Patent ID: 7875662

Claim:
A method of preparing surface-imprinted microspheres having a core-shell form and having imprinted sites that are able to recognize heavy metal ions for selective separation of heavy metal ions, the method comprising the steps of: a. reacting a metal salt of a heavy metal with a monomer having at least one group that reacts with the metal salt under conditions effective to prepare a metal ion-containing monomer; b. mixing the metal ion-containing monomer with a cross-linker monomer and a polymerization initiator in a solvent to provide a mixture; c. subjecting styrene to dispersion polymerization to provide polystyrene beads that serve as a core; d. causing absorption of dibutyl phthalate onto the polystyrene beads to provide dibutyl phthalate-containing polystyrene beads; e. adding said mixture to the dibutyl phthalate-containing polystyrene beads, causing absorption of the metal ion-containing monomer onto the dibutyl phthalate-containing polystyrene beads, and causing polymerization of the absorbed monomer of the metal ion-containing monomer with the cross-linker monomer to provide the surface-imprinted microspheres having a polymer shell and a polystyrene core; and f. causing removal of the metal ions from the surface-imprinted microspheres to provide imprinted sites that are able to recognize said heavy metal ions for selective separation thereof.