Cr(Ⅵ)离子印迹聚合物的制备与应用

Research on synthesis and application of Cr(Ⅵ)ion-imprinted polymer

Cr(Ⅵ)被公认为高毒性和致癌性,离子印记技术是具有特异选择性的有效检测手段。以Cr(Ⅵ)阴离子基团作模板,4-乙烯基吡啶(4-VP)为功能单体,与甲基丙烯酸-2-羟乙酯(HEMA)以及乙二醇二甲基丙烯酸酯(EGDMA)共聚,制得Cr(Ⅵ)离子印迹聚合物。研究了不同的合成配比、淋洗方法、溶液pH对印迹聚合物吸附Cr(Ⅵ)的影响,结果表明,在Cr、4-VP、HEMA、EGDMA的摩尔质量比1∶4∶2∶20、采用盐酸硫脲搅拌淋洗24 h、溶液pH为0.4的条件下,制备的Cr(Ⅵ)离子印迹聚合物对2 mL 5 mg·L^(-1)的Cr(Ⅵ)溶液吸附效果最好。

Cr(Ⅵ)has been recognized as highly toxic and carcinogenic.Ion imprinting is an effective method with specificity and selectivity.The aim of this study is to prepare ion-imprinted polymers,which can be used for the selective removal of Cr(Ⅵ)anions from aqueous media.4-Vinyl pyridine(4-VP)was used as functional monomer.The ion-imprinted polymers were prepared by bulk polymerization in which 4-VP react with Cr(Ⅵ),2-hydroxyethyl methacrylate(HEMA)and ethylene glycol dimethacrylate(EGDMA),and then the template ions Cr(Ⅵ)were removed.The effect of synthetic schemes,the adsorption rate and the pH of the medium on adsorption capacity of Cr(Ⅵ)-imprinting polymer were studied.Under the optimal experimental conditions that the molar ratios of Cr、4-VP、HEMA、EGDMA was1∶4∶2∶20,Cr(Ⅵ)were removed using thiourea and hydrochloric acid for 24 h,the adsorption of Cr(Ⅵ)ion was highest at pH 0.4 with 2 mL and an initial concentration of Cr(Ⅵ)5 mg·L^(-1).