| 氨基化修饰介孔Fe3O4@SiO2@mSiO2磁性核壳复合微球的可控制备及吸附性能 | |
| Preparation and Adsorption Properties of Amino Modified Magnetic Mesoporous Microsphere Fe3O4@SiO2@mSiO2 | |
| 摘要: 以水热法制备的高磁饱和强度Fe3O4纳米颗粒为核，正硅酸乙酯（TEOS）为前驱体，采用改进的Stöber法，制备介孔SiO2包覆Fe3O4磁性核壳复合微球。利用XRD、SEM、TEM、N2吸附-脱附、FTIR和VSM对制备样品的物相结构、形貌和磁性能进行了测试表征。研究结果表明，制备的复合材料呈球形，粒径分布均一，材料的比表面积和磁饱和强度分别为413 m2·g-1和68.93 emu·g-1。研究了TEOS的添加量对复合微球形貌的影响，随着TEOS添加量的增加，SiO2壳层增厚，复合粒子形貌均匀，饱和磁化强度有所下降，仍具有良好的超顺磁性。在此基础上，通过接枝法在复合微球的表面接枝-NH2，制备了一种新型磁性纳米吸附剂（Fe3O4@SiO2@mSiO2-NH2），进而研究了其对水中重金属离子Cr（Ⅳ）的吸附性能。通过动力学拟合，Fe3O4@SiO2@mSiO2-NH2对Cr（Ⅳ）的吸附过程是准二级动力学模型占主导地位，探究了该材料对Cr（Ⅳ）的吸附过程和吸附机理。结果表明，其吸附机理及吸附容量与Cr（Ⅳ）的离子形态及-NH2有关，并通过吸附剂与吸附质之间的电子共用或静电吸附实现。 | |
| 关键词: 核壳结构 复合磁性微球 介孔二氧化硅 吸附性能 | |
| 基金项目: 国家自然科学基金青年基金（No.51402231）、教育部高等学校博士学科点专项科研基金（No.20136120120017）、陕西省科技厅自然科学项目（No.2014JQ2076）和陕西省2015年大学生创新创业训练计划项目（No.1153）资助。 | |
| Abstract: The SiO2 encapsulated Fe3O4 composite magnetic microsphere was synthesized by a modified Stöber method with Fe3O4 nanoparticles as cores. The structures and properties of the composite were characterized by XRD, SEM, TEM, N2 absorption-desorption, FTIR and VSM. The results showed that the as-prepared magnetic microspheres exhibited a spherical shape and uniform particle size distribution. This material possessed a BET surface area of 413 m2·g-1 and saturation magnetization of 68.93 emu·g-1, respectively. The particle morphology became more uniform with the increase of TEOS volumes when silica shell became thicker. The saturation magnetization of the nanocomposite particles decrease with the thickness of the silica shell increasing, the coercive force of particles was almost unchanged, and remained favorable to superparamagnetism. Based on the composite magnetic microsphere, the new magnetic nano-adsorbent Fe3O4@SiO2@mSiO2-NH2 was fabricated by coating silica from a covalent binding of amino(-NH2) onto the surface of Fe3O4@SiO2@mSiO2 microsphere. And the adsorption properties of the adsorbent for Cr(Ⅳ) ions were investigated. The study on kinetics of Cr(Ⅳ) showed that the adsorption reaction could be considered as the pseudo-second-order kinetic model. The adsorption capability was significantly affected by the distributions of Cr(Ⅳ) species and -NH2. The adsorption mechanisms of Cr(Ⅳ) including both ion exchange and electrostatic gravitation were also discussed. | |
| Keywords: core-shell structure composite magnetic microsphere mesoporous silica absorption property | |
| 投稿时间：2016-05-10 修订日期：2016-08-07 | |
| 摘要点击次数: 1669 | |
| 全文下载次数: 2168 | |
| 薛娟琴,徐尚元,朱倩文,强亮生,马晶.氨基化修饰介孔Fe3O4@SiO2@mSiO2磁性核壳复合微球的可控制备及吸附性能[J].无机化学学报,2016,32(9):1503-1511. | |
| 查看全文 查看/发表评论 下载PDF阅读器 | |
| Support information: | |
|
| |
|
| |
|
| |