The molar excess enthalpies and hydrophobic interaction for aqueous solution of butoxyethanols

Abstract

The molar excess enthalpies for aqueous solutions of 2-butoxyethanol (BE) and 2-t-butoxyethanol (t-BE) have been measured at 298.15K over the whole concentration range with a flow microcalorimeter.
All the solutions exhibit negative enthalpies of mixing and the absolute values show |H^E (t-BE)|>|H^E(BE)|. The enthalpic pair interaction parameters h_xx have been evaluated from the experimental data. All parameters h_xx have large positive values, suggesting the strong hydrophobic interaction in these solutions. The h_xx value of BE is larger than that of t-BE, which clearly indicates the orientation dependent contribution to the hydrophobic interaction.