镍离子印迹聚合物的制备表征及吸附性能

Preparation and characterization of nickel(Ⅱ) ion imprinted polymer and its adsorption property

以镍离子(Ni^(2+))为模板、4-乙烯基吡啶(4-VP)为功能单体、二乙烯基苯(DVB)为交联剂,采用沉淀聚合法制备了镍离子印迹聚合物,并采用正交试验对制备工艺进行优化,发现Ni^(2+)与4-VP用量比为1∶5(wt,质量比,下同)、Ni^(2+)与8-羟基喹啉(8-HQ)的用量比为1∶2、4-VP与DVB用量比为1∶6(Vol,体积比)、乙腈与甲苯(乙腈与甲苯的体积比为3∶1)的混合溶剂80mL时制备的聚合物具有最佳吸附能力。用红外光谱和扫描电子显微镜对聚合物的结构和形态进行表征,结果表明聚合物中存在与Ni^(2+)相互作用的特征基团。通过对聚合物吸附性能的测定,发现聚合物最佳吸附pH=8.0,达到吸附平衡的时间为4h,饱和吸附量为1.170mg/g,相对选择系数αNi/M远大于1,表明该聚合物对Ni^(2+)具有良好的选择吸附能力。

The nickel ion-imprinted polymer was prepared by using precipitation polymerization with Ni^2＋ as the template,4-vinylpyridine as functional monomer,divinylbenzene as crosslinking agent.The structure and shape of polymer were characterized by infrared spectrum（IR）and scanning electron microscope（SEM）.The result indicated that some characteristic groups in the polymer interacted with the template.Using orthogonal text to optimize the ratio of Ni^2＋/4-VP,Ni^2＋/8-HQ,4-VP/8-HQ,and the volume of solvent.The best adsorption capacity of polymer was obtainted when using Ni^2＋/4-VP of 1∶5,Ni^2＋/8-HQ of 1∶2,4-VP/8-HQ of 1∶6and the solvent volume of 80 mL.The adsorption and selectivity capacity of polymer were studied.The results showed that the optimum pH was 8.0and sorption equilibrium time was 4h.The maximum adsorption capacity was 1.170mg/g and the relatively selective factor（αNi/M）were greater than one.The polymer could be repeatedly used with high selectivity for nickel ion.