Cyclodextrin Assisted Self-Assembly of Stimuli-Sensitive Block Copolymers in Aqueous Media
Structures with well-defined architectures and tailored physical properties can be produced by supramolecular self-assembly of stimuli-sensitive polymeric inclusion complexes consisting of cyclodextrins. Recently, there has been significant interest in the use of double hydrophilic block copolymers to design novel supramolecular nanostructures as these polymers micellize under external stimuli, such as temperature, pH, and complexation. Cyclodextrins (CDs) have the ability to spontaneously complex with water-soluble guest molecules. The complexation of the polymer with CD induces self-assembly of the polymers. In this research, two systems were studied, a PEO-b-PNIPAM/α-CD system and a PPO-b-PMAA/β-CD system. First, the block copolymers were synthesized by ATRP to achieve well-defined monodisperse polymers. The chemical composition of the polymer was determined by NMR and gel permeation chromatography. Then, the microstructure and aggregation behaviour in aqueous solutions were studied using a combination of static and dynamic light scattering, and isothermal titration and differential scanning calorimetric techniques.