Phase behavior of aqueous solutions of ethaline deep eutectic solvent
| Autor: | Denis Morineau, Thibaut Sohier, Aicha Jani |
|---|---|
| Přispěvatelé: | Institut de Physique de Rennes (IPR), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), ANR-18-CE92-0011-01, Agence Nationale de la Recherche, GDR 2035, Centre National de la Recherche Scientifique, CPER PRINT2TAN, Rennes Metropole and Europe, ANR-18-CE92-0011,NanoLiquids,Modifications des Propriétés de Fluides Multiphasiques par Confinement Géométrique dans des Matériaux Mésoporeux Avancés(2018), ANR-18-CE92-0011,NANOLIQUIDS,PROPERTY CHANGES OF MULTIPHASIC FLUIDS BY GEOMETRICAL CONFINEMENT IN ADVANCED MESOPOROUS MATERIALS(2018), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
Materials science
Thermodynamics Context (language use) 02 engineering and technology 010402 general chemistry 01 natural sciences Ion law.invention chemistry.chemical_compound law Differential scanning calorimetry Phase (matter) Materials Chemistry Physical and Theoretical Chemistry Crystallization ComputingMilieux_MISCELLANEOUS Spectroscopy Phase diagram Aqueous solution Deep eutectic solvents 021001 nanoscience & nanotechnology Condensed Matter Physics Maximally freeze-concentrated solution Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Amorphous solid Deep eutectic solvent chemistry Ethaline 0210 nano-technology [PHYS.COND.CM-SCM]Physics [physics]/Condensed Matter [cond-mat]/Soft Condensed Matter [cond-mat.soft] |
| Zdroj: | Journal of Molecular Liquids Journal of Molecular Liquids, Elsevier, 2020, 304, pp.112701. ⟨10.1016/j.molliq.2020.112701⟩ Journal of Molecular Liquids, 2020, 304, pp.112701. ⟨10.1016/j.molliq.2020.112701⟩ |
| ISSN: | 0167-7322 |
| Popis: | International audience; We have established a detailed phase diagram of a prototypical DES as a function of the hydration level. Two distinct thermal phase behaviors are observed depending on the water content with respect to a cross-over composition Wg’ = 30%. For W < Wg’, the formation of ice is not observed under the experimental conditions used in this study, and the solution falls in the category of glassforming systems. Fully vitreous states could also be obtained between 30% and 50%, but they are metastable with respect to water crystallization. For W > Wg’, ice crystallization occurs but the residual DES solution remains amorphous (liquid or glassy). In the latter case, whatever the initial water fraction, this transformation finally ends at the fixed composition Wg’ corresponding to 6 to 10 water molecules per choline ion for the two studied DESs. We infer that the residual liquid water molecules forming this maximally freeze-concentrated solution are strongly interacting with DES molecular units. This situation is also known as the “water-in-DES” case. Conversely, ice crystallization concerns free water molecules, provided that W > Wg’, also known as the “DES-in-water” case. This entire phase behavior is explained in the context of maximally freeze-concentrated solutions and attributed to the concomitant effects of ice freezing depression, glassforming ability of weakly hydrated DES (W < Wg’) and water structure distortion. This study also highlights the potential of DESs for their uses in freeze-drying processes and biopreservative applications. |
| Databáze: | OpenAIRE |
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