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The molecular weight and polydispersity of the chains in a polymer brush are critical parameters determining the brush properties. However, the characterization of polymer brushes is hindered by the vanishingly small mass of polymer present in brush layers. In this study, in order to obtain sufficient quantities of polymer for analysis, polymer brushes were grown from high surface area fibrous nylon membranes by ATRP. The brushes were synthesized with varying surface initiator densities, polymerization times, and amounts of sacrificial initiator, then cleaved from the substrate, and analyzed by GPC and NMR. Characterization showed that the surface-grown polymer chains were more polydisperse and had lower average molecular weight compared to solution-grown polymers synthesized concurrently. Furthermore, the molecular weight distribution of the polymer brushes was observed to be bimodal, with a low molecular weight population of chains representing a significant mass fraction of the polymer chains at high s...

Block copolymers (BCPs) can self-assemble in selective solvents to form morphologies based on their chemistries and architectures. In this study, we investigate BCPs having both brush and linear segments in what is referred to as “toothbrush” architecture. Using anionic polymerization, we have synthesized a linear poly(styrene-block-isoprene) followed by growing poly(ethylene oxide) grafts from the isoprene block to form a brush segment. A combination of nonselective and selective solvents is used to drive the self-assembly of the toothbrush polymers. Analysis by dynamic light scattering and transmission electron microscopy show that the self-assembly is highly influenced by the density of grafts in the brush segment, with densely grafted polymers forming only spherical micelles and sparsely grafted brushes forming higher order structures including cylindrical micelles and vesicles. Additionally, calculations of micelle corona graft density and corona thickness indicate that the corona of the micelles for...