Date of Award

2017

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Graduate Group

Chemical and Biomolecular Engineering

First Advisor

Robert A. Riggleman

Abstract

Inhomogeneous polymeric materials is a large family of promising materials including but limited to block copolymers (BCPs), polymer nanocomposites (PNCs) and microscopically confined polymer films. The promising application of the materials originates from the materials' unique microstructures, which offer enhanced mechanical, thermal, optical and electrical properties to the materials. Due to the complex interactions and the large parameter space, behaviors of the microstructures formed by grafted nanoparticles and nanorods in PNCs are difficult to understand. Separately, because of relatively weak interactions, the microstructures are typically achieved through rapid processing that are kinetically controlled and beyond equilibrium. However, efficient simulation framework to study nonequilbrium dynamics of the materials is currently not available. To attack the first difficulty, I extended an efficient simulation framework, polymer nanocomposite field theory (PNC-FT), to incorporate grafted nanoparticles and nanorods. This extended framework is demonstrated against existing experimental studies and implemented to study how the nanoparticle design affects the nanoparticle distribution in binary homopolymer blends. The grafted nanoparticle model is also used as a platform to adopt an advanced optimization method to inversely design nanoparticles which are able to self-assemble into targeted two dimensional lattices. The nanorod model under PNC-FT framework is used to investigate the design of nanorod and block copolymer thin films to control the nanorod distribution. To attack the second difficulty, I established an efficient framework (SCMF-LD) based on a recently proposed dynamic mean field theory and used SCMF-LD to study how to kinetically control the nanoparticle distribution at the end of solvent annealing block copolymer thin films. The framework is then extended to incorporate hydrodynamics (SCMF-DPD) and the extended framework is implemented to study morphology development in phase inversion processing polymer thin films, where hydrodynamic effects play an important role. By exploring both equilibrium and nonequilibrium properties in a spectrum of inhomogeneous polymeric material systems, I successfully extended PNC-FT and established SCMF-LD and SCMF-DPD frameworks, which are expected to be efficient and powerful tools in studies of inhomogeneous polymeric material design and processing.

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