Direct continuous synthesis of macroRAFT-grafted Fe3O4 nanoclusters for the preparation of magnetic

A new method for synthesizing magnetic nanocomposite latex particles with a significant magnetic response and high coating rate is reported herein. Based on a microflow platform, Fe3O4 nanoclusters grafted with macroRAFT agents were continuously synthesized within 90 s. The obtained clusters present high monodispersity, narrow size distribution, and excellent saturation magnetization. Moreover, the macroRAFT polymer chains grafted on the surface of the nanoclusters can be reactivated for polymerizing hydrophobic monomers without using any surfactant, to achieve the coating of magnetic particles. The resulting polymer shell can protect the magnetic core and maintain a substantial magnetic response. Furthermore, by optimising the reaction conditions, the encapsulation efficiency can be significantly improved for the efficient preparation of magnetic nanocomposites.

Highlights

•Synthesized modified Fe3O4 nanoclusters with well monodispersity and magnetic response by using REEP strategy.

•Clarified formation mechanism of macroRAFT-grafted Fe3O4 nanoclusters via in situ modification and self-assembly process.

•Regulated the binding form of macroRAFT agents on the surface of Fe3O4 nanoclusters towards high encapsulation efficiency.

•Revealed the importance of matching macroRAFT copolymers with monomers for effective seeded emulsion polymerization.

DOI：https://doi.org/10.1016/j.powtec.2023.118364‍‍‍‍