产品类型:纳米材料 规格/参数:1g 价格(元):10000 时间:2019-09-18 17:24:33 交易状态:等待报价


          to prepare Fe3O4 , NH4 Fe(SO4) 2 ·12H2O (8.35 g) and (NH4)2Fe(SO4)2·6H2O(3.40
          g) were dissolved in 400mL water at 50 °C to synthesize iron oxides under a N2 atmosphere. Then, the iron oxides were precipitated with 20 mL NH3·H2O
          (8 mol/L). The mixed solution was sonicated (200W, 40kHz) for 10 min. After
          that, the final mixture was adjusted to pH11. The reaction was allowed to
          proceed at 50 °C and stirred for 1 h. The precipitate was separated by an
          external magnetic field and washed with double-distilled water to pH7. Next,
          1.7mL PVP (25.6 g/L) was added to the mixture that the obtained precipitate was
          dispersed in 20 mL water. The mixture was stirred vigorously at room
          temperature for 1 day. The Fe3O4 microspheres were
          gathered by an external magnetic field, which were washed with water and
          ethanol, respectively. The product was dried at 25 °C.

          In 350mL
          ethanol/water (4:1, v/v), 1.4g Fe3O4 microspheres were
          dispersed and 5 mL NH3·H2O was stirred at30 °C for 15
          min. Four-milliliter TEOS was added in the dispersion, and the mixture was
          stirred at 25 °C for 8 h. The product was magnetically separated and rinsed
          three times with ethanol. The obtained Fe3O4@SiO2 was dispersed in 140 mL isopropanol.

          40-mL Fe3O4@SiO2 solution which was diluted
          with 100 mL isopropanol, 0.2 mL APTES was added. The mixture was sonicated (200
          W, 40 kHz) for 30 min under a N2 atmosphere and kept stirring at 70
          °C for 6 h to obtain Fe3O4@SiO2-NH2.
          Finally, the products were washed with water and ethanol, respectively, and
          dried under vacuum.

          In 50
          mL of DMF, 0.2g GO was dispersed with the aid of ultrasonication. Then, 0.1g of
          NHS and 0.2 g of EDC were added to the dispersion. The mixture was stirred
          vigorously for 2 h at room temperature. Next, 0.5g Fe3O4@SiO2-NH2 was added to the mixture. The mixed solution was stirred overnight at room
          temperature. The products were washed with water and air-dried for further use.Composite
          materials of graphene oxide (GO) to Fe3O4@SiO2-NH2 (Fe3O4@SiO2@GO) were prepared .

          Fe3O4@SiO2@G was
          synthesized by hydrazine reduction of the Fe3O4@SiO2@GO,
          and 0.2 g Fe3O4@SiO2@GO was dissolved in 100
          mL water. Then, 200 μL hydrazine (85 %) was added to the mixture, and the
          reaction was churned for 2h at 95 °C. Finally, the polymers were washed
          thoroughly with water and dried at 80 °C.