A novel magnetic Zn (II) ion-imprinted polymer was prepared by the surface ion-imprinted technique by using magnetic Fe3O4@SiO2 microspheres as supporter, methacrylic acid and salicylaldoxime as monomers, ethylene glycol dimethacrylate as the crosslinker. The products were characterized by Fourier transform infrared, X-ray photoelectron spectrometer, vibrating sample magnetometer and scanning electron microscope. The adsorption experiments showed that the imprinted polymer was employed successfully in comparison with non-imprinted polymer. When the temperature was in a range of 291-297 K, the maximum adsorption was about 52.69 mg g(-1) with an optimal pH 6.0 for an equilibrium time of 40 min. The imprinted polymer possessed high selectivity and specific recognition towards Zn (II). The Langmuir adsorption model was more favourable than the Freundlich or the Temkin adsorption model. Thermodynamic experiment showed that the adsorption was a spontaneous and endothermic process for Zn (II). The mechanism for Zn (II) adsorption on the imprinted polymer was investigated.
Keywords: adsorption; magnetic polymers; molecular imprinting; selectivity; zinc ion.