Amphiphilic acrylamide block copolymer: RAFT block copolymerization and monolayer behaviour

Abstract

RAFT polymerization of acrylamide monomers with long alkyl sidechains was studied for application to block copolymer synthesis and nanoscale assembly using the Langmuir-Blodgett technique. Controlled radical polymerization was demonstrated by optimizing the chain transfer agent (CTA) concentration: amphiphilic acrylamide block copolymer, poly(N-dodecylacrylamide)-block-poly(N-tert-pentylacrylamide) (pDDA-b-ptPA) was obtained with high molecular weight (1.3 × 104) and narrow molecular distribution (Mw/Mn = 1.4). The diblock copolymer formed a stable monolayer at the air-water interface under a surface pressure of 30 mN m-1, but the presence of the junction between pDDA and ptPA affected the monolayer mechanical properties at higher surface pressures. Results provide insight into the two-dimensional self-assembly of amphiphilic block copolymers consisting of molecular-level amphiphilic block components.