title: Chemical enrichment and separation of uranyl ions in aqueous media using novel polyurethane foam chemically grafted with different basic dyestuff sorbents.
abstract: The new type of the grafted polyurethane foam sorbents were prepared by coupling polyether polyol, toluene diisocyanate and basic dyestuff (Methylene blue, Rhodamine B and Brilliant green). The Me.B-PUF, Rh.B-PUF and Br.G-PUF were characterized using UV/vis, IR and TGA. The adsorption properties and chromatographic behaviour of these new adsorbents for preconcentration and separation of uranium(VI) ions at low concentrations from aqueous thiocyanate media were investigated by a batch process. The maximum sorption of U(VI) was in the pH ranges 1-4. The kinetics of sorption of the U(VI) by the Grafted-PUF were found to be fast with half life of sorption (t(1/2)) in 2.43min. The average sorption capacity of different sorbents 0.124meqg(-1) for uranyl ions, enrichment factors approximately 40 and the recovery 98-100% were achieved (R.S.D. approximately 0.73%). The basic dyestuff Grafted-PUF could be used many times without decreasing their capacities significantly. The value of the Gibbs free energy (DeltaG) for the sorbents is -7.3kJmol(-1), which reflects the spontaneous nature of sorption process. The sorption mechanism of the metal ion onto Grafted-PUF was also discussed.
authors.affiliation: Chemistry Department, Faculty of Science, Ain Shams University, Cairo, Egypt.
authors.forename: M F
authors.initials: MF
authors.lastname: El-Shahat
authors.forename: E A
authors.initials: EA
authors.lastname: Moawed
authors.forename: A B
authors.initials: AB
authors.lastname: Farag