磁性羟基磷灰石复合材料的制备及其吸附性能研究

发布时间：2018-06-08 04:46

  本文选题：磁性Fe_3O_4/HA复合微粒 + 机械混合法　； 参考：《沈阳大学》2017年硕士论文

【摘要】：近年来,随着生活水平的提高,人们的环保意识逐渐提高,对工业排放废水中重金属离子的处理问题成为热点。羟基磷灰石(HA)晶体结构具有的独特性,使其对重金属离子的容纳性更为广泛,吸附固定性和交换能力较强。除此之外,它还具有制备方便简单、原料丰富、成本较低等优势。因此,HA成为一种可以用于吸附去除废水中以及土壤里的重金属离子的新型环境功能材料。而粉体不利于回收的情况限制了HA的实际应用。本文通过引入纳米Fe3O4磁性粒子,使HA的复合材料具有磁性,在添加外界磁场的条件下,利于粉体分离回收。本文以Ca(NO3)2·4H2O水溶液和(NH4)2HPO4水溶液为前驱体,用高浓度的十二烷基基硫酸钠(SDS)作为模版,采用水热法制备出纳米HA,并通过X-射线衍射仪、扫描电镜(SEM)、傅里叶红外光谱分析(FT-IR)等方法对其进行综合表征。结果表明:通过此法可以制备出分布均匀棒状纳米HA。在pH=7时,会生成少量的Ca HPO4(DCP)杂相;当pH=11时,可制备纯净的HA粉体。通过在80℃和600℃进行烧结发现,600℃进行烧结获得的粉体结晶度更高,粉体尺寸增大。以Fe Cl2.4H2O和FeCl3.6H2O为前驱体,以NaOH为沉淀剂,通过共沉淀的方法制备纳米四氧化三铁(Fe3O4)并通过XRD、SEM等方法对其进行表征,结果表明:可以获得纳米级的Fe3O4磁性微球,并且获得的Fe3O4粒子分布比较均匀,无明显团聚现象。本文通过机械混合法和原位复合法两种方法合成了磁性Fe3O4/HA复合微粒,并利用XRD、SEM、粉体磁性吸附测试等方法对其进行分析。结果表明,通过两种方法均能获得磁性Fe3O4/HA复合微粒,但是通过机械混合法获得的粉体团聚现象较为严重,随着Fe3O4含量的增加,团聚现象更加明显。而原位复合法获得的粉体粒径分布均匀,随着Fe3O4与HA摩尔比由1:1变为1:3,其粉体的结晶程度更高,粉体分散性更好,晶胞尺寸更大。随着反应温度由60℃升高至80℃,Fe3O4/HA磁性复合材料的结晶效果更加的明显,晶粒尺寸更大。但当反应温度为180℃时,Fe3O4被氧化生成Fe2O3,导致粉体失去磁性。分别用HA、Fe3O4以及磁性Fe3O4/HA复合微粒对浓度为20mg/L的重金属Cu2+离子进行吸附性能实验研究。结果表明:两种复合方法制备磁性Fe3O4/HA复合微粒对重金属离子都具有一定的去除能力。原位复合法制备的磁性Fe3O4/HA比机械混合法制备的磁性Fe3O4/HA去除率更高,可达95%以上。对比两种方法制备的粉体吸附容量,原位复合法制备的磁性粉体平衡吸附容量为11.17mg/g,高于机械混合法。因此,原位复合法制备生成的磁性Fe3O4/HA吸附性能比机械混合法制备的粉体更好。
[Abstract]:In recent years, with the improvement of living standards, people's awareness of environmental protection has gradually improved, and the treatment of heavy metal ions in industrial wastewater has become a hot issue. The crystal structure of hydroxyapatite (HA) is unique, which makes it more tolerant to heavy metal ions, and has stronger adsorption, fixation and exchange ability. In addition, it has the advantages of simple preparation, abundant raw materials and low cost. Therefore, hyaluronic acid (HA) has become a new environmental functional material for the adsorption and removal of heavy metal ions in wastewater and soil. However, the fact that the powder is unfavorable to recovery limits the practical application of HA. In this paper, the nano-Fe _ 3O _ 4 magnetic particles were introduced to make the HA composite have magnetic properties, and it is advantageous to the separation and recovery of the powder under the condition of adding external magnetic field. In this paper, Nano-HAs were prepared by hydrothermal method using aqueous solution of Cagno _ 3H _ 3H _ 2O and NH _ 4N _ 2HPO _ 4 as precursors, using high concentration of sodium dodecyl sulfate (SDS) as template, and using X-ray diffractometer. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were used to characterize them. The results show that the uniform rod shaped nano-HAA can be prepared by this method. At pH = 7, a small amount of CaHPO _ 4 / DCP-phase was formed, and when pH = 11:00, pure HA powder could be prepared. By sintering at 80 鈩，

本文编号：1994536