包覆型MCM-48磁性复合材料的制备及其吸附性能的研究

发布时间：2018-02-26 22:24

本文关键词： 溶胶凝胶法介孔材料纳米颗粒比表面积孔容孔径　出处：《广西师范大学》2017年硕士论文　论文类型：学位论文

【摘要】：介孔材料MCM-48型分子筛由于自身条件的优越性,在催化、吸附分离、医药等方面都具有非常有潜力的应用前景,可以用作吸附剂、催化剂和主体材料来合成新型的碳纤维、电子迁移光敏剂、非线性光学材料、半导体材料以及量子团簇等。因其具有较大的孔径,可以从污水中较好地吸附Ag、Hg、Pb、Cd等离子半径较大且不容易被微孔分子筛吸附的重金属离子。在含有较高硫酸根离子的情况下,可以去除浓度较低的铬酸根与砷酸根,还可以吸附污水中的有机污染物苯、甲苯及具有挥发性的一些有机化合物。同时,由于磁性纳米材料具有超顺磁性、高的饱和磁强度、高的矫顽力、制备工艺简单及耐腐蚀、耐磨损等一系列的优点,但是颗粒易团聚一直以来是铁氧体制备的最大难题,这就导致磁性纳米材料在应用上受到很大程度的限制。鉴于目前存在的问题,制备核壳式的磁性复合材料Y@MCM-48,以铁氧体为核MCM-48为壳来实现两种材料的性能互补,解决自身存在的问题,本文的主要工作内容如下:通过溶胶凝胶法制备介孔材料MCM-48,分别改变制备过程中模板剂的种类,表面活性剂与硅源的摩尔比,水浴搅拌温度观察复合材料的形貌与性能变化,表征结果显示,所得到的介孔材料MCM-48微观结构为尺寸较为均一的球形形貌,表面积为 1030.07～1252.48m2/g,孔容为 0.77-1.31cm3/g,孔径为 2.01-3.56nm,粒径直径分布在300～500nm之间。首先用溶胶凝胶法制备出CoFe2O4磁性颗粒,然后利用溶胶凝胶法在磁性颗粒CoFe204表面包裹一层有序介孔二氧化硅,形成以磁性纳米颗粒为核的磁性复合材料CoFe2O4@MCM-48,分别改变制备过程中钴铁尖晶石的添加量,表面活性剂与硅源的摩尔比,乙二醇(F108)的用量观察复合材料的形貌与性能变化,表征结果显示,所得到的CoFe2O4@MCM-48复合材料的微观结构为尺寸均一的球形形貌,表面积为982.86-1078.46m2/g,孔孔容为0.69～1.30cm3/g,孔径为1.86～2.52nm,粒径直径分布在350～500nm之间。
[Abstract]:Mesoporous MCM-48 molecular sieves have potential applications in catalysis, adsorption and separation, medicine and so on because of their own advantages. They can be used as adsorbents, catalysts and host materials to synthesize new carbon fibers. Electron transfer Guang Min, nonlinear optical materials, semiconductor materials and quantum clusters, etc., due to their large pore size, The heavy metal ions with large plasma radius and not easily adsorbed by microporous molecular sieve can be adsorbed from the wastewater. The chromate and arsenate with lower concentration can be removed under the condition of higher sulfate ion. It can also adsorb benzene, toluene and some volatile organic compounds in wastewater. At the same time, due to its superparamagnetism, high saturation magnetic intensity, high coercivity, simple preparation process and corrosion resistance, Wear resistance and other advantages, but the agglomeration of particles has always been the biggest problem in the preparation of ferrite, which leads to the application of magnetic nanomaterials is greatly limited. The core-shell magnetic composite Y@ MCM-48 was prepared. The ferrite was used as the core MCM-48 shell to realize the complementary performance of the two materials and to solve the existing problems. The main work of this paper is as follows: the mesoporous material MCM-48 was prepared by sol-gel method. The types of template, the molar ratio of surfactant to silicon source, and the temperature of water bath agitation were used to observe the morphology and properties of the composite. The results showed that the MCM-48 microstructure of the mesoporous material was spherical with a uniform size, with a surface area of 1030.07 and 1252.48m2 / g, pore volume of 0.77-1.31 cm ~ (-3) / g, pore size of 2.01-3.56 nm and diameter distribution of 300 ~ 500nm. Firstly, the magnetic particles of CoFe2O4 were prepared by sol-gel method. Then the magnetic particle CoFe204 surface was coated with ordered mesoporous silica by sol-gel method, and the magnetic composite CoFe2O4 / MCM-48 with magnetic nanoparticles as the core was formed. The amount of cobalt-ferrite spinel was changed respectively during the preparation process. The morphologies and properties of the composites were observed by the molar ratio of surfactant to silicon, and the amount of ethylene glycol F108). The characterization results showed that the microstructure of the CoFe2O4@MCM-48 composites was spherical with uniform size. The surface area is 982.86-1078.46 m2 / g, the pore volume is 0.69 ~ 1.30 cm ~ (-3) / g, the pore diameter is 1.86 ~ 2.52 nm, and the diameter distribution is between 350 ~ 500 nm.
【学位授予单位】：广西师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB33;O647.3

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