Metal Ion-Selective Adsorbent Prepared by Surface-Imprinting Polymerization

Abstract

We propose a metal ion-imprinted microsphere as a new metal ion-selective adsorbent. Imprinted microspheres were prepared by seeded emulsion polymerization of divinylbenzene, styrene, 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 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 μm. 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 (Cu(II), Ni(II), and Co(II)) were examined, and the imprinted effects were verified on Cu(II)- and Ni(II)-imprinted microspheres. The imprinted microspheres adsorbed the corresponding guest ion more effectively than did unimprinted ones.