Cu^(2+)印迹磁性壳聚糖微球的表征及吸附性能

Characterization and Properties of Cu^(2+) Ion-Imprinted Magnetic Chitosan Beads and their Cu^(2+) Adsorption Performance

以磁性Fe_3O_4为磁核,Cu^(2+)为模板离子,壳聚糖为功能单体,制备了Cu^(2+)印迹磁性壳聚糖微球(MIPs)。采用透射电镜、红外光谱分析、振动样品磁强计和X射线衍射仪对MIPs进行表征。结果表明,MIPs具有三维网状的多孔结构,并且Fe_3O_4被壳聚糖包埋且分布均匀。同时通过振动样品磁强计测得其饱和磁化强度为10.8 emu×g^(-1),具有一定的磁性能。采用静态吸附法研究了MIPs对Cu^(2+)的吸附。结果表明,最佳吸附p H值为5;吸附3 h达到吸附平衡;MIPs对Cu^(2+)的吸附符合准二级动力学方程。并对MIPs的选择识别能力进行了评价,结果表明:MIPs对Zn^(2+)、Co^(2+)、Ni^(2+)的相对选择性系数K'分别为2.07、2.59、3.44,对Cu^(2+)具有较高的选择识别性能。并且,MIPs再生-重复使用10次吸附容量没有明显的降低。

Cu^2＋ ion imprinted magnetic chitosan beads（MIPs） were synthesized using Fe3O4 as the magnetic core, Cu^2＋ as the template ion, and chitosan as the functional monomer. The structure and properties of the MIPs were studied by TEM, XRD, VSM, FTIR and XRD, and the results show that the MIPs has a 3-dimension network structure with Fe3O4 uniformly distributed inside. The magnetic properties were measured by vibrating sample magnetometer and the saturation magnetization was 10.8 emu·g-1. Cu^2＋ adsorption was investigated by a static adsorption method. The results show that the optimum adsorption p H value is - 5, and the adsorption equilibrium is established within 3 h. The kinetic study shows that the adsorption process follows the pseudo-second-order kinetic equations. The selection recognition ability of the MIPs were evaluated by relative selectivity coefficient（K＇） in an aqueous solution. The results show that the MIPs has a high selectivity toward Cu^2＋, and the relative selectivity coefficient（K＇） of MIPs for Cu^2＋/Zn^2＋, Cu^2＋/Ni^2＋ and Cu^2＋/Co^2＋ are 2.07, 2.59 and 3.44, respectively. Furthermore, the MIPs can be regenerated and reused for 10 times without a significantly decrease of adsorption capacity.