Group and Group‐Interaction Contribution Method for Estimating the Melting Temperatures of Deep Eutectic Solvents

AIChE Journal ◽  
2021 ◽  
Author(s):  
Xiao‐Jing Hou ◽  
Liu‐Ying Yu ◽  
Chao‐Hong He ◽  
Ke‐Jun Wu
Keyword(s):  
Group Interaction ◽  
Deep Eutectic Solvents ◽  
Melting Temperatures ◽  
Interaction Contribution

scholarly journals Deliquescence Behavior of Deep Eutectic Solvents

2021 ◽  
Vol 11 (4) ◽  
pp. 1601
Author(s):  
Henrik Palmelund ◽  
Jukka Rantanen ◽  
Korbinian Löbmann
Keyword(s):  
Hydrogen Bond ◽  
Room Temperature ◽  
Deep Eutectic Solvents ◽  
Storage Conditions ◽  
Ambient Conditions ◽  
Hydrogen Bond Donor ◽  
Eutectic Melting ◽  
Melting Temperatures ◽  
Hydrogen Bond Interactions ◽  
The Individual

Deep eutectic solvents (DESs) are formed by a hydrogen bond donor and an acceptor. The hydrogen bond interactions between these two components significantly depress the melting temperature of the mixture. DESs have been used as an alternative for organic solvents in various branches of the chemical industry. Many DESs are very hygroscopic and water is known to change the properties of DESs, but there has neven been a systematic study performed on the deliquesence behavior of DESs. Therefore, this study investigated the thermal and deliquescent behavior of four DESs. The DES mixtures were stored in desiccators at different relative humidities (RH) to investigate the critical RH (RH0) for deliquescence. It was found that, due to the formation of a eutonic mixture, the RH0 to induce deliquescence for a given DES mixture was lower compared to the individual components comprising the DES. The results showed that, even though all investigated DESs had eutectic melting temperatures above room temperature, but due to the low RH0, they were able to appear liquid at room temperature under ambient conditions. The eutonic and eutectic compositions were identified at different compositions for the DESs. The results emphasize that great care must be taken to control the process and storage conditions for DESs.

scholarly journals Activity modelling of the solid–liquid equilibrium of deep eutectic solvents

2019 ◽  
Vol 91 (8) ◽  
pp. 1341-1349 ◽  
Author(s):  
Laura J.B.M. Kollau ◽  
Mark Vis ◽  
Adriaan van den Bruinhorst ◽  
Gijsbertus de With ◽  
Remco Tuinier
Keyword(s):  
Melting Point ◽  
Binary Mixtures ◽  
Order Term ◽  
Deep Eutectic Solvents ◽  
Melting Point Depression ◽  
Ideal Behavior ◽  
Liquid Phase Boundary ◽  
Melting Temperatures ◽  
Sustainable Solvents ◽  
Solid Liquid

Abstract Compared to conventional solvents used in the chemical industry, deep eutectic solvents (DESs) are considered as promising potentially sustainable solvents. DESs are binary mixtures and the resulting liquid mixture is characterized by a large melting point depression with respect to the melting temperatures of its constituents. The relative melting point depression becomes larger as the two components have stronger attractive interactions, resulting in non-ideal behavior. The compositional range over which such binary mixtures are liquids is set by the location of the solid–liquid phase boundary. Here we present experimental phase diagrams of various recent and new DESs that vary in the degree of non-ideality. We investigate whether thermodynamic models are able to describe the solid–liquid equilibria and focus on relating the parameters of these models to the non-ideal behavior, including asymmetric behavior of the activity coefficients. It is shown that the orthogonal Redlich–Kister-like polynomial (OP) expansion, including an additional first order term, provides an accurate description. This theory can be considered as an extension of regular solution theory and enables physical interpretation of the fit parameters.

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