Supramolecular micellization of diblock copolymer mixtures mediated by hydrogen bonding for the observation of separated coil and chain aggregation in common solvents

This paper describes a new approach towards preparing self-assembled hydrogen-bonded complexes that have vesicle and patched spherical structures from two species of block copolymer in non-selective solvents. The assembly of vesicles from the intermolecular complex formed after mixing polystyrene-block-poly(4-vinyl phenol) (PS-b-PVPh) with poly(methyl methacrylate)-block-poly(4-vinylpyridine) (PMMA-b-P4VP) in tetrahydrofuran (THF) is driven by strong hydrogen bonding between the complementary binding sites on the PVPh and P4VP blocks. In contrast, well-defined patched spherical micelles form after blending PS-b-PVPh with PMMA-b-P4VP in N,N-dimethylformamide (DMF): weaker hydrogen bonds form between the PVPh and P4VP blocks in DMF, relative to those in THF, which results in the formation of spherical micelles that have compartmentalized coronas that consist of PS and PMMA blocks.