Development of Novel Metal Ion Selective Ion-exchange Resin Based on Surface Template Polymerization

开发高选择性的金属络合树脂是金属资源再利用的重要研究方向。有必要建立生产具有特定离子识别能力的材料(宿主或人工受体)的方法学。表面印迹是在离子交换树脂的合成过程中，在油水界面引入特殊的分子识别位点的一种方法。我们合成了铜(II)和锌(II)印迹树脂，因为这两种金属离子具有不同的配位模式。我们选择了油酸组胺作为功能单体，二乙烯基苯作为交联剂。印迹树脂对金属离子具有较高的吸附活性，但选择性较低。为了提高金属离子的选择性，我们在聚合过程中通过加入助表面活性剂来稳定O/W乳液。在添加非离子表面活性剂的情况下，铜(II)的选择性显著提高。我们还制备了对Cd(II)具有高选择性的Cd(II)印迹树脂。用含磷酸酯基团的表面活性剂合成了稀土离子Eu(III)和La(III)的印迹树脂。在以Dolpa为功能单体的情况下，Eu(III)-印迹树脂对Eu(III)具有较高的选择性，证明了表面印迹树脂作为分离金属离子的新型材料的可能性。我们新开发的表面印迹是离子交换树脂的一种有用的方法，因为通过设计各种功能表面活性剂和助表面活性剂的组合，可以提高金属离子的选择性。

It becomes an important research area to develop highly selective metal-chelating resin in regard to reusing metal sources. It is necessary to establish the methodology for producing materials (host or artificial receptor) that have specific ability for ion recognition. Surface imprinting is an approach to introduce special molecular recognition sites on the oil-water interface during the synthesis of ion-exchange resins.We synthesized Cu (II)-and Zn (II)-imprinted resins because these are typical metal ions which have different coordination mode. We chose oleic histamine amide as a functional monomer and divinylbenzene as a cross-linker. The imprinted resins have higher activities for absorption of metal ions but have less selectivity. For improvement of the metal ion selectivity, we stabilized the o/w emulsion during the polymerization by adding co-surfactants. In the case of adding nonion surfactant, the selectivity for Cu (II) was remarkably improved. We also prepared Cd (II)-imprinted resins that have high selectivity for Cd (II). We synthesized imprinted resins for lanthanide ions such as Eu (III) and La (III) by using surfactants containing phosphoric ester groups. In the case of using DOLPA as a functional monomer, Eu (III)-imprinted resin showed high selectivity for Eu (III).It is demonstrated the possibilty of applying the surface imprinted resins as novel materials for separating metal ions. Surface imprinting that we have been newly developed is a useful method for ion-exchange resins, because it is possible to improve the metal ion selectivities by various combination of designed functional surfactant and co-surfactant.