磁性四氧化三铁复合颗粒的制备及其在吸附金属离子方面的应用

发布时间：2018-02-26 08:16

本文关键词： 四氧化三铁复合粉体改性重金属离子吸附　出处：《中国海洋大学》2015年硕士论文　论文类型：学位论文

【摘要】：四氧化三铁因为具备良好的物理化学稳定性、生物兼容性和特殊的磁性能,使它在磁分离、催化剂、磁流体、生物医学和环境治理等领域得到广泛应用。本文采用沉淀法和溶剂热法两种方法制备出磁性纳米Fe304颗粒,并探讨了不同制备方法、反应时间和温度对Fe304颗粒晶型和性状的影响。通过改进的Stober法和沉淀聚合法在四氧化三铁颗粒表面包覆二氧化硅和聚甲基丙烯酸酯(PMMA),并在氨基改性后进行了重金属离子的吸附测试。具体研究内容如下：(1)利用共沉淀法和溶剂热法分别制备出纯度较高的纳米四氧化三铁颗粒,通过XRD、 SEM和VSM等测试手段进行表征。结果显示,共沉淀法制得的Fe304颗粒粒径较小,但团聚比较严重：溶剂热法制备出的Fe304颗粒分散性比较好,形状规则,具有良好的超顺磁性能。因此,我们选用溶剂热法制备的纳米Fe304颗粒作为后期实验的核心粒子,而且此方法在无水环境下反应,避免了Fe304的氧化问题,操作简单可行。(2)利用改进的Stober法在纳米Fe304颗粒表面包覆上一层SiO2,讨论了正硅酸乙酯(TEOS)的加入量对包覆结果的影响。通过XRD、SEM、TEM等检测方法进行表征,得出最佳包覆的配比,制备出颗粒粒径均匀、形状规则、分散性较好的Fe3O4@SiO2复合颗粒。(3)利用悬浮聚合法在Fe3O4@SiO2复合颗粒表面包覆PMMA。讨论了预先用硅烷偶联剂(KH-570)处理对包覆结果的影响。通过XRD、SEM、TG和FT-IR等测试方法对样品表征,实验表明,在预先将Fe3O4@SiO2复合颗粒用KH-570处理后,得到的Fe3O4@SiO2@PMMA复合颗粒形状更加规则圆整而且表面光滑。(4)利用氨基化的方法对Fe3O4@SiO2@PMMA复合颗粒进行修饰,由FT-IR分析可知,Fe3O4@SiO2@PMMA复合颗粒表面接上氨基。(5)用氨基化的Fe3O4@SiO2@PMMA复合颗粒进行Cu2+和Ni2+的吸附试验。将复合颗粒分别加入到Cu2+溶液和Ni2+的溶液中,通过紫外-可见分光光度计测量吸附量的大小。讨论了吸附量随反应时间和pH值的变化。结果表明,当pH=5.5时,复合颗粒在2.5 h时,对Cu2+的最大吸附量约为170 mg/g;当pH=7时,复合颗粒在2h时对Ni2+的最大吸附量达到72 mg/g。
[Abstract]:Due to its good physical and chemical stability, biological compatibility and special magnetic properties, iron trioxide makes it in magnetic separation, catalyst, magnetic fluid, In this paper, magnetic Fe304 nanoparticles were prepared by precipitation method and solvothermal method, and different preparation methods were discussed. The effects of reaction time and temperature on the crystal shape and properties of Fe304 particles were studied. Silica and PMMA were coated on the surface of Fe _ 2O _ 4 particles by modified Stober method and precipitation polymerization method, and heavy gold was prepared after modification by amino groups. The specific contents of the study are as follows: 1) Nano-sized iron trioxide particles with high purity were prepared by co-precipitation method and solvothermal method respectively. The results showed that the particle size of Fe304 prepared by co-precipitation method was small, but the agglomeration was serious. The Fe304 particles prepared by solvothermal method had good dispersion and regular shape. Therefore, Fe304 nanoparticles prepared by solvothermal method were chosen as the core particles in the later experiment, and the reaction in anhydrous environment avoided the problem of Fe304 oxidation. The effect of the content of tetraethylorthosilicate (TEOS) on the coating results was discussed. The optimum coating ratio was obtained by means of XRDX SEMTEM and other methods. The particle size is uniform and the shape is regular. Fe3O4@SiO2 composite particles with good dispersion were coated on the surface of Fe3O4@SiO2 composite particles by suspension polymerization. The effect of pre-treatment with silane coupling agent (KH-570) on the coating results was discussed. The samples were characterized by XRD-SEMTG and FT-IR. After the Fe3O4@SiO2 composite particles were treated with KH-570 in advance, the shape of the Fe3O4@SiO2@PMMA composite particles was more regular and round and the surface was smooth. 4) the Fe3O4@SiO2@PMMA composite particles were modified by amino method. FT-IR analysis showed that Fe3O4SiO2PMMA composite particles were coated with amino groups. (5) Aminated Fe3O4@SiO2@PMMA composite particles were used to adsorb Cu2 and Ni2. The composite particles were added to Cu2 solution and Ni2 solution, respectively. The adsorption capacity was measured by UV-Vis spectrophotometer. The change of adsorption capacity with reaction time and pH value was discussed. The results showed that the maximum adsorption capacity of Cu2 was about 170mg / g when pH=5.5 was 2.5 h, and when pH = 7:00, the maximum adsorption capacity of Cu2 was about 170mg / g. The maximum amount of Ni2 adsorbed by the composite particles at 2h was 72 mg / g.
【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ138.11;O647.3

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