Preparation And Application Of Magnetic Nanocomposite Polymer Microspheres

Magnetic nanocomposite polymer materials have received voluminous interest, which due to the combination of unique properties of organic and inorganic component in one material. The magnetic nanocomposites polymer microspheres are of particular interest because of the combination of excellent magnetic properties, stability, and good biocompatibility. Two types of magnetic polymer microspheres, methods of their synthesis,properties and application have been prepared and studied in this article. The main content is as follows.1). The monodisperse cross-linked PS-DVB-GMA-amino-Fe₃O₄ magnetic microspheres with functional group of amino were synthase by seed swelling method. PS microspheres were used as seed particles, and glycidyl acrylate as monomer in the swelling polymerization. Then the poly（styrene-glycidyl methacrylate）（PS-DVB-GMA）microspheres were modified with ethylene diamine to form amino-groups. Subsequently,Fe₃O₄ nanoparticles were grafted on the microspheres through in situ co-precipitation reaction. The morphology, composition, magnetic properties, and crystalline structure of the magnetic microspheres were characterized by scanning electron microscope with energy dispersive analysis of X-rays（SEM/EDS）, transmission electron microscopy（TEM）, vibrating sample magnetometer（VSM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR） and thermogravimetric analysis（TGA） methods,respectively. The composite magnetic microspheres could be easily separated from suspension by magnetic decantation using a permanent magnet.2). The PGMA-N-oleoylsarcosine-Fe₃O₄ microspheres were synthesized by grafting N-oleoylsarcosine-Fe₃O₄ onto the walnut like poly glycidyl methacrylate microspheres（PGMA） at high temperature. The PGMA microspheres were prepared by dispersion polymerization, and the N-oleoylsarcosine-Fe₃O₄ was synthase by co-precipitate method.The morphology, composition, magnetic properties, and crystalline structure of the magnetic microspheres were characterized by scanning electron microscope with energy dispersive analysis of X-rays（SEM/EDS）, transmission electron microscopy（TEM）,vibrating sample magnetometer（VSM）, X-ray diffraction（XRD）, Fourier transform infrared spectroscopy（FTIR） and thermogravimetric analysis（TGA） methods, respectively.Compared with the magnetic microspheres introduced in 1), the walnut like PGMA microspheres loaded more Fe₃O₄ nanoparticles.