Tunable assembly and disassembly of responsive supramolecular polymer brushes

Abstract

We report the synthesis and assembly of light-responsive supramolecular polymer brushes based on the host–guest interaction between β-cyclodextrin (β-CD) on star-like side chains and azobenzene groups on a polymer backbone. The fraction of the hydrophilic–hydrophobic units can be easily controlled via changing the ratio of host and guest molecules. The supramolecular polymer brushes can self-assemble into unimolecular micelles, multi-molecular micelles, and vesicles with tunable sizes from 28 to 300 nm in water, respectively, with the decrease of β-CD side chains. The assemblies of micelles or vesicles can be disassembled by the trigger of UV light irradiation due to the responsive azobenzene groups. In addition, the phase transition temperature of the supramolecular polymer brushes increases with the decrease of the side chains. The micelles or vesicles can further assemble into strawberry superstructures by increasing the temperature. Our work provides a platform for the generation of assemblies across a wide range of scales, from polymer brushes to micelles or vesicles and superstructures.