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Redox potentials depend on the nature of the solvent/electrolyte through the solvation energies of the ionic solute species. For concentrated electrolytes, ion solvation may deviate significantly from the Born model predictions due to ion pairing and correlation effects. Recently, Ghorai and Matyushov [J. Phys. Chem. B 124, 3754–3769 (2020)] predicted, on the basis of linear response theory, an anomalous trend in the solvation energies of room temperature ionic liquids, with deviations of hundreds of kJ/mol from the Born model for certain size solutes/ions. In this work, we computationally evaluate ionic solvation energies in the prototypical ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate (BMIM/BF4), to further explore this behavior and benchmark several of the approximations utilized in the solvation energy predictions. For comparison, we additionally compute solvation energies within acetonitrile and molten NaCl salt to illustrate the limiting behavior of purely dipolar and ionic solvents. We find that the overscreening effect, which results from the inherent charge oscillations of the ionic liquid, is substantially reduced in magnitude due to screening from the dipoles of the molecular ions. Therefore, for the molten NaCl salt, for which the ions do not have permanent dipoles, modulation of ionic solvation energies from the overscreening effect is most significant. The conclusion is that ionic liquids do indeed exhibit unique solvation behavior due to peak(s) in the electrical susceptibility caused by the ion shell structure; redox potential shifts for BMIM/BF4 are of more modest order ∼0.1 V, but may be larger for other ionic liquids that approach molten salt behavior. [ABSTRACT FROM AUTHOR]

Crystal polymorphism of complex liquids plays a crucial role in industrial crystallization, food technology, pharmaceuticals, and materials engineering. However, the experimental identification of unknown crystal structures can be challenging, particularly for high-viscosity complex liquids, such as ionic liquids (ILs). In this study, we performed a molecular dynamics simulation coupled with metadynamics to investigate an imidazolium IL (1-alkyl-3-methylimidazolium hexafluorophosphates). The simulation employed two distinct radial-distribution functions, represented by Gaussian window functions as collective variables, and revealed at least two crystal-like phases distinct from the known α and β crystal phases typically formed by this IL. Additionally, the simulation unveiled a unique phase characterized by the ordered spatial arrangement of anion aggregations. These crystal-like and unique phases emerged regardless of the potential used. The simulation methodology presented here is broadly applicable for exploring unknown phases in complex systems and contributes to the design of functional materials, such as porous ILs for gas molecule capture and separation. [ABSTRACT FROM AUTHOR]

In this work, we propose and validate a generalization of the Helmholtz model that can account for both "bell-shaped" and "camel-shaped" differential capacitance profiles of concentrated electrolytes, the latter being characteristic of ionic liquids. The generalization is based on introducing voltage dependence of both the dielectric constant "ϵr(V)" and thickness "L(V)" of the inner Helmholtz layer, as validated by molecular dynamics (MD) simulations. We utilize MD simulations to study the capacitance profiles of three different electrochemical interfaces: (1) graphite/[BMIm+][ BF 4 − ] ionic liquid interface; (2) Au(100)/[BMIm+][ BF 4 − ] ionic liquid interface; (3) Au(100)/1M [Na+][Cl−] aqueous interface. We compute the voltage dependence of ϵr(V) and L(V) and demonstrate that the generalized Helmholtz model qualitatively describes both camel-shaped and bell-shaped differential capacitance profiles of ionic liquids and concentrated aqueous electrolytes (in lieu of specific ion adsorption). In particular, the camel-shaped capacitance profile that is characteristic of ionic liquid electrolytes arises simply from combination of the voltage-dependent trends of ϵr(V) and L(V). Furthermore, explicit analysis of the inner layer charge density for both concentrated aqueous and ionic liquid double layers reveal similarities, with these charge distributions typically exhibiting a dipolar region closest to the electrode followed by a monopolar peak at larger distances. It is appealing that a generalized Helmholtz model can provide a unified description of the inner layer structure and capacitance profile for seemingly disparate aqueous and ionic liquid electrolytes. [ABSTRACT FROM AUTHOR]

This work employs a combination of density functional theory-infrared (IR), conductor-like screening model for real solvents (COSMO-RS), and molecular dynamic (MD) methods to investigate the impact of hydroxyl functional groups on CO2 capture within dicationic ionic liquids (DILs). The COSMO-RS reveals that hydroxyl groups in DILs reduce the macroscopic solubility of CO2 but improve the selectivity of CO2 over CO, H2, and CH4 gases. Quantum methods in the gas phase and MD simulations in the liquid phase were conducted to delve deeper into the underlying mechanisms. The IR spectrum analysis confirms red shifts in CO2's asymmetric stretching mode and blue shifts in the CR–HR bond of the dication, indicating CO2–DIL interactions and the weakening of the anion–cation interactions caused by the presence of CO2. The results show that the positioning of anions around hydroxyl groups and HR atoms in rings inhibits the proximity of CO2 molecules, causing the hydrogen atoms within methylene groups to accumulate CO2. van der Waals forces were found to dominate the interaction between ions and CO2. The addition of hydroxyl groups strengthens the electrostatic interactions and hydrogen bonds between dications and anions. The stronger interaction energy between ions in [C5(mim)2-(C2)2(OH)2][NTf2]2 limits the displacement of CO2 molecules within this DIL compared to [C5(mim)2-(C4)2][NTf2]2. Compared to [C5(mim)2-(C4)2][NTf2]2, [C5(mim)2-(C2)2(OH)2][NTf2]2 exhibits stronger ion–ion interactions, higher density, and reduced free volume, resulting in a reduction in CO2 capture. These results provide significant insights into the intermolecular interactions and vibrational properties of CO2 in DIL complexes, emphasizing their significance in developing efficient and sustainable strategies for CO2 capture. [ABSTRACT FROM AUTHOR]

Experimental and theoretical advances for understanding the temperature of maximum density (TMD) of aqueous solutions are outlined. The main equations that relate the TMD behavior to key thermodynamic properties are stated. The experimental TMD data are classified as a function of the nature of the solute (inorganic electrolytes, non-electrolytes, organic salts and ionic liquids, and amino acids and proteins). In addition, the experimental results that explore the effect of pressure are detailed. These experimental data are rationalized by making use of qualitative and semi-quantitative arguments based on the thermodynamics of aqueous systems. The main theoretical and simulation advances in TMD for aqueous solutions are also shown—including new calculations in the context of the scaled particle theory—and their ability to reproduce the experimental data is evaluated. Finally, new experiments and theoretical and simulation developments, which could give important insights into the problem of TMD for aqueous solutions, are proposed. [ABSTRACT FROM AUTHOR]

We study a united-atom model of the ionic liquid 1-butyl-1-methylpyrrolidinium bis(trifluoromethyl)sulfonylamide to determine to what extent there exist curves in the phase diagram along which the microscopic dynamics are invariant when expressed in dimensionless, or reduced, form. The initial identification of these curves, termed isodynes, is made by noting that contours of reduced shear viscosity and reduced self-diffusion coefficient coincide to a good approximation. Choosing specifically the contours of reduced viscosity as nominal isodynes, further simulations were carried out for state points on these, and other aspects of dynamics were investigated to study their degree of invariance. These include the mean-squared displacement, shear-stress autocorrelation function, and various rotational correlation functions. These were invariant to a good approximation, with the main exception being rotations of the anion about its long axis. The dynamical features that are invariant have in common that they are aspects that would be relevant for a coarse-grained description of the system; specifically, removing the most microscopic degrees of freedom in principle leads to a simplification of the potential energy landscape, which allows for the existence of isodynes. [ABSTRACT FROM AUTHOR]

Recent experimental results have demonstrated that zwitterionic ionogel comprised of polyzwitterion (polyZI)-supported lithium salt-doped ionic liquid exhibits improved conductivities and lithium transference numbers than the salt-doped base ionic liquid electrolyte (ILE). However, the underlying mechanisms of such observations remain unresolved. In this work, we pursued a systematic investigation to understand the impact of the polyZI content and salt concentration on the structural and dynamic properties of the poly(MPC) ionogel of our model polyZI ionogel, poly(2-methacryloyloxyethyl phosphorylcholine) [poly(MPC)] supported LiTFSI/N-butyl-N-methylpyrrolidinium TFSI base ionic liquid electrolyte. Our structural analyses show strong lithium–ZI interaction consistent with the physical network characteristic observed in the experiments. An increase in polyZI content leads to an increased fraction of Li+ ions coordinated with the polyZI. In contrast, an increase in salt concentration leads to a decreased fraction of Li+ ions coordinated with the polyZI. The diffusivities of the mobile ions in the poly(MPC) ionogel were found to be lower than the base ILE in agreement with experiments at T > 300 K. Analysis of ion transport mechanisms shows that lithium ions within the poly(MPC) ionogel travel via a combination of structural, vehicular diffusion, as well as hopping mechanism. Finally, the conductivity trend crossover between the poly(MPC) ionogel and the base ILE was rationalized via a temperature study that showed that the base ILE ions are influenced more by the variation of temperature when compared to the poly(MPC) ions. [ABSTRACT FROM AUTHOR]

Monoolein-based liquid crystal phases are established media that are researched for various biological applications, including drug delivery. While water is the most common solvent for self-assembly, some ionic liquids (ILs) can support lipidic self-assembly. However, currently, there is limited knowledge of IL-lipid phase behavior in ILs. In this study, the lyotropic liquid crystal phase behavior of monoolein was investigated in six protic ILs known to support amphiphile self-assembly, namely ethylammonium nitrate, ethanolammonium nitrate, ethylammonium formate, ethanolammonium formate, ethylammonium acetate, and ethanolammonium acetate. These ILs were selected to identify specific ion effects on monoolein self-assembly, specifically increasing the alkyl chain length of the cation or anion, the presence of a hydroxyl group in the cation, and varying the anion. The lyotropic liquid crystal phases with 20–80 wt. % of monoolein were characterized over a temperature range from 25 to 65 °C using synchrotron small angle x-ray scattering and cross-polarized optical microscopy. These results were used to construct partial phase diagrams of monoolein in each of the six protic ILs, with inverse hexagonal, bicontinuous cubic, and lamellar phases observed. Protic ILs containing the ethylammonium cation led to monoolein forming lamellar and bicontinuous cubic phases, while those containing the ethanolammonium cation formed inverse hexagonal and bicontinuous cubic phases. Protic ILs containing formate and acetate anions favored bicontinuous cubic phases across a broader range of protic IL concentrations than those containing the nitrate anion. [ABSTRACT FROM AUTHOR]

In this study, we extended the optimized potentials for liquid simulation-ionic-liquid virtual site (OPLS-VSIL) force field (FF) to imidazolium-based dicationic ionic liquids (DILs) and evaluated the ability of different OPLS-based FFs (i.e., OPLS-2009IL, 0.8*OPLS-2009IL, and OPLS-VSIL) in predicting different properties of the studied DIL by comparing their results with ab initio molecular dynamics (AIMD) simulation and experimental results. To achieve this purpose, MD simulations with three different OPLS-based FFs as well as AIMD simulation were performed for [C3(mim)2][NTF2]2 DIL and its structural, dynamical, vibrational, and volumetric properties were analyzed. Structural properties of the studied DIL, i.e., radial distribution functions (RDFs), structure factor, and hydrogen-bond network, showed that compared to 0.8*OPLS-2009IL FF, there is a much better agreement between the results of both OPLS-2009IL and OPLS-VSIL FFs with the AIMD simulation. On the other hand, the results of dynamical properties, such as mean square displacements, van Hove correlation functions as well as hydrogen bond, ion pair, and ion cage dynamics, depicted that in both 0.8*OPLS-2009IL and OPLS-VSIL FFs, the dynamics of the system is almost similar, and compared to OPLS-2009IL FF, they have better agreements with experimental results where they exist. So, it can be seen that although reducing the total charge of studied DIL by 20% leads to an increase in the dynamics of the system, the type distribution of partial charges on each atom does not significantly affect the system's dynamics. The calculated infrared (IR) and power spectra showed that the vibrational features of studied DIL in three OPLS-based FFs are mostly the same and reducing total charge and different type distribution of partial charges have no significant effect on the studied system. Furthermore, in volumetric properties, OPLS-VSIL FF shows somehow better agreement with experimental results. Overall, the evaluation of different structural, dynamical, vibrational, and volumetric properties of [C3(mim)2][NTF2]2 DIL shows that the OPLS-VSIL FF may be the best choice among the different studied OPLS FFs. [ABSTRACT FROM AUTHOR]

Electrochemical Double Layer Capacitors (EDLCs) with ionic liquid electrolytes outperform conventional ones using aqueous and organic electrolytes in energy density and safety. However, understanding the electrochemical behaviors of ionic liquid electrolytes under compressive/tensile strain is essential for the design of flexible EDLCs as well as normal EDLCs, which are subject to external forces during assembly. Despite many experimental studies, the compression/stretching effects on the performance of ionic liquid EDLCs remain inconclusive and controversial. In addition, there is hardly any evidence of prior theoretical work done in this area, which makes the literature on this topic scarce. Herein, for the first time, we developed an atomistic model to study the processes underlying the electrochemical behaviors of ionic liquids in an EDLC under strain. Constant potential non-equilibrium molecular dynamics simulations are conducted for EMIM BF4 placed between two graphene walls as electrodes. Compared to zero strain, low compression of the EDLC resulted in compromised performance as the electrode charge density dropped by 29%, and the performance reduction deteriorated significantly with a further increase in compression. In contrast, stretching is found to enhance the performance by increasing the charge storage in the electrodes by 7%. The performance changes with compression and stretching are due to changes in the double-layer structure. In addition, an increase in the value of the applied potential during the application of strain leads to capacity retention with compression revealed by the newly performed simulations. [ABSTRACT FROM AUTHOR]

We present a strategic approach for enhancing the ionic conductivity of block copolymer electrolytes. This was achieved by introducing mixed ionic liquids (ILs) with varying molar ratios, wherein the imidazolium cation was paired with either tetrafluoroborate (BF4) anion or bis(trifluoromethylsulfonyl)imide (TFSI) anion. Two polymer matrices, poly(4-styrenesulfonate)-b-polymethylbutylene (SSMB) and poly(4-styrenesulfonyl (trifluoromethanesulfonyl)imide)-b-polymethylbutylene (STMB), were synthesized for this purpose. All the SSMB and STMB containing mixed ILs showed hexagonal cylindrical structures, but the type of tethered acid group significantly influenced the interfacial properties. STMB electrolytes demonstrated enhanced segregation strength, which was attributed to strengthened Coulomb and hydrogen bonding interactions in the ionic domains, where the ILs were uniformly distributed. In contrast, the SSMB electrolytes exhibited increased concentration fluctuations because the BF4 anions were selectively sequestered at the block interfaces. This resulted in the effective confinement of imidazolium TFSI along the ionic domains, thereby preventing ion trapping in dead zones and facilitating rapid ion diffusion. Consequently, the SSMB electrolytes with mixed ILs demonstrated significantly improved ionic conductivities, surpassing the expected values based on the arithmetic average of the conductivities of each IL, whereas the ionic conductivity of the STMB was aligned with the expected average. The methodology explored in this study holds great promise for the development of solid-state polymer electrolytes. [ABSTRACT FROM AUTHOR]

Due to the importance of supercapacitors in electronic storage devices, improving their efficiency is one of the topics that has attracted the attention of many researchers. Choosing the proper electrolyte for supercapacitors is one of the most significant factors affecting supercapacitors' performance. In the present paper, we compare liquid electrolytes (ionic liquid electrolytes) and solid electrolytes (polymer electrolytes) by molecular dynamics simulation to summarize their pros and cons. We consider polymer electrolytes in linear and network configurations. The results show that although ionic liquid-based supercapacitors have a larger differential capacitance since they have a smaller operation voltage, the energy stored is less than polymer electrolyte-based supercapacitors. Also, our investigations indicate that polymer electrolyte-based supercapacitors have more mechanical stability. Therefore, they can be considered a very suitable alternative to liquid electrolyte-based supercapacitors since they do not have known liquid electrolyte problems and display better performance. [ABSTRACT FROM AUTHOR]

Highly acidic protic ionic liquids (PILs) are promising materials for potential electrochemical applications due to their high proton conductivity and excellent thermal stability. Still, little is known about the correlation between charge transport and structural dynamics as well as the proton transport mechanism despite the large body of literature on this topic. Here, we have examined the charge transport and structural dynamics by employing broadband dielectric spectroscopy in two highly acidic PILs in their supercooled liquid and glassy states, which included the same anion [TfO]− and different cations, [Tau]+ vs [Ahs]+. Unlike many other ionic liquids, the conductivity relaxation time τe of two studied PILs is substantially faster than the structural relaxation time τα. The decoupling behavior between charge transport and structural dynamics of two materials, which is manifested by a decoupling index Rτ, varies between 0.3 and 2.3 over the temperature range above Tg. Moreover, "Walden" plots of the molar conductivity vs the viscosity qualify both compounds as "Super ILs." All findings support the physical picture of large, polar, and orientationally correlated ion clusters, where the slow α-relaxation can be identified as structural relaxation associated with cooperative reorientations of the cluster macrodipole. In contrast, the shortest timescale for diffusive charge transport, τe, is 1–2 decades shorter than τα, implying that proton hopping is triggered by "single particle" (ions or ion pair) rotations and jumps on a sub-length scale of the cluster size, a dynamics being present even in the glassy state as indicated by a strong β-relaxation. These results demonstrate the practicality of employing highly acidic PILs in electrochemical fields. [ABSTRACT FROM AUTHOR]

Knowledge of the physical properties of ionic liquids (ILs), such as the surface tension and speed of sound, is important for both industrial and research applications. Unfortunately, technical challenges and costs limit exhaustive experimental screening efforts of ILs for these critical properties. Previous work has demonstrated that the use of quantum-mechanics-based thermochemical property prediction tools, such as the conductor-like screening model for real solvents, when combined with machine learning (ML) approaches, may provide an alternative pathway to guide the rapid screening and design of ILs for desired physiochemical properties. However, the question of which machine-learning approaches are most appropriate remains. In the present study, we examine how different ML architectures, ranging from tree-based approaches to feed-forward artificial neural networks, perform in generating nonlinear multivariate quantitative structure–property relationship models for the prediction of the temperature- and pressure-dependent surface tension of and speed of sound in ILs over a wide range of surface tensions (16.9–76.2 mN/m) and speeds of sound (1009.7–1992 m/s). The ML models are further interrogated using the powerful interpretation method, shapley additive explanations. We find that several different ML models provide high accuracy, according to traditional statistical metrics. The decision tree-based approaches appear to be the most accurate and precise, with extreme gradient-boosting trees and gradient-boosting trees being the best performers. However, our results also indicate that the promise of using machine-learning to gain deep insights into the underlying physics driving structure–property relationships in ILs may still be somewhat premature. [ABSTRACT FROM AUTHOR]

A reliable uncertainty estimator is a key ingredient in the successful use of machine-learning force fields for predictive calculations. Important considerations are correlation with error, overhead during training and inference, and efficient workflows to systematically improve the force field. However, in the case of neural-network force fields, simple committees are often the only option considered due to their easy implementation. Here, we present a generalization of the deep-ensemble design based on multiheaded neural networks and a heteroscedastic loss. It can efficiently deal with uncertainties in both energy and forces and take sources of aleatoric uncertainty affecting the training data into account. We compare uncertainty metrics based on deep ensembles, committees, and bootstrap-aggregation ensembles using data for an ionic liquid and a perovskite surface. We demonstrate an adversarial approach to active learning to efficiently and progressively refine the force fields. That active learning workflow is realistically possible thanks to exceptionally fast training enabled by residual learning and a nonlinear learned optimizer. [ABSTRACT FROM AUTHOR]

In this paper, we present a covariant approach that utilizes Noether's second theorem to derive a symmetric stress tensor from the grand thermodynamic potential functional. We focus on the practical case where the density of the grand thermodynamic potential is dependent on the first and second coordinate derivatives of the scalar order parameters. Our approach is applied to several models of inhomogeneous ionic liquids that consider electrostatic correlations of ions or short-range correlations related to packing effects. Specifically, we derive analytical expressions for the symmetric stress tensors of the Cahn–Hilliard-like model, Bazant–Storey–Kornyshev model, and Maggs–Podgornik–Blossey model. All of these expressions are found to be consistent with respective self-consistent field equations. [ABSTRACT FROM AUTHOR]

We present a hydrodynamic theory describing pair diffusion in systems with periodic boundary conditions, thereby generalizing earlier work on self-diffusion [B. Dünweg and K. Kremer, J. Chem. Phys. 99, 6983–6997 (1993) and I.-C. Yeh and G. Hummer, J. Phys. Chem. B 108, 15873–15879 (2004)]. Its predictions are compared with Molecular Dynamics simulations for a liquid carbonate electrolyte and two ionic liquids, for which we characterize the correlated motion between distinct ions. Overall, we observe good agreement between theory and simulation data, highlighting that hydrodynamic interactions universally dictate ion correlations. However, when summing over all ion pairs in the system to obtain the cross-contributions to the total cationic or anionic conductivity, the hydrodynamic interactions between ions with like and unlike charges largely cancel. Consequently, significant conductivity contributions only arise from deviations from a hydrodynamic flow field of an ideal fluid, which is from the local electrolyte structure as well as the relaxation processes in the subdiffusive regime. In the case of ionic liquids, the momentum-conservation constraint additionally is vital, which we study by employing different ionic masses in the simulations. Our formalism will likely also be helpful to estimate finite-size effects of the conductivity or of Maxwell-Stefan diffusivities in simulations. [ABSTRACT FROM AUTHOR]

Room temperature ionic liquids (RT-ILs) are promising electrolytes for electrocatalysis. Understanding the effects of the electrode–electrolyte interface structure on electrocatalysis in RT-ILs is important. Ultrafast mass transport of redox species in N-methyl-N-ethyl-pyrrolidinium polybromide (MEPBr2n+1) enabled evaluation of the reorganization energy (λ), which reflects the solvation structure in the inner Helmholtz plane (IHP). λ was achieved by fitting the electron transfer rate-limited voltammogram at a Pt ultramicroelectrode (UME) to the Marcus–Hush–Chidsey model for heterogeneous electron transfer kinetics. However, it is time-consuming or even impossible to prepare electrode materials, including alloys of numerous compositions in the form of UME, for each experiment. Herein, we report a method to evaluate the λ of MEPBr2n+1 by scanning electrochemical cell microscopy (SECCM), which allows high throughput electrochemical measurements using a single electrode with high spatial resolution. Fast mass transport in the nanosized SECCM tip is critical for achieving heterogeneous electron transfer-limited voltammograms. Furthermore, investigating λ on a high-entropy alloy materials library composed of Pt, Pd, Ru, Ir, and Ag suggests a negative correlation between λ and the work function. Given that the potential of zero charge correlates with the work function of electrodes, this can be attributed to the surface-charge sensitive ionic structure in the IHP of MEPBr2n+1, modulating the solvation energy of the redox-active species in the IHP. [ABSTRACT FROM AUTHOR]

In recent years, perovskite solar cells (PSCs) have been attracting more and more attention. Although perovskite materials have high defect tolerance, defects remain the main factor that seriously affects the efficiency and stability of PSCs. Herein, the ionic liquid of 1-butyl, 3-methylimidazolium acetate ([BMIM][ACO]) was introduced into the SnO2/perovskite interface for the first time. Thanks to the dipoles formed by ILs spontaneously, the work function of SnO2 was reduced and the transport ability of carriers was improved as well. Moreover, the Lewis acidity and lone pair electrons of [BMIM][ACO] contribute to the passivation of I– defects, Pb2+ defects, or Pb-I anti site defects. In addition, the presence of dipoles will repel the approach of photogenerated holes and the reverse transport of electrons, reducing the recombination of defect sites through field-effect passivation. The solar cell with efficiency of 19.43% was obtained under such a dual passivation effect, and the best device maintained 75.21% of the initial efficiency after 80 h of continuous illumination. [ABSTRACT FROM AUTHOR]

Despite the presence of molecular hydrogen (H 2) in various technical applications involving ionic liquids (ILs), its effect on the bulk and interfacial properties of ILs is poorly understood. The present study investigates the influence of dissolved H 2 on the viscosity, surface tension, and phase composition of three imidazolium-based ILs by experiments and Molecular Dynamics (MD) simulations between (303 and 393) K from (0.1 to 31) MPa. The surface light scattering and pendant-drop experiments showed for all three ILs that the saturated liquid viscosity does not significantly change with increasing H 2 pressure, while the surface tension decreases about 5% at 8 MPa. The MD simulations could be used to clarify microscopic origins for the behavior of the macroscopic properties. They revealed not only a compensation of compression and solvation effects due to hydrostatic pressure and dissolved H 2 on the viscosity, but also a weak enrichment of H 2 at the IL-gas interfaces. [Display omitted] • First-time study on bulk and interfacial properties of ILs containing dissolved H 2. • Minor effect of H 2 on measured saturated viscosities of three imidazolium-based ILs. • Decreased measured surface tensions with increased H 2 pressure by up to 6% at 8 MPa. • Impact of H2 on viscosity, surface tension, and solubility captured by simulations. • Bulk solvation and surface enrichment effects of H 2 in ILs revealed by simulations. [ABSTRACT FROM AUTHOR]

The fruit extract of Buchanania obovata and the eutectic-based ionic liquid were utilized, in an eco-friendly, inexpensive, simple method, for synthesizing zinc oxide nanoparticles (ZnO NPs). The influence of the reducing, capping and stabilizing agents, in both mediums, on the structure, optical, and morphological properties of ZnO NPs was extensively investigated. The surface plasmon resonance peaks were observed at 340 nm and 320 nm for the fruit-based and the eutectic-based ionic liquid mediums, respectively, indicating the formation of ZnO NPs. XRD results confirmed the wurtzite structure of the ZnO NPs, exhibiting hexagonal phases in the diffraction patterns. The SEM and TEM images display that the biosynthesized ZnO NPs exhibit crystalline and hexagonal shape, with an average size of 40 nm for the fruit-based and 25 nm for the eutectic-based ionic liquid. The Brunauer–Emmett–Teller (BET) surface area analysis, revealed a value ∼13 m2 g−1 for ZnO NPs synthesized using the fruit extract and ∼29 m2 g−1 for those synthesized using the eutectic-based ionic liquid. The antibacterial activity of the biosynthesized ZnO NPs was assessed against clinically isolated Gram-negative (E. coli) and Gram-positive (S. aureus) bacterial strains using the inhibition zone method. The ZnO NPs produced from the eutectic-based ionic liquids confirmed superior antibacterial activity against both S. aureus and E. coli compared to those mediated by the utilized fruit extract. At a concentration of 1000, the eutectic-based ionic liquid mediated ZnO NPs displayed a maximum inhibition zone of 16 mm against S. aureus, while against E. coli, a maximum inhibition zone of 15 mm was observed using the fruit extract mediated ZnO NPs. The results of this study showed that the biosynthesized ZnO NPs can be utilized as an efficient substitute to the frequently used chemical drugs and covering drug resistance matters resulted from continual usage of chemical drugs by users. [ABSTRACT FROM AUTHOR]

Ionic liquids are known as efficient pretreatment solvents for cellulosic biomass, but typical cellulose-dissolving ionic liquids are toxic to microorganisms, hindering the fermentation process for bioethanol production. Although the ionic liquids can be removed by washing after pretreatment, it negatively impacts the energy balance. Therefore, successive/simultaneous biomass pretreatment, hydrolysis, and fermentation processes with low-toxicity ionic liquids are desired. Herein, especially for the beginners and students, the toxicity of ionic liquids and their mechanisms by which the microorganisms are destroyed are simply discussed. Furthermore, two currently evolving solutions, low-toxicity ionic liquids and ionic liquid-resistant microorganisms for bioethanol production, are discussed. To the best of my knowledge, this is the first review specifically focusing on bioethanol fermentation in ionic liquid solutions, whereas there are many reports on cellulose dissolution. [ABSTRACT FROM AUTHOR]

We present a simple method to prepare diverse benzimidazolium and imidazolium ionic liquids (ILs) from common starting materials imidazole and benzimidazole. These green ILs promote the synthesis of N‐substituted piperazinyl propargylamines via a versatile CuI‐catalyzed coupling of aldehydes, secondary amines, and alkynes under ultrasound. Remarkably, the method works across a broad range of substrates, including diversely substituted aldehydes, heterocycles, cyclic amines, and phenylacetylenes. To understand this versatility, we investigated the influence of IL structure (N‐substitution, anion) on reactivity. Symmetrical long‐chain substituents on the benzimidazolium cation and bromide (Br−) anions led to the most efficient propargylamine formation. This approach offers a sustainable and efficient route to propargylamines with minimal waste and catalyst/IL recyclability over five cycles. [ABSTRACT FROM AUTHOR]

Nature has inspired scientists to fabricate adhesive materials for applications in many burgeoning areas. However, it is still a significant challenge to develop small‐molecule adhesives with high‐strength, low‐temperature and recyclable properties, although these merits are of great interest in various aspects. Herein, we report a series of strong adhesives based on low‐molecular‐weight molecular solids driven by the terminal modification of ionic liquids (ILs) and subsequent supramolecular self‐assembly. The emergence of high strength and liquid‐to‐solid transitions for these supramolecular aggregates relies on modifying IL with a high melting point motif and enriching the types of noncovalent interactions in the original ILs. Using this strategy, we demonstrate that our IL‐based molecular solids can efficiently obtain a high adhesion strength (up to 8.95 MPa). Importantly, we elucidate the mechanism underlying the reversible and strong adhesion enabled by monomer‐to‐polymer transitions. These fundamental findings provide guidance for the design of high‐performance supramolecular adhesive materials. [ABSTRACT FROM AUTHOR]

Nature has inspired scientists to fabricate adhesive materials for applications in many burgeoning areas. However, it is still a significant challenge to develop small‐molecule adhesives with high‐strength, low‐temperature and recyclable properties, although these merits are of great interest in various aspects. Herein, we report a series of strong adhesives based on low‐molecular‐weight molecular solids driven by the terminal modification of ionic liquids (ILs) and subsequent supramolecular self‐assembly. The emergence of high strength and liquid‐to‐solid transitions for these supramolecular aggregates relies on modifying IL with a high melting point motif and enriching the types of noncovalent interactions in the original ILs. Using this strategy, we demonstrate that our IL‐based molecular solids can efficiently obtain a high adhesion strength (up to 8.95 MPa). Importantly, we elucidate the mechanism underlying the reversible and strong adhesion enabled by monomer‐to‐polymer transitions. These fundamental findings provide guidance for the design of high‐performance supramolecular adhesive materials. [ABSTRACT FROM AUTHOR]

Background: There is a growing demand for fast and reliable plant biomolecular analyses. DNA extraction is the major bottleneck in plant nucleic acid-based applications especially due to the complexity of tissues in different plant species. Conventional methods for plant cell lysis and DNA extraction typically require extensive sample preparation processes and large quantities of sample and chemicals, elevated temperatures, and multiple sample transfer steps which pose challenges for high throughput applications. Results: In a prior investigation, an ionic liquid (IL)-based modified vortex-assisted matrix solid phase dispersion approach was developed using the model plant, Arabidopsis thaliana (L.) Heynh. Building upon this foundational study, the present study established a simple, rapid and efficient protocol for DNA extraction from milligram fragments of plant tissue representing a diverse range of taxa from the plant Tree of Life including 13 dicots and 4 monocots. Notably, the approach was successful in extracting DNA from a century old herbarium sample. The isolated DNA was of sufficient quality and quantity for sensitive molecular analyses such as qPCR. Two plant DNA barcoding markers, the plastid rbcL and nuclear ribosomal internal transcribed spacer (nrITS) regions were selected for DNA amplification and Sanger sequencing was conducted on PCR products of a representative dicot and monocot species. Successful qPCR amplification of the extracted DNA up to 3 weeks demonstrated that the DNA extracted using this approach remains stable at room temperature for an extended time period prior to downstream analysis. Conclusions: The method presented here is a rapid and simple approach enabling cell lysis and DNA extraction from 1.5 mg of plant tissue across a broad range of plant taxa. Additional purification prior to DNA amplification is not required due to the compatibility of the extraction solvents with qPCR. The method has tremendous potential for applications in plant biology that require DNA, including barcoding methods for agriculture, conservation, ecology, evolution, and forensics. [ABSTRACT FROM AUTHOR]

Nano vehicles for drug delivery with stimuli‐responsive characteristics are gaining prominence due to their ability to enhance traditional drug delivery methods by minimizing side effects and improving drug efficacy. Among the various stimuli‐responsive systems, pH‐responsive drug delivery nano vehicles have garnered significant attention. Utilizing this pH variance, tailored drug delivery nano vehicles can release encapsulated drugs on demand. Here, we developed pH‐responsive catanionic vesicles to create customized drug delivery nano vehicles responsive to stimuli, particularly pH. we have designed catanionic vesicles through interacting two oppositely charged surface active ionic liquids (SAILs), i. e. cationic ‐methyl‐4‐(2‐(dodecyloxycarbonylmethyl)morpholin‐4‐ium bromide [C12EMorph][Br] with anionic Choline Oleate ([Ch][Ol]). The spherically shaped micellar aggregates of [C12EMorph][Br] are transformed into pH responsive vesicular nanoaggregates through judicious addition of [Ch][Ol]. The morphological transition was studied through various analytical techniques including DLS, FRET and SANS. We used these pH responsive vesicular nanoaggregates to load representative hydrophobic drug curcumin in order to enhance its solubility, efficacy and bioavailability. This innovative approach in designing pH‐responsive vesicular nanoaggregates using two biocompatible SAILs signifies a breakthrough in biomedical research, holding promise for advancements in drug delivery and therapeutic applications. [ABSTRACT FROM AUTHOR]

Mechanical energy harvesting performances of poly(vinylidene fluoride) (PVDF) based composites are most often correlated with their polar phase and the individual piezoelectricity of the used filler materials. Here we show that the significant enhancement of space charge polarization of the said composites can play the key dominant role in determining their mechanical energy harvesting performance regardless of their polar phase and individual piezoelectricity of the used fillers. For this purpose, ionic liquid has been incorporated into PVDF/0.5(Ba0.7Ca0.3)TiO3–0.5Ba(Ti0.8Zr0.2)O3 (BCZT) composites which led to a huge enhancement in space charge polarization. The gradual addition of ionic liquid into 10 wt% BCZT loaded PVDF (PBCZT) has helped in extraordinarily enhancing the conductivity gradually which has confirmed the huge enhancement of space charge polarization. However, after a certain limit of ionic liquid addition, the polar phase of the composite films is decreased. Despite this, the output voltages from the piezoelectric and piezo-tribo hybrid nanogenerators (PENGs and HNGs, respectively) fabricated by using the developed films have been found to be increased gradually with the increase in the ionic liquid amount in PBCZT composite. As the amount of BCZT filler was kept fixed for all the films, this result has confirmed the key role of space charge polarization of PVDF-based composites in determining their mechanical energy harvesting performances compared to the effect of polar phase and individual piezoelectricity of filler. The optimized PENG and HNG devices have shown the output voltage as high as 52 and 167 V, respectively, with power densities ∼85 and 152 μ W cm−2 which predicted their excellent usability in real life energy conversion devices. This work also shows that the effect of extraordinarily enhanced space charge polarization is effective in improving the performance of all types of mechanical energy harvesting devices regardless of their mechanisms (piezoelectric or hybrid). [ABSTRACT FROM AUTHOR]

High-entropy alloys show broad application prospects in electrocatalysis due to their high catalytic activity, conductivity and structural stability. However, achieving their mild and scalable synthesis still remains a great challenge. This paper reports a strategy for the synthesis of CrFeCoNiRu0.5 high entropy nano-alloy/carbon (termed as CrFeCoNiRu0.5-HENA/C) using a chelate-based ionic liquid. Cr(III), Fe(III), Co(II), Ni(II) and Ru(III) were coordinated with salicylic acid ionic liquid to form a viscous metal complex solution, followed by low temperature carbonization and subsequent high temperature annealing. The resulting CrFeCoNiRu0.5- HENA/C consists of a three-dimensional carbon framework and CrFeCoNiRu0.5-HENA nanocrystal. The carbon framework offers high ion/electron conductivity and good affinity with NO3- and CO2 due to the presence of hydrophilic oxygen-containing groups and highly electronegative nitrogen atoms. The CrFeCo-NiRu0.5-HENA nanocrystal has a small size of 52.5 x 1.2 nm, good element homogeneity and high crystallinity. Such a unique structure improves the adsorption capacity towards NO3 - and CO2 and the electrocatalytic activity towards the C-N coupling reaction. The CrFeCoNiRu0.5-HENA/C electrocatalyst exhibits a high urea yield of 35.57 x 0.81 mmol gcatalyst -1 h-1 with a high faradaic efficiency of 21.02-0.77%, which is much better than that of multi-component nano-alloys from Cr, Fe, Co, Ni and Ru. This study also provides an approach for the construction of high-entropy nano-alloys in catalysis, sensing and energy storage and conversion. [ABSTRACT FROM AUTHOR]

Electroreduction of CO2 to energy chemicals in aqueous electrolytes is usually limited by logy OER at the anode and competing HER at the cathode. An N-doped carbon encapsulated Cu-CoO composite (CuCo@NC) fabricated by the facile pyrolysis of Cu and Co salts and melamine mixture was used as a cathode for CO2 reduction to CO and CH4, coupled with the anodic oxidation of CH3OH to dimethoxymethane in an ionic liquid-methanol medium to boost the anode reaction. The electrolytic system exhibits efficient redox activity with a higher average FEDMM (58.7%) within 48 h and high instantaneous FEC1 (99.1%) for CO + CH4 at 24 h. Simultaneous production of the high-value chemicals DMM and CO + CH4 in an electrolysis cell is achieved. The surface composition and structure of this composite with higher saturation magnetization, specifically the contribution of the Cu, CuOx, and CoOx crystallines to the catalytic performance of CO2eRR and magnetic properties, were explored. The catalytic system achieves high activity within 72 h of continuous electrolysis, and the electrode and ionic liquid can remain intact after being used three times, indicating the high operational stability of the CO2eRR system. [ABSTRACT FROM AUTHOR]

Developing efficient catalysts to convert CO2 into value‐added chemicals is valuable for reducing carbon emissions. Herein, a kind of novel thiolate‐based ionic liquid with sulfur as the active site was designed and synthesized, which served as highly efficient catalyst for the reductive N‐functionalization of CO2 by amines and hydrosilane. By adjusting the CO2 pressure, various N‐formamides and N‐methylamines were selectively obtained in high yields. Remarkably, at the catalyst loading of 0.1 mol %, the N‐formylation reaction of N‐methylaniline exhibited an impressive turnover frequency (TOF) up to 600 h−1, which could be attributed to the roles of the ionic liquids in activating hydrosilane and amine. In addition, control experiments and NMR monitoring experiments provided evidence that the reduction of CO2 by hydrosilane yielded formoxysilane intermediates that subsequently reacted with amines to form N‐formylated products. Alternatively, the formoxysilane intermediates could further react with hydrosilane and amine to produce 4‐electron‐reduced aminal products. These aminal products served as crucial intermediates in the N‐methylation reactions. [ABSTRACT FROM AUTHOR]

Current self‐healing ionogels are unable to undergo closed‐loop recycling and are unsuitable for large‐scale fabrication, which increases their manufacturing costs and limits their practical applications. In this study, self‐healing thermochromic ionogels with room‐temperature closed‐loop recyclability and self‐healing capability are large‐scale prepared by the in situ synthesis of imine bond cross‐linked supramolecular polymers in binary ionic liquids. The resulting ionogels show excellent mechanical and environmental stability, high solar modulation capability, and long service life, which can provide spontaneous solar modulation for buildings and vehicles to reduce cooling‐related energy consumption. The temperature‐responsive hydrogen bonding between supramolecular polymers and ionic liquids influences the dissolution state of the supramolecular polymers, allowing the self‐healing thermochromic ionogels to switch between transparent and opaque states through reversible agglomeration of ILs inside the ionogels. Dynamic imine bonds enable the ionogels to spontaneously heal themselves at room temperature and to be depolymerized into monomers in an extremely high yield and purity under hydrochloric acid catalysis at room temperature. The recovered monomers can be used to re‐manufacture self‐healing thermochromic ionogels without losing their original mechanical properties or thermochromic capability. This study provides a new route for developing functional self‐healing ionogels that can be large‐scale fabricated and closed‐loop recycled. [ABSTRACT FROM AUTHOR]

The carbonyl cluster compound [GeRu6(CO)18HI] is unique in regard to its structure and bonding with a GeRu6 cluster core, a planar GeRu4HI unit, extensive multi‐center bonding, and an aromatic ring current similar to benzene (9‐10 nA T−1). The open‐shell cluster core is a Ge‐centered five‐membered Ru4(Ru2) ring with CO ligands and an additional H and I atom, each bridging two Ru atoms on opposite sides of the cluster core. The compound is prepared at 130 °C in a weakly‐coordinating ionic liquid. [ABSTRACT FROM AUTHOR]

Carbon capture, utilization, and storage (CCUS) are among the key technologies to achieve large‐scale carbon emission reduction globally. Deep eutectic solvents (DESs) are considered as designable solvents, which has attracted intensive attention for CO2 capture. Here, a series of binary DESs are synthesized through one‐step mixing with the starting materials of protic ionic liquid (PIL) and amine. The eutectic behavior was investigated by measuring the melting point of PILs and amine. The saturated vapor of these DESs and industrial MDEA solution were measured and compared. These DESs are investigated to have high absorption capacity (0.1 g ⋅ g−1 at 1.0 bar and 25 °C), superior apparent absorption rate constant (0.381 min−1 vs 0.012 min−1 of 70 wt.% MDEA), moderate interaction with CO2 (the enthalpy change is as low as −34.8 kJ ⋅ mol−1). The absorption mechanism is also investigated by NMR analysis. Eight absorption/desorption regeneration experiments are carried out to show their reversibility. Considering the advantages, including convenience of synthesis, large absorption capacity, fast absorption rate, and moderate interaction energy as well as good regeneration, these DESs are believed to be as potential CO2 absorbent in practical applications. [ABSTRACT FROM AUTHOR]

Satellite propulsion uses liquid mono or bi‐propellants composed of a hydrazine in combination with a strong oxidant. However, hydrazines are highly toxic. As a result, many research efforts for more environmentally compatible propellants have been made over the past decade. In this study we evidence green formulations that retain high propulsive performances. They are based on the dinitramide anion. From an initial library of 37 ammonium dinitramides 3 best candidates were selected after evaluation of their potential syntheses, calculated theoretical performances, experimental synthesis optimizations and decomposition temperatures. These three salts were then formulated to obtain acceptable sensitivities and melting points, which eventually led to only one formulation being retained: a 40 : 60 mixture of dimethylammonium dinitramide and ammonium dinitramide phlegmatized by 10 % of glycerol. [ABSTRACT FROM AUTHOR]

We synthesized several protic ionic liquids (ILs) composed of onium cations and the (trifluoromethylsulfonyl)(vinylsulfonyl)amide anion. The addition of a base catalytically facilitated their transformation into zwitterions (ZIs) under solvent-free conditions, which is a convenient method for synthesizing ZIs from ILs. [ABSTRACT FROM AUTHOR]

Lipases, crucial catalysts in biochemical synthesis, find extensive applications across industries such as food, medicine, and cosmetics. The efficiency of lipase-catalyzed reactions is significantly influenced by the choice of solvents. Polar organic solvents often result in a decrease, or even loss, of lipase activity. Conversely, nonpolar organic solvents induce excessive rigidity in lipases, thereby affecting their activity. While the advent of new solvents like ionic liquids and deep eutectic solvents has somewhat improved the activity and stability of lipases, it fails to address the fundamental issue of lipases' poor solvent tolerance. Hence, the rational design of lipases for enhanced solvent tolerance can significantly boost their industrial performance. This review provides a comprehensive summary of the structural characteristics and properties of lipases in various solvent systems and emphasizes various strategies of protein engineering for non-aqueous media to improve lipases' solvent tolerance. This study provides a theoretical foundation for further enhancing the solvent tolerance and industrial properties of lipases. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) based on hybrid anions have recently garnered attention as beguiling alternative electrolytes for energy storage devices. This attention stems from the potential of these asymmetric anions to reduce the melting point of ILs and impede the crystallization of ILs. Furthermore, they uphold the advantages associated with their more conventional symmetric counterparts. In this study, we employed dispersion-corrected density functional theory (DFT-D) calculations to scrutinize the interplay between two hybrid anions found in ionic liquids [FTFSA]− and [MCTFSA]− and the [C4mpyr]+ cation, as well as in lithium polysulfides in lithium–sulfur batteries. For comparison, we also examined the corresponding ILs containing symmetric anions, [TFSA]− and [FSA]−. We found that the hybrid anion [MCTFSA]− and its ionic liquid exhibited exceptional stability and interaction strength. Additionally, our investigation unveiled a remarkably consistent interaction between ionic liquids (ILs) and anions with lithium polysulfides (and S8) during the transition from octathiocane (S8) to the liquid long-chain Li2Sn (4 ≤ n ≤ 8). This contrasts with the gradual alignment observed between cations and lithium polysulfides during the intermediate state from Li2S4 to the solid short-chain Li2S2 and Li2S1. We thoroughly analyzed the interaction mechanism of ionic liquids composed of different symmetry anions and their interactions with lithium polysulfides. [ABSTRACT FROM AUTHOR]

At temperatures ranging from 293.15 to 343.15 K and atmospheric pressure, the densities, refractive indices, dynamic viscosities, surface tensions, and sound speeds for [Cnmpyr][[NTf2] (n = 3,4,6,8), [Cnmpyr][[N(CN)2] (n = 3,4), [Cnmim][[N(CN)2] (n = 2,4) and [Bnzmim][[N(CN)2] were measured and discussed. As expected, all properties decrease as the temperature rises, with dynamic viscosity being the property most affected by the temperature change. Using linear correlation as a function of temperature, the density, speed of sound, surface tension, and refractive index are calculated, whereas the dynamic viscosity is correlated using the well-known Vogel–Fulcher–Tamman (VFT) equation. Using the experimental density data, the corresponding coefficients of thermal expansion were calculated. Furthermore, the Laplace–Newton equation was utilized to determine the isentropic compressibility. Results unveiled that the type of anions has the higher influence on the physical properties of the studied ionic liquids, while the elongation of the alkyl chain is less significant. [ABSTRACT FROM AUTHOR]

Knowing about the dissolution kinetics and solubility is necessary for controlling crystallization separation process of lysozyme. In this study, the impact of four ionic liquids (ILs), namely, 1-butyl-3-methylimidazolium tetrafluoroborate [C4mim]BF4, 1-butyl-3-methylimidazole chloride [C4mim]Cl, 1-butyl-3-methylimidazole bromide [C4mim]Br, and 1,3-dimethylimidazolium iodide [dmim]I, on the dissolution rate of lysozyme was determined in an aqueous solution at 20 ℃, pH 5.01, under 101.3 kPa. The results revealed that the dissolution rate of lysozyme increased with increasing concentrations of [C4mim]BF4 and [C4mim]Cl, while it remained stable with increasing concentrations of [C4mim]Br. In contrast, the dissolution rate gradually decreased with increasing concentrations of [dmim]I. This suggests that the interaction between lysozyme molecules is influenced by the ILs, leading to variations in the dissolution rates. Additionally, the effect of anions and cations on the equilibrium solubility was analyzed. The results indicated that the order of anionic and cationic effects on equilibrium solubility is as follows: BF4− < Cl− < Br− = [C4mim]+ < [dmim]+ < I−. Furthermore, dissolution kinetic models were established, which could be used to predict the dissolution behavior of large molecules like lysozyme in ILs aqueous solution. These findings have significant implications for the design of crystallization process and optimization of parameters during lysozyme recovery. [ABSTRACT FROM AUTHOR]

Since the 21st century, transparent flexible sensors (TFSs) have been widely employed in abundant fields, such as smart glasses, intelligent watches, robots, electronic skin, especially biomedicine. Presently, various materials have been developed, such as metal‐based, carbon‐based, conductive polymer‐based, and ionic liquid‐based (IL‐based) materials. Compared with the first three materials, IL, as a novel material, with the tendency of green chemistry development, has a high application prospect in TFSs. Based on this, this paper mainly discusses recent advances in TFSs based on ILs, with special emphasis on the role of ILs and the factors influencing transparency as well as electricity. The current challenges and opportunities for each type of sensors based on IL are also studied. [ABSTRACT FROM AUTHOR]

The speciation of uranium bis(trifluoromethylsulfonyl)imide (TFSI) species formed from UI3(THF)4 in butyl-methylpiperidinium bis(trifluoromethylsulfonyl)imide ([BMPip][TFSI]) and [BMPip][TFSI]/HTFSI was investigated by X-ray absorption fine structure (XAFS) spectroscopy. Following the dissolution of UI3(THF)4 in the room temperature ionic liquid (RTIL), X-ray absorption near edge spectroscopy (XANES) indicates that U(III) did fully oxidize to U(VI) in [BMPip][TFSI] while a U(VI)/U(IV) mixture was obtained in [BMPip][TFSI]/HTFSI media. Extended X-ray absorption fine structure (EXAFS) results are consistent with the formation of UO2(TFSI)2(THF)3 in [BMPip][TFSI]. The U-S(TFSI) distance (i.e., 3.81(4) Å) is consistent with the presence of TFSI ligands coordinated to the UO22+ unit in monodentate mode. In [BMPip][TFSI])/HTFSI, EXAFS indicates the presence of UO2(TFSI)2(THF)3 (~ 35%) and of a U(IV) species coordinated to THF and TFSI ligands. The number of TFSI ligands coordinated to U(IV) (i.e., ~ 0.5) is consistent with the presence of an outer-sphere U(IV)-TFSI complex. [ABSTRACT FROM AUTHOR]

In this study, a biphasic system combining oil and ionic liquid was utilized for lipase-catalyzed transesterification of salmon oil and alcohol to concentrate n-3 PUFAs, notably EPA and DHA. Various process variables, such as enzyme type, quantity, alcohol chain length, temperature, reactant proportions, and ionic liquid selection, were systematically assessed to optimize the process and enhance the yield of these valuable fatty acids. It was found that the Novozym 435 and Lipolase 100L Type EX emerged as the most effective enzymes. The impact of varying alcohol chain lengths (C1–C8) was examined, revealing that the Novozym 435 enzyme displayed its peak synthetic activity with 2-propanol. The results revealed a substantial increase in the overall activity during the transesterification reaction when employing ILs featuring hydrophobic cations and anions with low nucleophilicity. Specifically, the [omim+][NTf2−] ionic liquid exhibited the highest level of activity. This research holds promise for more efficiently and sustainably obtaining concentrated n-3 PUFAs from fish oil while reducing environmental impact relative to other existing concentration processes. [ABSTRACT FROM AUTHOR]

Ionic liquids (ILs) are widely adopted as lubricating materials in engineering fields for steel sliding contacts, and the adsorption structure and kinematic state of friction surfaces are crucial for understanding the improvement of tribological properties in experiments. In this study, we employed molecular dynamics methods to examine the structure and shear dynamics of five ILs with the same cationic triethanolamine paired with carboxylate anions of different alkyl chain length, confined between two crystalline iron surfaces. The results show that the chain length of anions influence the quantity of hydrogen bonds formed, the distribution on the iron surfaces, the thickness of the adsorption layers during the sliding process and the overall motion state. Under elastohydrodynamic lubrication conditions, ILs with longer alkyl chain exhibit less friction on a macroscopic scale due to the weaker hydrogen bonds between the anions and cations, the formation of thicker adsorption layers between sliding surfaces, and the overall pronounced layering phenomenon. These atomic insights into the structure and state of motion during friction can help promote the use of ILs as lubricating materials in engineering applications. [ABSTRACT FROM AUTHOR]

Ionic liquid functionalised egg residues were tested for their biosorption ability towards water soluble anionic 'orange G' dye. Egg residues after ionic liquid treatment were characterised via FTIR, SEM and TGA. Adsorption process was optimised by evaluating different experimental parameters including effect of adsorbent dose, contact time, agitation speed, temperature and pH. Modified egg shell membrane (MESM) exhibited higher efficiency for orange G dye adsorption followed by unmodified egg shell membrane (ESM) and powdered egg shell (PES). Equilibrium states were achieved in 1 hour for the different studied initial dye concentrations at acidic pH, 120 rpm and 30°C. Under optimum conditions >95% dye is removed with 27 mg/g adsorption capacity of MESM for 80 ppm dye solution. Study was further extended to find the best-fitted kinetic and isothermal model. It was found that the process follows pseudo-second-order kinetics and Langmuir isothermal model. Adsorbent was regenerated and reused without significant loss of efficiency. This research work presented that ionic liquid modified egg shell membrane is highly efficient with regard to its ecological perspective and cost effectiveness for the removal of toxic dye from wastewater. [ABSTRACT FROM AUTHOR]

A novel magnetic nanocomposite modified with a new branched polymer containing nitrogen-rich ligand moieties was synthesized and used to stabilize Pd nanoparticles. The resulting catalyst was characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, vibrating sample magnetometry, thermogravimetric analysis and energy-dispersive X-ray. The synthesized catalyst has been applied as an efficient catalyst in the reduction of nitro compounds to corresponding amines and reductive degradation of organic dyes such as methyl orange and methyl red. The catalyst showed high stability and reusability for 10 runs without significant loss in catalytic activity. [ABSTRACT FROM AUTHOR]

Ionic liquids are the base for electrospray propulsion, yet few have been explored. The performance of an externally wetted electrospray thruster is characterized for seven different ionic liquids: 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-B F 4), dicyanamide (EMI-DCA), bistrifluoromethylsulfonylimide (EMI-Im), thiocyanate (EMI-SCN), ethylsulphate (EMI-EtOSO 3), triflate (EMI-OTf), and trifluoromethanesulfonate (EMI-TFA). This research marks the first time that the latter four liquids are reported for externally wetted emitters. A complete thruster assembly has been tested with each of the propellants. Using time-of-flight mass spectrometry and a Faraday cup for beam divergence, the performance of these ionic liquids has been characterized, assessing thrust, specific impulse and thrust efficiency. EMI-B F 4 , EMI-DCA and EMI-SCN operated in pure ionic regime while EMI-Im, EMI-EtOSO 3 , EMI-OTf and EMI-TFA operated in mixed regime. • Characterization of externally wetted electrospray thruster with 7 ionic liquids. • Ionic liquids with higher conductivity exhibited higher emitted current. • Ionic liquids with higher conductivity showed better performance at same voltage. • EMI-BF4, EMI-DCA, and EMI-SCN operate in pure ionic regime. • EMI-EtOSO3, EMI-Im, EMI-OTf, and EMI-TFA operate in mixed regime. [ABSTRACT FROM AUTHOR]

In the current study, the synthesis of an imidazolium ionic liquid (imi@MCM‐41/Fe3O4) was carried out with the aim of its application as an additive to enhance the electrochemical properties of anion exchange membranes. In heterogeneous membranes, resin particles act as functional groups, and the uniform distribution of these particles on the membrane surface and their amount have a significant effect on the electrochemical properties of the resulting membranes. Imidazolium groups can act as functional groups in anion exchange membranes. Therefore, the addition of an ionic liquid with imidazolium functional groups was carried out with the double aim of increasing the number of functional groups and obtaining a more uniform distribution of resin particles on the membrane surface. The FTIR and SEM analyses confirmed the functionalization of ionic liquid with imidazolium groups and their size on a nanometer scale. The effect of the ionic liquid to the resin ratio on the electrochemical properties and on the hydrophilicity of the membrane was investigated. The results showed that the uniform distribution of resin particles on the membrane surface in the presence of ionic liquid nanoparticles as well as the presence of ionic liquid functional groups significantly improved the electrochemical properties of the membrane. At a concentration of 1 wt.%, the ion exchange capacity, permselectivity, and electrical resistance were enhanced by 73%, 9%, and 47%, respectively. [ABSTRACT FROM AUTHOR]

A new protic ionic liquid (IL) was synthesized by the neutralization reaction of 1H-benzotriazole (BTA) and bis(2-ethylhexyl) phosphoric acid (HDEHP) and evaluated as a catalyst in the esterification reaction of oleic acid and polyethylene glycol (PEG) 400, as well as an anti-wear and anti-corrosion additive in the synthesized ester. The response surface methodology (RSM) was used to design the experiments and optimization of the esterification reaction, which at the optimum conditions (1 wt% of IL, at the molar ratio of acid/alcohol of 1.55, the reaction temperature of 200 °C for 24 h) the maximum conversion of esterification was achieved (more than 99%). Unlike most ILs, [BTAH][DEHP] was fully miscible in synthesized ester and did not separate from the esterification process. [BTAH][DEHP] IL significantly reduced corrosion of copper, aluminum, and steel strips. Also, tribological evaluations illustrated that the 1, 2.5, 5, and 7.5 wt% of [BTAH][DEHP] IL in the PEG400 Oleate reduced the coefficient of friction to 30, 42, 46, and 59%, respectively. Using inexpensive raw materials, a simple synthesis procedure, and preparing green lubricant without catalyst separating, as well as suitable anti-corrosion and anti-wear and friction-reducing properties, could be addressed as advantages of the proposed method. [ABSTRACT FROM AUTHOR]

Capturing carbon dioxide is vital for mitigating global warming and supporting chemical processes. Ionic liquids (ILs) have emerged as promising solvents for CO2 capture. Using ASPEN simulation software, this study explores three specific ILs: [emim][triflate], [bmim][MeSO3], and [bmim][NTf2]. Their selection is based on exploitable differences in energy. The study models CO2 solubility and validates it against published data. It also considers the decomposition of ILs using a more accurate vapor loss model. Simulated equations predict CO2 and IL behavior more accurately than published ASPEN studies, optimizing the process for minimal energy consumption. Commercial considerations and rigorous engineering calculations guide the analysis, encompassing energy and economic factors. [ABSTRACT FROM AUTHOR]