Chloromethylated magnetic polystyrene composite nanoparticles prepared via RAFT-mediated surfactant-free emulsion polymerization

Abstract

Polystyrene-based magnetic composite nanoparticles with well-defined core-shell morphology, customizable surface functionalization, and adjustable magnetic properties are promising catalyst support materials. In this work, chloromethylated magnetic polystyrene composite nanoparticles are successfully prepared through RAFT-mediated surfactant-free emulsion polymerization. A comprehensive investigation is carried out to explore the influence of copolymer monomer ratios and polymerization degrees on emulsion polymerization conversion and encapsulation efficiency. The results unveil the critical importance of moderately adjusting the hydrophobic/hydrophilic properties of the macroRAFT agents in achieving an effective encapsulation process. Excessive monomer addition is found to disrupt the conditions necessary for emulsion polymerization by causing the detachment of macroRAFT agents from the surface of the modified Fe3O4 nanoclusters. These results are instructive for the future rational design and synthesis of high-performance catalysts.