Synthesis of a new ionic imprinted polymer for the extraction of uranium from seawater

The ionic imprinted polymer (IIP) of uranyl ion (UO22+) as the template was synthesized by the formation of binary complexes of UO22+ with 2,4-dioxopentan-3-yl methacrylate as functional monomer followed by thermal copolymerization with ethylene glycol dimethacrylate as cross-linking monomer in the presence of 2,2'-azobisisobutyronitrile as initiator and 1,4-dioxane as porogenic solvent. 50 mmol L-1 HCl solution was used to leach out UO22+ ions from the IIP. Similarly, the control polymer was prepared under identical experimental conditions without using UO22+ ions. The above synthesized polymers were characterized by infra-red spectroscopy, thermo-gravimetric analysis and Barrett-Emmett-Teller surface area measurement. The maximum adsorption capacities of IIP and CP in (NH4)4[UO2(CO3)3] solution were 15.3 and 11.2 mg U g-1, respectively. The kinetics of adsorption followed a pseudo-second-order rate equation. The prepared IIP was successfully used to extract uranium from real seawater sample. (author)