In this article, we report on the extraction of Sr(II) ions from aqueous solution with a series of poly(N-vinyl imidazole)-based hydrogels. The hydrogels were synthesized by the crosslinking of N-vinyl imidazole with four different crosslinkers with ? rays as initiators. The well-characterized hydrogels were used as Sr(II) sorbents. Sr(II) uptake was determined with a colorimetric method with Rose Bengal anionic dye. Scanning electron microscopyenergy-dispersive spectroscopy analysis of the Sr(II)-loaded polymers was recorded to ascertain the uptake of Sr(II) ions. The experimental adsorption values were analyzed with the Freundlich and Temkin equations, and the kinetics of adsorption were investigated with a pseudo-second-order sorption kinetic model. The results show that the equilibrium data fit well in the Freundlich isotherm and followed a pseudo-second-order kinetic model. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012