Reply to “Comment on ‘Hydrophobic effects on partial molar volume’ ” [J. Chem. Phys. 123, 167103 (2005)

Abstract

In the Comment on our paper [J. Chem. Phys. 123, 167103 (2005), preceding paper], Graziano argues based on the scaled particle theory that the partial molar volume change in the transfer of a hydrophobic solute from “hypothetical nonpolar water” to water can be explained simply by the difference in the effective size of solvent molecules. Opposing to the argument, we clarify using the reference interaction site model theory that the attractive interactions represented by the hydrogen bonding play an essential role for the volume change, and that the explanation given by Graziano replaces the real physics by a fake model based on an “effective” molecular diameter. We also make a general argument against the use of hard-sphere models when one considers the properties of hydration.