METAL-ION IMPRINTED RESIN PREPARED USING AN INTERACTION AT THE AQUEOUS-ORGANIC INTERFACE AND ITS CHARACTERIZATION

A concept of ''Surface Imprinting'' has been proposed by the present a uthors. First, rye prepared a metal ion-imprinted microsphere on the b asis of the concept. The imprinted microspheres as a new metal ion-sel ective adsorbent were synthesized by seeded emulsion polymerization of divinylbenzene, styrene, butyl acrylate, and methacrylic acid. The im printed structure was introduced on the carboxylated microsphere by Su rface-Imprinting, in which the carboxyl groups were reorganized throug h complexation with metal ions on the surface, and then fixed by cross linking polymerization in their specific orientation. Cu(II), Ni(II), and Co(II)-imprinted microspheres were obtained as submicron particles with average diameters of 0.55 similar to 0.60 mu m. They were immedi ately used as a metal ion-selective adsorbent without any further trea tment, such as grinding or sieving. The adsorption behaviors of metal ions {Cu(II), Ni(II), and Co(II)} were examined, and the imprinted eff ects were verified on these imprinted microspheres. The imprinted micr ospheres adsorbed the corresponding guest ion more effectively than di d unimprinted ones. Furthermore, a Cu(II)-imprinted microsphere was st udied in detail in order to obtain information about the origin of the imprinting effect. Unimprinted and Cu(II)-imprinted microspheres were prepared under several pH (4.0, 5.0, 5.6, or 6.0) conditions in the i mprinting step. The obtained microspheres were characterized for parti cle form, size-distribution pattern, average diameter, Cu(II) adsorpti on behavior, and so on. Spectroscopic studies were also performed on C u(II)-loaded microspheres. The collected data indicate thai the origin of the imprinting effect on a Cu(II)-imprinted microsphere is an inte raction between Cu(II) and the carboxylate group at the aqueous-organi c interface, supporting the concept of Surface Imprinting.