Efficient Fabrication of Janus Particles with Active Groups and Application in Emulsion Stabilization and Interfacial Catalysis

Janus particles have garnered significant attention due to their unique asymmetric structure. Researchers are dedicated to developing an industrial-scale production method for Janus particles. Herein, an oil-in-water emulsion was prepared through one-step mixing of functional monomer glycidyl methacrylate (GMA) and the fluorocarbon monomer (perfluorodecyl)ethyl acrylate (FC), which were simultaneously transformed into Janus particles (PFC–PGMA–NH2) with an epoxy group by ultraviolet (UV)-induced free radical polymerization. The incorporation of a composite surfactant solution, comprising sodium dodecyl sulfate (SDS) and a fluorocarbon surfactant (Zonyl FS-300), not only bolsters the stability of the emulsion but also confers control over droplet morphology. By manipulating the surface tension at the interface by varying the ratio of the surfactant to the monomer, fast and precise tuning of the internal droplet geometry was achieved from one-phase to two-phase PFC-in-PGMA/PGMA-in-PFC/Janus emulsions. The incorporation of active epoxy groups into the PFC–PGMA particles facilitates the selectively postfunctionalization reactions to produce amphiphilic PFC–PGMA–NH2 Janus particles. At the oil/water emulsion interface, the conversion rate of the gold-loaded PFC–PGMA–NH2@Au Janus catalyst reached 84.13% after 2 h, exhibiting a remarkable enhancement of 12.7 times compared to that achieved through oil–water two-phase interface catalysis under identical reaction conditions. As solid amphiphilic surfactants, Janus particles with precisely adjustable hydrophilic/hydrophobic properties exhibit exceptional capabilities in stabilizing emulsions. Therefore, they play a crucial role in enhancing catalytic efficiency and regulating active sites during two-phase catalysis. They are expected to be used in protein immobilization, interfacial biocatalysis, and other fields.