Control of Self-Assembled Structure through Architecturally and Compositionally Complex Block Copolymer Surfactant Mixtures

Abstract

The self-assembly of binary mixtures of architecturally and compositionally diverse surfactant-like polystyrene–poly(2-vinylpyridine) (PS–PVP) block copolymers (BCPs) in solution and in thin films has been systematically studied. PS–PVP BCPs of different molecular architecture synthesized by living anionic polymerization, including linear diblocks, triblocks, and branched star-like copolymers all having different block sizes, styrene to 2-vinylpyridine ratios, and variations in numbers of arms, were employed as constituent building blocks for the construction of advanced copolymeric ensembles. While ensembles formed from monomodal PS–PVP BCPs exhibit simple spherical aggregate structures in the PS-selective solvent toluene, aggregates created by mixing PS–PVP BCPs of different architecture display structures that include spherical, worm-like and large compound micellar aggregates. This result is attributed to the complex, architecture-induced diversity of microphase segregation in the mixed systems, where...