Designing Low-Viscosity Deep Eutectic Solvents with Multiple Weak-Acidic Groups for Ammonia Separation

Author(s):  
Yanning Cao ◽  
Jiayin Zhang ◽  
Yongde Ma ◽  
Wenquan Wu ◽  
Kuan Huang ◽  
...  
2019 ◽  
Vol 64 (7) ◽  
pp. 3068-3077 ◽  
Author(s):  
Luhong Zhang ◽  
Haopeng Ma ◽  
Guangsen Wei ◽  
Bin Jiang ◽  
Yongli Sun ◽  
...  

2021 ◽  
pp. 103512
Author(s):  
Chen Fan ◽  
Lijiao Wen ◽  
Yuhang Shan ◽  
Yuwei Shan ◽  
Xueli Cao

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 853
Author(s):  
Laura V. Hoyos ◽  
Laura Ramírez ◽  
Cristhian J. Yarce ◽  
Carlos Alvarez-Vasco ◽  
Nelson H. Caicedo Ortega

Glycolipids have become an ecofriendly alternative to chemically obtained surfactants, mainly for the cosmetic, pharmaceutical, and food industries. However, the sustainable production of these compounds is still challenging, because: (i) water is a recognized inhibitor, (ii) multiphases make the use of cosolvent reaction medium necessary, and (iii) there are difficulties in finding a source for both starting materials. This study used sugars and lipids from peach palm fruit shells or model compounds as substrates to synthesize glycolipids on five different renewable deep eutectic solvents (Re-DES) alone or with a cosolvent system. Substrate conversions up to 24.84% (so far, the highest reported for this reaction on DES), showing (1) the non-precipitation of glucose in the solvent, (2) emulsification and (3) low viscosity (e.g., more favorable mass transfer) as the main limiting factors for these heterogeneous enzymatic processes. The resulting conversion was reached using a cosolvent system Re-DES:DMSO:t-butanol that was robust enough to allow conversions in the range 19–25%, using either model compounds or sugar and fatty acid extracts, with free or immobilized enzymes. Finally, the characterization of the in-house synthesized glycolipids by surface tension demonstrated their potential as biosurfactants, for instance, as an alternative to alcohol ethoxylates, industrially produced using less sustainable methods.


Author(s):  
Ali Aminian

This study aims to use Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) to describe the phase behavior of systems containing DESs and ILs. The DESs are based on Tetrabutylammonium chloride ([N4444]Cl) and Tetrabutylammonium bromide (TBAB) as hydrogen bond acceptors, and levulinic acid (LevA) and Diethylene Glycol (DEG) as hydrogen bond donors in the mole ratio of 1:2 and 1:4, respectively. The predicted phase equilibrium data from PC-SAFT has been compared to those from COSMO-RS and NRTL predictions. ILs studied in this work are low viscosity ether-functionalized pyridinium-based ILs [EnPy][NTf2] and [CmPy][NTf2], while 1-(2-methoxyethyl)-1-methylpyrrolidiniumbis(trifluoromethylsulfonyl)-amide) ([COC2mPYR][NTf2]) and 1-propyl-3-methylimidazolium bis{trifluoromethylsulfonyl}imide ([Pmim][NTf2]) were used for the study of the LLE systems with n-heptane + thiophene and n-hexane + ethylbenzene, respectively. In the last part, mixtures of linear alkanes and perfluoroalkanes have been studied to predict the phase behavior of perfluoroalkylalkanes with their linear alkane counterparts and comparisons have been made against SAFT-Mie pair potential.


2020 ◽  
Vol 56 (16) ◽  
pp. 2399-2402 ◽  
Author(s):  
Wen-Jing Jiang ◽  
Fu-Yu Zhong ◽  
Lin-Sen Zhou ◽  
Hai-Long Peng ◽  
Jie-Ping Fan ◽  
...  

It is found that ethylamine hydrochloride (EaCl) and phenol (PhOH) can form a new type of deep eutectic solvent (DES) with quite low viscosity, and two active sites for chemical absorption of NH3.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4208
Author(s):  
Ahmad Alhadid ◽  
Liudmila Mokrushina ◽  
Mirjana Minceva

Hydrophobic deep eutectic solvents (DES) have recently been used as green alternatives to conventional solvents in several applications. In addition to their tunable melting temperature, the viscosity of DES can be optimized by selecting the constituents and molar ratio. This study examined the viscosity of 14 eutectic systems formed by natural substances over a wide range of temperatures and compositions. The eutectic systems in this study were classified as ideal or non-ideal based on their solid–liquid equilibria (SLE) data found in the literature. The eutectic systems containing constituents with cyclohexyl rings were considerably more viscous than those containing linear or phenyl constituents. Moreover, the viscosity of non-ideal eutectic systems was higher than that of ideal eutectic systems because of the strong intermolecular interactions in the liquid solution. At temperatures considerably lower than the melting temperature of the pure constituents, non-ideal and ideal eutectic systems with cyclohexyl constituents exhibited considerably high viscosity, justifying the kinetic limitations in crystallization observed in these systems. Overall, understanding the correlation between the molecular structure of constituents, SLE, and the viscosity of the eutectic systems will help in designing new, low-viscosity DES.


Author(s):  
Edward D. De-Lamater ◽  
Eric Johnson ◽  
Thad Schoen ◽  
Cecil Whitaker

Monomeric styrenes are demonstrated as excellent embedding media for electron microscopy. Monomeric styrene has extremely low viscosity and low surface tension (less than 1) affording extremely rapid penetration into the specimen. Spurr's Medium based on ERL-4206 (J.Ultra. Research 26, 31-43, 1969) is viscous, requiring gradual infiltration with increasing concentrations. Styrenes are soluble in alcohol and acetone thus fitting well into the usual dehydration procedures. Infiltration with styrene may be done directly following complete dehydration without dilution.Monomeric styrenes are usually inhibited from polymerization by a catechol, in this case, tertiary butyl catechol. Styrene polymerization is activated by Methyl Ethyl Ketone peroxide, a liquid, and probably acts by overcoming the inhibition of the catechol, acting as a source of free radical initiation.Polymerization is carried out either by a temperature of 60°C. or under ultraviolet light with wave lengths of 3400-4000 Engstroms; polymerization stops on removal from the ultraviolet light or heat and is therefore controlled by the length of exposure.


Sign in / Sign up

Export Citation Format

Share Document