Synthesis And Characterization Of Magnetic P (St-co-MAA-co-AM)/SiO₂ Composite Microspheres

Oleic acid-coated Fe3O4 iron oxide nanoparticles were prepared by co-precipitation. P (St-co-MAA-co-AM) polymer microspheres were prepared by Micro-emulsion. A sol-gel procedure was used to cover magnetic P (St-co-MAA-co-AM) Microspheres with a silica layer, forming core/shell structure. It was also functioned with - COOH. Then Optical Microscopy and Transmission Electron Microscope were used to characterization the size and morphology of the magnetic microspheres. X-ray photoelectron spectroscopy was used to analysis the surface composition of the magnetic microspheres. Fourier Transform Infrared Spectrometer was used to characterization the surface composition and effect of the surface modification. Vibrating Sample Magnetometer was used to test the magnetization of the samples. Both the Optical Microscopy and transmission electron microscope photographs show that P (St-co-MAA-co-AM) /SiO₂ beads were about 2um in size. Transmission Electron Microscope also indicates that the surface of the polymer microspheres was coated with a layer of material. And X-ray photoelectron spectroscopy shows that P (St-co-MAA-co-AM) /SiO₂ microspheres contain both Si and O elements on its surface, but no Fe was found. Fourier Transform Infrared Spectrometer revealed that samples microspheres containing Si-O-Si bond. Taking both the X-ray Scanning photoelectron spectroscopy and Fourier Transform Infrared Spectrometer into account, we conclude that silica was coated on the surface of P (St-co-MAA-co-AM) beads. Fourier Transform Infrared Spectrometer spectra also show that P (St-co-MAA-co-AM) /SiO₂ microspheres were successfully functioned with–COOH. Vibrating Sample Magnetometer results shows that the sample shows good super-paramagnetic behavior. Finally, bioconjugation to IgG was also studied. The results show that samples have good biocompatibility.