Toward Molecular Recognition of REEs: Comparative Analysis of Hybrid Nanoadsorbents with the Different Complexonate Ligands EDTA, DTPA, and TTHA
| Autor: | Gulaim A. Seisenbaeva, Elizabeth Polido Legaria, Michail Samouhos, Vadim G. Kessler |
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| Rok vydání: | 2017 |
| Předmět: |
Stereochemistry
Chemistry Inorganic chemistry Extraction (chemistry) 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences Inorganic Chemistry Molecular recognition Desorption Chelation Physical and Theoretical Chemistry 0210 nano-technology Selectivity Ternary operation |
| Zdroj: | Inorganic chemistry. 56(22) |
| ISSN: | 1520-510X |
| Popis: | Highly efficient tailored SiO2-based nanoadsorbents were synthesized for the selective extraction of rare-earth elements (REEs). Three different complexonates (EDTA, DTPA, and TTHA) were investigated in terms of uptake capacity and selectivity, showing capacities of up to 300 mg of RE3+/g and distinct preferential trends depending on the complexonate. EDTA-functionalized nanoadsorbents showed higher uptake for Dy3+, DTPA-functionalized ones for Nd3+, and TTHA-functionalized ones for La3+. The selectivity was even more pronounced in desorption at pH 3, with separation factors of up to 76 in ternary mixtures. A broad comparative study of single-crystal structures of the complexes between REE and the nongrafted complexonates at different pHs led to a molecular understanding of their individual modes of action. EDTA-derived nanoadsorbents combine concerted action and chelation, whereas the latter is the preferential coordination mechanism for DTPA- and TTHA-derived nanoadsorbents. These different mechanisms r... |
| Databáze: | OpenAIRE |
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