Preparation and characterization of structure-tailored magnetic fluorescent Fe₃O₄/P(GMA–EGDMA–NVCz) core–shell microspheres

Fe₃O₄ nanoparticles were prepared by solvothermal reaction, and structure-tailored Fe₃O₄/poly(glycidyl methacrylate-ethyleneglycol dimethacrylate-N-vinylcarbazole) (Fe₃O₄/P(GMA–EGDMA–NVCz)) core–shell microspheres were achieved by distillation–precipitation polymerization of GMA, EGDMA, and NVCz in the presence of Fe₃O₄ nanoparticles. The properties of Fe₃O₄/P(GMA–EGDMA–NVCz) microspheres were characterized by transmission electron microscopy(TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), and fluorescence spectroscopy. The results showed that the size of Fe₃O₄/P(GMA–EGDMA–NVCz) core–shell microspheres could be controlled to 930–470 nm by adjusting the amount of shell monomers, corresponding magnetic content of 45–82 wt%, and saturation magnetization of 32–63 emu/g. Moreover, the intensity of the fluorescence increased considerably with the decrease of shell thickness and the increase of NVCz concentration in the monomer mixture.