分子印迹氨基功能化纳米Fe3O4高分子磁性复合材料的合成及其对海水中2,4,6-三氯苯酚的吸附性能

Synthesis of molecular printed amino-functionalized nano-Fe3O4-polymer magnetic composite and its adsorption properties on 2, 4, 6-trichlorophenol in seawater

  • 摘要: 为了实现海水中2, 4, 6-三氯苯酚(2, 4, 6-TCP)的选择性吸附和去除, 采用超声协助悬浮聚合法以2, 4, 6-三氯苯酚为模板制备了分子印迹氨基功能化纳米Fe3O4高分子磁性复合材料(nFe3O4@MIPNH2-polymer)。通过元素分析(EA)、X射线衍射(XRD)、傅里叶变换红外(FTIR)光谱分析、透射电子显微镜(TEM)、振动样品磁强计(VSM)等手段对nFe3O4@MIPNH2-polymer的组成、结构、形貌、磁性等进行表征, 并研究了其应用于吸附和去除海水中2, 4, 6-三氯苯酚(2, 4, 6-TCP)污染物的性能。 结果表明:合成的nFe3O4@MIPNH2-polymer平均粒径约为800 nm, 饱和磁化强度为32.6 emu·g-1;水溶液中2, 4, 6-TCP的饱和吸附量为105.26 mg·g-1, 高于非分子印迹氨基功能化纳米Fe3O4高分子磁性复合材料(nFe3O4@NH2-polymer)的饱和吸附量(76.92 mg·g-1), nFe3O4@MIPNH2-polymer对2, 4, 6-TCP的等温吸附线大体符合Langmuir模型。吸附热力学研究表明, nFe3O4@MIPNH2-polymer对2, 4, 6-TCP的吸附过程是自发的吸热熵增过程;吸附过程可在5 min内达到平衡, 动力学数据和准二级动力学模型符合较好;其吸附过程去除2, 4, 6-TCP的活化能为78.0 kJ·mol-1。海水中的共存物质对吸附2, 4, 6-TCP几乎无干扰, nFe3O4@MIPNH2-polymer经洗脱后可以循环使用5次以上。nFe3O4@MIPNH2-polymer能高选择性地有效去除海水中的2, 4, 6-TCP。

     

    Abstract: In order to realize selective adsorption and removal of 2, 4, 6-trichlorophenol (2, 4, 6-TCP) in seawater, a 2, 4, 6-trichlorophenol-imprinted amino-functionalized nano-Fe3O4-polymer magnetic composite (nFe3O4@MIPNH2-polymer) was synthesized via ultrasonic assisted suspension polymerization. The composition, structure, morphology and magnetism of nFe3O4@MIPNH2-polymer were characterized by means of Elemental Analysis (EA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The application for its adsorption and removal properties on 2, 4, 6-TCP pollutant from seawater was investigated. The results show that the nFe3O4@MIPNH2-polymer has an average size of around 800 nm, with the saturation magnetization intensity of 32.6 emu·g-1. Adsorption isotherm of 2, 4, 6-TCP onto nFe3O4@MIPNH2-polymer accords with Langmuir model, which demonstrate an excellent adsorption capacity with the maximum adsorption capacity at 105.26 mg·g-1, much higher than that of none-molecular imprinted amino-functionalized nano-Fe3O4-polymer magnetic material (nFe3O4@NH2-polymer, with the maximum adsorption capacity at 76.92 mg·g-1). The isothermal adsorption curve mainly obeys the Langmuir mode. The adsorption thermodynamic studies suggest that the adsorption processes of the 2, 4, 6-TCP by the nFe3O4@MIPNH2-polymer are endothermic, entropy favored, and spontaneous in nature, and the adsorption processes reach the equilibrium within 5 min and the kinetic data are well fitted to the pseudo-second-order model. The activation energy for the 2, 4, 6-TCP removal is 78.0 kJ·mol-1. There is almost no interference by the coexisting components in seawater for the adsorption of 2, 4, 6-TCP. The nFe3O4@MIPNH2-polymer can be reused at least 5 times after elusion. The 2, 4, 6-TCP in seawater can be selectively and effectively removed by the nFe3O4@MIPNH2-polymer.

     

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