Morphological tuning of assemblies of diblock copolymer micelles via core cross-linking

Abstract

Patchy micelles derived from diblock copolymers serve as versatile building blocks for colloidal assemblies due to their ability to mediate directional interactions via discrete surface patches. Here, we demonstrate a strategy for tuning the morphology of diblock copolymer micelles and their assemblies by controlling the degree of core cross-linking. By varying the amount of cross-linker, single-, two-, and three-patch micelles were formed, which subsequently guided the assembly into dimers, linear chains, and branched structures, respectively. A low degree of cross-linking led to significant core swelling, resulting in elongated cores and the formation of additional patches. Reducing the molecular weight of the copolymer also enabled morphological tuning at a smaller length scale. Furthermore, varying the degree of cross-linking in spherical micelles with long coronas led to the formation of structurally diverse dimers and chains, which were effectively used as templates to organize Au nanoparticles into spatially distinct paired and linear arrays.