不同类型核壳结构二氧化硅的制备与表征

发布时间：2018-03-12 19:07

本文选题：核壳结构　切入点：光谱分析　出处：《山东师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：近年来，“纳米热”已经是越来越让人们所熟悉，与纳米材料有关的研究与应用的成果也源源不断的出现在我们世人的眼前[1]。其中的有关纳米级的半导体材料的研究与应用也开始越来越受到人们的重视！Si作为第一代的半导体材料，它的地位与重要性是无法被取代的[2-3]。自核壳介孔SiO2纳米材料的出现开始，各国的科学家制备出了许多种不同形貌的核壳SiO2纳米材料（例如球状、棒状、片状等）[4-9]。美国加利福尼亚大学的Sang Hoon Joo[10]等人采用溶胶-凝胶法，充分水解了正硅酸四乙酯，然后采用了十四烷基三甲基溴化铵（TTAB）制备出了高性能的Pt/SiO2。许多科学家采用这种方法合成出来的核壳介孔SiO2的外貌和尺寸等，我们都可以通过对表面活性剂的调整来调节它们的尺寸大小[11-15]。Zhang[16]等人将正硅酸四乙酯水解，合成了有序介孔的SiO2磁性核壳纳米材料，这种核壳的优点有很多，例如：核壳的大小、厚度以及磁性粒子的包裹量都是可以进行调整的，并且这种核壳纳米材料的密度很低，壳层的比表面积较高，介孔的孔径大。赵东元等[17]用Stober法制备出了一种形态较为完整的核壳-结构介孔SiO2微球，这种方法制备的微球的直径大约在400nm，球形状态较为完整，并且介孔的孔径为3nm左右。Hyeon[18-22]课题组采用了一种新的方法，他们制备出了一种单分散性较好的Fe3O4/SiO2微球，采用这种方法制备的磁性SiO2微球的顺磁性很强，微球粒子的尺寸非常的均一，但是它存在的缺点就是：这种SiO2微球磁强度较低、而且关键的是它的表面结构没有一定的顺序性，这些缺点导致了它其在领域的应用与研究相对的匮乏。本文主要讲述了两种不同核壳结构纳米SiO2材料的制备与表征。：第一种核壳介孔二氧化硅的方法：第一步，，采用水解TEOS的方法制备SiO2微球，第二步：采用溶胶-凝胶法，在二氧化硅微球的表面包裹上一层有序介孔的SiO2核壳。第二种就是PS/SiO2核壳及二氧化硅空心球。第一步，制备聚苯乙烯微球，第二步，在聚苯乙烯微球的表面采用特殊的表面活性剂，制备上一种二氧化硅壳层；此时就已经制备好了PS/SiO2核壳，并对其进行各种表征。但是我们想到PS微球在高温中能够挥发的特点，利用此特性，对样品进行高温煅烧，除去聚苯乙烯球体，得到核壳二氧化硅空心微球。采用溶胶-凝胶法在特定条件下制备了核-壳二氧化硅微球，利用TEM和Raman光谱分别对核壳SiO2的微观结构进行了观察和光谱分析。分析结果表明：制备的核壳孔SiO2样品，是由外表面为孔径7nm，厚度30nm的SiO2壳层，包裹着核为直径为200nm的实心SiO2微球所组成，核壳的介孔壳层的比表面积较大，同时还具备着良好的光谱性质。
[Abstract]:In recent years, the "nano heat" is more and more people are familiar with the research and application of nano materials related to the results of Everfount also appeared in the research and application of nano semiconductor materials we the eyes of the world of the [1]. which also began to more and more people pay more attention to Si as the first generation of semiconductor materials! The position and importance of it is cannot be replaced from the [2-3]. core-shell mesoporous SiO2 nano materials, preparation of scientists prepared many different morphologies of SiO2 core-shell nano materials (such as spherical, rod, sheet etc.) [4-9].
The University of California Sang Hoon Joo[10] et al by using sol-gel method, the hydrolysis of TEOS four fully acetate, and then using the fourteen alkyl three methyl bromide (TTAB) was prepared by core-shell mesoporous SiO2 high performance Pt/SiO2. many scientists using this method, the synthesis of appearance and size, we can the surfactant adjustment to adjust the size of [11-15].Zhang[16], they will four ethyl orthosilicate hydrolysis, SiO2 magnetic core-shell nano ordered mesoporous materials were synthesized, there are a lot of advantages, such as: the core-shell core-shell magnetic particle size, thickness and the amount of all can be adjusted. And this kind of core-shell nano material density is very low, the shell of high specific surface area, pore diameters. Zhao Dongyuan [17] Stober was prepared by core-shell morphology is a complete - The structure of mesoporous SiO2 microspheres, microspheres prepared by this method is about 400nm diameter, spherical state is complete, and the pore size of mesoporous 3nm.Hyeon[18-22] research group has adopted a new method, they prepared a good monodisperse Fe3O4/SiO2 microspheres, magnetic SiO2 microspheres using this method the preparation of CIS strong magnetic microspheres, uniform particle size is very, but it has the drawback is: the SiO2 magnetic microspheres with low strength, but the key is the surface structure of it without certain order, these shortcomings led to it in the field of research and application of relative scarcity.
In this paper, the preparation and characterization of two nano SiO2 materials with different nuclear shell structures are described.
The first method of core-shell mesoporous silica by hydrolysis method: the first step, the preparation of TEOS SiO2 microspheres, the second step by a sol-gel method on the surface of silica microspheres coated with a layer of ordered mesoporous SiO2 core shell. The second is the PS/SiO2 core-shell and hollow silica spheres. The first step. Preparation of polystyrene microspheres, the second step, using special surfactant on the surface of polystyrene microspheres, preparation of a silica shell; this has prepared PS/SiO2 core-shell, and characterized by many. But we have the characteristics of PS microspheres in high temperature volatilization, using this characteristic of high temperature calcination of samples, removal of the polystyrene spheres, core-shell silica hollow microspheres were obtained by sol-gel method. Under certain conditions the preparation of core-shell silica microspheres, using TEM and Raman spectra respectively of core shell SiO The microstructure of 2 were analyzed and observed spectra. Analysis results show that the core-shell hole SiO2 sample preparation, is composed of outer surface diameter 7Nm, thickness 30nm SiO2 shell, which is wrapped around the nuclear 200nm diameter SiO2 solid microspheres, core-shell mesoporous shell of the specific surface area is large at the same time, also has a good spectral properties.

【学位授予单位】：山东师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;O613.72

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