Well-defined pH-responsive amphiphilic PDMAEMA-b-PPFS copolymers with two different PPFS block lengths were successfully synthesized by RAFT-mediated living radical polymerization. Micellization behavior in aqueous solution was studied systematically by fluorescence spectroscopy, SLS, DLS, and TEM. The copolymers formed spherical micelles consisting of dense PPFS cores surrounded by dangling PDMAEMA chains as the micelle corona. The micelles possessed larger sizes at low pH resulting from protonated PDMAEMA segments on the corona. In contrast, theRh gradually decreasedwhenpHwas increased, due to deprotonation of the coronas resulting in lower osmotic pressures. The copolymer with the longest PPFS block had the poorest water solubility (as expected) and consequently formed micelles with larger sizes and aggregation number but having a lower cmc. Further studies on the morphology and micellization behavior of these interesting systems are currently in progress in order to explore their potentials as drug delivery vehicles and rheology modifiers.
- Amphiphilic block copolymers
- Cyanopropyl dithiobenzoate
- Dimethylaminoethyl methacrylate
- pH-responsive polymers