Application Of Deep Eutectic Solvents Research Articles

Deep Eutectic Solvents for Starch Treatment.

In this review, the application of deep eutectic solvents (DESs) as starch solvents, plasticizers and for other treatment has been described. Starch, as one of the most abundant biopolymers, is considered for forming new biodegradable materials. This new approach, referring to applying deep eutectic solvents for dissolving starch, its plasticization and other modifications, was presented. A DES could be a good alternative for common starch plasticizers (e.g., glycerol, urea) as well as recently considered ionic liquids. The high variety of DES component combinations makes it possible to obtain materials with the properties specific for given applications.

Deep insights into the viscosity of deep eutectic solvents by an XGBoost-based model plus SHapley Additive exPlanation.

Deep eutectic solvents (DESs) are emerging as novel green solvents for the processes of mass transport and heat transfer, in which the viscosity of DESs is important for their industrial applications. However, for DESs, the measurement of viscosity is time-consuming, and there are many factors influencing the viscosity, which impedes their wider application. This study aims to develop a data-driven model which could accurately and rapidly predict the viscosity of diverse DESs at different temperatures, and furthermore boost the design and screening of novel DESs. In this work, we collected 107 DESs with 994 experimental values of viscosity from published works. Given the significant effect of water on viscosity, the water content of each collected DES was labeled. The Morgan fingerprint was first employed as a feature to describe the chemical environment of DESs. And four machine learning algorithms were used to train models: support vector regression (SVR), random forest (RF), neural network (NN), and extreme gradient boosting (XGBoost), and XGBoost showed the best predictive performance. In combination with the powerful interpretation method SHapley Additive exPlanation (SHAP), we further revealed the positive or negative effect of features on viscosity. Overall, this work provides a machine learning model which could predict viscosity precisely and facilitate the design and application of DESs.

Radical-mediated thiol–ene ‘click’ reactions in deep eutectic solvents for bioconjugation

Herein, we report the first application of deep eutectic solvents (DESs) in radical-mediated hydrothiolation reactions.

Applications of deep eutectic solvents in the extraction, dissolution, and functional materials of chitin: research progress and prospects

Deep eutectic solvents (DESs) as sustainable solvents for chitin extraction, dissolution, and functional materials.

Deep eutectic solvents: The new generation sustainable and safe extraction systems for bioactive compounds in agri food sector: An update

Extraction of functional and bioactive compounds with high volumes, quality, and bioactivity to improve their delivery particularly in food applications has always been a priority in food chemistry. The continuous search for newer, more sophisticated extraction mediums with improved sustainability, extractability, stability, bioactivity, and safety has resulted in the development of deep eutectic solvent (DES) based on the eutectic behavior of various salts. DESs are the mixtures of hydrogen bond donor (HBD) and hydrogen bond acceptor (HBA) with complexing agents having safe biological backgrounds and a promising approach for current innovations in green extraction technologies. Research efforts focused on their utilization as economic extraction mediums with relatively higher environmental and health safety have been growing fast. Significant publication count on DES for various food and pharmaceutical applications to overcome the limitations of conventional solvents has been reported in the last decade. Although, limited work has been carried out on the extraction of bioactive compounds from various biological sources yet the persuasive recognition of these extraction systems has fascinated the consideration of the research community for their investigation. This review focuses primarily on addressing the distinctive qualities of DES especially as extraction medium along with the conventional and neoteric extraction techniques for a wide range of bioactive compounds. The review summarizes the-state-of-the-art application of DESs in the extraction of bioactive compounds their classification, preparation, activity, safety concerns, recent trends, and future perspectives for their potential utilization in the food industry. Novelty impact statement DES is new generation solvents and based on the material from which they are derived they can be the safest, cheapest, and most effective extraction systems. Extraction efficiency and recycling of both the bioactive compounds and the solvent are significantly improved by using DES. Overall, the extractability, safety, cytotoxicity and ecotoxicity of the novel DESs need extensive research trials and clinical documentation.

Deep Eutectic Solvents as Promising Green Solvents in Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Droplet: Recent Applications, Challenges and Future Perspectives.

Deep eutectic solvents (DESs) have recently attracted attention as a promising green alternative to conventional hazardous solvents by virtue of their simple preparation, low cost, and biodegradability. Even though the application of DESs in analytical chemistry is still in its early stages, the number of publications on this topic is growing. Analytical procedures applying dispersive liquid–liquid microextraction based on the solidification of floating organic droplets (DLLME-SFOD) are among the more appealing approaches where DESs have been found to be applicable. Herein, we provide a summary of the articles that are concerned with the application of DESs in the DLLME-SFOD of target analytes from diverse samples to provide up-to-date knowledge in this area. In addition, the major variables influencing enrichment efficiency and the microextraction mechanism are fully investigated and explained. Finally, the challenges and future perspectives of applying DESs in DLLME-SFOD are thoroughly discussed and are critically analyzed.

Application of deep eutectic solvent as novel co-solvent for oil extraction from flaxseed using sonoenergy

The extraction of oil from flaxseeds were carried out using deep eutectic solvents (DESs) and organic solvents with ultrasound assisted extraction. Enhancement of solvent extraction was investigated by adding novel co-solvents in the form of DESs to tetrahydrofuran (THF) and n-hexane. COSMO-RS, UFF and DFT computational method was used to study the solubility of organic solvents and DESs for oil extraction from flaxseed. It was noted that the solvent share the same non-polar region on the σ-profiles with the flaxseed oil model. Different organic solvents were screened and it was found that n-hexane and THF can achieve the highest oil yield. The addition of DES to THF negatively impacted oil yield. On the other hand, the addition of DES to n-hexane can slightly improve the extraction yield and significantly reduce the extraction temperature in comparison to n-hexane alone. Application of DES as novel co-solvent with other organic solvents can be translated to economic benefits through reducing the energy consumption and operational risks associated with the use of flammable solvent such as n-hexane.

Effect of water on amine-based deep eutectic solvents (choline chloride + monoethanolamine): Structure and physicochemical properties

Water, can not only regulate the thermodynamic properties of deep eutectic solvent (DES), but also affect its supramolecular structure. Therefore, it is necessary and meaningful to study the effect of water on DES. In this work, amine functionalized DES (choline chloride + monoethanolamine) was successfully prepared, and the densities and viscosities of DES + H2O were measured from 293.15 K to 323.15 K. The effects of DES composition, water content and temperature on the excess molar volume, partial molar volume, apparent molar volume, limiting molar volume, coefficient of thermal expansion, viscosity deviation and activation energy for viscous flow were investigated. The hydration and structural changes of DES were analyzed. Additionally, the Redlich-Kister equation was used to correlate the excess properties of DES + H2O. Finally, a three-stage theory of effect of water on DES, namely the pure DES stage, the destruction stage and the thorough destruction stage, was proposed. Conclusively, it can be seen that an appropriate amount of water is very helpful to improve the properties of DES, otherwise the structural advantages of DES will be lost. It is hoped that this study will lay a foundation for the application of DES.

NH4Sb2(C2O4)F5: A novel UV nonlinear optical material synthesized in deep eutectic solvents

The deep eutectic solvents was first employed to solve the hydrolysis of Sb3+ cations in Sb(III)-oxyacid system to explore new nonlinear optical materials, producing a novel antimony(III) fluoride oxalate named NH4Sb2(C2O4)F5. The title compound featured a 3D noncentrosymmetric structure composed of [Sb2(C2O4)F5]- anionic clusters and NH4+ cations. The cooperative effect of the planar π-conjugated [C2O4]2- anionic groups and the Sb3+ cations with stereochemically active lone pairs induce a relatively strong SHG response (1.1×KH2PO4) and a large birefringence (0.111@546 nm), which was confirmed by detailed theoretical calculations. The overall performances indicate that NH4Sb2(C2O4)F5 is a potential ultraviolet nonlinear optical material. The successful application of deep eutectic solvents in the synthesis for easy hydrolytic materials system opens the door to exploring new inorganic solid functional materials.

Deep Eutectic Solvents Application in Food Analysis.

Current trends in Analytical Chemistry are focused on the development of more sustainable and environmentally friendly procedures. However, and despite technological advances at the instrumental level having played a very important role in the greenness of the new methods, there is still work to be done regarding the sample preparation stage. In this sense, the implementation of new materials and solvents has been a great step towards the development of “greener” analytical methodologies. In particular, the application of deep eutectic solvents (DESs) has aroused great interest in recent years in this regard, as a consequence of their excellent physicochemical properties, general low toxicity, and high biodegradability if they are compared with classical organic solvents. Furthermore, the inclusion of DESs based on natural products (natural DESs, NADESs) has led to a notable increase in the popularity of this new generation of solvents in extraction techniques. This review article focuses on providing an overview of the applications and limitations of DESs in solvent-based extraction techniques for food analysis, paying especial attention to their hydrophobic or hydrophilic nature, which is one of the main factors affecting the extraction procedure, becoming even more important when such complex matrices are studied.

Applications of Deep Eutectic Solvents Related to Health, Synthesis, and Extraction of Natural Based Chemicals

Deep eutectic solvents are liquid mixtures of solid components at room temperature, which present exceptional properties: high solvent capacity, high biodegradation, low volatile organic compound character, and relatively low toxicity. Furthermore, there are an important number of DES described, formed by different components and ratios, and thus, the studied applications are also numerous. In this review, we focused on the applications related to health. One of the most promising applications of DES is the development of oral liquid formulations of poorly soluble active pharmaceutical ingredients, although it currently remains at an early stage. We have analyzed the potential and limitations of DES with this regard. Furthermore, DES have been used as synthesis media. In this work, we revised the use of DES to obtain bioactive natural products via synthesis or extraction process. Finally, the usefulness of DES in other interesting applications for promoting health has been also examined: this is the case of genomics studies, nano-carriers for the encapsulation of anticancer drugs or stabilization of samples for medical purposes.

Biomass delignification with green solvents towards lignin valorisation: ionic liquids vs deep eutectic solvents

The use of renewable resources as feedstocks to ensure the production of goods and commodities for society has been explored in the last decades to switch off the overexploited and pollutant fossil-based economy. Today there is a strong movement to set bioeconomy as priority, but there are still challenges and technical limitations that must be overcome in the first place, particularly on biomass fractionation. For biomass to be an appellative raw material, an efficient and sustainable separation of its major components must be achieved. On the other hand, the technology development for biomass valorisation must follow green chemistry practices towards eco-friendly processes, otherwise no environmental leverage over traditional petrochemical technologies will be acquired. In this context, the application of green solvents, such as ionic liquids (ILs) and deep eutectic solvents (DES), in biomass fractionation is envisaged as promising technology that encompasses not only efficiency and environmental benefits, but also selectivity, which is a crucial demand to undertake cascade processes at biorefinery level. In particular, this article briefly discusses the disruptive achievements upon the application of ILs and DES in biomass delignification step towards an effective and selective separation of lignin from polysaccharides. The different physicochemical properties of these solvents, their interactions with lignin and their delignification capacity will be scrutinized, while some highlights will be given to the important characteristics of isolated lignin fractions for further valorisation. The advantages and disadvantages between ILs and DES in biomass delignification will be contrasted as well along the article.

Application of deep eutectic solvent in biodiesel reaction: RSM optimization, CI engine test, cost analysis and research dynamics

In this study, biodiesel was produced from waste cooking oil (WCO) in one step process with crude glycerol-ChCl based deep eutectic solvent (DES) and NaOH catalyst. Response surface methodology (RSM) technique was employed in predicting the optimal operating conditions and to study the relationship between reaction parameters and the yield of fatty acid methyl ester (FAME). The RSM coefficient of determination (R2) was observed to be 0.9965. The highest yield of biodiesel was 95% at the optimum reaction temperature of 65 °C with a reaction time of 90 min. The FAME produced was in compliance with the American standard for testing materials (ASTM) D6751-07 (2007) standards. CI engine test of B100 biodiesel fuel emitted lesser CO (2.01 g/kWh), HC (0.02 g/kWh) for engine load of 100% with little increase in CO2 when compared to petroleum-based diesel (PBD). Lower calorific value of biodiesel resulted in higher brake specific fuel consumption (BSFC) compared to the PBD. Computed biodiesel production cost was approximately 833.35 USD/ton. This investigation opens new pathway for utilizing crude glycerol-ChCl based DES as co-solvent for transesterification and other chemical reactions.

Application of deep eutectic solvents combined with vortex assisted dispersive liquid-liquid microextraction for five organophosphorus pesticides in juice and green tea beverage

Abstract In this study, a new microextraction method based on hydrophobic deep eutectic solvents was developed for the extraction and preconcentration of organophosphorus pesticides from beverage samples. The hydrophobic deep eutectic solvents were synthesized from choline chloride and 4-chlorophenol. Main experimental parameters of the microextraction method were investigated to improve the extraction efficiency. The proposed method achieved a satisfactory linear range between 50 and 2,000 μg L−1 with coefficient of determination greater than 0.9939. The extraction recoveries and enrichment factor of five organophosphorus pesticides at three added levels ranged from 71.68 to 113.18% and 71.43–111.11 were obtained with the acceptable relative standard deviation ranged from 1.37 to 11.92%. Limits of detection and quantification were found to be 0.05–0.3 μg L−1 and 0.17–1 μg L−1, respectively. Finally, the methods were successfully applied for the determination of five organophosphorus pesticide in orange juice and green tea.

Direct fractionation of wood chips by deep eutectic solvent facilitated pulping technology and application for enzyme hydrolysis

In the practical application of deep eutectic solvents (DESs) for fractionation of lignocelluloses, the rigorous requirements for the size of starting materials and the long duration of the treatment (even required 12 h) have impeded industrial applications of DES. Herein, the energy-efficient pulping technology was proposed for direct fractionation of wood chips by applying DES (choline chloride: lactic acid) as a cooking solvent. The combination of the pulping technology and DES treatment process enables direct fractionation of wood chips (by bypassing the excessive powderization step) and substantially reduces the pretreatment time owing to the synergistic effect of elevated temperature and pressure. The DES pulping technology can selectively dissolve lignin by cleavage of the lignin-carbohydrate complex (LCC) and β-O-4 linkages, the wood chips can be converted into DES-Pulp at a cooking temperature of 130 °C and preservation time of 1 h, which is an efficient pretreatment method for the enzymatic hydrolysis of wood chips. The enzymatic saccharification ratios of the DES-Pulps are between 35.4% and 88.2% at different DES cooking temperatures. The DES pulping process at a cooking temperature of 140 °C and cooking preservation time of 1 h exhibited the highest cellulose saccharification ratio of 88.2%. For DES-Pulp prepared from low cooking temperature, mechanical treatment can improve their saccharification efficiency, for example, the enzymatic hydrolysis efficiency of the DES-Pulp combined with PFI refining (10 min) was improved from 71.4% to 85.4% at a cooking temperature of 130 °C.

Molecular dynamic study of alcohol-based deep eutectic solvents.

The applicability of deep eutectic solvents is determined by their physicochemical properties. In turn, the properties of eutectic mixtures are the result of the components' molar ratio and chemical composition. Owing to the relatively low viscosities displayed by alcohol-based deep eutectic solvents (DESs), their application in industry is more appealing. Modeling the composition-property relationships established in polyalcohol-based mixtures is crucial for both understanding and predicting their behavior. In this work, a physicochemical property-structure comparison study is made between four choline chloride polyalcohol-based DESs, namely, ethaline, propeline, propaneline, and glyceline. Physicochemical properties obtained from molecular dynamic simulations are compared to experimental data, whenever possible. The simulations cover the temperature range from 298.15 to 348.15K. The simulated and literature experimental data are generally in good agreement for all the studied DESs. Structural properties, such as radial and spatial distribution functions, coordination numbers, hydrogen bond donor (HBD)-HBD aggregate formation, and hydrogen bonding are analyzed in detail. The higher prevalence of HBD:HBD and HBD:anion hydrogen bonds is likely to be the major reason for the relatively high density and viscosity of glyceline as well as for lower DES self-diffusions.

Applications of deep eutectic solvents for hard-to-separate liquid systems

• Three types of hard-to-separate systems are classified by solute polarity. • Three extraction approaches using DESs in separation are introduced. • Applications of DESs in various separation systems are reviewed. • Separation mechanism and guideline for DES screening are analyzed. • DES stability and methods for recycling of DESs after separation are discussed. Deep eutectic solvents (DESs) are low-freezing mixtures formed by hydrogen bond donor (HBD) and acceptor (HBA). The change of HBA and HBD type or their ratio gives rise to a variation of the formed DES structure and properties. Such designable features make DESs meet the specific separation requirement for various systems. This work overviews the applications of DESs in three typical hard-to-separate liquid systems classified based on the solute polarity, namely non-polar solute, mildly polar solute, and polar solute systems. For each type of hard-to-separate system, the features and problems are addressed, and the requirement for DESs are analyzed. Moreover, the separation mechanism and the guideline for screening DES are introduced, and the methods for recycling of DESs after separation are discussed. Finally, further research trends of using DESs in hard-to-separate systems are prospected.

Insights into the relationships between physicochemical properties, solvent performance, and applications of deep eutectic solvents.

Deep eutectic solvent (DES) is regarded as a new generation of green solvent due to its distinctive and tailorable physicochemical properties, such as low volatility, strong solubility, biodegradability, low-cost, environment-friendly, and feasibility of the structural design. As an alternative to traditional organic solvents and ionic liquids (ILs), DESs have been widely applied in many fields, such as organic chemical synthesis, electrochemical deposition, material preparation, biomass catalytic conversion, extraction and separation, detection and analysis, nanotechnology, gas absorption, and drug delivery. In this paper, through in-depth discussion on factors influencing the physicochemical properties of DESs, we summarized the relations between their composition, structure, and performance. Focusing on their solvent performance, we analyzed the latest research results of DESs with different physicochemical properties in various fields. It should be pointed out that designing and synthesizing DESs from the molecular structure aspect to regulate their physicochemical properties is the direction of accurately developing new functional applications of DESs.

Recent Applications of Deep Eutectic Solvents in Environmental Analysis

The incessant generation of toxic waste and the growing concern over the environment have led the scientific community to delve into the search for more sustainable systems. In this regard, the application of deep eutectic solvents (DESs) has become one of the main strategies in green chemistry. These solvents have emerged as a promising alternative to conventional toxic solvents and even to the well-known ionic liquids. Their unique properties, components availability, and easy preparation, among others, have led to a new trend within the scientific community and industry, based on the use of these up-and-coming solvents not only in science but also in quotidian life. Among the areas that have benefited from the advantages of DESs is analytical chemistry, in which they have been largely used for sample preparation, including the extraction and determination of organic and inorganic compounds from environmental samples. The considerable number of applications developed in the last year in this field and the increasing generation of new data necessitate the continuous updating of the literature. This review pretends to compile the most relevant applications of DESs in environmental analysis and critically discuss them to provide a global vision about the advantages and drawbacks/limitations of these neoteric solvents in the area of environmental analysis.

Application of deep eutectic solvents modified oxidized Hydrogen-substituted graphyne in adsorption and electrochemistry

Deep eutectic solvents (DES), as the reaction medium, had gained considerable attention in the fabrication of advanced carbon nanostructure materials due to their designability. Here, a DES-mediated strategy was investigated to modify the oxidized hydrogen-substituted graphyne (O-HsGY). Ten kinds of DES based on choline chloride were used to modify O-HsGY and improve its adsorption and electrochemical performance. The morphology of DES-mediated oxidized hydrogen-substituted graphyne (DES-O-HsGY) were characterized by field emission-scanning electron microscopy (FE-SEM) and showed some cavity structure. Brunauer Emmett teller and X-ray diffraction characterization confirmed that the material had a relatively average pore size and a wide layer spacing (0.388 nm), which was conducive to ion transport. The adsorption and electrochemical properties of DES-O-HsGY were also studied and presented the excellent performance. The DES (Choline chloride: Ethylene glycol, 1:2) modified material had the best adsorption performance for thiabendazole, and the maximum adsorption value was 0.85 mg/g. The obtained electrochemical testing results proved that the cyclic voltammetry characteristic curve of the modified material not only had stability and deformation resistance at high scanning rate of 300 mV/s, but also had good conductivity. Therefore, the DES-mediated oxidized hydrogen-substituted graphyne had the promising prospect in the field of adsorption and electrochemistry.