Preparation of Highly-Selective Metal Adsorbents by Surface Imprinting Method

我们提出了一种金属离子印迹微球作为一种新的金属离子选择性吸附剂。以二乙烯基苯、苯乙烯、丙烯酸丁酯和甲基丙烯酸为原料，采用种子乳液聚合法制备了分子印迹微球。通过表面印迹法在羧基化微球表面引入印迹结构，使羧基与表面金属离子络合，（在pH 5.0下），然后通过交联聚合固定在它们的特定取向上。得到Co（II）印迹微球为平均直径为0.55-0.60 μ m的亚微米颗粒。它们立即用作金属离子选择性吸附剂，而无需任何进一步处理，例如研磨和筛分。考察了金属离子的吸附行为，验证了印迹效果。印迹微球吸附相应的客体离子更有效地比unimprinted的。在表面印迹步骤中，在不同pH值（4.0，5.0，5.6，6.0）条件下制备了未印迹和Cu（II）印迹微球。以油烯基苯基膦酸氢酯为主体表面活性剂，十二烷基硫酸钠（SDS）为助表面活性剂，二乙烯基苯为树脂基体形成单体，采用乳液聚合法制备了表面印迹树脂。模板依赖性的选择性被清楚地证明为Cu（II），Zn（II），和Cd（II）。这种载磷树脂有望用于稀土金属和铀酰离子的选择性分离。

We propose a metal ion-imprinted microsphere as a new metal ion-selective adsoebent. Imprinted microspheres were prepared by seed emulsion polymerization of divinylbenzene, stirene, butyl acrylate, and methacrylic acid. The imprinted structure was introduced on the carboxylated microsphere by surface-imprinting, in which the carboxyl groups were reorganized through complexation with metal ions on the surface (at pH 5.0) and then fixed by crosslinking polymerization in their specific orientation.The Cu (II) , Ni (II) , and Co (II) -imprinted microspheres were obtained as submicron particles with average diameters of 0.55-0.60 mum. They were immediately used as a metal ion-selective adsorbent without any further treatment, such as grinding and sieving. The adsorption behaviors of metal ions were examined, and the imprinted effects were verified clearly. The imprinted microsheres adsorbed the corresponding guest ion more effectively than did unimprinted ones. Unimprinted and Cu (II) -imprinted microspheres were prepared under several pH (4.0,5.0,5.6,6.0) conditions in the surface-imprinting step. The maximum imprinting effect was provided by microspheres obtained at pH5.6.Surface-imprinted resins were also prepared by emulsion polymerization using oleyl phenyl hydrogenphosphonate as a host surfactant, sodium dodecyl sulfate (SDS) as a co-surfactant and divinylbenzene as a resin matrix-forming monomer. The template-dependent selectivity was clearly demonstrated for Cu (II) , Zn (II) , and Cd (II). This phosphate-carrying resin would be promising for selective separation of rare earth metal and uranyl ions.