冠醚包覆聚苯乙烯磁性颗粒的合成、表征及其对锶离子的吸附性能

为建立应用磁性颗粒快速分离低水平~(90)Sr的方法,分别以沉淀法合成Fe_3O_4纳米颗粒,微乳聚合法合成磁性聚苯乙烯-二乙烯苯颗粒(Pst-DVB@Fe_3O_4),并将4,4’(5’)-二叔丁基二环己基-18-冠-6(DtBuCH18C6)通过物理作用包覆在Pst-DVB@Fe_3O_4颗粒表面,最终生成一种新型的核-壳结构的DtBuCH18C6包覆的聚合物磁性颗粒(DtBuCH18C6@Pst-DVB@Fe_3O_4)。采用扫描电镜、红外光谱、X射线光电子能谱等方法对颗粒的形貌、结构、表面元素组成及含量进行分析。用于分离水溶液中Sr~(2+)的批实验结果表明,Sr~(2+)的吸附量随着pH值而增加,而在pH=11和pH=13之间急剧上升,温度升高,其吸附量增加。吸附动力学模型结果表明,Sr~(2+)在DtBuCH18C6@Pst-DVB@Fe_3O_4表面的吸附更接近于其和Sr~(2+)之间形成络合物的单层化学吸附过程,符合Langmuir模型。在优化的条件下其最大吸附容量为2.62 mg/g。

Synthesis and characterization of crown-ether-coated poly (styrene/divinylbenzene) magnetic particle and evaluation of its adsorption behavior for strontium ions

To develop a method for rapid separation of low level90Sr using magnetic particles, Fe3O4 nanoparticles were prepared by coprecipitation method, and poly (styrene/divinylbenzene) magnetic particles (Pst-DVB@Fe3O4, PF) were synthesized by emulsion polymerization. Finally a new kind of core-shell structure magnetic particle coated with DtBuCH18C6 (DtBuCH18C6@Pst-DVB@Fe3O4, DPF) was developed. The morphology, structure, composition and content of surface elements were analyzed by scanning electron microscope, FT-IR spectroscopy and X-ray photoelectron spectroscopy,etc. The batch experiment results for the separation of Sr2+ in aqueous indicated that the adsorption of Sr2+ to DPF increased with pH value and showed a drastic increase from pH 11 to pH 13. The kinetic model showed that the adsorption of Sr2+ to DPF was most likely to be a monolayer chemisorption processvia forming complexation between DPF and Sr2+, which was consistent with Langmuir isotherm model. The maximum adsorption capacity of Sr2+ to DPF was 2.62 mg/g under optional conditions.