Autor: |
Schaeffer, Nicolas, Passos, Helena, Gras, Matthieu, Mogilireddy, Vijetha, Leal, João P., Pérez-Sánchez, Germán, Gomes, José R. B., Billard, Isabelle, Papaiconomou, Nicolas, Coutinho, João A. P. |
Zdroj: |
Physical Chemistry Chemical Physics (PCCP); 4/21/2018, Vol. 20 Issue 15, p9838-9846, 9p |
Abstrakt: |
Ionic-liquid-based acidic aqueous biphasic systems (IL-based AcABS) represent a promising alternative to the solvent extraction process for the recovery of critical metals, in which the substitution of the inorganic salt by an acid allows for a ‘one-pot’ approach to the leaching and separation of metals. However, a more fundamental understanding of AcABS formation remains wanting. In this work, the formation mechanisms of AcABS are elucidated through a comparison with traditional aqueous biphasic systems (ABS). A large screening of AcABS formation with a wide range of IL identifies the charge shielding of the cation as the primary structural driver for the applicability of an IL in AcABS. Through a systematic study of tributyltetradecylphosphonium chloride ([P44414]Cl) with various chloride salts and acids, we observed the first significant deviation to the cationic Hofmeister series reported for IL-based ABS. Furthermore, the weaker than expected salting-out ability of H3O+ compared to Na+ is attributed to the greater interaction of H3O+ with the [P44414]+ micelle surface. Finally, the remarkable thermomorphic properties of [P44414]Cl based systems are investigated with a significant increase in the biphasic region induced by the increase in the temperature from 298 K to 323 K. These finding allows for the extension of ABS to new acidic systems and highlights their versatility and tunability. [ABSTRACT FROM AUTHOR] |
Databáze: |
Complementary Index |
Externí odkaz: |
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