Ionic Liquid Research Articles

Constructing promising amino acid hydrogel functionalized silica for mixed-mode chromatographic separation through crosslinking agent modification.

The paramagnetic ionic liquids 1-ethyl-3-methylimidazolium tetrachloroferrate ([Emim][FeCl4]) and 1-butyl-3-methylimidazolium tetrachloroferrate ([Bmim][FeCl4]), exhibiting Heisenberg spin exchange, were studied using Electron Paramagnetic Resonance (EPR) from 150 to 300K. In [Emim][FeCl4], an exchange-narrowed EPR Lorentzian line was observed in the liquid phase and in the solid phase between the solid-solid and melting/crystallization temperatures. In comparison, below the solid-solid transition, an additional EPR line appeared, resulting in two exchange-narrowed EPR Lorentzian lines. The two EPR lines likely originate from the two polymorphic forms of [Emim][FeCl4], whose crystal structures have been presented in the literature. We calculated the EPR linewidth for both lines resulting from the Heisenberg spin exchange using the observed EPR linewidths and the distances between the nearest-neighbor Fe3+ ions, following the Anderson-Weiss theory. The value of the exchange integral estimated from the additional broader EPR line, named the "low-temperature EPR line," is 0.06K. In contrast, the exchange integral estimated from the other narrower EPR line, named the "high-temperature EPR line," was 0.235K, implying that the crystal structure of [Emim][FeCl4] associated with this line has a stronger superexchange coupling than that associated with the low-temperature EPR line. The solid-solid transition in [Emim][FeCl4] and the melting/crystallization transition exhibited hysteretic behavior, which was also observed in differential scanning calorimetry measurements. The EPR spectrum of [Bmim][FeCl4] shows only one Lorentzian EPR line throughout the measured temperature region, regardless of temperature treatment. The width change of this EPR line indicates the glass transition in [Bmim][FeCl4] at 185K.

This study reports the fabrication and characterization of novel high-temperature proton exchange membranes composed of sodium alginate reinforced with tungsten trioxide-reduced graphene (WO3-rG) nanocomposites, polyethylene glycol (PEG), and ionic liquids (ILs). The pristine sodium alginate (SA) membrane was first modified with varying concentrations of WO3-rG to enhance its proton conductivity, mechanical characteristics, and thermal stability. The PEG was incorporated to improve flexibility and membrane hydration, along with diethylmethylammonium methanesulfonate ([DEMA][OMs]) IL. Additionally, characterization techniques were conducted, including proton conductivity (at ambient and elevated temperatures), swelling ratio, ion exchange capacity (IEC), water uptake, Fourier transform infrared (FTIR) spectroscopy, and tensile testing, to evaluate the membrane performance. The results show that the 3.23 wt% PEG/WO3-rG/SA membrane exhibited the highest proton conductivity at room temperature, reaching 2.33 × 10−1 S cm−1 at 25 °C, while the IL/PEG/WO3-rG/SA formulation demonstrated the most stable conductivity profile at elevated temperatures, maintaining 3.88 × 10−3 S cm−1 at 145 °C. In addition, the IL/PEG/WO3-rG/SA membrane showed an excellent IEC of 1.65 meq g−1 and remarkable mechanical flexibility, with an elongation at break exceeding 768%. Therefore, these findings confirm the positive role of WO3-rG, IL, and PEG in the membrane's structure and enhancing its functional properties, as well as improving its flexibility. The work showed that the IL/PEG/WO3-rG/SA composite is a promising candidate for high-temperature proton exchange membrane (HT-PEM) fuel cell applications, especially those operating above the boiling point of water.

The co-conversion of poly(ethylene terephthalate) (PET), CO2, and renewable carbon resources offers a sustainable strategy for reducing plastic waste and carbon emissions, but remains challenging. Here, we develop a one-pot cycloaddition-transesterification-glycolysis (CTG) tandem process to efficiently convert PET, CO2, and glycerol into bis-hydroxyethyl terephthalate (BHET) and glycerol carbonate, achieving yields of 92% and 99%, respectively. The process begins with the cycloaddition of ethylene oxide and CO2 in an ionic liquid, followed by transesterification with glycerol to produce glycerol carbonate and ethylene glycol. The in situ-generated ethylene glycol participates in PET glycolysis to yield BHET catalyzed by zinc acetate. Kinetic studies, isotope labelling, and theoretical calculations reveal that ethylene oxide serves two functions: (i) swelling the PET matrix to enhance mass transfer and (ii) providing ethylene glycol. The synchronized kinetics of cycloaddition, transesterification, and glycolysis enable ethylene oxide to play both roles effectively, significantly accelerating PET depolymerization at mild temperatures.

Highly sensitive flexible pressure sensors are crucial for wearable health monitoring and human–machine interaction. While the emerging iontronic sensors inherently offer high sensitivity, this can be further improved by engineering microstructured interfaces. In this study, we employ four different types of common fiber materials as substrates for fabricating ionic dielectric layers by a simple impregnation of ionic liquid (IL). A comparative study reveals that the porosity and microstructural architecture (e.g., fiber diameter) of the substrate material directly influences the amount of adsorbed IL and consequent sensing performance. We achieved the highest sensitivity by using a thin electrospun TPU/IL nanofiber mat (33 μm), which exhibited high sensitivities of 3.10 kPa−1, 1.85 kPa−1, and 1.02 kPa−1 in the pressure ranges of 0–200 kPa, 200–400 kPa, and 400–700 kPa, respectively. Furthermore, the sensor exhibited an excellent fast response (2.71 ms) and recovery time (8.71 ms), along with outstanding cyclic stability. This work provides valuable guidance for selecting and utilizing common fiber materials to develop high-sensitivity iontronic pressure sensors, paving the way for their practical application in next-generation wearable electronics.

Copper nanowires (CuNWs) are promising for flexible transparent electrodes but suffer from lack of effective strategies to inhibit the oxidation-induced conductivity degradation, especially during large-area electrode preparation. Herein, a benzotriazole-functionalized ionic liquid ([BTAMMIM]TFSI) is introduced as an antioxidant layer to protect the CuNWs networks. Remarkably, the sheet resistance of the protected electrodes increases by only 0.54% compared to bare CuNWs after 60-day air exposure. Density functional theory (DFT) calculations and experiments reveal that the benzotriazole-functionalized cations and [TFSI] anions synergistically coordinate with copper, enabling exceptional oxidation resistance. By integrating with superwettability-assisted interfacial transfer strategy, large-area CuNWs@[BTAMMIM]TFSI composite electrodes (40 × 25 cm2) are fabricated with 37.2 Ω sq-1 sheet resistance and 88.2% transmittance (550nm). The electrodes maintain performance under acidic/alkaline conditions (pH 3/13) and high humidity (85% RH) at 85 °C. A demonstrated flexible smart window exhibits high transmittance modulation (6.1%-68.2%), fast response (< 0.2 s) and long-term stability, highlighting their potential in flexible optoelectronics.

The hydrogen energy industry is rapidly developing, positioning hydrogen refueling stations (HRSs) as critical infrastructure for hydrogen fuel cell vehicles. Within these stations, hydrogen compressors serve as the core equipment, whose performance and reliability directly determine the overall system’s economy and safety. This article systematically reviews the working principles, structural features, and application status of mechanical hydrogen compressors with a focus on three prominent types based on reciprocating motion principles: the diaphragm compressor, the hydraulically driven piston compressor, and the ionic liquid compressor. The study provides a detailed analysis of performance bottlenecks, material challenges, thermal management issues, and volumetric efficiency loss mechanisms for each compressor type. Furthermore, it summarizes recent technical optimizations and innovations. Finally, the paper identifies current research gaps, particularly in reliability, hydrogen embrittlement, and intelligent control under high-temperature and high-pressure conditions. It also proposes future technology development pathways and standardization recommendations, aiming to serve as a reference for further R&amp;D and the industrialization of hydrogen compression technology.

Abstract The co‐conversion of poly(ethylene terephthalate) (PET), CO 2 , and renewable carbon resources offers a sustainable strategy for reducing plastic waste and carbon emissions, but remains challenging. Here, we develop a one‐pot cycloaddition–transesterification–glycolysis (CTG) tandem process to efficiently convert PET, CO 2 , and glycerol into bis‐hydroxyethyl terephthalate (BHET) and glycerol carbonate, achieving yields of 92% and 99%, respectively. The process begins with the cycloaddition of ethylene oxide and CO 2 in an ionic liquid, followed by transesterification with glycerol to produce glycerol carbonate and ethylene glycol. The in situ‐generated ethylene glycol participates in PET glycolysis to yield BHET catalyzed by zinc acetate. Kinetic studies, isotope labelling, and theoretical calculations reveal that ethylene oxide serves two functions: (i) swelling the PET matrix to enhance mass transfer and (ii) providing ethylene glycol. The synchronized kinetics of cycloaddition, transesterification, and glycolysis enable ethylene oxide to play both roles effectively, significantly accelerating PET depolymerization at mild temperatures.

At present, ionic liquids (ILs) are increasingly being used to extract natural products as green solvents, but their residues can lead to risks in terms of further use for the extracted herbal materials. Therefore, it is necessary to remove them with simple and effective methods. For example, after the toxic anthraquinones in Polygonum multiflorum are removed by extraction with the IL of [C4Bim][PTSA], it needs to be recovered and reused, and the useful stilbene glycosides should not suffer from obvious loss as they are the main functional components. In this study, an ultrasonic method with n-propanol was used to remove the residual [C4Bim][PTSA] in the solid powders of Polygonum multiflorum that had been extracted for anthraquinones. After single-factor optimization, the removal conditions were as follows: the removal temperature was 303.15 K, the solid–liquid ratio was 1:200 (w (1 g):v (200 mL)), the ultrasonic time was 40 min, and there were four operations. Under these conditions, ILs could be completely removed with almost no loss of stilbene glycosides in solid powders. After that, the IL in the extracting solution and scrubbing solution was recovered by the back-extraction method, and an IL with high purity could be obtained for reuse. The total recovery efficiency of the IL reached more than 98%. Then gas chromatography (GC) was conducted for the determination of residual ethanol and n-propanol in the solid powders of Polygonum multiflorum, which could be used to quickly detect the contents of two organic solvents within three minutes. Besides that, the method could also be applied to the determination of residual organic solvents in the raw materials of Polygonum multiflorum, and the results showed that the residue of ethanol and n-propanol in the solid powders were in accordance with the general provisions of the current Chinese Pharmacopoeia. According to the developed procedures and optimized conditions, the recovered IL could be reused in five runs at least. General applicability and greenness assessment for the developed process also proved that it is an ideal method, which has potential in large-scale application.

"From solvents to therapeutics: the expanding role of ionic liquids in dermatological drug administration".

Studying citric acid-mediated synthesis of gold nanoparticles in ionic liquids by in situ liquid phase STEM: A reproducible approach.

Valorization of tea (Camellia sinensis) waste: Extraction of bioactive compounds using ionic liquids and evaluation of their stability, efficiency, and volatile profiles during the process.

A novel ionic liquid 3-(2-hydrazinyl-2-oxoethyl)-1-methyl-1H-imidazol-3-ium chloride as a derivatization reagent for HPLC-HRMS determination of steroid hormones in urine.

Herein, we disclose an eco-friendly route for the synthesis of 2,4,5-triaryl-1H-imidazole derivatives. One-pot, three-component synthesis involving benzil, substituted aromatic aldehydes, and ammonium acetate in the presence of a catalytic amount of trihexyltetradecyl-phosphonium bis(2,4,4-trimethylpentyl)phosphinate (PBIL) ionic liquid in ethanol at room temperature yields corresponding 2,4,5-triaryl-1H-imidazole derivatives in appreciable yield. The use of ionic liquid as a green catalyst with ethanol, which is considered to be an environmentally benign solvent, simple workup procedure, and appreciable yield of the product are some of the notable advantages of this method.

Comparative thermo-electrochemical study of lignin- and starch-derived carbon electrodes modified with Zn(TFSI)2 and ionic liquids for lithium-ion battery applications.

Advancement in microalgal metabolites extraction techniques: Multi-factorial considerations.

Unveiling aggregation concentration in surfactants and ionic liquids using confocal Raman and hyper-Raman spectroscopies

Deciphering the role of non-covalent interactions in CO2 Capture: A DFT and COSMO-RS study of amino acid-based ionic liquids.

ABSTRACT Achieving efficient and stable formamidinium lead iodide (FAPbI 3 ) perovskite solar cells (PSCs) requires integrated control of crystallization kinetics and defect suppression. While ionic liquids (IL) have shown promise as multifunctional additives, their rational design remains challenging. Here, we develop an attention‐focus graph neural network (GNN) framework that combines the molecular features of IL with device‐level characteristics of FAPbI 3 PSCs. Our model identifies N‐methyl‐N‐butylpyrrolidinium bis(trifluoromethylsulfonyl)imide ([MBPY][TFSI]) as an ideal dual‐functional passivator. The [MBPY] + , acting as a Lewis base, passivates undercoordinated Pb 2+ via Pb‐N coordination bonds, whereas the [TFSI] − anion mitigates interfacial defects via hydrogen bonding with FA + . It is found that the [MBPY] + cation not only suppresses non‐radiative recombination but also enhances the moisture resistance of the perovskite layer due to its hydrophobic alkyl chains. With the synergetic effect of [MBPY] + and [TFSI] − additives, the PSCs achieve a power conversion efficiency (PCE) of 25.03% with an open circuit voltage of 1.182 V, and retain 90.5% of their initial PCE after 1200 h storage at room temperature in air atmosphere (35% relative humidity). This work contributes to ongoing computational and experimental efforts in accelerating the exploration and prediction of potential ionic liquid passivation materials for perovskite solar cells. image

Ionic liquids and eutectic mixtures for virus inactivation – A review of molecular mechanisms and environmental remediation potential