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Density functional theory studies of liquid -vapor nucleation and interfacial properties
Abstract
This dissertation is focused on the study of thermodynamic properties of liquid-vapor interfaces. As a result of this study an improved theory of liquid-vapor nucleation has been developed. This theory is based on the classical thermodynamics as well as on the density functional theory (DFT). Several DFT approaches with different approximations for the radial correlation function of the system have been considered. The Lennard-Jones (LJ) fluid and a weak dipolar fluid have been investigated within these approaches. The important characteristics of these fluids such as surface tension, the Tolman length, disjoining pressure near 9-3 LJ wall and the chemical potential as a function of liquid film thickness have been obtained. The microscopic consideration has provided all the necessary parameters for the further development of nucleation theory. The theory of heterogeneous nucleation on mesoscopic wettable particles has been developed with account of curvature and compressibility corrections. The homogeneous nucleation at high supersaturation of vapor also has been studied. The behavior of the planar surface tension and the Tolman length in the frameworks of local density approximation (LDA), weighted density approximation (WDA), random phase approximation (RPA) and modified mean field approximation (MMF) has been studied. The temperature dependencies for these quantities have been obtained. It has been found that the limiting value of the Tolman length for large droplets is very small, even less than a molecular size, and it becomes closer to zero with any improvement in the description of the radial correlation function of the system. Based on the nucleation theory developed, the most important characteristics of nucleation such as the chemical potential of the liquid condensate, its threshold value and formation free energy of the droplet have been obtained as well as other essential quantities for nucleation kinetics. Those include the nucleation barrier and the half-widths of formation free energy curve near equilibrium and the critical sizes of droplets.
Subject Area
Molecules|Fluid dynamics|Gases|Chemistry
Recommended Citation
Bykov, Tikhon Victorovich, "Density functional theory studies of liquid -vapor nucleation and interfacial properties" (2003). ETD collection for University of Nebraska-Lincoln. AAI3104606.
https://digitalcommons.unl.edu/dissertations/AAI3104606