| In this paper, new environment-friendly, low-cost, high adsorption magnetic nanoparticles were prepared. The Fe3O4 nanoparticles were prepared by coprecipitation method and solvothermal. The outer Si O2 layer was coated with St?ber method. The material as adsorption to remove the malachite green and other dyes were discussed. Moreover, the magnetic nanomaterials modified by the high polymer using in separation of protein and cancer cell were studied. The detailed contents were given as following:(1) The prepared conditions of coprecipitation and solvothermal methods was optimized, respectively. In coprecipitation, the influence of magnetic nanoparticles size by the molar ration of Fe2+ and Fe3+, the amount of ammonia, and the temperature were studied. The amount of citric acid as stabilizer effect on the stability and the centrifugation conditions were discussed. The results showed that, Fe2+ and Fe3+ ratio of 2:3, the amount of aqueous ammonia was added 5m L, the curing temperature was 50℃. Citric acid added in an amount 0.16 g. Centrifugation conditions 6000 rpm, 25 min. Under these conditions, the minimum size of the magnetic nanoparticles prepared can reach 50.34 nm, Pd I 0.131. The magnetic nanomaterials can be kept stable for 42 days. Solvothermal method, adjusting the reaction time 10h~18h, the size can be prepared for 195.2nm~296.5nm.(2) Core-shell structured Fe3O4@Si O2 was fabricated by a modied St?ber method. Moreover, an amino-modi?ed Si O2-coated Fe3O4 magnetite was prepared. Using Fourier transform infrared spectroscopy(FT-IR) detection of the core-shell structure chemically composed of nanoparticles. The nanoparticle morphology was observed by transmission electron microscopy(TEM) and hydrated particle size(DLS). Using the potentiometer(Zeta), the nanoparticle stability and surface charge were detected. The crystalline structure of the nanoparticles was studied by X-ray diffraction(XRD). The results showed that Fe3O4@Si O2 was successfully prepared, the size of Fe3O4@Si O2 and Fe3O4@Si O2-NH2 was 95.49 nm and 123.2nm, respectively. A microsphere was uniform and has a good stability.(3) The factors that affect the adsorption of dyes on Fe3O4@Si O2-NH2 and Fe3O4@Si O2 included the adsorbent dosage, initial p H, salt concentration, surfactant, adsorption time were investigated. The adsorption was calculated with Langmuir and Freundlich isotherm models. Quasi second-order kinetic model cationic dye malachite green adsorption kinetics was investigated. The optimum concentration of Fe3O4@Si O2-NH2 was 100mg/L, while the initial concentration of malachite green was 10 mg/L at p H 7. The results indicated the removal of the malachite green was over 90%. The malachite green removal e?ciency by Fe3O4@Si O2-NH2 was higher than that of Fe3O4@Si O2. In addition, the adsorption capacity could be affected by ionic strength. The experimental data fitted well with the Freundlich isotherm and the pseudo-second-order kinetic model. Real samples were treated and the experimental result showed that these real water samples had little interference. The Fe3O4@Si O2-NH2 nanoparticles as a magnetic adsorbent could be a promising future for environmental based process.(4) The separation of proteins and cancer cells by the magnetic nanoparticles was studied. In protein isolates, by use of the principle of Ni ions and histidine ligand chelated, the surface of the magnetic nanomaterials was connected to Ni ion for chelating functional groups that of NTA derivative and vinylimidazole. The results showed that, the size prepared Fe3O4@AM-NTA-Ni was 167.5nm; Fe3O4@VIM-Ni size was 158.6nm and had good adsorption. In terms of cancer cells separated, the size of Fe3O4@AM-HA and Fe3O4@AM-FA were 442 nm and 239 nm, respectively. The results laid the foundation for the further application of magnetic nanomaterials. |
