UCST behavior of polyampholytes based on stoichiometric RAFT copolymerization of cationic and anionic monomers

Abstract

Polyampholytes with controlled equimolar ratio of charges were synthesized by reversible addition–fragmentation chain transfer (RAFT) copolymerization of cationic and anionic monomers. The resulting charge-neutral polyampholytes exhibit upper critical solution temperature (UCST) thermoresponsive behavior in ethanol–water and methanol–water solvent mixtures based on electrostatic attraction. Finally, the temperature induced self-assembly of a polyampholyte with oligo(ethylene glycol) side chains into defined nanoparticles below the UCST transition is demonstrated.