Use Of Deep Eutectic Solvents Research Articles

Influence of choline-based ionic liquids as neoteric green solvents on aqueous solubility of lamotrigine and piroxicam drugs

Background: The low aqueous solubility of three important drugs (betamethasone (BETA), meloxicam (MEL) and piroxicam (PIR)) have been increased by use of deep eutectic solvents (DESs) based choline chloride/urea (ChCl/U), choline chloride/ethylene glycol (ChCl/EG) and choline chloride/glycerol (ChCl/G) as new class of solvents at T = (298.15 to 313.15) K. Methods: DESs were prepared by combination of the ChCl/EG, U and G with the molar ratios: 1:2. The solubility of drugs in the aqueous DESs solutions was measured at different temperatures with shake flask method. Results: The solubility of the investigated drugs increased with increasing the weight fraction of DESs. The solubility data were correlated by e-NRTL and Wilson models. Also, the thermodynamic functions, Gibbs energy, enthalpy, and entropy of dissolution were calculated. Conclusion: At the same composition of co-solvents and temperature, the BETA, PIR and MEL solubility was highest in (ChCl/U + water), (ChCl/U + water) and (ChCl/EG + water) respectively. The calculated solubility based on these models was in good agreement with the experimental values. In addition, the results show that, the main contribution for drugs solubility in the aqueous DES solutions is the enthalpy.

Application of deep eutectic solvents in water treatment processes: A review

Over the past decade, deep eutectic solvents (DESs) have gathered considerable attention in the research for functional and green solvents. The significant focus on the utilization of DESs can be attributed to their economic benefits over ionic liquids (ILs), practical usage through their flexible design, and environmental safety linked to their potential biodegradability and low toxicity, as well as low vapor pressure. Since their development in 2003, DESs have proved to offer tremendous opportunities, opening new perspectives as novel and refined materials. To date, significant advances have been achieved in the synthesis and applications of DESs, with more than ten thousand journal papers documented on this topic across different scientific fields. In particular, the use of DESs in water and wastewater treatment has rapidly emerged as a promising application area for advancing industrial and analytical processes given their beneficial and unique physicochemical properties. This review surveys the state-of-the-art on the application of different classes of DESs in water purification treatment, focusing on membrane separation, and microscale extraction processes. The current problems in the integration of DESs in water treatment processes and technologies are mentioned, and potential research directions to address the challenges are recommended.

Extraction of rare earth elements via electric field assisted mining applying deep eutectic solvents

Rare earth elements play an important role in our society, as they are used in green energy technologies. However, they are considered critical raw materials. For this reason, there is a concern for obtaining alternative and complementary sources for conventional mining. In light of this view, electric field assisted mining arises as a technique to extract species from soils using green electrolytes to help in the extraction of metals. The aim of this paper was to evaluate the effect of different types of biodegradable electrolytes, including the use of deep eutectic solvents, in the electromining process. Six experiments were conducted applying an electric field of 1.0 V cm−1, and all electrolytes were used at a concentration of 0.1 mol L−1. The results showed that different electrolytes achieved different selectivities. The maximum efficiency using acetic acid resulted in 69.1% of Ce4+, citric acid removed 62.3% of La3+, and oxalic acid extracted 21.5% of La3+. The electromining efficiencies using deep eutectic solvents presented minor results. Therefore, considering the biodegradability and selectivity of the organic acids used, electromining showed to be a promising eco-friendly alternative for preferential extraction of metal species from soils.

Combination of deep eutectic solvent and organic–inorganic hybrid monomer to prepare monolith for improvement of hydrophilic protein extraction

Two kinds of monomers based on deep eutectic solvents (DESs) and 3-aminopropyl triethoxysilane-methacrylic acid (APTES-MAA) have been synthesized and used to prepare hybrid monoliths for hydrophilic protein extraction. A typical polymerization system consists of APTES-MAA (hybrid monomer), choline chloride/methacrylic acid (MAA) [DES monomer]), and ethylene glycol dimethacrylate (EDMA) in the presence of binary porogens of PEG 20,000 and methanol. The combined effect of the DES monomer and hybrid monomer in the monolithic column material was demonstrated by the recovery of bovine serum albumin (BSA). Compared with the DES/APTES-MAA-free monolith, the poly(APTES-MAA-co-DES-co-EDMA) monolith displayed a higher recovery of 95.5% (relative standard deviation < 5.0%). Monolith-characterization studies including field emission scanning electron microscopy, nitrogen adsorption, and thermal gravimetric analysis showed that the simultaneous use of DES and hybrid monomer to prepare monolith formed a unique structure. The study on the affinity of the monolithic column to protein was carried out by extracting BSA, ovalbumin (OVA), cytochrome c (Cyt c), avidin, and horseradish peroxidase (HRP). Experimental results demonstrated that the proposed poly(APTES-MAA-co-DES-co-EDMA) monolith performed significantly better in the extraction of hydrophilic proteins (BSA, Cyt c, and avidin) than the hydrophobic protein (HRP) and amphiphilic protein (OVA). The separation performance of poly(APTES-MAA-co-DES-co-EDMA) monolith against the hydrophilic acidic protein and basic protein was evaluated using sodium dodecyl sulfate–polyacrylamide gel electrophoresis. The successful extraction of BSA from calf serum was also achieved using the resulting monolith as a solid-phase extraction adsorbent. Thus, poly(APTES-MAA-co-DES-co-EDMA) monolith could be a potential material to extract proteins according to their hydrophilicity/hydrophobicity and for further separation based on their acidity/basicity.

Boosting antibiotics performance by new formulations with deep eutectic solvents

The critical scenario of antimicrobial resistance to antibiotics highlights the need for improved therapeutics and/or formulations. Herein, we demonstrate that deep eutectic solvents (DES) formulations are very promising to remarkably improve the solubility, stability and therapeutic efficacy of antibiotics, such as ciprofloxacin. DES aqueous solutions enhance the solubility of ciprofloxacin up to 430-fold while extending the antibiotic stability. The developed formulations can improve, by 2 to 4-fold, the susceptibility of Gram-negative (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacteria to the antibiotic. They also improve the therapeutic efficacy at concentrations where bacteria present resistance, without promoting tolerance development to ciprofloxacin. Furthermore, the incorporation of DES decreases the toxicity of ciprofloxacin towards immortalized human epidermal keratinocytes (HaCat cells). The results herein reveal the pioneering use of DES in fluoroquinolone-based formulations and their impact on the antibiotic’s characteristics and on its therapeutic action.

Molecular dynamics study on the use of Deep Eutectic Solvents for Enhanced Oil Recovery

The suitability of using Deep Eutectic Solvents for chemical Enhanced Oil Recovery operations is analyzed from the nanoscopic viewpoint using classical molecular dynamics simulations. Four different eutectics were considered based on Choline Chloride, as hydrogen bond acceptor, plus urea, glycerol, ethylene glycol or levulinic acid, as hydrogen bond donors. Two main effects were studied to study their suitability: i) eutectic solutions – oil interfacial tension and ii) wettability of oil droplets on calcite surfaces in presence of eutectic solutions to study the possible evolution from oil wet to water wet behavior. Different eutectic concentrations in water halide solutions, as a model of brine in reservoirs, are studied. The main physical properties such as interfacial tension or contact angle are analyzed as well as the behavior of the oil in presence of the eutectic solutions in terms of intermolecular forces, energy of interactions, molecular arrangements and adsorption at the corresponding interfaces. The reported results allow to infer the nanoscopic effects on the basis of the use of eutectics for enhanced oil recovery operations, thus providing the information which may contribute to the development of environmentally friendly operations using these low-cost green solvents.

A review on recent applications of deep eutectic solvents in microextraction techniques for the analysis of biological matrices

In general, the analysis of biological matrices is challenging and a sample preparation step employing extraction/cleanup techniques is required. Liquid-phase microextraction using deep eutectic solvents has been exploited in numerous applications because these solvents exhibit fascinating physico-chemical properties in addition to simple and straightforward preparation. Varied configurations and strategies have been examined for the determination of different classes of analytes, and these methodologies offer environmentally friendly workflows with low solvent and sample consumption, rapid and simple experimental procedures, and satisfactory analytical performance. In this review, developments related to the use of deep eutectic solvents in microextraction approaches for the analysis of biological matrices are briefly discussed with a focus on studies reported from 2017 to 2021.

Deep Eutectic Solvents in Solar Energy Technologies.

Deep Eutectic Solvents (DESs) have been widely used in many fields to exploit their ecofriendly characteristics, from green synthetic procedures to environmentally benign industrial methods. In contrast, their application in emerging solar technologies, where the abundant and clean solar energy is used to properly respond to most important societal needs, is still relatively scarce. This represents a strong limitation since many solar devices make use of polluting or toxic components, thus seriously hampering their eco-friendly nature. Herein, we review the literature, mainly published in the last few years, on the use of DESs in representative solar technologies, from solar plants to last generation photovoltaics, featuring not only their passive role as green solvents, but also their active behavior arising from their peculiar chemical nature. This collection highlights the increasing and valuable role played by DESs in solar technologies, in the fulfillment of green chemistry requirements and for performance enhancement, in particular in terms of long-term temporal stability.

Application of Deep Eutectic Solvents in the Synthesis of Substituted 2-Mercaptoquinazolin-4(3H)-Ones: A Comparison of Selected Green Chemistry Methods.

In this study, deep eutectic solvents (DESs) were used as green and eco-friendly media for the synthesis of substituted 2-mercaptoquinazolin-4(3H)-ones from different anthranilic acids and aliphatic or aromatic isothiocyanates. A model reaction on anthranilic acid and phenyl isothiocyanate was performed in 20 choline chloride-based DESs at 80 °C to find the best solvent. Based on the product yield, choline chloride:urea (1:2) DES was found to be the most effective, while DESs acted both as solvents and catalysts. Desired compounds were prepared with moderate to good yields using stirring, microwave-assisted, and ultrasound-assisted synthesis. Significantly, higher yields were obtained with mixing and ultrasonication (16–76%), while microwave-induced synthesis showed lower effectiveness (13–49%). The specific contribution of this research is the use of DESs in combination with the above-mentioned green techniques for the synthesis of a wide range of derivatives. The structures of the synthesized compounds were confirmed by 1H and 13C NMR spectroscopy.

Towards azeotropic MeOH-MTBE separation using pervaporation chitosan-based deep eutectic solvent membranes

Deep eutectic solvents (DESs) are a new class of solvents that can offset some of the major drawbacks of common solvents and ionic liquids. When dealing with the preparation of dense membranes, the use of DESs is still challenging due to their low compatibility with the polymer phase. In this research, a novel L-proline:sulfolane (molar ratio 1:2) DES was synthesized and used for the preparation of more sustainable bio-based membranes using chitosan (CS) as a polymer phase. The compatibility among both phases (polymer and DESs) and their ability to form homogenous membranes was preliminary studied. In this regard, scanning electron and confocal microscopies were used to completely map the structure of the resulting membranes evidencing a complete homogenous structure. The membranes were also characterized in terms of contact angle (CA), Fourier transformed infrared spectroscopy (FTIR), mechanical resistance and swelling degree (uptake). Preliminary pervaporation tests for the separation of a methanol (MeOH)- methyl tert-butyl ether (MTBE) azeotropic mixture were, thus, performed. In this regard, the addition of DESs provided an enhanced separation efficiency in comparison to pristine CS membranes. Thanks to the morphology and properties exhibited, the newly developed membranes can be considered as excellent bio-based candidates to be explored in other gas selective and solvent oriented membrane operations.

The role of deep eutectic solvents in the production of cellulose nanomaterials from biomass

Abstract In recent years, the demand for environment-friendly products has been on an increasing trend among researchers and industry for sustainable development. Deep eutectic solvents are green solvents which, due to their properties (biodegradability, recyclability, low cost, availability, easy preparation, low toxicity, chemical and thermal stability), can be used in various fields such as polymer chemistry, which includes nanocellulose isolation and polysaccharides processing. Several studies have illustrated the effectiveness of using deep eutectic solvents instead of the conventional reaction system to produce and disperse nanomaterials. This work summarizes the use of deep eutectic solvents in the isolation of cellulosic nanomaterials from different types of biomass. Deep eutectic solvents demonstrate high effectiveness in swelling lignocellulosic biomass and producing cellulose nanomaterials. Overall, deep eutectics solvents represent an innovative and effective pretreatment process for the fractionation of raw cellulose-containing fibres to promote subsequent isolation of nanomaterials made from cellulose.

Antimycobacterial activity and phytochemical properties of Eucalyptus camaldulensis (eucalyptus) extracted by deep eutectic solvents

The tuberculosis (TB) is one of the world's top causes of illness and death, it is a major public health problem. Eucalyptus eucalyptus camaldulensis has been traditionally used against many diseases, such as respiratory disease infections, including pulmonary (TB),The investigate the antimycobacterial activity of extracts by different deep eutectic solvents against multidrug-resistant (MDR) Mycobacterium tuberculosis compared with aqueous traditional solvents and the correlation between the phytochemical composition and antimycobacterial activity, The deep eutectic solvents (DESs) and standard water solvents were used to extract the samples. Agar disc diffusion experiment was used to investigate the antimycobacterial activity of extracts against multidrug-resistant (MDR) Mycobacterium tuberculosis. The minimal inhibitory was determined spectrophotometrically at 570 nm and followed measured the bactericidal concentrations. Phytochemical analysis was used in the study to investigate the total phenolic and flavonoid concentrations (TPC and TFC), the demonstrated, extraction by DESs is more a beneficial procedure than traditional solvent extraction of camaldulensis extracts, which have remarkable effectiveness against tuberculosis activities. Therefore, the use of DES should be considered for further investigation.

Robust and Continuous Lipase-Catalyzed Reactions in Deep Eutectic Solvents: Low Viscosity and Double CLEA-LentiKats Immobilization (CLEA-LK-Lipases).

Deep Eutectic Solvents (DES) are used as reaction media for lipase-catalyzed esterifications in continuous devices. In particular, DES may be useful for lipophilization-like reactions involving substrates with unpaired solubilities. Aspects to be considered are the viscosity of the solvent, as well as the stability of the enzyme in the non-conventional media. The viscosity can be decreased by adding buffer as cosolvent (up to 20% v/v) and keeping the non-conventional nature. Lipases can be stabilized by following a double immobilization pattern, comprising CLEA formation and entrapment in LentiKats®. The low viscosity and high stability of the CLEA-LK-lipase enable the use of DES under flow conditions.

Amino Acid-Based Deep Eutectic Solvents in Biomass Processing - Recent Advances

The use of non-conventional solvent systems, such as deep eutectic solvents (DES), for biomass processing is a growing interest. DES are formed by two or more components, usually solids at room temperature, which can interact with each other via hydrogen bonding, from a hydrogen bond acceptor (HBA) and a hydrogen bond donor (HBD), resulting in a liquid phase. The most studied HBA in the literature is choline chloride with several HBD and their use have been extensively reviewed. However, other abundant and natural HBA can be successfully applied on the preparation of different DES, e.g., amino acids. These amino acid-based DES have been used in biomass pretreatment, providing the fractionation of the main macromolecular components by lignin solubilization. In addition, amino acid-based DES can be applied in biomass chemical conversion to obtaining platform chemicals such as furanic derivatives. Bearing this in mind, this review focuses on exploring the use of amino acid-based DES on biomass processing, from pretreatment to chemical conversion.

EXTRACTION OF FLAVONOIDS FROM KOENIGIA WEYRICHII USING DEEP EUTECTIC MIXTURE OF CHOLINE CHLORIDE + GLYCERINE

Koenigia Weyrichii (F. Schmidt) T.M. Schust. et Reveal, which grows on the Kola Peninsula, contains a significant amount of flavonoids in the aerial parts of the plant, rapidly builds up biomass, and is resistant to various climatic conditions. This makes K. Weyrichii a promising source of biologically active substances (BAS) in the Arctic zone. A relatively new method for extracting biologically active substances from plants is the use of deep eutectic solvents (DES), for example, a mixture of choline chloride with glycerol, which has shown high efficiency in the extraction of flavonoids from other plants. Previously, DES was not used for the extraction of biologically active substances from K. Weyrichii. The aim of this work is to evaluate the efficiency of ultrasonic extraction using traditional solvents (water, ethanol) and DES choline chloride + glycerol and to optimize the extraction conditions. Comparison of the total content of polyphenols, flavonoids, antioxidative, and antiradical activity in various extracts is carried out. It was found that the most favorable conditions for extraction are: water content in DES – 17.5 wt%, temperature – 65 °C, and time – 3 hours. At the same time, under identical extraction conditions (temperature and time), more target substances can be extracted with 60% ethanol than with DES. However, DES can be seen as an alternative to using ethanol. The data obtained can be useful for the further development of innovative technologies of the extraction of biologically active substances from plant material. Also, K. Weyrichii may be considered as a source of biologically active substances in cosmetics and the food industry.

Extraction of Vanadium from the Dust of Ore-Thermal Melting ?f Ilmenite Concentrate Using Deep Eutectic Solvents

During the production of titanium slag by melting ilmenite concentrate, a large amount of dust is formed, most of which is taken to the landfill. The problem of dust disposal and recycling is the most important task of titanium production, since valuable components that can be extracted are lost along with the dust. In addition, the storage of dust in open landfills causes great harm to the environment. The use of deep eutectic solvents as green solvents for dust leaching has great prospects. The possibility of extracting vanadium from the dust of ore-thermal melting using deep eutectic solvents based on choline chloride and carboxylic acids is investigated. The highest yield of vanadium was during leaching in the Oxaline system and amounted to 89 %. The results of leaching were compared with leaching with equivalent aqueous acid solutions. The effect of ultrasound on the time of the leaching process was also studied. The resulting vanadium-containing material can be used as an additive to the charge in the accompanying technology for the production of vanadium pentoxide.

Extraction of flavonoid compounds from bark using sustainable deep eutectic solvents

The use of green solvents in extraction processes, especially for applications of lignocellulosic biomass, has been extensively studied over the last years. Among the range of different green solvents, deep eutectic solvents (DES) show promising results for extraction processes. Therefore, the aim of this work was the use of DES as additives in aqueous mixtures for the selective extraction of flavonoid compounds from the bark of Larix decidua. For this purpose, bark has been treated using different solvent ratios consisting of a DES/H2O mixture (0, 25, 50 and 75 wt%). Two DES were studied, choline chloride:urea and choline chloride:1,4-butanediol. In order to study the success of the extractions, the extracts and the remaining solid fraction were characterised. From the results, it was concluded that the choline chloride:1,4-butanediol (75 wt%) gave the best results, obtaining the richest extracts in flavonoids (383 mg CE/g dried bark extract), as well as those with the highest antioxidant capacity. These good results confirm the capacity of this DES to obtain active biomolecules for further application.

Anhydrous proton conductivity of sulfonated polysulfone/deep eutectic solvents (DESs) composite membranes: Effect of sulfonation degree and DES composition

The potential use of deep eutectic solvents (DESs) for anhydrous conductivity of sulfonated polysulfone membrane is presented. To this end, different molar ratios of sodium bromide as hydrogen bond acceptor (HBA) and ethylene glycol as hydrogen bond donor (HBD) are used for the synthesis of DESs. Two sulfonation degrees (DS) of 30 and 40% are also adjusted for the synthesis of sulfonated polysulfones. The synthesized DESs have suitable thermal stability as well as low viscosity to provide interconnected ionic pathways within the membranes. The proton conductivity of membranes is mainly influenced by the HBD/HBA molar ratio of DES as well as the DS of sulfonated polymer. The maximum proton conductivity of 301 mS/cm at 100 °C is obtained for the polymer with 40% DS containing a DES with a higher HBD/HBA molar ratio. The prepared composite membranes have great potential for fuel cell performance, especially in anhydrous conditions.

Deep Eutectic Solvents: Green Approach for Cathode Recycling of Li‐Ion Batteries

The overarching demand of modern electronics and electrification of transportation has tremendously increased usage of rechargeable lithium‐ion batteries (LIBs). As a result, massive amounts of solid waste are generated from the end‐of‐life LIBs and expected to increase by two‐ to threefolds in the near future. Without proper recycling strategies and infrastructure, the immediate threat of environmental pollution and wastage of resources is clear. One way to circumvent these challenges is to recycle the spent LIBs and recover the components and materials, especially heavy metals for future repurposing applications. This review highlights the recent discoveries on the use of deep eutectic solvents (DESs) as an economical and environmentally friendly medium for metal recovery from spent LIBs. Herein, how the different hydrogen donors and acceptors affect the overall performance of DES in terms of leaching efficiency, time, temperature, and metal recovery rates are outlined. Very importantly, the mechanism of metal leaching from the metal oxides using DES is discussed. Finally, some potential strategies and opportunities for further development of novel DES for metal‐recovery from not only spent LIBs but also other industries such as, mining, oil, and agriculture are outlined.

Deep eutectic solvents – A new platform in membrane fabrication and membrane-assisted technologies

Deep eutectic solvents (DESs) are a new class of solvents that can offset some of the primary drawbacks of typical solvents and ionic liquids (ILs). Since DESs fall into the guidelines of “Twelve Principles of Green Chemistry”, their implementation in several types of applications has exponentially increased over the last years. The usage of DESs has been directed to the designing, manufacture and purification of new materials and feedstocks. Very recently, great attention has been paid to new pioneering attempts aiming at DESs into the field of chemical engineering, including membrane science and technology. Even if just a few works have been currently reported in applying DESs in membranes, the consideration on this new type of solvents is continuously growing. This review compares and discusses the documented discoveries and breakthroughs carried out in applying DESs in membrane science. The scope of this review is emphasized in various scopes: i) new sustainable membrane preparation, ii) membrane-based technologies aided by DESs, iii) target molecules-DES interactions and iv) new membrane-DES structures providing enhanced physicochemical properties and thus separation performance. Here, besides the relevant insights in the field, we give the key hypotheses and strategies used by the scientists to reach a successful merging of both areas since the use of DESs in membranes is still challenging due to the compatibility issues of the DESs and membrane phase (either polymer and inorganic). The future directions and perspectives on using DESs in membranes are also given.