溶胶凝胶法制备MCM-41复合材料及其吸附性能研究

发布时间：2018-04-04 01:39

  本文选题：MCM-41　切入点：溶胶-凝胶法　出处：《广西师范大学》2017年硕士论文

【摘要】：MCM-41分子筛介孔材料具有较高的比表面积、均匀的和可连续调控的孔径、一维的孔道结构,且具有可调控的形貌如球状、膜片及纤维状等许多优点,使得它们在工业催化、生物医药、吸附分离、纳米材料器件的制备以及环境保护等领域体现出巨大的应用前景。但由于MCM-41的水热稳定性低、反应活性低、无磁性、具有中性的骨架结构等性质又限制了 MCM-41在各方面的应用,因此吸引大量学者对其进行研究。本文主要研究Y/MCM-41复合材料的制备和性能。主要研究内容如下:1.采用溶胶-凝胶法合成MCM-41分子筛,通过改变制备过程中TEOS的加入量、氨水的加入量、搅拌时间和搅拌速度的工艺条件,合成出系列样品,并对样品进行表征。XRD表征说明TEOS=2.0ml、氨水=32.8ml、搅拌时间=4h时所制备MCM-41分子筛的结晶度最好;FT-IR表征说明所制备的所有样品都含有SiO2成分,且都不含有模板剂CTAB,说明此时的温度条件(550℃、6h、1℃/min)可以很好的去除模板剂,杜绝了模板剂对样品表征的影响:SEM分析说明TEOS=2.0ml、氨水=32.8ml、搅拌时间=4h时所制备MCM-41分子筛的颗粒性最好;BET分析所得样品具有较高的比表面积(742～1123m2/g),孔径均匀(2.5nm左右),因此可知所制备样品属于介孔材料;TEM表征说明TEOS=2.0ml、氨水=32.8ml、搅拌时间=4h时所制备MCM-41分子筛具有较为良好的长程有序六方孔道结构。2.以热溶剂法制备了 Fe3O4粒子,用XRD对其表征发现制备出来的Fe3O4粒子纯度较高,用SEM对其表征发现样呈现出很规则球形,样品大小基本一致,无团聚现象。另外以溶胶-凝胶法制备出Fe3O4/MCM-41复合材料,并改变了 Fe3O4、TEOS、氨水的加入量制备出一系列不同的Fe3O4/MCM-41复合材料,并对其进行表征。XRD表明Fe3O4=0.037g、TEOS=2.0ml、氨水=32.8ml时所制备Fe3O4/MCM-41复合材料具有相对较好的结晶度,且含有Fe3O4和MCM-41组分。FT-IR表明所制备的Fe3O4/MCM-41复合材料中MCM-41可能包覆在Fe3O4的表面。SEM表明Fe3O4=0.037g、TEOS=2.0ml、氨水=32.8ml时所制备Fe3O4/MCM-41复合材料具有相对较好的颗粒性和有序性。TEM表面Fe3O4=0.037g、TEOS=2.0ml、氨水=32.8ml时所制备Fe3O4/MCM-41复合材料具有更为良好的长程有序六方结构,且MCM-41成功包覆在Fe3O4的表面,证实了 FT-IR的可能性。BET分析表明所制备的复合材料具有良好的比表面积平均可达784m2/g,孔径基本维持在2.2～2.7nm之间,归属于介孔材料。因此我们成功制备出结晶度较高、比表面积较高且孔道结构规整的Fe3O4/MCM-41介孔复合材料。
[Abstract]:MCM-41 molecular sieve mesoporous materials have high specific surface area, uniform and continuously adjustable pore size, one-dimensional pore structure, and have many advantages such as ball shape, membrane and fiber, which make them catalyze in industry.Biomedicine, adsorption and separation, preparation of nanomaterials and environmental protection show great application prospects.However, because of its low hydrothermal stability, low reaction activity, non-magnetic properties and neutral skeleton structure, MCM-41 has limited its applications in various fields, so it has attracted a large number of scholars to study it.The preparation and properties of Y/MCM-41 composites are studied in this paper.The main research contents are as follows: 1.MCM-41 molecular sieve was synthesized by sol-gel method. A series of samples were synthesized by changing the amount of TEOS, the amount of ammonia, stirring time and stirring speed.The samples were characterized by XRD, 2.0 ml, 32.8 ml ammonia, and the crystallinity of MCM-41 molecular sieve was the best when stirring time was 4 h. All the samples were characterized by FT-IR, and all the samples contained SiO2.And no template agent CTAB was found, which indicated that the temperature of 550 鈩，

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