β-环糊精键合硅胶材料对钍的吸附

Adsorption of Thorium by Materials of β-Cyclodextrin Bonded Silica Gel

利用氨基功能化硅胶为固相载体,以可双向反应的环氧氯丙烷为链接剂,将β-环糊精吸附材料接枝到硅胶表面,制备了性能稳定、耐酸碱性的β-环糊精键合硅胶固相吸附富集材料。通过金属离子螯合剂二苯甲酰甲烷辅助作用对钍离子进行快速吸附,材料可重复利用。X-射线光电子能谱仪(XPS)对各实验材料进行了元素分析,确认了材料合成成功的可靠性,扫描电镜分析了材料的外部形貌,傅里叶红外对材料吸附钍离子前后进行了表征,紫外分光光度计对吸附后样品进行了浓度分析。酸性条件(pH=2～3)、室温下所制备材料对钍的吸附3h可达平衡,最大吸附容量可达7.8mg/g,吸附率达78%。以25mg/L的Fe3+、Al 3+,20mg/L的Ca2+、Zn2+、Fe2+、Mg2+、Cu2+为干扰离子,对Th4+的吸附几乎不产生影响。

An adsorption material with stable property and good resistance to acidity or basicity environment and so forth was prepared byβ-cyclodextrins grafted to the surface of silica gel using aminated silica gel as solid phase carrier, epoxy chloropropane as erosslinking agent. The chelator dibenzoylmethane was employed to assist the rapid adsorption of thorium. The materilas can be reused for many times. Xray photoelectron spectroscopy（XPS） was used to analyze the surface properties of the experimental materials to confirm the reliability of the synthetic materials. Scanning electron microscope （SEM） was employed to characterize the surface morphology of the material, FTIR was used to analyze the materials before and after the adsorption of thorium, and UV spectrophotometer was employed to determine the concentration of thorium after the adsorption. The adsorption of thorium using the material prepared can achieve equilibrium within 3 h at room temperature under the condition of pH= 2-3. The adsorption capacity is 7.8 mg/g, and the adsorption rate is up to 78%. In addition, the maximum allowed concentrations of interfering ions are found to be 25 mg/L for Fe3＋ or A1^3＋ , and 20 mg/L for Ca^2＋ , Zn^2＋ , Fe^2＋ , Mg^2＋ , or Cu^2＋.