Amphiphilic liquid-crystal block copolymer nanofibers via RAFT-mediated dispersion polymerization

Abstract

Well-defined, cholesteryl-based, amphiphilic block copolymer nanofibers have been obtained in a simple, one-pot, ethanol/water dispersion polymerization process using poly((meth)acrylic acid-co-(poly(ethylene glycol) (meth)acrylate) copolymers end-functionalized by a reactive trithiocarbonate end-group as macromolecular reversible addition–fragmentation chain transfer agents (macroRAFT agents). The resulting highly concentrated dispersions were analyzed by TEM (transmission electron microscopy), cryo-TEM, SAXS (small angle X-ray scattering) and SANS (small angle neutron scattering), which allowed the shape and size of the nanoobjects formed in situ to be fully characterized and which revealed moreover the presence of a smectic order in the hydrophobic cores. Due to this particular substructure, the nanofiber organization was observed over a broad composition range of the amphiphilic block copolymers.