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.magnified image

The self‐assembly of PVPh‐b‐PS in different solvents was studied. Upon replacing toluene by THF as the solvent, the morphology of the resulting aggregates change from core‐shell spheres, rod‐like micelles and vesicles to onion‐like aggregates. With increasing block copolymer concentration, morphologies such as honeycomb‐like films, surfaces of aggregated large porous spheres, or pincushion‐like spheres with protruding tubular vesicle aggregates are observed. These surface‐patterned films show significantly enhanced hydrophobicity. The results suggest that a superhydrophobic behavior can be achieved, with a maximum contact angle of 158°, by using the pincushion‐like micellar structure.

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