Macro-RAFT agent mediated dispersion polymerization: the monomer concentration effect on the morphology of the in situ synthesized block copolymer nano-objects

Abstract

The monomer concentration affecting the morphology of the in situ synthesized block copolymer nano-objects during the macro-RAFT agent mediated dispersion polymerization is investigated. It is found that the monomer concentration exerts great influence on both the polymerization kinetics of the poly(ethylene glycol) trithiocarbonate macro-RAFT agent mediated dispersion polymerization and the morphology of the in situ synthesized nano-objects of the poly(ethylene glycol)-block-polystyrene (PEG-b-PS) diblock copolymer. The poly(ethylene glycol) trithiocarbonate macro-RAFT agent mediated dispersion polymerization of styrene in the alcoholic solvent at 50% high monomer concentration follows similar kinetic behaviour to homogeneous RAFT polymerization as indicated by the linear ln([M]0/[M])-time plot, and the good control both on the molecular weight of the PEG-b-PS diblock copolymer and the molecular weight distribution is achieved. With the extension of the PS block, the morphology of the in situ synthesized PEG-b-PS nanoobjects changes from the porous nanospheres to the bicontinuous nanospheres and finally to the entrapped vesicles, which is much different from the dispersion RAFT polymerization under low monomer concentration. Our results demonstrate that the monomer concentration is an important parameter affecting the morphology of the in situ synthesized block copolymer nano-objects.

An insight into polymerization-induced self-assembly by dissipative particle dynamics simulation

“…10 Since the insolubility of the blocks increases with the block length extension during the course of polymerization, the amphiphilic diblock copolymers self-assemble into a set of polymer nano-objects. [11][12][13][14][15][16][17] A wide range of well-defined morphologies were produced by the PISA, including spheres, worms, vesicles, concentric vesicles, large-compound vesicles and so on. [18][19][20] Although the PISA has its inherent advantages in terms of versatility and efficiency, it is still a young field for researches and the fundamental understanding of the PISA remains incomplete in several aspects.…”

“…[18][19][20] Although the PISA has its inherent advantages in terms of versatility and efficiency, it is still a young field for researches and the fundamental understanding of the PISA remains incomplete in several aspects. 9,16,17,[21][22][23][24][25][26][27] For example, the essential difference between the PISA and traditional self-assembly is unclear; the physical mechanism (equilibrium or non-equilibrium behavior) underlying the balance between the polymerization and self-assembly needs to be explored; and the phase diagrams in the PISA should be mapped out to reproduce the PISA process. Insight into these problems can promote nano-object development from trial-and-error towards knowledge-driven innovation.…”

Surface functionalized nano‐objects from oleic acid‐derived stabilizer via non‐polar RAFT dispersion polymerization

“…S3). Many holes exist on the surface of this LCV . These observations suggest that there was inner wall fusion of small vesicles.…”

ICAR ATRP in PEG with Low Concentration of Cu(II) Catalyst: A Versatile Method for Synthesis of Block Copolymer Nanoassemblies under Dispersion Polymerization

“…In RAFT dispersion polymerization, it has been demonstrated that the size and/or morphology of block copolymer nanoassemblies is inherently dependent on the DP or chemical composition of block copolymers . Besides, the polymerization conditions, for example, the monomer concentration, also exert great influence on the morphology of block copolymer nanoassemblies, and high monomer concentration in RAFT dispersion polymerization usually favors synthesis of high order morphology of block copolymer nanoassemblies. Herein, the solid content (monomer concentration) and the DP of the PS block affecting the morphology of the PEG 113 ‐ b ‐PS nanoassemblies in the ICAR ATRP dispersion polymerization are checked.…”