Selective adsorption of metal ions to surface-template resins prepared by emulsion polymerization using 10-(p-vinylphenyl)decanoic acid

A monomer-type surfactant, 10-(p-vinylphenyl)decanoic acid (1), has been prepared and applied to an emulsifier for the preparation of surface-template resins. The hydrophobicity of 1 corresponded to that of C15H31COONa on the basis of the cmc values, while that of 1 on the enulsification corresponded to that of C12H25COONa. The monomers (DVB + St + 1) were copolymerized in a metal ion solution and the resulting polymers were evaluated for their surface-template effects. The suspension polymerization gave resins 0.08 mm in diameter and the adsorption of metal ions on Cu2+-imprinted resins attained equilibrium in 2 h. The surface-template effects based on the oriented 1 exceeded the inner-template resins in selective adsorption. On the other hand, the emulsion polymerization gave fine particles 200-300 nm in diameter. The resins showed excellent surface-template effects. The adsorption of metal ions was 50-100 times as much as that on the resins prepared by suspension polymerization (see Fig. 2 and Table 3). The metal-imprinted resins was 1.88 times more effective than the unimprinted results, and the Zn2+-imprinted resins showed more effective adsorption for Zn2+ than for CU2+ and for Ni2+. Such surface-template effects were also seen for CU2+- and Ni2+-imprinted resins. The selectivity (Cu2+/Zn2+) from the mixture of both metal ions was 3.7 for the Cu2+-imprinted resins prepared at 0.25 mol% 1. Furthermore, the metal-imprinted resins could be used repeatedly.