Deep eutectic solvents eutectogels: progress and challenges
06 Jun 2021-
TL;DR: Deep eutectic solvents (DESs) have received widespread attention for their advantages of good electrical conductivity, stability, environmental friendliness, and easy preparation with a wide range of applications.
Abstract: Deep eutectic solvents (DESs) have received widespread attention for their advantages of good electrical conductivity, stability, environmental friendliness, and easy preparation with a wide range of applications. However, it was not until recent years that DESs were used as gel electrolytes as environmentally friendly alternatives to ionic liquids (ILs). In this mini review, we first introduce the DESs related eutectogels (or ion gels), then introduce the types and applications of the gels, the opportunities and challenges of them are also summarized.
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26 Jul 2021
TL;DR: In this article, the phase separation principle of Ionic liquids and deep eutectic solvents-based ATPSs is discussed, and the applications in the extraction of natural active molecules are reviewed.
Abstract: Due to environmental protection requirements, extraction of bioactive compounds from plant materials using environment-friendly green solvents has always been a research hotspot. And great efforts of scholars have been made in this direction, as well as environment-friendly solvents have been used to develop many innovative extraction techniques. Ionic liquids (ILs) and deep eutectic solvents (DESs) are two kinds of typical designable green solvents, which are potential replacements for traditional volatile organic solvents used for extracting. Under the substances action of inorganic salts or polymers, ILs/DESs can form an aqueous two-phase system (ATPS), which has obvious advantages for separating natural products. This paper discussed the phase separation principle of ILs/DESs-based ATPSs and reviewed the applications in the extraction of natural active molecules in recent years, as well as to promote the development of separation of the active constituents in Chinese materia medica.
20 citations
01 Mar 2022
TL;DR: In this article , the phase separation principle of Ionic liquids and deep eutectic solvents-based ATPSs is discussed and reviewed for the extraction of natural active molecules in Chinese materia medica.
Abstract: Due to environmental protection requirements, extraction of bioactive compounds from plant materials using environment-friendly green solvents has always been a research hotspot. And great efforts of scholars have been made in this direction, as well as environment-friendly solvents have been used to develop many innovative extraction techniques. Ionic liquids (ILs) and deep eutectic solvents (DESs) are two kinds of typical designable green solvents, which are potential replacements for traditional volatile organic solvents used for extracting. Under the substances action of inorganic salts or polymers, ILs/DESs can form an aqueous two-phase system (ATPS), which has obvious advantages for separating natural products. This paper discussed the phase separation principle of ILs/DESs-based ATPSs and reviewed the applications in the extraction of natural active molecules in recent years, as well as to promote the development of separation of the active constituents in Chinese materia medica.
16 citations
TL;DR: In this paper , a series of novel deep eutectics solvents based on choline chloride and plant-derived polyphenols are reported. And the potential of these novel NADES for two applications: bioadhesives and corrosion protection.
Abstract: Natural deep eutectics solvents (NADES), owing to their high solvation capacity and nontoxicity, are actively being sought for many technological applications. Herein, we report a series of novel NADES based on choline chloride and plant-derived polyphenols. Most of the obtained phenolic NADES have a wide liquid range and high thermal stability above 150 °C. Among them, small-sized polyphenols, like pyrogallol, vanillyl alcohol, or gentisic acid, lead to low-viscosity liquids with ionic conductivities in the order of 10–3 S cm–1 at room temperature. Interestingly, polyphenols possess valuable properties as therapeutic agents, antioxidants, adhesives, or redox-active compounds, among others. Thus, we evaluated the potential of these novel NADES for two applications: bioadhesives and corrosion protection. The mixture of choline chloride-vanillyl alcohol (2:3 mol ratio) and gelatin resulted in a highly adhesive viscoelastic liquid (adhesive stress ≈ 135 kPa), affording shear thinning behavior. Furthermore, choline chloride-tannic acid (20:1) showed an extraordinary ability to coordinate iron ions, reaching excellent corrosion inhibitive efficiencies in mild steel protection.
12 citations
TL;DR: Deep eutectic solvents (DESs) as discussed by the authors are modified versions of ionic liquids (ILs) and are formed by the fusion of polar components (liquids or solids) via hydrogen bonding interactions.
Abstract: Deep eutectic solvents (DESs) are modified versions of ionic liquids (ILs) and are formed by the fusion of polar components (liquids or solids) via hydrogen bonding interactions. DESs are prepared by the simple mixing of two or three cheap constituents (that are capable of self-association) with gentle heating, which leads to a drastic decrease in their melting points. The resultant clear homogeneous mixture consists of cations, anions, as well as neutral molecules; this will contribute both ionic and molecular solvent properties to the DESs. DESs have emerged as alternatives to conventional organic solvents and ILs, which meet different criteria such as availability, low cost, low toxicity, biodegradability, recyclability, ease of preparation method, tunable, and designer physiochemical properties. Many of them have attracted considerable attention and haave been applied in distinct fields of chemistry. To summarize the full-scale development of DESs, this review discusses the history, classifications, various methods of preparation, properties, and some major applications in catalysis in the last three years. This review is expected to be helpful for the further development of DESs based on a summary of the fundamental research in the field.
11 citations
TL;DR: In this article , the potential of eutectogels formulated using NADES and durian seed gum for use as food coating was discussed, which could potentially help in reducing food wastes.
10 citations
References
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3,909 citations
TL;DR: Eutectic mixtures of urea and a range of quaternary ammonium salts are liquid at ambient temperatures and have interesting solvent properties.
3,550 citations
TL;DR: It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts.
Abstract: Deep Eutectic Solvents (DES) can be formed between a variety of quaternary ammonium salts and carboxylic acids. The physical properties are significantly affected by the structure of the carboxylic acid but the phase behavior of the mixtures can be simply modeled by taking account of the mole fraction of carboxylic acid in the mixture. The physical properties such as viscosity, conductivity, and surface tension of these DES are similar to ambient temperature ionic liquids and insight into the cause of these properties is gained using hole-theory. It is shown that the conductivity and viscosity of these liquids is controlled by ion mobility and the availability of voids of suitable dimensions, and this is consistent with the fluidity of other ionic liquids and molten salts. The DES are also shown to be good solvents for metal oxides, which could have potential application for metal extraction.
2,904 citations
TL;DR: Deep Eutectic Solvents (DES) as discussed by the authors are a class of solvents that can be defined as a mixture of two or more components, which at a particular composition present a high melting point depression becoming liquids at room temperature.
Abstract: Green technology actively seeks new solvents to replace common organic solvents that present inherent toxicity and have high volatility, leading to evaporation of volatile organic compounds to the atmosphere. Over the past two decades, ionic liquids (ILs) have gained enormous attention from the scientific community, and the number of reported articles in the literature has grown exponentially. Nevertheless, IL “greenness” is often challenged, mainly due to their poor biodegradability, biocompatibility, and sustainability. An alternative to ILs are deep eutectic solvents (DES). Deep eutectic solvents are defined as a mixture of two or more components, which may be solid or liquid and that at a particular composition present a high melting point depression becoming liquids at room temperature. When the compounds that constitute the DES are primary metabolites, namely, aminoacids, organic acids, sugars, or choline derivatives, the DES are so called natural deep eutectic solvents (NADES). NADES fully represen...
1,439 citations
TL;DR: Deep eutectic solvents (DES) as discussed by the authors have proven to offer tremendous opportunities and have opened new perspectives to produce novel and refined materials, such as polymer, metal deposition and nanomaterial science and sensing technologies.
393 citations