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

A new method for synthesizing magnetic nanocomposite latex particles with a significant magnetic response and high coating rate is reported herein. Based on a micro-flow platform, Fe3O4 nanoclusters grafted with macroRAFT agents were continuously synthesized within 90 s. The obtained clusters present high mono-dispersity, 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.