibrium. We calculate numerically the radial distribution function between hard sphere solute molecules in a simple associated fluid by means of integral equations. The results show that the solvent association alone does not bring about a significant solvophobic interaction between solute molecules, if compared with the hard sphere solvent at the same density. The results are interpreted as the competition of two effects, the solvophobic effect and the packing effect.