Hydrophilic Block Copolymer Aggregation in Solution Induced by Selective Threading of Cyclodextrins

Abstract

AbstractSummary: The inclusion of polymer chains by cyclodextrins (CDs) may generate column‐like supramolecules. Herein, we report that the selective threading of cyclodextrin rings onto one segment of a double hydrophilic diblock copolymer in water generates spherical aggregates. Poly(ethylene oxide)‐block‐poly((dimethylamino)ethyl methacrylate) (PEO‐b‐PDMA) may dissolve in water to form a homogeneous solution. However, when α‐CDs are introduced, they thread onto the PEO segments to form pseudopolyrotaxanes, which tend to aggregate. Instead of forming a precipitate, novel supramolecular particles are generated which are attributed to the stabilization of the soluble PDMA segments. The organization process and the assembly structure were characterized by dynamic light scattering, X‐ray diffraction, electron microscopy and 1D NOE NMR spectra. Such novel particles are biocompatible and could have potential applications as biomedical and stimulus‐response materials.Schematic presentation of the self‐assembly process.magnified imageSchematic presentation of the self‐assembly process.