Synthesis and self-assembly of complex bottlebrush polymers

Abstract

Bottlebrush polymers (BBPs) represent a class of grafted macromolecules obtaining side chains grafted per every repeating unit of a linear backbone. When chemically distinct side chains integrated in a BBP with various side chain composition or backbone sequence, the junction can be generated within the side chain or between the backbone. Thus, drastically different length scale of the self-assembly can be induced depending on the junction position. In this thesis, I explored synthesis and self-assembly of complex BBPs. With sophistically designed junctions in the bottlebrush architecture, it will offer immense potential for a well-defined nanoobject showing drastically different behavior of self-assembly depending on junction position. Firstly, I reported the backbone shiftable synthesis of Janus core-shell BBPs by moving the position of the backbone junction in the middle of core. Moving the backbone junction toward B/C interface favor to form a monolayer vesicle. Second, folding of BBPs with cross-linkable junction afforded a precision synthesis of hairy nanoparticle. Intrachain photodimerization converged the backbone into a compact globular conformation, translating the 1D molecular information into the 3D globular nanoparticle containing discrete subdomains. Lastly, I reported on a synthetic approach to monovalent gold nanoparticle (Au NP) hybrid BBP by attaching linear junction of the BBP on the Au NP. By covering the surface of NPs with linear junctions, connection of a single BBP per Au NP was occurred through the steric exclusion synthesis. Designed symmetry breaking of the BBP in a giant Au-BBP surfactant resulted in diverse organic/inorganic hybrid microphase separated structure.