Organic Ionic Liquids Research Articles

Designing dicationic organic salts and ionic liquids exhibiting high fluorescence in the solid state

Dicationic ionic liquids (DILs) are emerging as a powerful, next-generation approach to designing applied ILs because of their superior physicochemical properties as well as their diverse complexity and tunability for task specific applications. DILs are scarce in the literature compared to monocationic ILs (MILs), and one of their main issues is their expected tendency to possess higher melting temperatures. A series of 1,4-bis[2-(4-pyridyl)ethenyl]benzene and 1,4-bis[2-(2-pyridyl)ethenyl]benzene quaternary salts (Q-BPEBs) with different counterions (bromide, tosylate, and triflimide) and carbon chain lengths (C6, C9, and C12) have been synthesized for their potential as DILs with thermal properties and strong photoluminescent properties in the solid state. All Q-BPEB salts demonstrated robust thermal stabilities as determined by thermogravimetric analysis (TGA). The differential scanning calorimetry (DSC) thermograms for Q-BPEB tosylates and triflimides displayed crystalline polymorphisms before melting transitions as verified by polarizing optical microscopy (POM). The Q-BPEB bromide and tosylate salts all showed high melting points of above >170 °C because of their dicationic rigid structures and strong ionic interactions of their anions. Once the Q-BPEB tosylates were exchanged with triflimide ions, para- isomers 1aTf2N-1cTf2N still possessed very high melting points (>225 °C), however, the ortho- isomers 2aTf2N, 2bTf2N, and 2cTf2N exhibited melting points lower than 100 °C, classifying them as DILs. Their photoluminescent properties were also studied in methanol with the emission values of λem = 476-482 nm for the para- isomers and those of λem = 448-453 nm for the ortho- isomers. In the solid state, the Q-BPEB salts exhibited strong fluorescence with quantum yields of up to 50%. The relatively simple synthesis of these fluorescent dicationic organic salts and ILs are pertinent towards the scarcity of these materials in the literature and provide a deeper insight on the design of fluorescent ILs containing more than one charge center.

Material Aspects of Thin-Film Composite Membranes for CO2/N2 Separation: Metal–Organic Frameworks vs. Graphene Oxides vs. Ionic Liquids

Thin-film composite (TFC) membranes containing various fillers and additives present an effective alternative to conventional dense polymer membranes, which often suffer from low permeance (flux) and the permeability–selectivity tradeoff. Alongside the development and utilization of numerous new polymers over the past few decades, diverse additives such as metal–organic frameworks (MOFs), graphene oxides (GOs), and ionic liquids (ILs) have been integrated into the polymer matrix to enhance performance. However, achieving desirable interfacial compatibility between these additives and the host polymer matrix, particularly in TFC structures, remains a significant challenge. This review discusses recent advancements in TFC membranes for CO2/N2 separation, focusing on material structure, polymer–additive interaction, interface and separation properties. Specifically, we examine membranes operating under dry conditions to clearly assess the impact of additives on membrane properties and performance. Additionally, we provide a perspective on future research directions for designing high-performance membrane materials.

An Organic Acid-Alkali Coregulated Ionic Liquid Electrolyte Enabling Wide-Temperature-Range Proton Battery.

The broad applications of rechargeable batteries urge people to develop alternative energy storage devices with sustainable resources, high capacity, long cycling life, and wide-temperature operability. Aqueous proton batteries are considered as a state-of-the-art energy storage system due to their intrinsic safety and low cost. However, aqueous electrolytes have a low boiling point and narrow electrochemical stability window, limiting their applications in wide-temperature and high-energy batteries. Herein, a hybrid organic ionic liquid electrolyte with organic alkali 1-methyl-1,2,4-triazole (MTA) protonated by organic acid bis(trifluoromethysulfonyl)imide (HTFSI) as proton carriers and tetramethylene sulfone (TMS) as the solvent, noted as HTFSI-MTA-TMS, exhibited the stable electrochemical windows exceeding 5V at -20°C and 3.5V at 80°C. Benefiting from this electrolyte, the assembled MnO2-S//MoO3 button proton full battery can display an operation voltage up to 1.8V, energy density of 44.8Wh kg-1, and good cycling stability at room temperature when bis(trifluoromethanesulfonyl)imide manganese (II) salt (Mn(TFSI)2) is introduced into the electrolyte, and run well in a wide-temperature range (-20°C-60°C). The work reveals the potential of organic acid-alkali coregulated electrolytes to meet the need of energy storage in a wide-temperature range and will advance the development of high-energy proton batteries.

Synthesis, Characterization, Bioavailability and Antimicrobial Studies of Cefuroxime-Based Organic Salts and Ionic Liquids

Low oral bioavailability is a common feature in most drugs, including antibiotics, due to low solubility in physiological media and inadequate cell permeability, which may limit their efficacy or restrict their administration in a clinical setting. Cefuroxime is usually administered in its prodrug form, cefuroxime axetil. However, its preparation requires further reaction steps and additional metabolic pathways to be converted into its active form. The combination of Active Pharmaceutical Ingredients (APIs) with biocompatible organic molecules as salts is a viable and documented method to improve the solubility and permeability of a drug. Herein, the preparations of five organic salts of cefuroxime as an anion with enhanced physicochemical characteristics have been reported. These were prepared via buffer-assisted neutralization methodology with pyridinium and imidazolium cations in quantitative yields and presented as solids at room temperature. Cell viability studies on 3T3 cells showed that only the cefuroxime salts combined with longer alkyl chain cations possess higher cytotoxicity than the original drug, and while most salts lost in vitro antibacterial activity against E. coli, P. aeruginosa and B. subtilis, one compound, [PyC10Py][CFX]2, retained the activity. Cefuroxime organic salts have a water solubility 8-to-200-times greater than the original drug at 37 °C. The most soluble compounds have a very low octanol-water partition, similar to cefuroxime, while more lipophilic salts partition predominantly to the organic phase.

Application of ionic liquids as co-solvent for oil extraction from desert date

The extraction of oil from Balanites seed (desert date) using ultrasound-assisted extraction was investigated using organic solvent (ethyl acetate) and ionic liquid as co-solvent. The study found that an optimum oil yield of 28.67 % was obtained using a seed to solvent ratio of 1:6, an extraction temperature of 50 °C and an extraction time of 30 min when ethyl acetate was used as the sole solvent in the extraction system. Different types of ionic liquids as co-solvents were screened in this study and an improvement of oil yield (3–6 %) was observed using 1-butyl-3-methylimidazolium acetate. Additionally, the presence of ionic liquid as a co-solvent during the extraction process could achieve a similar oil yield at a lower extraction temperature. This indicates the potential breakdown of the lignocellulosic cell wall of the seed using 1-butyl-3-methylimidazolium acetate. The presence of 1-butyl-3-methylimidazolium acetate as co-solvent can enhance the penetration of the organic solvent into the Balanites seed matrix for oil extraction and can reduce the energy required for the extraction process.

Synergic Effects of Ordered Mesoporous Bifunctional Ionic Liquid: A Recyclable Catalyst to Access Chemoselective N-Protected Indoline-2,3-dione Analogous

SBA-15 and organic ionic liquid were incorporated in a post-grafting technique for generating a bifunctional ionic liquid embedded mesoporous SBA-15. The prepared heterogeneous catalyst was employed for the first time to synthesize N-alkylated indoline-2,3-dione at mild conditions to afford excellent yields in a short reaction time. The synthesized DABCOIL@SBA-15 catalyst was meticulously characterized by various techniques, such as FT-IR, solid-state 13C NMR, solid-state 29Si NMR, small-angle X-ray diffraction (XRD), and N2 adsorption–desorption. Further, the morphological behavior of the catalyst was studied by SEM and TEM. The thermal stability and number of active sites were determined by thermogravimetric analysis (TGA). The Hammett equation was used to analyze the synergetic effect of the catalyst and substituent effects on the N-alkylated products of 5-substituted isatin derivatives, which resulted in a negative slope. This negative slope indicates a positive charge in the transition state. Notably, the DABCOIL@SBA-15 catalyst demonstrated its practicality by being reused for seven cycles with consistently high catalytic activity.

Study on the efficient electrocatalytic depolymerization of α-O-4 bond in lignin assisted by simple electrolyte

Lignin is anticipated to serve as a replacement for dwindling fossil fuel resources owing to its abundant sources and renewable nature. The electrochemical oxidation technique for depolymerizing lignin has garnered significant interest for its environmentally friendly and mild operating conditions. Nevertheless, the current utilization of auxiliary electrolytes, predominantly organic bases, ionic liquids, and other specialized substances, poses a constraint on the widespread adoption of this approach. Furthermore, there is a scarcity of instances where electrochemical technology has been employed to depolymerize the α-O-4 bond in lignin for the production of highly selective acetals. In this study, a sodium chloride/methanol (NaCl/MeOH) system was utilized for the direct depolymerization of the α-O-4 bond in a lignin model molecule, specifically benzyl phenyl ether (BPE). The optimal conditions resulted in a 95.2 % conversion rate of the BPE substrate and a high yield of 94.5 % for the main product, benzaldehyde dimethyl acetal(Bda). This research offers a promising approach for the electrocatalytic depolymerization of α-O-4 bonds in lignin, leading to the selective production of acetal chemicals using a common auxiliary electrolyte at room temperature in just 2 h.

Reactive extraction of muconic acid by hydrophobic phosphonium ionic liquids - Experimental, modelling and optimisation with Artificial Neural Networks

Muconic acid is a six-carbon dicarboxylic acid with conjugated double bonds that finds extensive use in the food (additive), chemical (production of adipic acid, monomer for functional resins and bio-plastics), and pharmaceutical sectors. The biosynthesis of muconic acid has been the subject of recent industrial and scientific attention. However, because of its low concentration in aqueous solutions and high purity requirement, downstream separation presents a significant problem. Artificial Neural Networks and Differential Evolution were used to optimize process parameters for the recovery of muconic acid from aqueous streams in a system with n-heptane as an organic diluent and ionic liquids as extractants. The system using 120 g/L tri-hexyl-tetra-decyl-phosphonium decanoate dissolved in n-heptane, pH of the aqueous phase 3, 20 min contact time, and 45 °C temperature assured a muconic acid extraction efficiency of 99,24 %. Low stripping efficiency compared to extraction efficiency was observed for the optimum conditions on the extraction step (120 g/L ionic liquids dissolved in heptane). However, re-extraction efficiencies obtained for the recycled organic phase in three consecutive stages were close to the first extraction stage. The mechanism analysis proved that the analysed phosphonium ionic liquids (PILSs) extracts only undissociated molecules of muconic acid through H-bonding.

Acid-base neutralization strategy for immobilization amino acid ionic liquid within sulfonic acid-based COF as a switch for selective conversion of epoxides

Covalent organic frameworks (COFs) and ionic liquids (ILs) as raw materials exhibit effective catalytic performance and adsorption capabilities in the reaction of epoxides and atmospheric CO2, respectively. Nonetheless, bonding modes between ILs and COFs have restricted their utility, thereby constraining the in-depth study of synergistic catalytic mechanisms over these composite catalysts. Herein, a heterogeneous composite ([DBUH]2Cys@COF-X) were successfully prepared by the facile acid-base neutralization method, incorporating varying amounts of amino acid ILs ([DBUH]2Cys) into the pore channels of sulfonic acid-based COF (TpPa-SO3H). [DBUH]2Cys@COF-3 efficiently catalyzed epichlorohydrin with a yield of 96.38 % without any solvent or co-catalyst under atmospheric CO2. Notably, larger sterically hindered epoxides were selectively blocked on the surface of [DBUH]2Cys@COF-3, enabling [DBUH]2Cys@COF-3 to act as a gatekeeper for selectively catalyzing small sterically hindered epoxides due to [DBUH]2Cys was distributed within the pore channels of [DBUH]2Cys@COF-3. Through DFT calculations, comprehensive understanding of the synergistic activation conferred of -COO- and [DBUH]+ towards CO2 and epoxides in [DBUH]2Cys@COF-3 and the ring-opening mechanism was clarified. This work presents a fresh outlook on the catalyst design by the facile acid-base neutralization method for efficiently catalyzing small-hindered epoxides under atmospheric CO2.

Efficacy of tethered Pyridinium-Based ionic liquid immobilized on Zn-MOF-NH2 for effectively converting CO2 into cyclic carbonates under Co-Catalyst-free and solvent-free conditions

A new bifunctional heterogeneous catalyst system was developed by immobilization of pyridinium-based ionic liquid on Zn-MOF-NH2 to produce an IL-supported Zn-MOF-NH2 catalyst. The dual-functional one-component system, including both Lewis acid sites and IL functional sites, showed high catalytic activity for the CO2-epoxide cycloaddition reactions under mild solvent-free conditions. Different techniques such as FE-SEM, EDX, FT-IR, XRD, and BET were applied to characterize of the as-prepared catalyst. This efficient low-leaching catalyst system is separated by centrifugation and can be reused successfully for four successive cycles without altering the catalytic activity in CO2 epoxidation to cyclic carbonates. Due to the wide variety seen in both metal–organic frameworks (MOFs) and ionic liquids (ILs), we believe that this research represents a significant step forward in the potential applications of synthetic modification methods within MOFs.

Task-specific design of protic metal-based deep eutectic solvents for efficient separation of HCl/SO2

Efficient separation and recovery of hydrogen chloride (HCl) from HCl tail gas containing impurities such as sulfur dioxide (SO2) is very important from the viewpoint of economy and environment. However, due to the similar dissolution ability of SO2 and HCl, most solvents, including organic solvents, ionic liquids and deep eutectic solvents (DESs), show low SO2/HCl selectivity near 1.0 and are thus incompetent to separate SO2/HCl. To address this, we firstly reported the task-specific design of a novel class of protic metal-based DESs (PM-DESs) containing hydrochloride, metal chloride and sulfolane, which have good SO2 affinity but much inhibited HCl uptake, for the separation of HCl/SO2. The solubility data of SO2 and HCl in PM-DESs were determined and correlated by Krichevsky-Пiinskaya (K-I) equation. Among these PM-DESs, N,N-dimethylaniline hydrochloride (DMA·HCl) + zinc chloride (ZnCl2) + sulfolane exhibits satisfactory recyclability and selectivity up to 2.669 (100 kPa, 313.2 K), which is the highest value reported so far. Absorption of HCl/SO2 (50/50) mixed gas was also tested, with a high SO2/HCl selectivity of 3.250 obtained. In addition, the NMR and FTIR spectroscopic characterizations paired with quantum chemistry calculation were utilized to investigate the absorption mechanism from the perspective of atomic level. The DESs developed in the present work have the potential to separate and recycle HCl from SO2 owing to their good selectivity and desirable reversibility, and the strategy proposed in this work may offer new guidance for designing green media for HCl recovery.

Mechanistic Analysis and Process Simulation of Ethyl Acetate-Ethanol Separation by Complex Solvent Extractive Distillation.

Developing high-performance solvents for extraction and optimizing process technologies is crucial for efficient extractive distillation (ED) separation of azeotrope mixtures. In this paper, computer-aided screening was used to study the ED of azeotrope mixtures in ethyl acetate and ethanol systems using organic solvent dimethyl sulfoxide (DMSO) and ionic liquid (IL) ([EMIM][Ac]). The structural relationship between the ILs and the azeotrope mixture was analyzed by σ-profile, molecular surface electrostatic potential, interaction energy, and separation gradient. Subsequently, process simulation was carried out using Aspen Plus software and global optimization was performed with genetic algorithm, which found that both traditional organic solvents and ILs have good separation effects. But considering the high volatility of organic solvents and low saturation vapor pressure of ILs, it is considered to combine them to further explore the cost and carbon emission advantages in extractive distillation separation. Compared with pure organic solvent and pure ILs separation processes, the TAC of the process using an IL-based mixed solvent process decreased by 5.11 and 21.98%, respectively. The carbon emissions of the mixed extractant process were slightly higher than those of the pure organic solvent process, but the addition of ILs made very little volatilization of organic solvents, saving a charge for extractant use. By improving the process, waste heat is effectively recovered, which can save most of the utility engineering costs, and compared with the previous process, the total alkali consumption and carbon dioxide emissions are reduced by 9.43 and 27.17%, respectively. This exploration provides a theoretical reference for the development application and industrial research of ED processes using IL-based mixed solvents.

Recent Advances in Low‐Temperature Liquid Electrolyte for Supercapacitors

As one of the key components of supercapacitors, electrolyte is intensively investigated to promote the fast development of the energy supply system under extremely cold conditions. However, high freezing point and sluggish ion transport kinetics for routine electrolytes hinder the application of supercapacitors at low temperatures. Resultantly, the liquid electrolyte should be oriented to reduce the freezing point, accompanied by other superior characteristics, such as large ionic conductivity, low viscosity and outstanding chemical stability. In this review, the intrinsically physical parameters and microscopic structure of low-temperature electrolytes are discussed thoroughly, then the previously reported strategies that are used to address the associated issues are summarized subsequently from the aspects of aqueous and non-aqueous electrolytes (organic electrolyte and ionic liquid electrolyte). In addition, some advanced spectroscopy techniques and theoretical simulation to better decouple the solvation structure of electrolytes and reveal the link between the key physical parameters and microscopic structure are briefly presented. Finally, the further improvement direction is put forward to provide a reference and guidance for the follow-up research.

Hydrogen Bonds in Perovskite for Efficient and Stable Photovoltaic†

Comprehensive SummaryOwing to their distinctive optical and physical properties, organic‐inorganic hybrid perovskite materials have gained significant attention in the field of electronic devices, especially solar cells. The achievement of high‐performance solar cells hinges upon the utilization of top‐notch perovskite thin films. Nevertheless, the fabrication process involving solutions and the polycrystalline nature of perovskite result in the emergence of numerous defects within the perovskite films, consequently exerting a deleterious influence on the overall performance and stability of the devices. Improving the performance and stability of perovskite solar cells by additive engineering to suppress/passivate defects is a viable approach, which involves hydrogen bond interactions in these device engineering processes. This review explores the intrinsic hydrogen bonds in methylammonium and formamidium lead triiodide, while also considering cation rotations, phase transitions, and stability. Moreover, the review classifies additives into distinct categories, including organic small molecules, polymers, nanodots, classical salts, ionic liquids, and molten salts. The various forms and characterization techniques of hydrogen bonds are discussed, as well as their potential synergistic effects in conjunction with other chemical interactions. Furthermore, this review offers insights into the potential utilization of hydrogen bonds to further enhance the performance and stability of devices. Key ScientistsIn 2009, Tsutomu Miyasaka et al. prepared the first perovskite solar cell, which kicked off the research on perovskite light‐absorbing materials. However, the use of liquid electrolytes led to device instability. The transition to all‐solid‐state perovskite solar cells was realized by Nam‐Gyu Park's team in 2012, which was the beginning of high‐efficiency perovskite solar cells. Subsequently, a number of scientists have innovated the preparation ground process. Methods such as two‐step deposition by Michael Grätzel in 2013 and anti‐solvent extraction by Sang II Seok's team in 2014 were instrumental in advancing the development of perovskite. Liyuan Han's team then increased the cell's working area to 1 cm2 without compromising performance, making it possible to compare the performance metrics of perovskite solar cells with those of other types of solar cells on the same scale. Recently, You's team and Pan's team kept updating the world record by obtaining certified efficiencies of 25.6% and 25.8% in 2022 and 2023, respectively.

Enzymatic synthesis of tyrosol esters in organic solvents and ionic liquids: Correlation between enzyme activity and solvent properties

Tyrosol is a principle phenolic compound present in olive oil and wine with great pharmacological potentials due to its strong antioxidant property. Its application can be highly extended by increasing its lipophilicity through esterification. In this study, tyrosol esters were synthesized by enzymatic transesterification of tyrosol with vinyl esters, with a commercial lipase from Novozymes (Novozym 435, Candida antarctica lipase B (CALB) immobilized on macroporous acrylic resin beads) as the catalyst, both in organic solvents and in ionic liquids. Methyl tert-butyl ether (MTBE) was the best solvent, offering complete conversions towards the synthesis of tyrosol esters with varying chain lengths (C2-C18) within 1 h. Taking the enzymatic transesterification between tyrosol and vinyl acetate as the model reaction, 18 organic solvents and 24 ionic liquids were screened, and their solvent properties (i.e. hydrophobicity, polarity, viscosity, water activity, and partition coefficients of substrate and product) were correlated to the enzyme activity. Upon enzyme screening, four new lipases were found to be highly efficient, relative to the best-performed Novozym 435 and Lipozyme TLIM (Thermomyces lanuginosus lipase (TLL) immobilized on silica gel), in tyrosol ester synthesis. This work provides enzymatic methods of esterifying tyrosol that are much more efficient than those reported in literature, and will shed light on re-consideration of the roles of solvents in nonaqueous enzymology.

Organic Ionic Liquid Grafted Nano‐CeO2: A Highly Efficient Photocatalyst for Hydroxylation of Benzene and Reduction of Cr (VI)

AbstractAn ionic liquid, namely imidazolium sulfonic acid chloride (ISAC) has been electrostatically grafted over cerium oxide nanoparticles to produce a nanocomposite, nano‐CeO2‐IL. The as‐prepared composite was characterized by various analytical techniques such as XRD, FT‐IR, SEM, TEM, XPS, BET, UV‐DRS, PL, and TGA to confirm the grafting of ISAC over CeO2 NPs. The photocatalytic process is regarded as the method of choice for the elimination of air pollutants because of its great efficiency and relatively benign working conditions. According to UV‐DRS spectra, its optical gap is 2.07 eV, which is appropriate for the visible light spectrum. The composite was investigated as a visible‐light‐driven photocatalyst for hydroxylation of benzene to phenol and heavy metal Cr (VI) reduction. Moreover, the scavenger experiments confirmed the detection of ⋅OH radicals which played a crucial role in the photocatalytic experiments. Within 60 minutes, 98.5 % of benzene was converted to phenol with 82.7 % selectivity in addition to 93.63 % Cr (VI) reduction within 30 mins. The photocatalytic reduction of Cr(VI) to Cr(III) follows a first‐order model with a rate constant of 0.027 min−1. The remarkably high photocatalytic performance of the catalyst may be ascribed to the synergistic interaction between the nano‐CeO2 catalyst and ionic liquid.

Zwitterionic liquid-based gel electrolyte for high performance lithium metal battery at low temperatures

Gel electrolyte (GE) gains intensive attentions for lithium metal battery, especially those targeting to use at low temperatures. The liquid medium, as the core component, of most gel electrolytes (GEs) is organic liquid or ionic liquid, always suffering from serious safety issue and low transference number (t+). The low t + aggravates concentration polarization and thus leads to the increase of overpotential and undesirable side reactions. Herein, zwitterionic liquid (ZIL) with high stability and safety is prepared by mixing zwitterion (ZI) and lithium salt. The ZIL is then encapsulated into a SiO2 matrix to fabricate novel gel electrolyte (SiGE-ZIL). The low freezing point and strong mobility of ZIL confer SiGE-ZIL a high conductivity of 3.36 × 10−4 S cm−1 at −40 °C. Importantly, the large dipole moment of ZI effectively accelerates the dissociation of lithium salt, permitting a high t+ of 0.553 at −40 °C, which is 2.3 times of that of the analogous ionic liquid. The assembled LiFePO4/Li battery exhibits an excellent cycling stability with a capacity of 91.6 mAh g−1 at 600th cycle at 0.5C and 0 °C. Especially at −20 °C, the capacity can reach 67.1 mAh g−1 at 600th cycle under 0.5C, surpassing most of GE-based batteries.

Environmental Sustainability of π-Electron Donor-Based Deep Eutectic Solvents for Toluene Absorption: A Life-Cycle Perspective.

The novel π-electron donor-based deep eutectic solvents (DESs) have been shown to be a promising type of absorbent with excellent performance on toluene absorption. However, their greenness or sustainability is still unclear. Thus, to bridge the gap and give a comprehensive evaluation for their industrialization potential, the life cycle assessment (LCA) was used to evaluate the potential environmental impacts incurred from their production and usage for absorbing toluene. The environmental profiles are also compared with that of popular choline chloride (ChCl) based DES, common organic solvent triethylene glycol (TEG) and ionic liquid ([EMIM][Tf2 N]). The results indicate that among the involved hydrogen bond acceptors (HBAs), TEBAC generally imparts lower environmental impacts than other HBAs but has higher impacts than ChCl. Although TEBAC-PhOH is not the most environmentally friendly absorbent during the production stage, its outstanding absorption performance minimizes the environmental impact when absorbing the same mass of toluene. Furthermore, the environmental impacts of the toluene absorption process using TEBAC-PhOH is significantly lower than that of [EMIM][Tf2 N], slightly lower than TEG. Therefore, considering both absorption performance and environmental impacts, TEBAC-PhOH can be used as a promising "green and sustainable" toluene absorbent to traditional absorbents and ionic liquids.

Water-induced changes in choline chloride-carboxylic acid deep eutectic solvents properties

Deep eutectic solvents (DES) have become a promising alternative to molecular organic solvents and ionic liquids in a variety of scientific applications. Their customizable physicochemical properties make them attractive for extraction, catalysis, electrochemistry and drug delivery. Recently, the study of not so much DES themselves, as their mixtures with water, has attracted particular interest. In this study, six widely used DESs based on choline chloride and carboxylic acids (citric, tartaric, malic, glycolic, malonic and lactic) with a water content of 0–50 wt% were analyzed. Properties such as density, viscosity, conductivity and spectral properties of DES (IR spectroscopy and refractive index) were studied. The results show that in the entire range of water content under study, there are no abrupt changes in properties for all the studied parameters, which allows us to conclude that water is gradually incorporated into the DES structure without its destruction. However, within this class of eutectic solvents, subclasses can be distinguished, due to various changes in the studied properties. These results provide important information for optimizing the performance of DES in practical applications and highlight their potential as sustainable green solvents in modern science and technology.

An Ongoing Futuristic Career of Metal–Organic Frameworks and Ionic Liquids, A Magical Gateway to Capture CO2; A Critical Review

An Ongoing Futuristic Career of Metal–Organic Frameworks and Ionic Liquids, A Magical Gateway to Capture CO₂; A Critical Review