<i>n</i>-Butanol induced structural transformation of block copolymers

Polymer particles with precisely controlled shapes and internal architectures have garnered significant attention owing to their unique physical properties and diverse potential applications. In this study, we present a systematic investigation of the morphological evolution of polystyrene-<i>block</i>-poly(4-vinyl pyridine) (PS-<i>b</i>-P4VP) assemblies under three-dimensional (3D) confinement, induced by <i>n</i>-butanol through hydrogen bonding interactions with 4VP units. The selective localization of <i>n</i>-butanol within the P4VP domains leads to an expansion of its volume fraction and a substantial alteration in the hydrophilicity of the P4VP block. Consequently, these PS-<i>b</i>-P4VP self-assemble into particles with onion-like structure or spherical internal structure. Notably, the synergistic co-assembly of gold nanoparticles (AuNPs) with PS-<i>b</i>-P4VP yields core-shell-corona hybrid spheres and hybrid onion-like nanoparticles, which exhibit remarkable potential for applications in advanced sensing technologies, heterogeneous catalysis, and targeted drug delivery systems.