Block copolymer particles with tunable and robust internal nanostructures by combining hydrogen-bonding and crosslinking

Abstract

Nanostructured block copolymer (BCP) particles are attractive due to their ordered internal structures, unique shape and surface patterns; however, their structural integrity can be easily lost because of weak intermolecular interactions, which limits their practical applications. In this study, we present a simple and reliable method to fabricate nanostructured particles of polystyrene-block-poly(4-vinylpyridine) with tunable and robust nanostructures by employing hydrogen-bonding and cross-linking strategies. The key feature of poly(4-vinylpyridine) is the presence of reactive pyridyl moieties, which allow precise regulation of internal nanostructures via hydrogen bonds and locking of the structural integrity via quaternarization by feeding hydrogen bond donors and cross-linkers, respectively. The solvent resistance is well proven by immersing the particles in either selective solvents of the continuous phase or good solvent of the BCP. Furthermore, mesoporous BCP particles derived from the cross-linked particles are obtained simply by a swelling/deswelling treatment. This study provides a way to improve the structural robustness of BCP particles and could be a key step that advances the functionalization and subsequent applications of such nanostructured BCP colloidal particles.