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Abstract
Polymer films are a subject of both technological importance and fundamental scientificinterest. Very often polymer films are created under far-from-equilibrium conditions. Polymerfilm growth is a complex process due to polymers complicated structure and interactionsthat include internal degrees of freedom, limited bonding sites, chain relaxation, chain-chaininteractions, etc.My doctoral research focusses on the computational study of polymer films grown by anexperimental growth technique referred to as vapor deposition polymerization (VDP), where a 2D substrate is exposed to gas phase monomers from the top and a polymer film grows on the substrate through a polymerization reaction occurring during the growth process.A lattice Monte Carlo (MC) model was used to study polymer film growth and to examinethe effects of random angle deposition, monomer diffusion, monomer adsorption, and polymerization reaction in determining polymer film properties. In addition to the aforementioned stochastic processes, our model also implemented the processes of polymer chain initiation, extension, and merger. In our analysis, the spatial and temporal behavior of kinetic roughening were extensivelystudied using finite-length scaling and height-height correlations. The scaling behaviors atlocal and global length scales were found to be very different. The global and local scalingexponents for morphological evolution were evaluated for varying system parameters. A systematic study was performed to discover the universality class of our VDP growth model.We also studied the aggregation mechanism of polymers grown by VDP. The behavior ofpolymer chain length distributions were carefully analyzed and the dynamic scaling approach was employed to highlight the dependence of polymer aggregation on the system parameters. As the ratio of diffusion rate to the deposition rate was increased in the VDP growth, we observed a systematic change in the aggregation mechanism that prevented the manifestation of a unique scaling function for chain aggregates.Finally, we calculated the conformational properties of polymer chains and studied theirdependence on system parameters. The structural studies were useful in understanding the bias in the preferred growth direction of the films as diffusion was increased in the system.