铜离子印迹聚合物的吸附性能研究

Investigation on the adsorption performance of copper ion-imprinted polymers

以二苯氨基脲为功能单体,合成了铜离子印迹聚合物(Cu^(2+)-IIPs),并用于Cu^(2+)的快速吸附检测。对Cu^(2+)-IIPs进行了表征,考察了其对Cu^(2+)的吸附特性。结果表明,Cu^(2+)-IIPs为球型状颗粒且粒径分布均匀,印迹位点位于表面及空穴中,对Cu^(2+)的吸附过程符合准二级动力学模型,吸附速率受表面吸附和内部扩散共同影响。较之Langmuir模型和Tempkin模型,Freundlich模型能更好地拟合吸附等温线,说明属于多层吸附;ΔG^(0),ΔH^(0)和ΔS^(0)的数据显示,吸附是一个自发进行的、吸热的、熵增大的过程;Cu^(2+)-IIPs对Cu^(2+)的吸附量远大于具有相似结构和性质的其它重金属离子,因而具有良好的吸附选择性。

By using diphenylcarbazide as functional monomer, copper ion-imprinted polymers(Cu^(2+)-IIPs) were synthesized for the rapid adsorption and detection of Cu^(2+). The prepared polymers were characterized, and its adsorption performance for Cu^(2+)was investigated in detail. The results showed that the polymers were spherical particles with uniform size distribution, and the imprinting sites located on the surface and in the holes of the polymers. The adsorption process conformed to the pseudo-second-order kinetic model, revealing the adsorption rate was affected by both surface adsorption and internal diffusion. Compared with Langmuir model and Tempkin model, Freundlich model fitted the adsorption isotherms better, indicating the sorption was a multi-layer sorption. The values of ΔG^(0), ΔH^(0) and ΔS^(0) showed that the adsorption was a spontaneous, endothermic and entropy enhanced process.The adsorption amount of Cu^(2+)onto the obtained IIP material was much higher than those of several other heavy metal ions with smilar structures and properties, thus the material had good adsorption selectivity.