Enhanced and selective adsorption of heavy metal ions on ion-imprinted simultaneous interpenetrating network hydrogels

摘要

Ion recognition-based separation techniques have received much attention because of the high selectivity for target ions. In this study, a novel Cu(II) ion-imprinted hydrogel [Cu(II)-IIH] with interpenetrating network structure has been pre- pared to remove Cu(II) ions with high selectivity. The Cu(II)-IIH was prepared by free radical/cationic hybrid photopo- lymerization of acrylamide (AAm) and triethylene glycol divinyl ether (DVE-3) using Cu(II) ions as template. The ability of the Cu(II)-IIH to adsorb and remove Cu(II) ions from aqueous solutions was assessed using a batch adsorption technique. The maximum adsorption capacity was observed at pH 5.0, and the adsorption process could be well described by the Freundlich isotherm. The adsorption equilibrium was achieved within 16min, and the kinetics of adsorption followed a pseudo-second-order rate equation. Selective adsorption study indicated that ion imprinting resulted in stronger af?nity of the Cu(II)-IIH toward Cu(II) ions than other competitor metal ions compared with the non-imprinted hydrogel. The prepared Cu(II)-IIH was repeatedly used and regenerated for ?ve times without a signi?- cant decrease in metal binding af?nity.