18-冠-6/LA/Fe3O4复合磁性纳米粒子的制备及其吸附性能研究

Fe₃O₄磁性纳米粒子（MNPs）比表面积大、吸附能力强，且在外磁场作用下易于液固分离，冠醚具有对铀酰离子选择性配位的能力。本研究制备了兼具两者特点和优势的18-冠-6/LA/Fe₃O₄复合磁性纳米粒子。其结构经红外（IR）、扫描电镜-X射线能谱（SEX/EDX）、振动样品磁强计（VSM）、热综合分析仪（TGA）进行表征，表明18-冠-6/LA/Fe₃O₄复合磁性纳米粒子的粒径为12～23 nm，饱和磁化强度为56.34 emu/g。用制得的复合磁性纳米粒子对溶液中铀酰离子进行初步吸附实验，在选定的条件下，平衡吸附率达95%，操作方法快速简便，吸附后的磁粒子可方便地进行富集和回收。

Preparation and Adsorption Property of Magnetic 18-crown-6/LA/Fe3O4 Composite Nanoparticles

Fe₃O₄ magnetic nanoparticles (MNPs) have large specific surface area, high adsorption capacity, and can be separated conveniently from liquid with outer magnetic field. The crown ether has the ability to select coordination of uranyl ion. In the study, the magnetic 18-crown-6/LA/Fe₃O₄ composite nanoparticles which combined the characteristics and advantages of both the crown ether and Fe₃O₄ MNPs were prepared. The nanocomposite was characterized by infrared radiation (IR), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), vibrating sample magnetometer (VSM) and thermal gravimetric analysis (TGA). The results indicate that the size and the saturation magnetization of the nanocomposite are 12-23 nm and 56.34 emu/g, respectively. Preliminary experiments for the adsorption of uranyl ion were carried out. In the selected conditions, the equilibrium adsorption rate reaches 95%. Meanwhile, the magnetic nanocomposite can be recycled and enriched easily.