Aqueous solution properties of pH-responsive AB diblock acrylamido copolymers synthesized via aqueous RAFT

AB diblock and AB statistical copolymers of sodium 2-acrylamido-2-methylpropanesulfonate (AMPS) and sodium 3-acrylamido-3-methylbutanoate (AMBA) have been prepared via aqueous reversible addition-fragmentation chain transfer (RAFT) polymerization. Such AB diblock copolymers were tailored to undergo reversible pH-induced self-assembly given the tunable hydrophilic/hydrophobic nature of the AMBA species. Using a combination of H-1 NMR spectroscopy, dynamic light scattering, and fluorescence spectroscopy, it has been shown that these AB diblock copolymers exhibit reversible micellization below pH 5.5 with the aggregate sizes dependent on the block copolymer composition.