Multiscale and stochastic simulations of nanostructured interfaces in aqueous systems

Recently, interfacial nanostructures have attracted considerable interest due to different applications in materials science, catalysis, nanotechnology, and biotechnology. Robust and accurate simulation tools can help broaden the capability to synthesize, control, and manipulate nanostructured materials. In this study, mesoscopic and self-consistent multiscale simulations have been developed to investigate the relationship between the macroscopic process variables and morphological evolution of interfacial nanostructures.; This dissertation is broadly divided into two parts. In the first part, Brownian dynamics simulation (BDS) is used to investigate the influence of interfacial reaction rate on the morphology of interfacial nanostructures synthesized by electrodepositon. It is shown that the size dispersion of metallic nanoparticles growing on randomly distributed nucleation sites can be reduced by lowering the interfacial reaction rate. For nanostructured coatings on fibers, a morphological transition from dense to open coatings is obtained as the process changes from reaction controlled to diffusion controlled. A thorough quantitative description of the morphological evolution of the coating and a comparison with lattice-based mesoscopic simulation for asymptotic scaling laws are presented for the first time.; In the second part, a concurrent multiscale simulation for colloidal deposition is developed by self consistently coupling BDS with continuum-level conservation equations. The technique is validated for non-interacting particles, and shown to be computationally efficient as compared to brute-force BDS. The simulation technique is extended to colloidal deposition in the presence of particle interactions. For the first time, simulations of irreversible colloidal deposition are shown to predict kinetics and structure consistent with experiments without the use of adjustable parameters. Subsequently the effects of particle desorption and surface diffusion on colloidal deposition are examined. For the first time, consistent with experimental observations, the simulations demonstrate that asymptotic coverage of small particles exhibits non-monotonic trends, while those of large particles increase monotonically with increasing ionic strength. For large particles, surface diffusion is shown to induce ordered structures, and the critical ionic strength required for disorder-order transition decreases with decreasing particle size. Finally, the influence of dipole interactions on the structure and surface pressure of colloidal monolayers at fluid-fluid interfaces is studied.