Controlling the nanoscale structure, rheology and phase behavior of block copolymer based nanocomposites
At high polymer concentrations, solvent-selective block copolymer molecules self-assemble into concentrated micellar solutions that form highly-ordered, nanostructured, soft solids. Controlling the solvent quality allows for high densities of deformable (soft) particles to be achieved. Solvent stable nanoparticles dispersed in these soft solids will sample the solvent-swollen continuous structure providing a method to template, store, and define the environment of nanoparticulate material. Dispersed phase materials including metal oxide nanoparticles and globular proteins have been studied, providing composite systems in two interesting limits; hard particles dispersed in a dense dispersion of soft particles and a dense dispersion of soft particles with a bimodal level of softness. We characterize the impact of added nanoparticles on the local micelle packing, flow mechanism, and overall structure of the soft solid. These materials have rich phase behavior offering considerable potential in templating, transport properties and nanostructure control through both molecular design and processing.