Impact of Backbone Composition on Homopolymer Dynamics and Brush Block Copolymer Self-Assembly.

Four series of brush block copolymers (BBCP), with near identical side chain compositions but varying backbone structures, were synthesized to investigate the effect of backbone structure on the process of thermal BBCP self-assembly to photonic crystals (PCs). Each of the self-assembled PC films were examined by reflection measurements, small angle X-ray scattering measurements, and scanning electron microscopy to compare the resulting properties of the polymeric photonic crystal and the nanostructured morphology impacted by the backbone structure. It was found that the composition of the brush backbone within a BBCP has a dramatic effect on the ability of the BBCP to self-assemble into ordered nanostructures and on the local ordering of the nanostructure morphology accessed with higher molecular weight (MW) BBCPs (> 1,500 kg/mol).