磁性介孔二氧化硅的聚合物包覆改性及应用研究

发布时间：2018-04-27 01:08

本文选题：磁性介孔二氧化硅 + 壳聚糖　；参考：《安徽大学》2015年硕士论文

【摘要】：磁性介孔二氧化硅是一种新型的纳米复合材料,具有较大的比表面积、规整的纳米尺寸的孔结构、生物相容性、生物可降解性,被广泛应用于靶向载药、催化、固定化酶以及污水处理等方面。壳聚糖是自然界中第二大多糖甲壳素,脱乙酰之后的产物,具有廉价、生物相容性、生物可降解性、无毒和吸附性质等优点,被广泛应用于污水处理、生物医药等领域。为了得到兼具二者优点的复合材料,本文制备出了壳聚糖包覆的磁性介孔二氧化硅(Fe3O4/mSiO2/CS)复合材料；为了增强壳聚糖包覆的磁性介孔二氧化硅纳米粒子的性能,在此体系中引入了聚甲基丙烯酸,主要的研究内容和结论如下：(1)分别采用水热法和化学共沉淀法制备了四氧化三铁(Fe3O4)纳米粒子,并以两种方法得到的Fe304纳米粒子为核,通过溶胶-凝胶法包覆二氧化硅,并通过离子交换的方法,用硝酸铵-乙醇混合溶液移除表面活性剂,得到介孔结构的Fe3O4/mSiO2纳米粒子。由于以水热法制备的Fe304纳米粒子为核得到的Fe3O4/mSiO2纳米粒子团聚现象比较严重,所以采用化学共沉淀法制备的Fe304纳米粒子为核获得Fe3O4/mSiO2纳米粒子。分别用FTIR、TEM、XRD等表征方法对Fe3O4/mSiO2纳米粒子进行表征。结果显示：Fe3O4/mSiO2纳米粒子的尺寸为100nm,单分散性良好；比表面积和孔体积分别为665.48m2/g和1.00cm3/g,孔径分布呈单峰,具有均匀的介孔结构且尺寸为2.9nm。(2)以Fe3O4/mSiO2纳米粒子为核,采用“两步法”和“一步法”两种方式得到Fe304/mSi02/CS纳米粒子。两步法：首先对Fe3O4/mSiO2纳米粒子进行羧基化改性,然后再利用羧基和壳聚糖上的氨基的作用把壳聚糖包覆在Fe3O4/mSiO2纳米粒子上,所得到的Fe3O4/mSiO2/CS纳米粒子中,壳聚糖的厚度为10nm；测试了Fe3O4/mSiO2/CS纳米粒子对药物释放的pH响应性,结果证明其具有pH响应性。由于“两步法”的操作繁琐且实验过程中用到的甲苯、N,N-二甲基甲酰胺(DMF)和二甲基亚砜(DMSO)等有机溶剂比较难除去,因此,又采用“一步法”制备Fe3O4/mSiO2/CS纳米粒子。一步法：通过Y-缩水甘油醚氧丙基三甲氧基硅烷(KH560)把壳聚糖直接包覆在Fe3O4/mSiO2纳米粒子上,得到Fe3O4/mSiO2/CS纳米粒子,并用于吸附水中的亚甲基蓝,通过表征可得Fe3O4/mSiO2/CS纳米粒子的形貌为球形,壳聚糖壳层的厚度为5nm。Fe3O4/mSiO2/CS纳米粒子对亚甲基蓝具有良好的吸附效果,吸附量为43mg/g,吸附动力学符合二阶动力学方程,吸附等温线符合Freundlich等温模型,吸附染料之后有很好的磁响应性能,并且能够快速分离。(3)为了进一步提高对亚甲基蓝的吸附能力,以Fe3O4/mSiO2纳米粒子为核,采用原位聚合法把壳聚糖和聚甲基丙烯酸共同包覆在Fe3O4/mSiO2纳米粒子上,得到Fe3O4/mSiO2/CS-PMAA纳米粒子。通过TEM、RT-IR、TGA和Zeta电位等表征方法对其表征,结果表明CS和PMAA所占的比重为23%,包覆聚合物之后Zeta电位向更负的位置移动,磁饱和强度由21.9eum/g降到6.1um/g,但仍然具有超顺磁性。研究了吸附时间和初始浓度对Fe3O4/mSiO4/CS-PMAA纳米粒子吸附亚甲基蓝的影响,结果显示：Fe3O4/mSiO2/CS-PMAA纳米粒子对亚甲基蓝的吸附量达到101mg/g,吸附动力学符合二阶动力学方程,吸附等温线符合Freundlich等温模型。
[Abstract]:Magnetic mesoporous silica is a new kind of nanocomposite. It has large specific surface area, regular nano size pore structure, biocompatibility and biodegradability. It is widely used in targeted drug loading, catalysis, immobilized enzyme and sewage treatment. Chitosan is second most sugar chitin in nature and deacetylation. The later products, with the advantages of cheap, biocompatibility, biodegradability, non-toxic and adsorption properties, are widely used in the fields of sewage treatment, biological medicine and other fields. In order to obtain the composite materials with two advantages, the chitosan coated magnetic mesoporous silica (Fe3O4/mSiO2/CS) composite was prepared in order to enhance the shell. The properties of magnetic mesoporous silica nanoparticles coated with chitosan have been introduced in this system. The main contents and conclusions are as follows: (1) Fe3O4 nanoparticles were prepared by hydrothermal method and chemical coprecipitation method respectively, and the Fe304 nanoparticles obtained by two methods were nucleated by sol-gel. The Fe3O4/mSiO2 nanoparticles of mesoporous structure were obtained by the method of ion exchange and the method of ion exchange. The mesoporous structure was obtained by removing the surface active agent in the mixture of ammonium nitrate and ethanol. The aggregation of Fe3O4/mSiO2 nanoparticles obtained by the Fe304 nanoparticles prepared by hydrothermal method was more serious, so the chemical coprecipitation method was used to prepare the nanoparticles. The Fe304 nanoparticles are nucleed to obtain Fe3O4/mSiO2 nanoparticles. The Fe3O4/mSiO2 nanoparticles are characterized by FTIR, TEM and XRD respectively. The results show that the size of Fe3O4/mSiO2 nanoparticles is 100nm, and the monodisperse property is good; the specific surface area and pore volume are 665.48m2 /g and 1.00cm3/g, the pore size distribution is single peak and uniform. The mesoporous structure and the size of 2.9nm. (2) were nucleated with Fe3O4/mSiO2 nanoparticles. The "two step" and "one step" method were used to obtain the Fe304/mSi02/CS nanoparticles. The two step method: the carboxylation of the Fe3O4/mSiO2 nanoparticles was first modified, and then the chitosan was coated on the Fe3O4 with the action of the carboxyl group and the amino group on the chitosan. On the /mSiO2 nanoparticles, the thickness of the chitosan was 10nm in the obtained Fe3O4/mSiO2/CS nanoparticles, and the pH responsiveness of the Fe3O4/mSiO2/CS nanoparticles to the drug release was tested. The results showed that the chitosan was pH responsive. The "two step" operation was complicated and the toluene, N, N- two methylformamide (DMF) and two methyl methamides used in the experimental process. DMSO and other organic solvents are difficult to remove. Therefore, Fe3O4/mSiO2/CS nanoparticles are prepared by one step method. One step method: using Y- glycidyl methoxypropyl trimethoxy silane (KH560) to encapsulate chitosan directly on Fe3O4/mSiO2 nanoparticles and get Fe3O4 /mSiO2/CS nanoparticles and used to adsorb methylene blue in water. The morphology of Fe3O4/mSiO2/CS nanoparticles is spherical. The thickness of the chitosan shell is 5nm.Fe3O4/mSiO2/CS nanoparticles with a good adsorption effect on methylene blue. The adsorption capacity is 43mg/g. The adsorption kinetics accords with the two order kinetic equation. The adsorption isotherm is consistent with the Freundlich isothermal model. After the adsorption, the dye is good. (3) in order to further improve the adsorption capacity of methylene blue, Fe3O4/mSiO2 nanoparticles are used as core. In situ polymerization, chitosan and polymethacrylic acid are coated on Fe3O4/mSiO2 nanoparticles, and Fe3O4/ mSiO2/CS-PMAA nanoparticles are obtained by TEM, RT-IR, TGA and Zeta potential. The results show that the proportion of CS and PMAA is 23%. After coated polymers, the Zeta potential moves to a more negative position, the magnetic saturation intensity is reduced from 21.9eum/g to 6.1um/g, but it still has superparamagnetic. The effect of adsorption time and initial concentration on the adsorption of methylene blue with Fe3O4/mSiO4/ CS-PMAA nanoparticles is studied. The results showed that the adsorption capacity of Fe3O4/mSiO2/CS-PMAA nanoparticles to methylene blue reached 101mg/g, and the adsorption kinetics accorded with the two order kinetic equation, and the adsorption isotherm accorded with the Freundlich isothermal model.

【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB383.1;TQ127.2

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