Halogen-Bond Mediated 3D Confined Assembly of AB Diblock Copolymer and C Homopolymer Blends

Zheng, X. et al. Small, 2021, 2007570, https://doi.org/10.1002/smll.202007570

Halogen-bond driven assembly, a world parallel to hydrogen-bond, has emerged as an attractive tool for constructing (macro)molecular arrangement. An I….N bond mediated confined-assembly pathway to enable order-order phase transitions is reported here. Polystyrene-b-poly(4-vinyl pyridine) (PS-b-P4VP) AB diblock copolymers are chosen as halogen acceptor, while an iodotetrafluorophenoxy substituted C-type homopolymer, (poly(3-(2,3,5,6-tetrafluoro-4-iodophenoxy)propyl acrylate), PTFIPA) is designed as halogen donor, synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Formation of halogen bonding donor–acceptor pairs induce an order-to-order morphology transition sequence changing from spherical cylindrical lamellar inverse cylindrical. Subsequent selective swelling/deswelling of the P4VP domains gives rise to further internal morphology transitions, creating tailored mesoporous microparticles, disassembled nanodiscs, and superaggregates. © 2021 Wiley‐VCH GmbH