Functional copolymer brushes composed of a hydrophobic backbone and densely grafted conjugated side chains via a combination of living polymerization with click chemistry

A series of well-defined copolymer brushes, PS-g-P3HT, composed of a hydrophobic coil-like PS backbone and densely grafted rod-like P3HT side chains were successfully synthesized by a combination of the quasi-living Grignard metathesis (GRIM) method, reversible addition-fragmentation chain transfer (RAFT), and click reaction. The molecular weight distribution of the resulting PS-g-P3HT copolymer brushes was rather narrow (polydispersity index, PDI < 1.2). The grafting efficiency was very high (i.e., the efficiency of all click reactions >96%). The self-assembly of PS-g-P3HT at the air/water interface was explored using the Langmuir-Blodgett (LB) technique. Quite intriguingly, circular domain arrays composed of the non-crystallized P3HT nanofibers were observed at high surface pressure.