Doctor of Philosophy (PhD)
For over a century, nucleation for all systems was thought simplistically to be a process that advances through the formation of critical clusters with a well-defined composition. Our results show intriguing nucleation mechanisms that challenge the aforementioned notion. We employed the simple TraPPE-UA (transferable potential for phase equilibria – united atom) force field and the AVUS-HR approach (a combination of aggregation-volume-bias Monte Carlo, umbrella sampling, and histogram reweighting), to investigate the homogeneous vapor-to-liquid nucleation of various nucleating systems. We found out that these systems could nucleate through a variety of unique non-ideal mechanisms. Alongside existing experimental investigations, this dissertation presents pioneering works on the computer simulation of nucleation in multicomponent systems. Our results are very relevant to atmospheric aerosol formations but may also find its applications in drug encapsulations and the design of nanomaterials as well as in sorting out experimental and theoretical discrepancies. This dissertation outlines the results of a series of nucleation investigations involving unary, binary, and ternary nucleating systems. Introductory and background information regarding nucleation, computer simulations, the classical nucleation theory and the AVUS – HR approach are provided in Chapters 1 and 2. The major findings of this work are given in Chapters 3, 4, 5, and 6. They are presented here in order of increasing complexity. Chapter 3 is on unary nucleation of 1-pentanol. Chapter 4 is on the investigation of the n-Nonane/1-Alcohol binary series. Finally, our pioneering works on the various ternary nucleation studies are discussed in Chapters 5 and 6.
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Nellas, Ricky Bendanillo, "Atom-Based Computer Simulation Studies of Gas-to-Liquid Nucleation in Atmospherically Relevant Systems: Clarifying Discrepancies and Elucidating Mechanisms" (2009). LSU Doctoral Dissertations. 930.