Neutron investigations of the processes of self-diffusion of molecules in the heavy water-glycerol system as functions of the temperature and concentration

Vasylkevych, OA, Slisenko, VI
Dopov. Nac. akad. nauk Ukr. 2018, 8:52-57
Section: Physics
Language: Ukrainian
Abstract: 

The results of studies of the self-diffusion of glycerol molecules in a solution of heavy water-glycer ol at two concentrations x = 0.046 molar fractions and x = 0.055 mol. f. in the temperature range 2-10 °C by the method of quasi-elastic scattering of slow neutrons are presented. The values of the total coefficient of self-diffusion and its one-particle and collective components are obtained. Anomalous behavior has been revealed in their temperature dependence: at T = 3 °C and the solution concentration, especially at x = 0.046 mol. f., a deep minimum is observed. Herewith. the lifetime of glycerol molecules in the vibrational state increases substantially. This can be explained by the fact that glycerol molecules at a given temperature and concentration effectively bind water molecules, forming complexes and thereby reducing their mobility. The change in the concentration of glycerol molecules to 0.055 mol. f. leads to a sharp increase (by 40 %) in the intensity of diffusion processes.

Keywords: clusterization. water, glycerol, quasi-elastic scattering of slow neutrons, self-diffusion coefficient, single-particle and collective components of the coefficient of self-diffusion
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