Precise Localization of Inorganic Nanoparticles in Block Copolymer Micellar Aggregates: From Center to Interface

Abstract

Localization of inorganic nanoparticles (NPs) into polymer matrix plays a crucial role in determining the performance of the hybrid materials. Herein, we employed a simple, yet versatile hydrogen bonding directed supramolecular assembly (HBSA) strategy to control the localization of Au NPs from the center to the interface in polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) cylindrical micellar aggregates by tailoring the selectivity of polymer brushes on the surface of Au NPs. PS-b-P4VP(PDP)x comb–coil supramolecules were constructed by PS-b-P4VP and n-pentadecylphenol (PDP) via the hydrogen bonding between the pyridine of P4VP and the hydroxyl of PDP. PS-tethered Au NPs (PS-Au NPs) were selectively localized in the PS domain while a binary mixture of PS and P4VP-tethered Au NPs (PS/P4VP-Au NPs) were adsorbed to the interface between PS and P4VP(PDP)x domains presumably due to the redistribution of PS and P4VP ligands on the Au NPs surface, triggering the formation of amphiphilic surfactant-like NPs. Isolated cylindrical micellar aggregates with controlled localization of Au NPs were obtained by the selective disassembly of the supramolecules. Moreover, supramolecular block domain size, composition of the supramolecules, size of the Au NPs, and volume fraction of the Au NPs were carefully investigated to reveal their effects on the morphology of hybrid micellar aggregates and localization of NPs. These hybrid micellar aggregates with controlled localization and loading efficiency of Au NPs may extend the applications of the hybrid micellar aggregates and find more potential uses in optical/electronic devices, catalysis, and drug delivery system.