镉离子(Ⅱ)印迹聚合物的制备及性能研究

Research on synthesis and performance of Cd(Ⅱ)ion imprinted polymer

为有效应对环境中重金属镉的污染问题,文中采用沉淀聚合法,以Cd(Ⅱ)为印迹离子,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,通过对印迹聚合体系的条件进行系统优化,制备了系列镉离子印迹聚合物(Cd(Ⅱ)-IIPs)及相应的非印迹聚合物(NIPs),同时在竞争离子的存在下,考察了其对Cd(Ⅱ)的吸附效果及识别选择性。结果表明:以4-乙烯基吡啶(4-VP)为功能单体,模板与功能单体和交联剂的摩尔比为1∶4∶30时,制备的聚合物(Cd(Ⅱ)-IIP_(9))对Cd(Ⅱ)的吸附效果最好。吸附过程主要以准二级动力学为主,更符合Freundlich多层吸附行为,吸附量为529.73 mg/g,印迹因子达1.87。说明与非印迹聚合物NIP 9相比,Cd(Ⅱ)-IIP_(9)对Cd(Ⅱ)具有较高的吸附量和良好的识别选择性,有望用于环境中Cd(Ⅱ)的分离去除。

In order to effectively deal with the environmental pollution caused by heavy metal cadmium,a series of imprinted polymer(Cd(Ⅱ)-IIPs)and non-imprinted polymers(NIPs)were synthesized by adopting the method of precipitation polymerization,Cd(Ⅱ)as the template ion,using the cross-linking agent of EDMA,and systematically optimizing the synthesis conditions of the imprinted polymer system.While in the presence of competing ions,the adsorption effect and recognition selectivity of the imprinted polymer for Cd(Ⅱ)were studied.Research shows imprinted polymer(Cd(Ⅱ)-IIP_(9))is preparation to used 4-VP as the functional monomer and the molar ratio of 1∶4∶30 among template ion,functional monomer and cross-linking agent,which has the best adsorption effect to Cd(Ⅱ).The adsorption process is mainly quasi-second-order kinetics,which is relatively consistent with the Freundlich multilayer adsorption behavior.The adsorption capacity of Cd(Ⅱ)is 529.73 mg/g and the date of imprinting factor is 1.87.This indicates that compared with the non-imprinted polymer-NIP 9,Cd(Ⅱ)-IIP_(9) has higher adsorption capacity and good recognition selectivity for Cd(Ⅱ),which is expected to be used for the separation and removal of Cd(Ⅱ)in the environment.