Molecular level insight into deep eutectic solvents (DES)
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Deep eutectic solvents (DES) are mixtures of two or more substances which liquefy at a much lower temperature than the primary substances melting points (eutectic point). They are classified according to several main types depending on their constituents. DES are distinguished from usual eutectic mixtures and highlighted with the deep prefix, because their melting temperature is supposed to be significantly lower than the ideal eutectic temperature. Moreover, defining a mixture as a deep eutectic solvent is not simple and the current definitions need to be extended nowadays in order to address the nature of DES more rigorously. DES display the essential advantage of having good environmental bio-compatibility and low toxicity. They are a cheap, sustainable and promising alternatives to ionic liquids and conventional liquids in various processes. Despite the fact that DES as designer solvents possess wide range applications, there is a lack of fundamental information about them. |
Paper examples:
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Strong microheterogeneity in novel deep eutectic solvents (209)
With the increasing application of template-assisted syntheses in DESs and successful application of hydrophobic DES in extraction processes, where microheterogeneity plays a major role, suggestions for novel DES, which exhibit strong microheterogeneity are desirable. Therefore, classical molecular dynamics simulations were carried out on systems constructed of choline chloride and some of its derivatives mixed with ethylene glycol in a molar composition of 1 : 2. The derivatives consisted of a series of cations with elongated alkyl side chains and elongated alcohol side chains. Of these series only choline chloride ethylene glycol has been investigated experimentally, the other systems are suggested and theoretically investigated as possible targets for synthesis in order to exploit the microheterogeneity in DES, which is known to occur for longer side chains in ionic liquids.
Keywords: Deep eutectic solvent, molecular dynamics simulations, microheterogeneity, neoteric solvents -
SO2 in DES (183)
Since DES can be applied in gas capture, for example for SO2 absorption, we performed ab initio molecular dynamics studies of both the pure choline chloride/glycerol DES and the same mixed with SO2. In order to investigate application of DES for SO2 capture as promising alternative to conventional desulfurization technique. We identified the hydrogen bonding and other specific interactions between all components. With addition of SO2, we observed that SO2 is not incorporated into the hydrogen bond network, but rater perturbs it by forming complexes with the chloride anions. Furthermore, the SO2 molecules show significant interactions among themselves and also with the nonpolar CH-groups in the system. The reduction of anion-OH interactions might be responsible for the more fluid state of the SO2-DESs mixture than compared to the pure DES.
Keywords: Deep eutectic solvent, ab initio molecular dynamics simulations, SO2 absorption
