离子液体修饰磁性石墨烯基纳米复合材料的制备与应用研究

发布时间：2018-01-06 20:38

本文关键词：离子液体修饰磁性石墨烯基纳米复合材料的制备与应用研究　出处：《西北师范大学》2015年硕士论文　论文类型：学位论文

【摘要】：磁性纳米材料具有独特的结构和优异的磁学性能,在自动控制、信息存储、生物医药、污水处理等领域得到广泛的应用。磁性纳米复合材料是将磁性纳米颗粒通过物理或化学的方法与其它前驱体结合而形成,该磁性纳米复合材料兼具各组分的优势,尤其在污水处理方面具有广阔的应用前景。本论文围绕Fe3O4纳米颗粒和磁性石墨烯基复合材料的设计和制备以及其在污水处理等方面开展相关研究,主要内容和结果如下:首先,以磁性离子液体[BMIm]FeCl4为铁源,采用简单的化学共沉淀方法制备出Fe3O4磁性纳米颗粒。该Fe3O4纳米颗粒的粒径较小,大多数粒径分布在5-7nm范围之间,而小粒径Fe3O4会存在团聚现象。X射线衍射(XRD)谱图分析表明,Fe3O4纳米颗粒的特征衍射峰峰型较为尖锐,结晶性良好。采用该合成方法制备出的小粒径Fe3O4纳米颗粒具有良好的铁磁性,可望在磁性复合材料应用领域有着巨大的潜能。其次,以石墨粉为原料,采用改进的Hummers法制备氧化石墨,氧化石墨经超声剥离得到单分散的氧化石墨烯。磁性离子液体[BMIm]Fe Cl4与氧化石墨烯在π-π作用下结合,经共沉淀作用在氧化石墨烯的表面原位生长出Fe3O4磁性纳米颗粒。通过控制反应物的添加量,制备出不同比例的氧化石墨烯@Fe3O4磁性纳米复合材料。扫描电子显微镜(SEM)和透射电子显微镜(TEM)分析表明,在氧化石墨烯的存在下,小粒径的Fe3O4纳米颗粒均匀的沉积在氧化石墨烯的表面,说明氧化石墨烯对Fe3O4纳米颗粒的团聚起到了一定的抑制作用。研究结果表明,氧化石墨烯含量为19.3 wt%的复合材料样品最佳。对亚甲基蓝的吸附性能显示氧化石墨烯@Fe3O4磁性纳米复合材料的吸附效果明显增强,可快速的达到吸附平衡,且在外加磁场的作用下表现出良好的磁响应性。再次,对实验进行设计与改进,在氧化石墨烯和二价铁离子的存在下,通过逐滴加入氨水来控制反应的pH。经简单的一步法制备出石墨烯@Fe3O4纳米复合材料。Fe3O4纳米颗粒均匀的沉积在石墨烯的表面上,粒径分布范围在10-20 nm范围之间。大比表面积的石墨烯对亚甲基蓝有很好的吸附效果,吸附量为45.2mg/g,该复合材料同样具有良好的磁响应性。最后,采用改进Hummers法制备的氧化石墨烯经硼氢化钠还原得到褶皱的石墨烯。将石墨烯溶解分散在中间体[BMIm]Cl中,同时加入一定量的磁性离子液体[BMIm]Fe Cl4经简单共沉淀法制备石墨烯@Fe3O4磁性纳米复合材料。小粒径的Fe3O4纳米颗粒不仅均匀的沉积在石墨烯的表面,而且有效的打开了石墨烯的片层。小粒径的Fe3O4纳米颗粒和大比表面积的石墨烯使得该磁性复合材料对亚甲基蓝表现出优异的吸附性能。
[Abstract]:Magnetic nano materials with unique structure and excellent magnetic performance, automatic control, information storage, biological medicine, widely used in sewage treatment and other fields. The magnetic nano composite magnetic nanoparticles by physical or chemical methods and other precursor combination formed, the advantages of each component of the magnetic nano composite material both, especially has broad application prospect in wastewater treatment. This paper focuses on the design and preparation of Fe3O4 magnetic nanoparticles and graphene based composite materials and in the aspect of sewage treatment and other related research carried out, the main contents and results are as follows: firstly, the magnetic ionic liquid [BMIm]FeCl4 as iron source, using a simple chemical preparation Fe3O4 magnetic nanoparticles Co precipitation method. The Fe3O4 nano particle size is small, most of the particle size distribution in the range of 5-7nm, while the small size Fe3O4 Agglomeration of.X ray diffraction (XRD) spectra analysis showed that the characteristic diffraction peak of Fe3O4 nanoparticles is relatively sharp, good crystallinity. Using granule prepared the synthetic method for Fe3O4 nanoparticles with good ferromagnetism, is expected to have great potential applications in the field of magnetic composite materials. Secondly, with graphite powder as raw material, graphite oxide prepared by modified Hummers method, graphite oxide by ultrasonic stripping to obtain graphene oxide monodisperse. Magnetic ionic liquid [BMIm]Fe Cl4 and graphene oxide in interaction with Fe3O4, the growth of magnetic nanoparticles on the surface of graphene oxide in situ by coprecipitation. Controlling the amount of reactants, prepared graphene oxide @Fe3O4 magnetic nano composite material in different proportions. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analysis showed that the graphite oxide By the presence of Fe3O4 nanoparticles deposited on the surface of small size uniform in graphene oxide, indicating agglomeration of graphene oxide on Fe3O4 nanoparticles has played a certain effect. The results show that the graphene content of graphite oxide composite samples of 19.3 wt%. The best adsorption of methylene blue on display adsorption the effect of graphene oxide @Fe3O4 Nanocomposites were enhanced, can quickly reach the adsorption equilibrium, and in the presence of an external magnetic field showed good magnetic response. Again, for the design and improvement of experiment on graphene oxide and two valent iron ions in the presence of ammonia was added dropwise to the to control the reaction by pH. one step method is simple to produce particles of.Fe3O4 nano graphene @Fe3O4 nanocomposites uniformly deposited on the surface of graphene on the particle size distribution in the range between 10-20 nm. Good adsorption effect than the graphene surface area of methylene blue, the adsorption capacity was 45.2mg/g, the composites have good magnetic response. Finally, the improved graphene oxide Hummers was prepared by sodium borohydride to get graphene folds. The graphene solution dispersed in the intermediate [BMIm]Cl at the same time, adding a certain amount of magnetic ionic liquid [BMIm]Fe Cl4 by a simple coprecipitation method to prepare graphene @Fe3O4 nanocomposites. Fe3O4 nanoparticles with small particle size and uniform surface not only deposited on the graphene, but also effectively opened the layers of graphene. The graphene nano particles with small particle size and large surface area Fe3O4 the methylene blue showed excellent adsorption properties of the magnetic composite materials.

【学位授予单位】：西北师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TB33

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