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Synthesis of Next-Generation Block Copolymer Architectures

Block copolymers are becoming increasingly important for a variety of applications due to their ability to self-assemble into ordered structures. Increasing the toolbox to manipulate the equilibrium behavior of self-assembly of block copolymers grants access to otherwise unachievable morphologies and therefore wider applications. And yet, the fundamental understanding has been limited by i) theory and computational modeling, ii) sub-unit characterization tools and iii) facile synthetic methods. The objective of this dissertation is to develop synthesis procedures to design next generation block copolymer architectures with the ability to alter self-assembly and the ultimate morphology. This dissertation provides a summary of the historical context of development of theories for block copolymer phase separation in chapter 1, and the development of precision synthetic methodologies to achieve tailored block copolymer architectures in chapter 2. These are provided to help orient the reader for the results presented in later chapters. In chapter 3, the concept of single molecule insertion is applied to install labels within a linear diblock copolymer backbone. The installation of the label can be done independently at the chain-end and/or the block copolymer junction. This study helps building fundamental understanding on the self-assembly and packing frustration of block copolymers. In chapter 4, the concept of single molecule insertion is applied to synthesize asymmetric simple graft copolymers. Structures that lie along the continuum between simple linear diblock and symmetric miktoarms stars. This study helps building fundamental understanding of the effect of polymer architecture and the effect of chain crowding on the phase behavior. In chapter 5, the synthesis of a series of star shaped block copolymer structures is described which is inspired by surface active proteins used by the Siamese fighting fish (Betta splendens, Regan, 1910). These architectures are studied towards their surface activity at an oil/water interface in regard to arm number, volume fraction and pH level. A new parameter, the reconfiguration of chain assembly, is introduced.