scholarly journals Deep Eutectic Solvents: Are They Safe?

2021 ◽  
Vol 11 (21) ◽  
pp. 10061
Author(s):  
Laura Lomba ◽  
Mª Pilar Ribate ◽  
Estela Sangüesa ◽  
Julia Concha ◽  
Mª Pilar Garralaga ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Organic Acids ◽  
Scientific Community ◽  
Eutectic Mixture ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Toxicity Data ◽  
Environmental Toxicity ◽  
Form Part ◽  
New Type

Deep eutectic solvents (DESs) are a relatively new type of solvent that have attracted the attention of the scientific community due to their environmentally friendly properties and their versatility in many applications. Many possible DESs have been described and, thus, it is not easy to unequivocally characterize and generalize their properties. This is especially important in the case of the (eco)toxicity information that can be found for these mixtures. In this review, we collect data on the human and environmental toxicity of DESs, with the aim of gathering and exploring the behavioral patterns of DESs. The toxicity data found were analyzed attending to different factors: hydrogen bond donors or acceptors that form part of the eutectic mixture, pH, and the presence of organic acids in the DES molar ratio of the components, or interactions with natural compounds. In the case of ecotoxicity, results generally depend on the biomodel studied, along with other factors that have been also revised. Finally, we also carried out a revision of the biodegradation of DESs.

scholarly journals Tetraethylammonium Acetate and Tetraethylammonium Bromide-Based Deep Eutectic Solvents as Thermodynamic CO2 Gas Hydrate Inhibitors

2020 ◽  
Vol 10 (19) ◽  
pp. 6794
Author(s):  
Vinayagam Sivabalan ◽  
Nurasyikin Hasnor ◽  
Bhajan Lal ◽  
Zamzila Kassim ◽  
Abdulhalim Shah Maulud
Keyword(s):  
Hydrogen Bond ◽  
Ethylene Glycol ◽  
Gas Hydrate ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Tetraethylammonium Bromide ◽  
Hydrate Dissociation ◽  
Co2 Gas ◽  
Vapor Equilibrium ◽  
Liquid Vapor

The thermodynamic gas hydrate suppression behavior of four Deep Eutectic Solvents (DESs) was evaluated in this paper. The mixtures of Hydrogen Bond Acceptors (HBA), Tetraethylammonium Acetate (TEAAC), and Tetraethylammonium Bromide (TEAB) with Hydrogen Bond Donors (HBD), Mono-Ethylene Glycol (MEG), and Glycerol were used to make the DES. The DESs were made at a 1:7 molar ratio for the combinations of TEAAC:MEG, TEAAC:Glycerol, TEAB:MEG, and TEAB:Glycerol. The Hydrate Liquid-Vapor Equilibrium (HLVE) data for CO2 were evaluated through the T-cycle method at different temperature (273.15–283.15 K) and pressure (2–4 MPa) conditions in the presence and absence of 5 wt % aqueous DES solutions. The inhibition effects showed by the DESs, including average suppression temperature (ΔŦ) and gas hydrate dissociation enthalpies (ΔHdiss), were also calculated. The average suppression temperature values of the DESs ranged between 0.4 and 2.4, with the highest inhibition to lowest inhibition order being TEAB:Glycerol > TEAB:MEG > TEAAC:Glycerol > TEAAC:MEG. A comparison of the DES with conventional Thermodynamic Hydrate Inhibitors (THIs) showed that studied Deep Eutectic Solvents had better gas hydrate inhibition. The results proved that DES has the potential to be one of the promising alternatives in gas hydrate inhibition.

scholarly journals A brief review on eutectic mixture and its role in pharmaceutical field

2020 ◽  
Vol 11 (3) ◽  
pp. 3017-3023
Author(s):  
Balakrishnan I ◽  
Jawahar N ◽  
Senthil Venkatachalam ◽  
Debosmita Datta
Keyword(s):  
Drug Delivery ◽  
Hydrogen Bond ◽  
Deep Eutectic Solvent ◽  
Eutectic Mixture ◽  
Deep Eutectic Solvents ◽  
Hydrogen Bond Donor ◽  
Liquid Form ◽  
Hydrogen Bond Acceptor ◽  
Pharmaceutical Industries ◽  
Natural Deep Eutectic Solvent

Eutectic mixture (EM) is as a mixture of more than one substance that does not interact individually to create a new entity but in a particular ratio that exhibits a lower range of melting point than it had in individual. EM should be formulated in such a way that it should have major advantages in pharmaceutical industries. EM can be a mixture of Active Pharmaceutical Ingredients (APIs), or different ratios of APIs and excipients, or various excipients. Deep eutectic solvents containing APIs (API-DES) considered as an innovative approach to form different APIs in the liquid state. This new approach of liquid form is versatile and plays an important role in drug delivery. The selection of ideal hydrogen bond-donor (HBD) and hydrogen bond-acceptor (HBA) is an essential parameter. Ionic liquids (IL), derivatives of deep eutectic solvents (DES) have got much attention since it can replace harmful organic solvent by their extraordinary properties. Therapeutic deep eutectic solvents (THEDESs) are considered to be an exceptional option in the advancement of biomedicine. This can be utilized for improvising drug solubility, bioavailability as well as drug permeation through the skin. Natural deep eutectic solvent (NADES) can be considered as an alternate option, replacing harsh solvents. It has special characteristics of better biodegradability and biocompatibility. These NADES mainly used to separate and purification of natural compounds. This review focuses on the eutectic mixture and its application in the area of drug delivery systems, and pharmaceutical and pharmacological fields.

Deacidification of Crude Rice Bran Oil (CRBO) to Remove FFA and Preserve γ-Oryzanol Using Deep Eutectic Solvents (DES)

2019 ◽  
Vol 964 ◽  
pp. 109-114 ◽  
Author(s):  
Siti Zullaikah ◽  
Nizar Dwi Wibowo ◽  
I Made Gede Eris Dwi Wahyudi ◽  
M. Rachimoellah
Keyword(s):  
Hydrogen Bond ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Choline Chloride ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Extraction Temperature ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
C 50

High content of free fatty acids (FFA) in crude rice bran oil (CRBO) needs to be separated through deacidification. Generally, deacidification process that is widely used are chemical and physical processes which causes the loss of bioactive compounds (γ-oryzanol) and un-environmentally friendly. The liquid-liquid extraction (LLE) using deep eutectic solvents (DES) to remove FFA and preserve g-oryzanol would be implemented in this study. DES with different hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) with certain molar ratio such as Choline Chloride (ChCl)-Ethylene glycol 1:2 (DES I), ChCl-Glycerol 1:1 (DES II), ChCl-Urea 1:2 (DES III), ChCl-Oxalic acid 1:2 (DES IV), and Betaine Monohydrate-Glycerol 1:8 (NADES) were used as solvent to extract FFA from dewaxed/degummed RBO (DDRBO) for certain extraction time (30, 60, 120, 180, and 240 min) and extraction temperature (30°C, 40°C, 50°C, 60°C, and 70°C) under stirring (200 rpm). Deacidification using DES I for 240 min. and temperature of 50 °C was the optimum solvent to remove FFA (19.03 ± 2.33 %) and preserve g-oryzanol (recovery of g-oryzanol was 51.30 ± 1.77 %). The results also revealed that the longer time of extraction would be increased removal of FFA and decreased recovery of g-oryzanol. The higher temperature of extraction would be increased removal of FFA. In this work, temperature of 50 °C was the best extraction temperature of FFA since DES has highest solubility at this temperature.

scholarly journals Absorptive Desulfurization of Model Biogas Stream Using Choline Chloride-Based Deep Eutectic Solvents

2020 ◽  
Author(s):  
Edyta Słupek ◽  
Patrycja Makoś
Keyword(s):  
Hydrogen Bond ◽  
Density Functional ◽  
Absorption Rate ◽  
Choline Chloride ◽  
Dimethyl Disulfide ◽  
Deep Eutectic Solvents ◽  
Absorption Capacity ◽  
Molar Ratio ◽  
Absorption Mechanism ◽  
Hydrogen Bond Acceptor

The paper presents a synthesis of deep eutectic solvents (DESs) based on choline chloride (ChCl) as hydrogen bond acceptor and phenol (Ph), glycol ethylene (EG), and levulinic acid (Lev) as hydrogen bond donors in 1:2 molar ratio. DESs were successfully used as absorption solvents for removal of dimethyl disulfide from (DMDS) from model biogas steam. Several parameters affecting the absorption capacity and absorption rate has been optimized including kind of DES, temperature, the volume of absorbent, model biogas flow rate, and initial concentration of DMDS. Furthermore, reusability and regeneration of DESs by means of adsorption and nitrogen barbotage followed by the mechanism of absorptive desulfurization by means of density functional theory (DFT) as well as FT-IR analysis were investigated. Experimental results indicate that the most promising DES for biogas purification is ChCl:Ph, due to high absorption capacity, relatively long absorption rate, and easy regeneration. The research on the absorption mechanism revealed that van der Waal interaction is the main driving force for DMDS removal from model biogas.

scholarly journals Effect of Four Novel Bio-Based DES (Deep Eutectic Solvents) on Hardwood Fractionation

Molecules ◽  
2020 ◽  
Vol 25 (9) ◽  
pp. 2157 ◽  
Author(s):  
Paulo Torres ◽  
Mercè Balcells ◽  
Enrique Cequier ◽  
Ramon Canela-Garayoa
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Scale Up ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Olive Pomace ◽  
Hydrogen Bond Donor ◽  
Hydrogen Bond Acceptor ◽  
Raw Glycerol ◽  
Lignin Recovery

Using the basic principle of construction between a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), four bio-based deep eutectic solvents (DESs) were prepared in a 1:2 molar ratio of HBA:HBD. 2,3-Dihydroxypropyl-1-triethylammonium chloride ([C9H22N+O2]Cl−) was synthesized from raw glycerol and used as an HBA. Lactic acid, urea, pure glycerol, and ethylene glycol were selected as HBD. Attempts to prepare DESs, using citric acid and benzoic acid as HBDs, were unsuccessful. All these DESs were characterized using FTIR and NMR techniques. Besides, physicochemical parameters such as pH, viscosity, density, and melting point were determined. The behavior of these DES to fractionate olive pomace was studied. Lignin recovery yields spanned between 27% and 39% (w/w) of the available lignin in olive pomace. The best DES, in terms of lignin yield ([C9H22N+O2]Cl− -lactic acid), was selected to perform a scale-up lignin extraction using 40 g of olive pomace. Lignin recovery on the multigram scale was similar to the mg scale (38% w/w). Similarly, for the holocellulose-rich fractions, recovery yields were 34% and 45% for mg and multi-gram scale, respectively. Finally, this DES was used to fractionate four fruit pruning samples. These results show that our novel DESs are alternative approaches to the ionic liquid:triethylammonium hydrogen sulfate and the widely used DES: choline chloride:lactic acid (1:10 molar ratio) for biomass processing.

scholarly journals Batch Stirred-Tank Green Extraction of Salvia fruticosa Mill. Polyphenols Using Newly Designed Citrate-Based Deep Eutectic Solvents and Ultrasonication Pretreatment

2020 ◽  
Vol 10 (14) ◽  
pp. 4774
Author(s):  
Spyros Grigorakis ◽  
Abedalghani Halahlah ◽  
Dimitris P. Makris
Keyword(s):  
Hydrogen Bond ◽  
Lactic Acid ◽  
Deep Eutectic Solvents ◽  
Extraction Process ◽  
Dry Mass ◽  
Stirred Tank ◽  
Molar Ratio ◽  
Salvia Fruticosa ◽  
The One ◽  
Optimal Settings

A series of citrate salts were tested as hydrogen bond acceptors to synthesize deep eutectic solvents (DES) based on lactic acid and glycerol, used as hydrogen bond donors. The DES produced were then screened to identify the highest performing system for the effective extraction of polyphenolic phytochemicals from the medicinal plant Salvia fruticosa Mill. (Greek sage). The most efficacious DES was the one composed of lactic acid and sodium citrate dibasic, at a molar ratio of 15:1 (LA-SCDB15). Furthermore, for the first time there has been evidence concerning DES pH and extraction efficiency. Using this solvent, a batch, stirred-tank extraction process was developed, by employing ultrasonication pretreatment and response surface methodology. The optimal settings determined were stirring speed 900 rpm, proportion of DES/water 77% (w/v), and ultrasonication pretreatment time 15 min. By adjusting these optimal settings, the predicted maximum total polyphenol yield was calculated to be 79.93 ± 1.92 mg gallic acid equivalents g−1 dry mass. The examination of temperature effects demonstrated that the batch, stirred-tank extraction stage was very energy-efficient, with a barrier of 7.64 kJ mol−1. Comparison of the extraction of Salvia fruticosa polyphenols with other green processes previously developed, illustrated the high extraction capacity of LA-SCDB15. The major polyphenols identified in the extracts produced under optimized settings were chlorogenic acid, luteolin 7-O-glucuronide and rosmarinic acid.

scholarly journals EFFECTS OF MOLAR RATIO, FREQUENCY, WATER CONTENT AND TEMPERATURE ON DIELECTRIC PROPERTIES OF DEEP EUTECTIC SOLVENTS

2022 ◽  
Vol 52 (1) ◽  
pp. 27-33
Author(s):  
Naciye Kutlu ◽  
Merve Sılanur Yılmaz ◽  
Gizem Melissa Erdem ◽  
Ozge Sakiyan ◽  
Aslı Isci
Keyword(s):  
Hydrogen Bond ◽  
Dielectric Constant ◽  
Acetic Acid ◽  
Dielectric Properties ◽  
Water Content ◽  
Choline Chloride ◽  
Free Water ◽  
Deep Eutectic Solvents ◽  
Molar Ratio ◽  
Hydrogen Bond Acceptor

In this study, deep eutectic solvents (DESs) were prepared using choline-chloride as the hydrogen-bond acceptor and glycerol, formic acid and acetic acid as the hydrogen-bond donor. The effect of different process parameters such as molar ratio (1:2, 1:3 and 1:4), water content (15%, 30% and 45%), temperature (25, 50 and 75 °C) and frequency on dielectric properties of the DESs were examined. In conclusion, the highest dielectric constant value was detected at 25 °C for all DESs. Moreover, for all DESs, it was found that a decrease in water content resulted in a decrease in both dielectric constant and loss factor values. This can be explained by the absence of free water molecules which are responsible from dipole rotation mechanism. In light of the results, if DES will be used in microwave extraction, formic or acetic acid containing DESs might give more successful results compared to the one with glycerol.

scholarly journals The Influence of Hydrogen Bond Donors on the CO2 Absorption Mechanism by the Bio-Phenol-Based Deep Eutectic Solvents

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7167
Author(s):  
Ze Wang ◽  
Zonghua Wang ◽  
Jie Chen ◽  
Congyi Wu ◽  
Dezhong Yang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Hydrogen Bond ◽  
Co2 Capture ◽  
Deep Eutectic Solvents ◽  
Reaction Pathways ◽  
Co2 Absorption ◽  
Absorption Mechanism ◽  
New Type ◽  
Steric Hinderance ◽  
Hydrogen Bond Donors

Recently, deep eutectic solvents (DESs), a new type of solvent, have been studied widely for CO2 capture. In this work, the anion-functionalized deep eutectic solvents composed of phenol-based ionic liquids (ILs) and hydrogen bond donors (HBDs) ethylene glycol (EG) or 4-methylimidazole (4CH3-Im) were synthesized for CO2 capture. The phenol-based ILs used in this study were prepared from bio-derived phenols carvacrol (Car) and thymol (Thy). The CO2 absorption capacities of the DESs were determined. The absorption mechanisms by the DESs were also studied using nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and mass spectroscopy. Interestingly, the results indicated that CO2 reacted with both the phenolic anions and EG, generating the phenol-based carbonates and the EG-based carbonates, when CO2 interacted with the DESs formed by the ILs and EG. However, CO2 only reacted with the phenolic anions when the DESs formed by the ILs and 4CH3-Im. The results indicated that the HBDs impacted greatly on the CO2 absorption mechanism, suggesting the mechanism can be tuned by changing the HBDs, and the different reaction pathways may be due to the steric hinderance differences of the functional groups of the HBDs.

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