Metal-imprinted microsphere prepared by surface template polymerization and its application to chromatography

A metal ion-imprinted microsphere was prepared by surface molecular templat e polymerization. Trimethylolpropane trimethacrylate (TRIM), zinc ions, 1,1 2-dodecanediol-O, O'-diphenyl phosphonic acid (DDDPA) were used as a crossl inking agent, an imprint molecule, and a functional host molecule. The Zn(I I)-imprinted microspheres, which are spherically well-defined particles, we re prepared by using water-in-oil-in-water (W/O/W) multiple emulsions. The combination of TRIM and DDDPA serves to align the recognition sites resulti ng in better template sites produced on the polymer surface. We firstly con ducted diagnostic zinc- and copper-ion adsorption tests with the Zn(II)-imp rinted and unimprinted microspheres in order to make an assessment on the e ffectiveness of the molecular imprinting technique. Further, the metal-impr inted microspheres were applied to the column operation. The separation and recovery of metals were carried out by an adsorption column packed with th e Zn(II)-imprinted microspheres. This performance was compared to that of c ommercial chelating resins that possess similar phosphoric functional group s. The Zn(II)-imprinted polymer shows an extremely high selectivity to the imprinted zinc ions compared to that of the commercial chelating resin. (C) 2000 John Wiley & Sons, Inc.