How the Polymerization Procedures Affect the Morphology of the Block Copolymer Nanoassemblies: Comparison between Dispersion RAFT Polymerization and Seeded RAFT Polymerization

Abstract

Polymerization-induced self-assembly (PISA) is proven to be a powerful approach of in situ synthesis of block copolymer (BCP) nanoassemblies, and polymerization conditions are found to be correlative to the block copolymer morphology. In this study, three PISA formulations, e.g., the poly(ethylene glycol) macro-RAFT agent mediated dispersion RAFT polymerization, seeded dispersion RAFT polymerization, and seeded emulsion RAFT polymerization, are comparatively investigated. Our results reveal that dispersion RAFT polymerization undergoes much slower than other two PISA formulations of seeded dispersion RAFT polymerization and seeded emulsion RAFT polymerization. Besides, the results reveal that the BCP morphology of poly(ethylene glycol)-block-polystyrene (PEG45-b-PS) produced via three PISA cases is much different. That is, dispersion RAFT polymerization affords vesicles, seeded dispersion RAFT polymerization affords the mixture of vesicles and porous nanospheres, and seeded emulsion RAFT polymerization af...