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We present a novel mechanism for the extraction of metals from aqueous phases to room-temperature ionic liquids (ILs) by use of a high-temperature salt as an extraction agent. The mechanism capitalizes on the fact that charged metal complexes are soluble in ILs; this allows for extraction of charged complexes rather than the neutral species, which are formed by conventional approaches. The use of a well-chosen extraction agent also suppresses the competing ion-exchange mechanism, thus preventing degradation of the ionic liquid. The approach permits the use of excess extractant to drive the recovery of metals in high yield. This work presents both a thermodynamic framework for understanding the approach and experimental verification of the process in a range of different ILs. The method has great potential value in the recovery of metals, water purification and nuclear materials processing.

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The sodium chloride extraction from aqueous solutions by using hydrophobic trialkylammonium alkanoate ionic liquids (ILs) is studied experimentally. The water solubility in these ILs is also determined. It is found that trialkylammonium alkanoate ILs show sodium chloride extraction efficiencies up to 0.101 g NaCl extracted/g NaCl start. This efficiency cannot be explained by the low water uptake (up to 0.02 g water /g IL ) in the IL. Instead, the sodium chloride extraction must be attributed to other factors, such as steric hindrance considerations. Steric hindrance considerations also explain the dependence of sodium chloride extraction efficiency on the IL structure. Kinetic experiments were performed to ensure a state of chemical equilibrium.

The selective extraction of metals from aqueous mixtures has generally relied on the use of selective ionophores. We present an alternative strategy that exploits a recently developed approach to extraction into an ionic liquid phase, and show that a high degree of control over selectivity can be obtained by tuning the relative concentrations of extraction agents. A thermodynamic model for the approach is presented, and an experimental separation of strontium and potassium ions is performed. It is shown that tuning the concentrations of the species involved can shift the ratio of potassium to strontium in the ionic liquid phase from 4:1 to 3:4. This extraction is performed under mild conditions with relatively common reagents. The result is a proof-of-concept for a novel separations scheme that could have great importance in a wide range of technological applications.

In this study, we used mixtures of carboxylic acids and amines as solvents for the liquid-liquid extraction of copper salts with various anions from aqueous phase, and systematically varied the...

<p>La pandemia de COVID-19 ha cambiado la forma en que los profesores universitarios transmiten sus conocimientos a sus alumnos. Se ha acelerado la introducción de una nueva forma de enseñanza: el “aula invertida” (“flipped classroom” en inglés). El aula invertida permite impartir una clase interactiva y con mayor flexibilidad para adaptar la experiencia de aprendizaje. Esto ofrece varios beneficios en la época de COVID-19, donde el aprendizaje en línea se ha convertido en el estándar. El smartphone a menudo se ve como una distracción, sin embargo, en el ramo del aula invertida este puede convertirse en una divertida herramienta de monitoreo para el progreso del aprendizaje de los estudiantes. Las experiencias adquiridas durante la pandemia de COVID-19 pueden ayudar en el desarrollo de nuevas formas de enseñanza.</p>