Liquid Solvent Research Articles

Ionic Liquid Boosting the Electrochemical Stability of a Poly(1,3-dioxolane) Gel Electrolyte for High-voltage Solid-State Lithium Batteries.

Poor interfacial contact between solid-state electrolytes and electrodes limits high-voltage performance of solid-state lithium batteries. A new gel electrolyte is proposed via in-situ polymerization, incorporating fluoroethylene carbonate (FEC) solvent and ionic liquid1-butyl-1-methylpiperidinium bis(trifluoromethylsulfonyl)imide (PP14 TFSI). This combination synergistically enhances Li ion transport, achieving a transfer number of 0.58 and improved electrochemical performance. FEC protects the Al current collectors from LiPF6 corrosion and promotes a protective interfacial layer formation. PP14 TFSI improves interfacial contact and provides stable components. An interface layer of fluorine and nitrogen composites forms, preventing side reactions. LiCoO2 ||PPE||Li cell exhibits robust cycling stability at 4.45 V, retaining ~80 % capacity after 200 cycles at room temperature with 0.2 C and 1 C rates, showing increased coulombic efficiency. NCM811||PPE||Li cell also displays exceptional cycling. In-situ polymerization and FEC-ionic liquid coordination enable high-voltage solid-state lithium metal batteries for practical use.

Natural Biomass Soups (NBSs): New Green Solvents Replacing Ionic Liquids and Deep Eutectic Solvents for Lithium-Ion Batteries Recovery

Natural Biomass Soups (NBSs): New Green Solvents Replacing Ionic Liquids and Deep Eutectic Solvents for Lithium-Ion Batteries Recovery

Batteries or silos: Optimizing storage capacity in direct air capture plants to maximize renewable energy use

Direct air capture (DAC) of carbon dioxide is among the technologies that is forecast to play a major role in achieving the global ambition to constrain atmospheric temperature rise to below two degrees Celsius by 2100. However, DAC is an energy intensive chemical process, whose designs are currently incompatible with intermittent renewable energy (RE) sources. This research develops a model to enable the flexible operation of DAC, to maximize RE usage. A new model of the chemical process flow of a liquid solvent DAC that includes silos to store CaCO3 and CaO is developed. A linear programming optimization model that minimizes energy costs while achieving the CO2 capture targets of the DAC plant is developed. Scenario analysis establishes the storage silo size and battery storage size needed to reduce renewable energy curtailment to zero for a given RE profile. Simulations with a representative 336-hour RE profile reveal that two silos of sizes 660 tons and 370 tons would be needed to support flexible DAC plant operations and reduce RE curtailment to zero. For the same profile, a 355 MWh/65 MW battery would be required to achieve zero renewable curtailment. The results demonstrate that flexible operation of DAC is achievable, and DAC plants can adapt to variable RE without the need for battery energy storage. Furthermore, considering the scale of storage needed to minimize RE curtailment in a commercial-scale DAC plant, the results suggest that using physical storage silos could be more cost-effective than using battery energy storage.

Electromigration separation of lithium isotopes: The effect of ionic liquid ratios

This study is based on the system of “anodic aqueous solution | crown ether-ionic liquid organic solution | cathodic aqueous solution”, the influence of ionic liquid ratio in organic solution under different voltages on Li+ transport and lithium isotope separation was investigated. It is found that ionic liquids have multiple roles. In addition to improving the conductivity of organic solutions and enhancing Li+ transport capacity between aqueous solution and organic solution through ion exchange. Ionic liquids are even to realize the migration of lithium ions from aqueous solution to organic solution through solvation. There is an obvious synergistic enhancement between ionic liquid solvation and electric field. Based on this, three types of Li+ transport across the aqueous-organic interface are proposed. The influencing mechanism of ionic liquid ratio, voltage on Li+ migration ratio and lithium isotope separation is discussed in detail.

Effects of operating temperature on Li-O2 battery with ionic liquid-based binary electrolyte

Awaiting a breakthrough, the Li-oxygen battery (LOB) is considered a promising candidate to meet the high energy demands in the future. Among various critical challenges which hamper its development, the mystery of the electrolyte with optimal properties remains unsolved to this day. In this study, we comprehensively investigated the effects of operating temperature (20C, 40 °C and 60 °C) on the electrochemical performance of LOBs incorporated with room temperature ionic liquid (RTIL) and organic solvent binary electrolyte. We designed and investigated 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1im][Tf2N]) RTIL and dimethyl sulfoxide (DMSO) organic solvent at various volume ratios ((4:1), (1:1), (1:4)). Among the binary electrolytes, ([C2C1im][Tf2N]/DMSO (1:4)) delivered the highest discharge capacities of 3.70 Ah g− 1 (20 °C), 4.0 Ah g− 1 (40 °C) and 3.65 Ah g− 1 (60 °C) as compared with pure [C2C1im][Tf2N] and DMSO. Cycling stability tests showed superior stability of the binary electrolyte ([C2C1im][Tf2N]/DMSO (1:4)) irrespective of the operating temperature. From viscosity and ionic conductivity measurements (at 20–60 °C), [C2C1im][Tf2N]/DMSO (1:4) exhibited the highest ionic conductivity and the lowest viscosity compared with other binary electrolytes (even with pure electrolytes) at any given temperature. Cyclic voltammetry (CV) tests revealed the highest reaction rates for [C2C1im][Tf2N]/DMSO (1:4) binary electrolytes than pure electrolytes. The superior performance of [C2C1im][Tf2N]/DMSO (1:4) binary electrolyte was ascribed to enhanced stability against reactive intermediate species during oxygen reduction reaction (ORR), increased ionic conductivity, low viscosity (comparable with organic electrolytes), improved oxygen solubility, and relatively low evaporation rates.

Phase Behavior and Structure of Poloxamer Block Copolymers in Protic and Aprotic Ionic Liquids.

Ionic liquids are promising media for self-assembling block copolymers in applications such as energy storage. A robust design of block copolymer formulations in ionic liquids requires fundamental knowledge of their self-organization at the nanoscale. To this end, here, we focus on modeling two-component systems comprising a Poly(ethylene oxide)-poly (propylene oxide)-Poly(ethylene oxide) (PEO-PPO-PEO) block copolymer (Pluronic P105: EO37PO58EO37) and room temperature ionic liquids (RTILs): protic ethylammonium nitrate (EAN), aprotic ionic liquids (1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), or 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4). Rich structural polymorphism was exhibited, including phases of micellar (sphere) cubic, hexagonal (cylinder), bicontinuous cubic, and lamellar (bilayer) lyotropic liquid crystalline (LLC) ordered structures in addition to solution regions. The characteristic scales of the structural lengths were obtained using small-angle X-ray scattering (SAXS) data analysis. On the basis of phase behavior and structure, the effects of the ionic liquid solvent on block copolymer organization were assessed and contrasted to those of molecular solvents, such as water and formamide.

Towards more predictive correlations for conjugated mass transfer across a droplet interface

Most studies of heat or mass transfer in dispersed, two-phase flows are either analytical or empirical, and therefore limited to simplified or specific operating conditions. In this frame, Direct Numerical Simulations (DNS) can be a powerful tool to address the needs arising from the development of new liquid–liquid solvent extraction processes, involving e.g., more viscous solvents or different hydrodynamic conditions. In this study, a large parametric study, in the range: Reynolds number Re∈[1,500], Péclet number Pee∈[10,1000], viscosity ratio μ∗∈[0.05,20] and a thermodynamic equilibrium coefficient k∈[0.1,10] , of mass transfer from an isolated droplet is achieved by DNS to propose a physically based correlation of the apparent Sherwood number, Sh, that is sufficiently generic to apply to emerging and future applications. The updated correlations derive first from a solid analysis of the features, in terms of concentration fields inside and outside the droplet and interface properties, to challenge the validity of the assumptions of mass transfer correlations. Then, we propose proper modifications in the formulation of existing models. In a second step, the accuracy and the robustness of the new models have been assessed by comparison with Sh obtained from DNS. The proposed correlations are applicable for mass transfer as well as for heat transfer problems, in most configurations encountered in chemical plants.

Deep eutectic solvent liquid phase microextraction, powered by ultrasonic system, for determination of β-carotene in food samples

The research work is mainly concerned with the extraction of β-carotene, which is a terpenoid compound, from food and fruit samples using deep eutectic solvent based liquid phase extraction. Deep eutectic solvent liquid phase microextraction method, powered by ultrasonic mixing, (DES-UP-LPME) was carried out with deep eutectic solvent (DES) consisting of tetrabutylammoniumbromide (TBAB) and decanoic acid (DA). Key parameters such as pH, sample volume, tetrahydrofuran (THF) volume, DES type and volume, matrix effect, ultrasonication/centrifugation time were optimized to increase the extraction efficiency of β-carotene. Quantitative recoveries were obtained when pH, TBAB:DA ratio and sample volume were 3, 1:3 and 30, respectively. The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.005 µg/mL and 0.015 µg/mL, respectively. Various food samples were analyzed spectrophotometrically by using the developed DES-UP-LPME at 450 nm. The addition/recovery studies were also performed on water samples to evaluate the accuracy of the method.

A radiochemistry laboratory exercise: determination of uranium in tap water by solvent extraction and liquid scintillation counting

Environmental radiochemistry is a key pillar of the education of nuclear engineering students and young professionals. Teaching the fundamentals of this multidisciplinary field is best performed also through well-designed hands-on experiments. A simple and fast radiochemical procedure has been developed to determine uranium in tap water by liquid scintillation counting. The proposed method provides reliable and repeatable results, with accuracy and precision within 5%. It can be proficiently executed by undergraduate students, who have appreciated the engagement and got acquainted with standard analysis protocols, from sample collection and manipulation to radiometric measure and data analysis.

Magnetically Recyclable Nanoscale Zero-Valent Iron-Mediated PhotoRDRP in Ionic Liquid toward Smart, Functional Polymers.

A facile method based on recyclable nanoscale zero-valent iron (nZVI)-mediated photoinduced reversible deactivation radical polymerization in ionic liquid (IL) leads to the synthesis of narrow disperse poly(tert-butyl methacrylate) (PTBMA), amphiphilic PTBMA-block-poly(poly(ethylene glycol)methacrylate) diblock copolymer and double hydrophilic poly(methacrylic acid)-block-poly(poly(ethylene glycol)methacrylate) (PMAA-b-PPEGMA) diblock copolymers thereof. Stimuli response of the synthesized PMAA-b-PPEGMA diblock copolymer against variation in pH and temperature is assessed. Recyclability of the nZVI (catalyst) and IL (solvent) is established. Polymerization may be switched ON or OFF, simply by turning the UVA light irradiation ON or OFF, offering temporal control. The diblock copolymer self-aggregates into spherical nanoaggregates which are employed for encapsulation of coumarin 102 (C102, a typical hydrophobic dye), describing their potential application in drug delivery applications. The facile synthesis strategy may open up new avenues for the preparation of intelligent functional polymers for engineering and biomedical applications.

Modelling of Diffusion Process in Vacuum Drying of Propellants

One crucial step in the propellant-making process that takes a lot of time and energy is drying. The study of inert propellants' vacuum drying behaviours – which mimics those of real propellants – is the main focus of this work. This study presents the development of analytical and numerical models for the vacuum drying of inert pro-pellants, which were validated through an in-house vacuum drying experiment. The calculation of effective diffusivity, a crucial parameter characterising the rate of solvent vapour transfer during the vacuum drying of inert propellant samples, is one of the outcomes of this work. It involves removing liquid solvents from the texture of a propellant. Conclusions and suggestions for technical practice are developed based on the studyʼs findings.

Lysozyme aggregation and unfolding in ionic liquid solvents: Insights from small angle X-ray scattering and high throughput screening

Understanding protein behaviour is crucial for developing functional solvent systems. Ionic liquids (ILs) are designer salts with versatile ion combinations, where some suppress unfavourable protein behaviour. This work utilizes small angle X-ray scattering (SAXS) to investigate the size and shape changes of model protein hen egg white lysozyme (HEWL) in 137 IL and salt solutions. Guinier, Kratky, and pair distance distribution analysis were used to evaluate the protein size, shape, and aggregation changes in these solvents. At low IL and salt concentration (1 mol%), HEWL remained monodispersed and globular. Most ILs increased HEWL size compared to buffer, while the nitrate and mesylate anions induced the most significant size increases. IL cation branching, hydroxyl groups, and longer alkyl chains counteracted this size increase. Common salts exhibited specific ion effects, while the IL effect varied with concentration due to complex ion-pairing. Protein aggregation and unfolding occurred at 10 mol% IL, altering the protein shape, especially for ILs with multiple alkyl chains on the cation, or with a mesylate/nitrate anion. This study highlights the usefulness of adopting a high-throughput SAXS strategy for understanding IL effects on protein behaviour and provides insights on controlling protein aggregation and unfolding with ILs.

Study of [Bmim]Cl/LiCl Co-Solvent Dissolution of Waste Wool

Waste wool was subjected to dissolution using an ionic liquid solvent, 1-butyl-3-methylimidazole chloride salt ([Bmim]Cl), with lithium chloride (LiCl) as an additive. This study’s objective was to examine the impact of LiCl on keratin’s solubility in [Bmim]Cl and characterise the structure and properties of keratin post-dissolution and regeneration. The results indicated that LiCl exhibits efficient solubility in [Bmim]Cl, enhancing keratin dissolution. Investigations employing Infrared, XRD and small-angle X-scattering spectroscopy, along with SDS-PAGE, demonstrated a degradation of the α-helical keratin structure during the dissolution process. This was accompanied by a reduction in molecular weight; however, keratin retained its protein nature. Atomic force microscopy (AFM) results revealed that keratin could proliferate on the slide surface or establish a continuous film. An integrative analysis suggested that wool protein macromolecules could be deconstructed by [Bmim]Cl and LiCl actions, inducing minor structural alterations in wool. This study proposes a groundwork for future research into keratin’s adsorption behaviour on textile materials, without significantly modifying the wool keratin structure or function.

Superlong supercooling solvents (SSSs): Alternative green solvents to ionic liquids and deep eutectic solvents for lithium-ion batteries recycling

Water, supercritical fluids, ionic liquids and deep eutectic solvents (DESs) have been considered as green solvents for many years. The demand of green and sustainable development requires the search of novel green solvents. Some of the reported DESs might be not be the real DESs because we observe that these so-called reported liquid DESs become solid after exposure to the room temperature for many hours or days. Here, we for the first time propose a new concept of green solvents, superlong supercooling solvents (SSSs), as the green alternatives to water, supercritical fluids, ionic liquids and DESs. SSSs are the metastable liquid solvents either single component or multiple components due to the superlong supercooling effect at the temperature around or a little higher than room temperature. SSSs should condense after a superlong time; however, SSSs could be used as the green solvents before the condensation due to the superlong supercooling. Typical application example of SSSs is that SSSs could leach nearly 100% valuable metals from lithium-ion batteries cathode at low temperature, which is much higher than that by reported DESs and ILs at the same conditions. The new concept of SSSs would be very helpful for expanding the area of green solvents and green chemistry for building a greener world.

Determination of remdesivir in human plasma using (deep eutectic solvent-ionic liquid) ferrofluid microextraction combined with liquid chromatography

A microextraction technique based on ferrofluids was developed for the preconcentration and quantification of Remdesivir in human plasma samples. This method utilized a new type of magnetic colloids created by combining silica-coated magnetic particles with modified ionic liquid and natural hydrophobic deep eutectic solvent as the carrier liquid. The efficiency of the sorption and desorption steps was optimized using a chemometrics approach. Under the optimized conditions, the calibration curve exhibited linearity in the concentration range of 0.5 to 500.0 μg L−1, with a limit of detection and quantification of 0.2 and 0.5 μg L−1, respectively. The method precision was evaluated by assessing intra- and interday precision at three different analyte concentrations, yielding values of 8.9% and 16.8%, respectively. Moreover, the method accuracy fell within the range of 90.9% to 107.5%. This proposed method offers a green and environmentally friendly sample preparation technique for conducting pharmacodynamic, pharmacokinetic, and therapeutic drug monitoring studies of Remdesivir in biological fluids. Importantly, this technique eliminates the need for external energy sources or the use of dispersive solvents, providing a more efficient and sustainable approach.

Comparative analysis of isopropyl alcohol dehydration using ionic liquids and deep eutectic solvent

The current article deals with the separation of the azeotropic mixture of isopropyl alcohol (IPA) and water using an ionic liquid, 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) and Deep Eutectic Solvents (DESs), Choline Chloride/glycerol (Glyceline) and Choline Chloride/Ethylene Glycol (Ethaline). Conventional dimethyl sulfoxide (DMSO) solvents are used to compare the results for IPA dehydration. Process modelling and simulation were carried out in the Aspen Plus simulator (v.8.6). The NRTL model was used to calculate the thermodynamic properties as well as the vapour-liquid equilibria of the ternary systems. The process parameters such as entrainer flow rate, binary feed stage, entrainer feed stage, column stages, reflux ratio, reboiler and condenser duties were evaluated using sensitivity analysis and design spec tools of the simulator. The industrial process for both systems, containing a separation column and a recovery column, was simulated at a steady state. Both processes were optimised using the optimisation tool of the simulator and compared based on the energy requirement. Further, based on the simulation results, we proposed an alternate process design for solvent recovery using a flash drum. The results show that more than 99.9 mol% IPA purity can be achieved using both ILs as well as DESs. The overall energy requirement for the separation of IPA-water mixture using [EMIM][BF4] entrainer in a conventional process was found to be lower than DMSO. The proposed alternate process further reduces the energy requirement compared to the conventional process for both IL and DESs systems.

Predicting Gaseous Solute Diffusion in Viscous Multivalent Ionic Liquid Solvents.

Calculating solute diffusion in dense, viscous solvents can be particularly challenging in molecular dynamics simulations due to the long time scales involved. Here, a new scaling approach is developed for predicting solute diffusion based on analyses of CO2 and SO2 diffusion in two different multivalent ionic liquid solvents. Various scaling approaches are initially evaluated, including single and separate thermostats for the solute and solvent, as well as the application of the Arrhenius relationship and the Speedy-Angell power law. A very strong logarithmic correlation is established between the solvent-accessible surface area and solute diffusion. This relationship, reflecting Danckwerts' surface renewal theory and the Vrentas-Duda free volume model, presents a valuable method for estimating diffusion behavior from short simulation trajectories at elevated temperatures. The approach may be beneficial for enhancing predictive modeling in similar challenging systems and should be more broadly evaluated.

Nucleoside Analogs: A Review of Its Source and Separation Processes.

Nucleoside analogs play a crucial role in the production of high-value antitumor and antimicrobial drugs. Currently, nucleoside analogs are mainly obtained through nucleic acid degradation, chemical synthesis, and biotransformation. However, these methods face several challenges, such as low concentration of the main product, the presence of complex matrices, and the generation of numerous by-products that significantly limit the development of new drugs and their pharmacological studies. Therefore, this work aims to summarize the universal separation methods of nucleoside analogs, including crystallization, high-performance liquid chromatography (HPLC), column chromatography, solvent extraction, and adsorption. The review also explores the application of molecular imprinting techniques (MITs) in enhancing the identification of the separation process. It compares existing studies reported on adsorbents of molecularly imprinted polymers (MIPs) for the separation of nucleoside analogs. The development of new methods for selective separation and purification of nucleosides is vital to improving the efficiency and quality of nucleoside production. It enables us to obtain nucleoside products that are essential for the development of antitumor and antiviral drugs. Additionally, these methods possess immense potential in the prevention and control of serious diseases, offering significant economic, social, and scientific benefits to the fields of environment, biomedical research, and clinical therapeutics.

Combined density functional theory and molecular dynamics analyses on Lithium/Sodium ion interaction and diffusion in gel polymer electrolytes with poly-vinylidene fluoride scaffold, propylene carbonate/Ionic Liquid solvent, and perchlorate salt

Choice of a proper electrolyte is very crucial to enhance the overall performance of a metal-ion battery. In this work, dispersion corrected density functional theory and classical molecular dynamics simulations are carried out to explore the metal ion (Li+ and Na+) interaction and diffusion through polyvinylidene fluoride (PVDF)-based gel polymer electrolytes. Four types of polymer/solvent/salt electrolyte systems are investigated considering PVDF scaffold for each case, and conventionally used propylene carbonate and rarely used, albeit cheaper, ionic liquid [BMIM][ClO4] as solvent, along with metal perchlorate salts LiClO4 and NaClO4. Inter-unit interactions within the electrolyte clusters, electrolyte uptake, and electrochemical stability of the electrolytes are explained by gas-phase DFT analyses, considering the polymer/solvent/salt components in 1:1:1 molecular ratio. Diffusion of the ions and ionic conductivity of the electrolytes are explored by MD simulation referring to two different size and time scales. From the DFT-based non-bonding interaction analyses, metal ions are found to exhibit strong non-covalent interactions with the adjacent O and F atoms, where the O atoms are parts of PC and [ClO4]- ions, and F atoms are from the PVDF chains. [BMIM]+, [ClO4]-, and PVDF are found to interact through weak van der Waals type hydrogen bonds. Both DFT and MD calculations suggest that, Li+ and Na+ ions are primarily coordinated with [ClO4]- ions. Dynamics studies confirm that for PVDF/IL/salt, total ionic conductivity is predominated by [BMIM]+ and [ClO4]-, exhibiting lower metal ion diffusivity as compared to PC-containing electrolytes. For both Li- and Na-ion systems, owing to the availability of higher number of charge carriers, electrolytes containing ILs show higher ionic conductivity compared to those containing PC as the solvent.

Solid-phase Spectrophotometric Determination of Synthetic Food Colourants in Confectionery Products

Abstract: We suggest a simple method of solid-phase spectrophotometric determination of the following synthetic food colourants: quinoline yellow Е104, sunset yellow FCF Е110, Ponceau 4R Е124, patent blue V Е131, brilliant blue FCF Е133. Methods: The method implies the use of a polymethacrylate matrix for solid-phase extraction of these colourants from confectionery products. Results: While the contact time for the matrix and the colourant solution was 15 minutes, the detection limits were 1.7; 1.6; 5.8; 2.9; 2.9 mg·L–1 for colourants E104, E110, E124, E131, E133, correspondingly. The standard deviation of the results by determination of synthetic food colourants in confectionery products did not exceed 13 %. Conclusion: Compared to spectrophotometric determination involving liquid solvent extraction, the method of determination of synthetic colourants we developed offers the following advantages: sufficient increase of determination sensitivity, which results from accumulation of the analyte and elimination of the possible aliquote turbidity as well as zero colourant loss by absorption into supernatant liquid and the solid phase of the matrix.