| The goal of this dissertation is to elucidate the relationship between soot surface morphology and soot surface growth rates. Surface growth is the primary process by which mass is added to soot. Previous mechanistic understanding of surface processes has been limited to simple descriptions of surface geometry. In this study, surface growth is modeled via chemical similarity to polycyclic aromatic hydrocarbons.;First, a combination of quantum chemistry and reaction rate analysis is used to explore key surface reactions. The previously studied five-member ring migration reaction is re-examined including additional dissociation product channels. The formation of the additional products at high-temperature and the high stability of intermediates at low temperature led to more detailed chemical description in the following surface kinetic model. Next, surface reactions which form and rearrange five- and six-member ring groups are studied. The first of these reactions is the ring collision reaction in which a five-member ring combines with a neighboring five-member ring to create a five- and six-member ring complex. Then, the ring flip reaction in which the five- and six-member ring complex reverses its orientation is discussed. Lastly, embedded-ring migrations, a class of reactions based on the ring flip reaction, are examined.;Finally, detailed surface kinetic Monte Carlo simulations are performed. These simulations incorporate the results of the reaction rate analysis along with other reactions from the literature into a full mechanism for surface evolution. The focus of these simulations is on surface morphology and the growth rates. Growth rates are found to be highly dependent on surface morphology. Morphology, in turn, is greatly affected by the rates of key reactions and by substrate environment including temperature and gas phase species concentrations. The initial substrate was only found to affect growth rates and morphology in an initial period of growth for base case simulations. In contrast, reduction of acetylene concentration results in significant differences between growth of coronene and decacene. Growth rates for substrates lie between 10 4 and 105 C-atoms s-1 for most conditions. This is a similar range predicted in previous studies and is also in agreement with initial growth rates from experimental data. |
