Preparation And Adsorption Properties Of Magnetic Ion-imprinted Polymer

Magnetic ion imprinted polymer is one of high polymers which is prepared by ionimprinting technology and matched the template ion on a spatial structure and ion bindingsites. Form functional groups which has magnetism and combines ion binding sites onsurface of polymer. Due to specificity adsorption for the target ion and good stability,magnetic ion imprinted polymer can be used widely in solid-phase extraction, metal ionsensors and so on.Magnetic ion imprinted polymer was synthesized by inverse emulsion poly-merization, using Ni2+as the template ion, chitosan as the functional monomer,glutaraldehyde as the crosslinker, kerosene as dispersion medium, Tween80and Span80asthe emulsifier, Fe3O4/SiO2as the magnetic core. Many factors influnced polymer’sadsorption performance. The experimental results showed that the optimal reactionconditions was that the HLB value was5, the reaction temperature was40℃, the amountof emulsifier was0.08g/mL, the crosslinking agent was2.5mL/g, the reaction time was5h. Adsorption experiments showed that the initial concentration was10mg/L, pH was5~6,the adsorption conditions was24h, the adsorption was2.5mg/g, the amount of adsorptionfor Ni2+reached100%. Fe3O4, Fe3O4/SiO2and M-IIP were characterized by Fouriertransform infrared spectroscopy, laser particle size analyzer, X-ray diffraction vibratingsample magnetometer and thermal gravimetric analysis in terms of structural analysis andperformance testing. Use0.25mol/L EDTA elute Ni2+, the adsorption capacity changedlittle after five times studies, which indicated that M-IIP had good repeatability.Adsorption capacity of Ni2+, Cr3+and Cu2+were measured. respectively, selectivitycoefficient K of Ni2+/Cr3+and Ni2+/Cu2+were2.008and215.55, relative selectivitycoefficient K ’ were18and154, K and K’ were higher than1, which indicated that M-IIPhad obviously imprinting effect for template ion. Finally, in the coexisting conditions ofNi2+, Cr3+and Cu2+, M-IIP can achieve selectivity separation for Ni2+,which indicated fullythe magnetic ion imprinted polymer has a strong selective recognition.