Hydrodynamic self-consistent field theory: Computational fluid dynamics for inhomogeneous polymeric fluids and nanocomposites

A host of advanced polymeric materials have been developed in recent years which may be used to produce new industrial products with superior physical characteristics and which may be used as templates in nanoscale patterning applications. These materials typically exhibit micro-scale inhomogeneities that are a function of their composition and processing history. Inhomogeneities translate directly into inconsistencies in material parameters, and new numerical techniques are needed to predict the influence of processing conditions on polymer morphology in an efficient and cost effective manner.; In this dissertation, we present a method for simulating hydrodynamic transport of inhomogeneous polymeric fluids which is composed of four fully-coupled components: a self-consistent field description of the polymer microphysics, Navier-Stokes type hydrodynamics, a constitutive equation modeling polymer viscoelasticity, and a flow penalization scheme for simulating moving boundary surfaces of arbitrary shape and composition. The model is implemented on a periodic cartesian grid using a Fourier spectral-spatial discretization and a semi-implicit time discretization.; We validate the method by reproducing known properties of phase separating diblock copolymer melts, two component homopolymer blends, viscous flow past a cylinder, and viscoelastic phase separation of glassy/elastic polymers. The method is then employed to investigate phase separation of multi-component fluids, effects of solid boundaries and contaminants, the effects of hydrodynamic transport in pressure driven and wall driven flows, and self-assembly of polymer-solid nanocomposites.; We find that surface effects and hydrodynamic transport both play an important role in determining local micro-domain structure. Solid boundaries and contaminants produce surface directed nucleation and growth, and enforce boundary conditions which can induce long range order. Hydrodynamic transport results in rotation and alignment of component interfaces which can be significant near solid surfaces. These effects may compete, resulting in flow-rate dependent meta-stable states. We also observe that nanoparticle shape and size play important roles in polymer-solid nanocomposites, with non-spherical particles exhibiting nematic transitions and fluid-mediated interactions during phase separation. More generally, we find that this method is a flexible, practical approach for investigating dynamic processes in most any polymeric fluid or polymer-solid nanocomposite.