Manifestation of hydration effects in dioxane-water solutions by concentration-dependent changes of thermal and elastic properties

Properties of 1,4-dioxane and 1,3-dioxane aqueous solutions were studied versus the solute concentration. Concentration-dependent changes of molar volume and isentropic compressibility were determined based on the measured density of the solutions and ultrasound propagation velocity. Concurrently, thermal effusivity dependence on dioxane concentration was studied by photoacoustic measurement technique. It has been proved that the application of these experimental methods allows to construct a picture of structural changes in aqueous 1,4-dioxane solutions, which is consistent with results reported previously. The investigation of relatively less recognized 1,3-dioxane solutions in a water rich region has shown a more distinct hydrophobic behaviour of this isomer, compared to 1,4-dioxane.