USING NMR SPECTROSCOPY FOR DETERMINING TERMODYNAMIC PROPERTIES OF WATER BOUND WITH OX-50 NANOSILICA
Thermodynamic characteristics of water bound with OX-50 nanosilica (specific surface area SBET ≈ ≈ 50 m2/g) in different media (water, air, chloroform, and gaseous methane) have been determined using a low-temperature 1H NMR spectroscopy method. The difference in the hydration properties of OX-50 silica before and after transition from the aqueous suspension to the hydrated powder has been shown. The size distributions of water clusters in the systems under study calculated with the Gibbs-Thomson equation are presented. It was found that the average size of these water structures is much larger in the suspension than in the hydrated powders.