Morphology Control of Multicompartment Micelles in Water through Hierarchical Self-Assembly of Amphiphilic Terpolymers

Coban D., Gridina O., Karg M., Gröschel A.H.

Abstract

Multicompartment micelles (MCMs) allow the simultaneous storage of multiple cargoes such as dyes, catalysts, or drugs, and have therefore gained attention in catalysis, nanotechnology, and nanomedicine. In the present work, we describe design rules to control the morphology of MCMs in water including spheres, cylinders, sheets, and vesicles. For that, we synthesized a series of poly(ethylene oxide) (PEO)-b-polystyrene (PS)-b-poly(methyl acrylate) (PMA) triblock terpolymers and systematically varied the length of the PS and PMA block. Using a stepwise hierarchical assembly process, we first form patchy precursor micelles in organic solvent with PS core and mixed PEO/PMA corona. In the second step, these micelles act as subunits, which assemble (or cluster) in water into MCMs, where PEO forms the stabilizing corona, PS the compartment, and PMA the inner core. We find that the shape of the final MCM can be predicted by ascribing a Janus balance to precursor micelles as the molar ratio of PEO to PMA, which provides a synthetic handle to target specific MCM morphologies.