Olieinik A. Nature of thermodynamic and kinetic properties of water on the liquid-vapour coexistence line.

The Thesis is devoted to the investigation of liquid water properties in the whole temperature interval from the supercooled region to the critical point. The main attention is focused on the temperature dependence of the specific volume, the heat of evaporation as well as the kinematic shear viscosity and the self-diffusion coefficient. The most general principles of the thermodynamics of irreversible processes and kinetic theory were used: the principle of corresponding states, the Hilbert principle for the expansion of thermodynamic quantities with respect to structural functions of the H-bond network, the principle of additivity for contributions to the chemical potential and kinetic coefficients caused by different physical mechanisms. The Thesis shows that the water specific volume and heat of vaporization have argon-like behavior in suitable normalized variables. Small deviations from argon-like behavior are used for the determination of the average number of H-bonds per molecule. It is shown that values of this number obtained from the analysis of the specific volume, heat of vaporization, and the kinematic viscosity are in the quite satisfactory agreement between each other. A new consistent interpretation of the phenomenon of maximal water density near 4?C is proposed. The maximum appears due to the superposition of argon-like contribution and the hydrogen bonds contribution, which have different temperature dependence. It is shown that the ice density, calculated on the basis of the proposed approach in the Thesis, is in full agreement with the experimental data. It is concluded that the argon-like temperature dependence of thermodynamic characteristics is explained by the rotational motion of water molecules. As a result, in thermodynamic calculations we should use the self-averaging potential which has quasi Lennard-Jones form. The temperature dependence of the kinematic shear viscosity of water was studied in details. It was established that the dependence is the sum of three independent contributions: argon-like and two hydrogen bonds contributions. One of these contributions is invoked by the strong orientation correlations. It decreases exponentially and, in fact, is different from zero only in the supercooled region and near the melting point. The second contribution reflects the decrease in momentum transfer between neighboring layers of fluid moving relative to each other due to the formation of hydrogen bonds between them. The formula, describing the dependence argon-like contribution to the shear viscosity of water temperature and specific volume, is suggested.