Synthesis and Self-Assembly of Amphiphilic Asymmetric Macromolecular Brushes

Two well-defined amphiphilic asymmetric macromolecular brushes, one bearing hydrophilic poly(ethylene glycol) (PEO) and hydrophobic polystyrene (PS) side chains on poly(glycidyl methacrylate) (PGMA) backbone and the other bearing pendant PEO and poly(styrene-block-N-isopropylacrylamide) (PS-b-PNIPAM) block copolymer side chains, were synthesized by grafting from approach based on a combination of click chemistry and in situ reversible addition−fragmentation chain transfer (RAFT) polymerization. PGMA backbone was synthesized by atom transfer radical polymerization (ATRP), and a polymer backbone with pendant hydroxyl and azide groups (PGMA−OH/N3) was obtained after ring-opening reaction of the epoxide rings on PGMA. RAFT chain transfer agent (CTA) was introduced to the polymer backbone by facile click reaction between alkyne-terminated RAFT CTA and PGMA−OH/N3. PEO side chains were grafted onto the polymer backbone by esterification between carboxyl end group of PEO and hydroxyl group on the polymer backbone...