Popis: |
A Cu–Al layered double hydroxide intercalated with ethylenediaminetetraacetate (edta•Cu–Al LDH) was prepared by the dropwise addition of a Cu–Al nitrate solution to an edta solution at constant pH values of 8.0, 9.0, and 10.0. The edta•Cu–Al LDH had Hedta 3− in the interlayer. Furthermore, the preparation at pH 8.0 resulted in the intercalation of Cu(edta) 2− . The edta•Cu–Al LDH was found to take up rare earth ions from aqueous solution. The uptake of Sc 3+ and Y 3+ by edta•Cu–Al LDH was attributed to both the chelating functions of the edta ion in the interlayer and the chemical properties of Cu–Al LDH itself. The uptake of La 3+ by edta•Cu–Al LDH was primarily caused by the chelating function of edta ions in the interlayer. The edta ions in the edta•Cu–Al LDH interlayer formed chelate complexes in the order Sc 3+ > Y 3+ > La 3+ due to their relative stabilities, Sc(edta) − > Y(edta) − > La(edta) − . Thus, edta ions retain their chelating function even when intercalated in a Cu–Al LDH interlayer. |