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Information × Registration Number 0220U102919, 0116U007066 , R & D reports Title Kinetics of phase transformations in condensed systems. The development of theory of nucleus interactions at high energies. popup.stage_title Head Bakai Oleksandr S., Registration Date 24-06-2020 Organization National Science Center "Kharkiv Institute of Physics and Technology" popup.description2 During the processes of nucleation and growth of a precipitate cluster from a supersaturated solution, the diffusion flux between the cluster and the solution changes the solute concentration near the cluster-solution interface from its average bulk value. This feature affects the rates of attachment and detachment of solute atoms at the interface, and, therefore, the entire nucleation-growth kinetics is altered. To illustrate the results of this approach, for the case of homogeneous nucleation, we calculate the total (including the contribution from heterophase fluctuations) solubility and the nucleation rate as functions of two parameters of the model – the reduced interface energy and the inverse second Damköhler number, and we compare these results to the classical ones. One can conclude that discrepancies with classical nucleation theory are great in the diffusion-limited regime, when the rate of bulk diffusion is small compared to the rate of interface reactions, while in the opposite interface-limited case they vanish. The kinetics of the formation of fractal aggregates of silicon dioxide during the combustion of a stoichiometric mixture of methane and air with an admixture of hexamethyldisiloxane is presented. The oxidation of hexamethyldisiloxane proceeds very rapidly with the formation of silicon dioxide molecules and compact clusters of silicon dioxide at a distance of a few millimeters from the burner. At a sufficiently high concentration of hexamethyldisiloxane, random collisions of nanoparticles lead to agglomerates with a fractal-like structure. The onset of fractal-like aggregates is controlled by the kinetics of collision and fusion processes. A model that describes the evolution of the particle size distribution of fractal-like silicon dioxide is formulated, which includes generation, convection, sintering and Smolukhovsky's coagulation. The simulation results are compared with experimental data. Product Description popup.authors Bakai Oleksandr S. Borysenko Oleksandr O. Kotlyar Volodymyr Lavrova Galyna M. Lazarev Mykola P. Oleksiyechkin Mykola V. Stepanovsky Yuriy P. Turkin Anatoliy A. Fateev Mykhaylo P. Chechkin Oleksiy V. Shebeko Oleksandr V. popup.nrat_date 2020-07-03 Close