METAL-ION-SELECTIVE EXCHANGE RESINS BY MATRIX IMPRINT WITH METHACRYLATES

Various attempts have been made to increase the ion selectivity of exchange resins by carrying out cross-linking polymerization of monomeric or oligomeric complex-forming compounds in the presence of metal ions. The authors have succeeded in increasing the selectivity by cross-linking copolymerization of well-defined metal complexes containing polymerizable ligands. According to their concept, removal of the metal ions from the resin with suitable eluants should leave the arrangement of binding groups intact, which are thus tailored for subsequent binding of the type of ion used to prepare the resin. This is illustrated in the case of ion-exchange resins synthesized by polymerization of copper (II) methacrylates. It was found that these resins could selectively remove Cu2+ ions from wastewater. This shows that the metal complexes present during the polymerization imprint the cavity structure of the resin in such a way that ions of the same element are preferably taken up in the cavities after elution of these metal ions.