In Situ and Online Monitoring Polymerization-Induced Micellization

The polymerization-induced micellization of poly(ethylene oxide)- b -poly(styrene- alt -maleic anhydride) (PEO- b -P(S- alt -MAn)) in CHCl 3 was monitored in situ by laser light scattering. Reversible addition−fragmentation chain transfer (RAFT) polymerization was used to grow the P(S- alt -MAn) block onto the PEO macromolecular chain transfer agents (macro-CTAs) at 55 °C. The whole process underwent three stages over time: the induction period, the formation of loose aggregates, and the formation of micelles. The polymerization process and the micellization process were affected mutually: the increase in the degree of polymerization induced the micellization of PEO- b -P(S- alt -MAn); meanwhile, the formation of core−shell micelles retarded the polymerization rate. At higher polymer concentrations, the mutual effect was even stronger, where smaller size micelles with higher density were obtained.