| Abstract: | A new quasichemical model of the supramolecular structure of the liquid consisting of chain-like and comb-like hydrogen-bonded aggregates with branches of unit length has been developed. Analytical expressions for structural characteristics (size and structure distributions of aggregates), dielectric (permittivity, dipole correlation factor), optic (mean molecular anisotropy in liquid, optic correlation factor, anisotropic Rayleigh light scattering ratio) and thermodynamic (energy of intermolecular interactions in liquid, vaporisation enthalpy) properties of the liquid as functions of structural and thermodynamic aggregation parameters have been derived. The analytical model developed creates the foundation for studying the role of branched aggregates in the supramolecular structure of liquids and various macroscopic properties determined by different molecular parameters. The model is applied to pure methanol at ambient conditions. The dependence of structural characteristics of liquid, dipole correlation factor, permittivity, mean molecular anisotropy in liquid, vaporisation enthalpy on the equilibrium constants of chain-like and branched aggregation is studied. The results are compared with experimental data and computer simulation. The influence of branching degree of aggregates on different physicochemical properties of liquid is revealed and discussed. |
