Fe3O4@SiO2@PAA多层核-壳结构复合微球的制备及吸附染料研究

以溶剂热法合成Fe3O4磁性微球,并以正硅酸四乙酯(TEOS)为硅源,通过溶胶-凝胶法在Fe3O4磁性微球表面包裹SiO2壳层,利用3-(异丁烯酰氧)三甲氧基硅烷(APTES)对SiO2壳层进行修饰后,通过交联沉淀聚合法在SiO2壳层外部合成聚丙烯酸(PAA)层,形成Fe3O4@SiO2@PAA多层核-壳结构复合微球。利用透射电子显微镜(TEM)、红外光谱(FT-IR)和热重分析仪(TGA)对合成材料的形貌和结构进行表征,并就多层结构复合微球对染料的吸附性能进行研究。结果显示:制备的Fe3O4磁性微球具有良好的水分散性,其表面可分步包裹SiO2和PAA壳层,形成Fe3O4@SiO2@PAA多层核-壳结构复合微球,该复合微球对罗丹明6G和亚甲基蓝的吸附量分别达到1.04和1.14 mg/g(吸附质量浓度为2.4 mg/L,吸附时间为10 min),表现出良好的染料吸附性能。
In the present study, Fe3O4 magnetic nanoparticles were fabricated by solvothermal method. Tetraethyl orthosilicate(TEOS)was used as precursor to fabricate a layer of SiO2 on the surface of Fe3O4 nanoparticles. 3-(methacryloyl oxygen)trimethoxy silane(APTES)was used as silane coupling agent to modify the surface of SiO2@Fe3O4 with double carbon bonds, then Fe3O4/silicon dioxide/poly(acrylate acid)(Fe3O4@SiO2@PAA)multi-layer core-shell structural composite microspheres were prepared by cross-linking precipitation polymerization of acrylate acid and divinyl benzene monomers without the use of surfactants and stabilizers. The as-synthesized particles have been characterized by means of transmission electron microscopy(TEM), Fourier transform infrared spectroscopy(FT-IR)and thermogravimetric analysis(TGA). The size of the prepared Fe3O4 nanoparticles was about 150-250 nm. The Fe3O4 nanoparticles exhibited good water-solubility and were successfully encapsulated by SiO2 shell. The PAA was successfully grafted onto the surface of SiO2 to form Fe3O4@SiO2@PAA multilayer core-shell composite microspheres. The results of Fe3O4@SiO2@PAA microspheres showed high performance in the adsorption of Rhodamine 6G and methylene blue. The 10-minute adsorption reached 1.04 mg/g and 1.14 mg/g