Sorption of europium(III) and copper(II) by a mesostructured silica doped with acyl-hydroxypyrazole derivatives: Extraction, kinetic and capacity studies

The solid–liquid extraction of copper(II) and europium(III) by a mesostructured silica doped with two 4-acyl-5-hyroxy-pyrazole: 1-phenyl-3-methyl-4-stearoyl-5-pyrazolone (HPMSP) with one chelating head and 1,12-bis(1′-phenyl-3′-methyl-5′-hydroxy-4′-pyrazolyl) (HL-10-LH) with two chelating heads has been studied. The solid–liquid extraction occurs at a weaker pH than in liquid–liquid extraction. A theoretical model is used to determine the stoichiometries of the extracted complexes in the doped silica. Some extracted complexes found are comparable to those obtained in solvent extraction Cu(PMSP)2, Cu(L-10-L) and Eu(PMSP)3. The complex formed in the doped silica between HL-10-LH and Eu is the same as the one formed in micellar extraction. Kinetics sorption were also studied at 25 °C. The best fit is obtained with the pseudo-second order model. Extraction capacity of the doped materials is determined and comparable to the extraction capacity of europium by HL-10-LH solubilized in cetyltrimethylammonium bromide micelles.