Makhlaichuk V. Visco-elastic and polarization properties of systems with spherical and anisotropic molecules in the gas and liquid phases

In the dissertation work, the visco-elastic and polarization properties of systems with spherical and anisotropic molecules in the gas and liquid phases are considered by methods of statistical physics and using the similarity principle of the corresponding states. Within the framework of the approach genetically related to the works of Fisher, the model of the dielectric constant of water vapor was constructed, which is considered as a mixture of monomers and dimers. It has been established that thermal excitations of dimer oscillations accompanied by fluctuations of their dipole moments lead to the effective polarizability of the water dimer, which is two orders of magnitude higher than its electronic polarizability and the thermal excitations of dimer oscillations reach 6-8% in the heat capacity of water vapor. It is established that the anomalously large value of the dielectric constant of liquid water is determined by the superposition of the contributions: the electronic polarizability of the monomers, dimers, tetramers, etc., the dipole contributions from these clusters, as well as their effective polarizabilities. The inadequacy of activation theories to the determination of shear viscosity and diffusion coefficients in liquids has been proved. Kinetic coefficients are essentially collective in nature and are a superposition of two components of the thermal motion of molecules in liquids: the circulatory motion of small groups of molecules, that is, the movements at nanoscale and the vortex motion generated by hydrodynamic fluctuations on mesoscale. It is established that the shear viscosity of liquids is determined by the effects of friction between molecular layers moving one relative to another and a corresponding formula for shear viscosity is proposed, and the contributions of the collective drift of molecules in the field of thermal hydrodynamic fluctuations reach (20-25)% of the total self-diffusion coefficient in liquids. A generalized principle of similarity is formulated with respect to viscosity and self-diffusion processes in all low-molecular-weight argon-like liquids, including water (for temperatures above Т_Н). It is shown that contributions to the self-diffusion coefficient of water in aqueous electrolyte solutions, which correspond to circulatory mixing of particles and are described using the Einstein formula, are determined by the radii of particles, which are associated with the excluded volume at the triple point and do not depend on temperature. The self-diffusion coefficient of cations is determined by the effective radii that reflect the existence of weak hydration effects in aqueous solutions.