Preparation And Application Of Functional Magnetic Nanocomposites

magnetic nanoparticles have a large surface area, good superpara-magnetism, good magnetic response, etc. Its have a good prospect in biological sense, targeted drugs, biological immobilized enzyme, controlled release, high density information storage, magnetic resonance imaging, immunoassays, DNA and cell separation, hyperthermia. Humic acid (HA) is rich natural organic macromolecules. HA contains a large number of hydrophilic functional group as carboxyl group, hydroxyl group and carbonyl group, therefore, the hydrophilic organic compound HA having good adsorption properties. Fe3O4-HA functional magnetic nanocomposites were successfully modified by humic acid, basis on our group research on preparation of multifunctional composite materials, therefore, Fe3O4-HA functional magnetic nanocomposites overcome the disadvantage of magnetic nano-particles, which have poor corrosion resistance, easy agglomeration, difficult separation and washing, etc. Fe3O4-HA functional magnetic nanocomposites have magnetic and ligand property, which ingeniously combines the advantages of magnetic nano-particles and HA. Fe3O4-HA functional magnetic nanocomposites have broad application prospects in the aspect of pollution control and rare earth separation. The results of the academic paper are as follows:1. First, Fe3O4 magnetic microspheres are modified by hydrothermal synthesis method. The structures and properties of the composite microsphere are characterized by transmission electron microscopy (TEM), optical contact angle measurement (OCA), Fourier transform infrared spectroscopy(FTIR), X-ray difrraction(XRD), vibrating sample magnetometer (VSM). The results demonstrate that Fe3O4 magnetic microspheres have good crystal structure and good monodispersity, the average particles size is 300 nm and the saturation magnetization is 77.0 emu/g. Fe3O4 magnetic microspheres have good superparamagnetism.2. Fe3O4-HA functional magnetic nanocomposites are prepared by the method of change PH. The structures and properties of the composite microspheres are characterized by transmission electron microscopy(TEM), optical contact angle measurement(OCA), Fourier transform infrared spectroscopy(FTIR), X-ray diffraction(XRD), vibrating sample magnetometer(VSM). The results show that Fe3O4-HA magnetic nanocomposites have good crystal structure and good monodispersity, the average particles size is 320 nm, the thickness of the humic acid layer is about 10 nm, the saturation magnetization is 75.3 emu/g.3. Adsorption behavior of Fe3O4-HA functional magnetic nanocomposites in pollution water containing organic dye methylene blue(MB) were studied by ultraviolet and visible spectrophotometer. The results show that Fe3O4-HA functional magnetic nanocomposites have good performance to adsorpt MB, the maximum adsorption rate was 92%, Fe3O4-HA have high adsorption efficiency and reusability.4. It evaluated Fe3O4-HA adsorbent for the adsorption of Europium, Neodymium and the influences of adding anionic to adsorption. The results show that Fe3O4-HA functional magnetic nanocomposites have good adsorption performance of rare earth ions, the maximum adsorption rate was 96%, Fe3O4-HA have high adsorption efficiency and reusability. Fe3O4-HA adsorbent can selectively adsorb Nd3+, when PO43- concentration is 1.0 mol/L.