Template-Dependent Selectivity in Metal Adsorption on Phosphoric Diester-Carrying Resins Prepared by Surface Template Polymerization Technique

The surface templated resins for three different metal ions such as Cu²⁺, Zn²⁺ or Cd²⁺ as the template guest were prepared by emulsion polymerization using oleyl phenyl hydrogenphosphate as a host surfactant, sodium dodecyl sulfate (SDS) as a co-surfactant and divinylbenzene as a resin matrix-forming monomer. The Cu²⁺-imprinted resin adsorbed Cu²⁺ much more effectively than did the nonimprinted, the Zn²⁺- and Cd²⁺-imprinted ones. On the other hand, the Cd²⁺-imprinted resin showed a more highly effective binding to Cd²⁺ than those of the Cu²⁺-imprinted, Zn²⁺-imprinted, and nonimprinted resins. In fact, the Cu²⁺-imprinted resin did not adsorb any significant amount of Cd²⁺. The selective feature of the surface templated resins to the target ion was thus successfully demonstrated. The template-dependent selectivity should be ascribed to a favorable placement of the surface-anchored metallophilic groups for multidentate coordination to the specific metal ion.