Synthesis of Ternary, Hydrophilic−Lipophilic−Fluorophilic Block Copolymers by Consecutive RAFT Polymerizations and Their Self-Assembly into Multicompartment Micelles

Abstract

Linear amphiphilic diblock and ternary triblock copolymers were synthesized by the RAFT method in three successive steps, using oligo(ethylene oxide) monomethyl ether acrylate, butyl or 2-ethylhexyl acrylate, and 1H,1H,2H,2H-perfluorodecyl acrylate. The diblock and the triblock copolymers, which consist of a hydrophilic, a lipophilic, and a fluorophilic block, self-assemble in water into spherical micellar aggregates. Imaging by cryogenic transmission electron microscopy (cryo-TEM) revealed that the cores of the micellar aggregates made from these “triphilic” copolymers undergo local phase separation to form various ultrastructures, which depend sensitively on the given block sequence. While the sequence hydrophilic−lipophilic−fluorophilic resulted in multicompartment cores with core−shell−corona morphology, the sequence lipophilic−hydrophilic−fluorophilic provided new “patched double micelle” and larger “soccer ball” structures.