Novel studies of phase and structural transitions in bulk and vicinal water

Abstract

The paper presents the results of studies obtained by the differential scanning calorimetry method on phase (freezing, melting, evaporation) and structural transitions taking place from −50 to 100°C in the bulk and adsorbed water on the surface of pure silica gel and bovine serum albumin (BSA) and on the silica gel surface covered with BSA. Cyclic changes of heat flow which were associated with changes in the properties of water due to changing temperature were observed. The occurrence of structural transitions called the “paradoxical efffect” in the bulk water and in the aqueous adsorption layer at subambient and elevated temperatures was confirmed. They are due to cyclic changes of some properties of water, particularly of a tetrahedral ice-like structure found in bulk and vicinal water. Depending on the process course (cooling or heating of the sample), water structure either undergoes cyclic reproduction (during the cooling process) or decay (during heating) in the systems studied that include water.