Ionic Liquid Research Articles

Effect of Pyrrolidinium Based Ionic Liquid on Thermo Physical and Electrochemical Properties of Binary Aqueous Solutions of Benzylamine and Benzamide at Different Equidistant Temperatures (288.15 K to 318.15 K)

Effect of Pyrrolidinium Based Ionic Liquid on Thermo Physical and Electrochemical Properties of Binary Aqueous Solutions of Benzylamine and Benzamide at Different Equidistant Temperatures (288.15 K to 318.15 K)

Curing kinetics effect on thermo-mechanical properties of an epoxy resin cured by imidazolium-based ionic liquid

Curing kinetics effect on thermo-mechanical properties of an epoxy resin cured by imidazolium-based ionic liquid

Upcycling of Polystyrene Waste to Poly(ionic liquid) Materials

Upcycling of Polystyrene Waste to Poly(ionic liquid) Materials

Crystallization Control of Blade‐Coated Wide Bandgap FACs‐Based Perovskite

AbstractTransforming perovskite solar cells into commercial production requires advanced scalable deposition technology. However, the deposition of high‐quality perovskite thin films using the blade coating method presents challenges, especially in controlling the nucleation and crystallization of perovskite. In this work, an effective approach is proposed for controlling nucleation and crystallization by simultaneously incorporating two kinds of ionic liquid, namely 1H‐imidazole acetate (IMAc), and 1‐buty‐3‐methylimidazolium tetrafluoroborate (BMIMBF4), into the precursor solution. This innovative strategy initiates π–π interactions between IM and BMIM cations, thereby enhancing the interaction between cations and the Pb‐I framework. The competitive mechanism of interaction with Pb‐I framework effectively suppresses the formation of unfavorable mesophase, thereby enabling a single crystallization pathway from NMP + PbI2 to α‐perovskite. Consequently, this method effectively reduces defects and enhances the crystal quality of α‐perovskite film. Based on this strategy, the power conversion efficiency of the p‐i‐n wide bandgap perovskite device prepared by the blade coating method, is increased to 21.31%, representing one of the highest efficiencies achieved with this technology for 1.68 eV bandgap FACs‐based perovskites. Thus, this approach emerges as a feasible breakthrough strategy that may unleash the full potential of perovskite solar cells.

Ionic Liquid Additive Mitigating Lithium Loss and Aluminum Corrosion for High-Voltage Anode-Free Lithium Metal Batteries.

Concentrated electrolytes based on lithium bis(fluorosulfonyl)imide (LiFSI) have been proposed as an effective Li-compatible electrolyte for anode-free lithium metal batteries (AFLMBs). However, these electrolytes suffer from severe aluminum corrosion at an elevated potential. To address this issue, we propose a binary ionic liquid (IL) electrolyte additive comprising the 1-methyl-1-butyl pyrrolidinium cation (Pyr14+), difluoro(oxalate)borate anion (DFOB-), and difluorophosphate (PO2F2-) anion to mitigate the Li inventory loss and Al corrosion in 4 M LiFSI/DME electrolyte simultaneously. On the anode side, the IL additive facilitates the formation of a robust Li3N- and LiF-rich solid electrolyte interphase, promoting highly reversible Li plating/stripping and uniform Li deposition. Additionally, the ILs alter the Li+ solvation structure, leading to enhanced tLi+ and rapid Li+ desolvation kinetics. Concurrently, on the cathode side, the ILs aid in the generation of dense LiF- and AlF-rich passivation films against Al corrosion. By using the IL-added electrolyte, the Cu||LiMn0.7Fe0.3PO4 cell operates stably at 4.5 V, and the Cu||NCM613 cell with a high loading of 4.0 mA h cm-2 sustains 142 cycles until 80% capacity retention. This research contributes to a deeper understanding of the IL additive mechanism at the electrode-electrolyte interfaces and offers a straightforward approach to designing practical high-voltage AFLMB electrolytes.

Shaping a gallium alloy and an ionic liquid into spherical mirrors for future liquid-based telescopes—experimental setup and demonstration in parabolic flights

Shaping a gallium alloy and an ionic liquid into spherical mirrors for future liquid-based telescopes—experimental setup and demonstration in parabolic flights

Fe3O4@SiO2@[Aminoglycol][Formate] as a new superparamagnetic nanocatalyst and [Aminoglycol][Formate] as a novel ionic liquid catalyst for preparation of new dimethyldihydropyrimido[4,5-b]quinolone derivatives.

Efficient synthesis of novel dimethyldihydropyrimido[4,5-b]quinolones via three-component condensation of barbituric acid, arylaldehydes, and 3,4-dimethylaniline catalyzed by Fe3O4@SiO2@[Aminoglycol][Formate] as a new superparamagnetic nanocatalyst and [Aminoglycol][Formate] as a novel ionic liquid catalyst was described. The new heterogeneous nanocatalyst was characterized by FE-SEM, XRD, FT-IR, TGA-DTG, and VSM techniques. The new ionic liquid was characterized by 13CNMR, 1HNMR, and FT-IR techniques. The present work has advantages, such as excellent yields, short reaction times, environmentally friendly protocol, easy separation, and purification of products. The catalysts kept its catalytic properties after even five recoverability and reusability.

Mechanically Reinforced Pseudosolid Polyelectrolyte Membranes via Layer‐by‐Layer Assembly for High‐Performing Lithium‐Metal Batteries

AbstractIonogels are emerging as high‐potential pseudosolid electrolytes for lithium‐metal batteries (LMBs), leveraging their intrinsic high ionic conductivity from entrapped ionic liquid (IL) electrolytes. However, their practical application is hindered by poor mechanical strength stemming from the confinement of ILs within a polymer matrix. To address this challenge, the formation of conformal polyion coatings with functional groups is reported to be relevant to LMBs’ application on ionogels, utilizing a layer‐by‐layer (LbL) assembly strategy. This approach significantly enhances the mechanical strength (Young's modulus and tensile strength) and electrochemical performance of ionogels, owing to the tailored interface modifications introduced by functional groups’ specific conformal polyion coatings. The core of this methodology leverages the inherent ionic structure of ionogels to enable facile interface modification through Coulombic interactions between polyanions and polycations. These conformally coated interface functionalized membranes show improved electrochemical performance when integrated with cathode materials such as LiFePO4 (LFP) and LiNi0.8Mn0.1Co0.1O2 (NMC811) in an LMB configuration, underscoring their potential for robust, high‐conductivity, pseudosolid membranes for LMB applications. These innovative pseudosolid membranes offer improved mechanical and electrochemical properties, leading to higher battery efficiency and safety, making them promising candidates for next‐generation LMB technology.

Development of an Ionic Conductive Elastomer from the Photocopolymerization of a Ternary Polymerizable Deep Eutectic Solvent for Human Motions Sensing.

Polymerizable deep eutectic solvents (PDES) represent a novel class of ionic liquids characterized by the presence of polymerizable groups in their hydrogen-bond donor or acceptor components. Within the realm of flexible electronics, PDES is emerged as a promising material for the fabrication of sensors that exhibit both flexibility and stretchability. This research employs the UV-initiated photocopolymerization of a ternary PDES composed of choline chloride (ChCl), 2-hydroxyethyl acrylate (HEA), and itaconic acid (IA), to synthesize an ionic conductive elastomer (ICE) that boasts desirable comprehensive performances, which can be controlled by meticulously adjusting the ratios of these components. The fabrication process is streamlined and efficient, utilizing cost-effective and eco-friendly materials. This elastomer exhibits favorable ionic conductivity (1.70 × 10-2-5.45 × 10-2 S m-1), mechanical strength (0.48-1.21MPa stress at break, 395-701% elongation at break), adhesion capacity (49-120kPa adhesion strength), and sensing sensitivity toward human motions.

Tailoring of Novel Ru (III) and Cr (III) Salen Complexes as Catalysts for a Sustainable and Green Synthesis of Dihydro‐tetrazolo [1,5‐a] thiazolo [4,5‐d] pyrimidin‐6‐yl morpholine: Experimental and Theoretical Approaches

ABSTRACTTwo novel Cr (III) and Ru (III) salen complexes based on {3,4‐Bis‐[(5‐chloro‐2‐hydroxy‐benzylidene)‐amino]‐phenyl}‐phenyl‐methanone ligand (CSAB) were synthesized. The complexes were characterized using various spectral and analytical methods. The catalytic performance of the CSAB complexes was investigated via a four‐component condensation reaction involving aromatic aldehydes, rhodamine, morpholine, and 5‐aminotetrazole under mild, environmentally friendly conditions. Different Lewis acids, bases, ionic liquid catalysts, solvents, and catalyst amounts were assessed to optimize the reaction parameters. Both catalyst systems demonstrated robust catalytic activity under strictly managed conditions, with the heterogeneous catalyst CSAB‐Ru showing superior efficacy compared to the homogeneous CSAB‐Cr catalyst. The study confirmed the catalytic capabilities of both complexes and evaluated their recyclability and reusability. The heterogeneous catalyst (CSAB‐Ru) could be reused seven times, whereas the homogeneous catalyst (CSAB‐Cr) could be recycled four times. Both complexes demonstrated strong catalytic activity and selectivity, resulting in high product yields. The study provides insights into the synthetic applications of novel CSAB complexes, highlighting their potential in organic transformations. It emphasizes their ease of use, safety, stability, component availability, quick reaction times, and high yields, making them promising for future industrial applications.

Study of Ionanofluids Behavior in PVT Solar Collectors: Determination of Thermal Fields and Characteristic Length by Means of HEATT® Platform

Solar electric and solar thermal energies are often considered as part of the solution to the current energy emergency. The pipes of flat plate solar devices are normally heated by their upper surfaces giving rise to an asymmetric temperature field in the bulk of the fluid, which influences the heat transfer process. In the present work, a study of the characteristic length of tubes, or most efficient distance at which heat transfer occurs, in flat photovoltaic-thermal (PVT) hybrid solar devices has been carried out using three heat transfer fluids: water, [Emim]Ac ionic liquid and ionanofluid of graphene nanoparticles suspended in the former ionic liquid. The mean objective of the study was to know whether the heat transfer occurs in optimal conditions. Experimental measurements have been made on a commercial PVT device, and numerical simulations have been performed using the HEATT® platform to determine the characteristic length of the process. The tests conducted showed a clear improvement in the temperature jump of the fluid inside the collector when INF is used compared to water and ionic liquid and even a higher overall energy efficiency. Electricity generation is not greatly affected by the fluid used, although it is slightly higher when water is used. Slower fluid velocities are recommended if high fluid outlet temperatures are the goal of the application, but this penalizes the overall thermal energy production. The characteristic process length is not typically achieved in parallel tube PVT collectors with ordinary flow rates, which would require a speed, and consequently, a flow rate, about 10 times lower, which penalizes the performance (up to four times), although it increases the fluid outlet temperature by 234%, which can be very interesting in certain applications. Ionanofluids may in the medium term become an alternative to water in flat plates or vacuum solar collectors for applications with temperatures close to or above 100 °C, when their costs will hopefully fall. The results and methodology developed in this work are applicable to solar thermal collectors other than PVT collectors.

The Interaction Between Fluorinated Additives and Imidazolyl Ionic Liquid Electrolytes in Lithium Metal Batteries: A First‐Principles Study

ABSTRACTThis investigation employs first‐principles calculations to explore the interaction between imidazolium ionic liquids (ILs) and fluoride additives on lithium metal surface. Our focus lies in the comprehensive analysis of three distinct categories of fluorinated additives, each differing in their degree of fluorination. The computations reveal that fluorination plays a significant role in determining both the ionic conductivity and the formation of the solid–electrolyte interphase (SEI) film. Specifically, heightened fluorination enhances the oxidative stability of the system but diminishes the strength of solvent binding, resulting in the formation of larger salt/anion clusters and a decrease in ionic conductivity. Conversely, increased fluorination facilitates the interaction between fluorinated additives and the lithium metal surface, thereby aiding in the formation of a stable SEI film characterized by an abundance of inorganic LiF components. This is important as it serves to suppress dendrite growth and mitigate interface side reactions. Considering the combined influences of ionic conductivity and film formation, 1FP is suggested as the optimal candidate for pyridine‐based additive systems, with FEC preferred for cyclic ester‐based additive systems and BC for chain ester‐based additive systems. This study provides theoretical references for the design of ionic liquid‐fluorinated additive electrolyte systems that can protect the lithium metal anode.

New emerging materials with potential antibacterial activities.

The increasing prevalence of multidrug-resistant pathogens is a critical public health issue, necessitating the development of alternative antibacterial agents. Examples of these pathogens are methicillin-resistant Staphylococcus aureus (MRSA) and the emergence of "pan-resistant" Gram-negative strains, such as Pseudomonas aeruginosa and Acinetobacter baumannii, which occurred more recently. This review examines various emerging materials with significant antibacterial activities. Among these are nanomaterials such as quantum dots, carbon quantum dots, metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and layered double hydroxides, all of which demonstrate excellent antibacterial properties. Interestingly, including antibacterial agents within the structure of these materials can help avoid bacterial resistance and improve the long-term efficacy of the materials. Additionally, the antibacterial potential of liquid solvents, including ionic liquids and both deep eutectic solvents and natural deep eutectic solvents, is explored. The review discusses the synthesis methods, advantages, and antibacterial efficacy of these new materials. By providing a comprehensive overview of these innovative materials, this review aims to contribute to the ongoing search for effective solutions to combat antibiotic resistance. Key studies demonstrating antibacterial effects against pathogens like Escherichia coli, Staphylococcus aureus, and multidrug-resistant strains are summarized. MOFs have exhibited antibacterial properties through controlled ion release and surface interactions. COFs have enhanced the efficacy of encapsulated antibiotics and displayed intrinsic antibacterial activity. Other nanomaterials, such as quantum dots, have generated reactive oxygen species, leading to microbial inactivation. This review aims to provide insights into these new classes of antibacterial materials and highlight them for addressing the global crisis of antibiotic resistance. KEY POINTS: • Nanomaterials show strong antibacterial effects against drug-resistant bacteria • Emerging solvents like ionic liquids offer novel solutions for bacterial resistance • MOFs and COFs enhance antibiotic efficacy, showing promise in combating resistance.

Electrochemical biosensors for dopamine.

Dopamine (DA), a key catecholamine, plays a pivotal role in the regulation of human cognition and emotions. It has profound effects on the hormonal, memory, and cardiovascular systems. Anomalies like Alzheimer's, Parkinson's, schizophrenia, and senile dementia are linked to abnormal DA levels. Consequently, the precise determination of DA levels in biological systems is critical for the accurate diagnosis and treatment of these disorders. Among all analytical techniques, electrochemical studies provide the most selective and highly sensitive methods for detecting DA in biological samples. Ascorbic acid and uric acid are two examples of small biomolecules that can obstruct the detection of DA in biological fluids. To address this issue, numerous attempts have been made to modify bare electrodes to separate the signals of these substances and enhance the electrocatalytic activity towards DA. Various surface modifiers, including coatings, conducting polymers, ionic liquids, nanomaterials, and inorganic complexes, have been employed in the modification process. Despite the reported success in DA detection using electrochemical sensors, many of these approaches are deemed too complex and costly for real-world applications. Therefore, this review aims to provide an overview of DA electrochemical biosensors that are practical for real-world applications.

Understanding the Mid-Infrared Spectra of Protic Ionic Liquids by Density Functional Theory.

Protic ionic liquids (PILs) are promising candidates as electrolytes for proton exchange polymer membrane fuel cells. In order to optimize their properties, a detailed understanding of the molecular interactions within the bulk and at the electrode-electrolyte interface is needed, which can be obtained by infrared spectra. A prerequisite for extracting information on the molecular structure and inter- or intramolecular interactions from an experimental spectrum is a reasonable interpretation of the observed spectral features. Here, we employed density functional theory to understand the vibration modes of PILs composed of ammonium cations and different counteranions. Different from the previous calculation methods performed on small cluster model systems consisting of isolated species, a periodically repeated system of four ion pairs was used in order to approximate the bulk liquid environment. The computed frequencies and IR intensity match well with the corresponding experimental spectra, allowing for its proper interpretation, especially the characteristic features of the interionic interaction. The presented approach enables accurate computation of a variety of ionic liquid systems in a highly efficient way.

Nanodomains and Their Temperature Dependence in a Phosphonium-Based Ionic Liquid: A Single-Molecule Tracking Study.

Ionic liquids (ILs) exhibit a unique nanoscale structure (i.e., nanodomains) characterized by their organization into distinct domains. We present evidence of nanodomains in trihexyl(tetradecyl)phosphonium chloride, [P66614][Cl], using single-molecule tracking (SMT) and the maximum entropy method (MEM) to analyze single-molecule trajectories. The diffusion properties of ATTO 647N were assessed as the temperature of [P66614][Cl] increased from 20 °C (4020 cP), 35 °C (1239 cP), 45 °C (599 cP) to 50 °C (439 cP). The MEM analysis revealed a distinct two-population distribution of diffusion coefficients representing nanodomains in [P66614][Cl] at 20 °C (4020 cP). The slow population accounts for 16%, with a diffusion coefficient of 0.104 μm2/s, while the fast population constitutes 84% with a diffusion coefficient of 0.634 μm2/s. Two diffusing populations were also measured for the chemically different probes ATTO 647N, DiD, and Nile Blue chloride in [P66614][Cl] at 20 °C. In contrast, only a single fast population was measured in [P66614][Cl] at 50 °C. At a similar viscosity (640 cP) but a lower temperature of 20 °C, trihexyl(tetradecyl)phosphonium bis[(trifluoromethyl)-sulfonyl]imide, [P66614][NTf2], also showed only a single diffusing population. The elimination of the slow population and the presence of a single diffusing population in [P66614][Cl] as the temperature increases and the viscosity decreases is consistent with liquid-liquid phase separation (LLPS) as a mechanism of nanodomain formation. In addition, the measurement of two diffusing populations for three fluorophores with different chemical structures is also consistent with a physical mechanism, and not a chemical mechanism, for nanodomain formation.

Ionic Gel Chemical Sensors with Damage Tolerance for Monitoring Lithium‐ion Battery Electrolyte Leakage and Battery Safety

AbstractGiven the frequent occurrence of lithium‐ion battery (LIB) incidents, gas sensors monitoring LIB safety are imperative yet deficient. Here, a new class of LIB electrolyte sensors based on ionic gels is presented, in which ions instead of electrons act as charge carriers and interact with analyte molecules for improved sensitivity. The ionic gels are readily synthesized through the photopolymerization of ionic liquids (ILs) incorporating C═C bonds with structurally analogous ILs devoid of C═C bonds. Through systematic investigation, PF6− is identified as the optimal ion carrier for LIB electrolyte sensing. Trace amounts of LIB electrolyte (20 nL) leakage can be detected within seconds. Interestingly, the devices exhibit decent damage tolerance. More importantly, multiple sensors with decent consistency can be batch‐fabricated on a large scale, which is essential for practical applications. Remarkably, the devices exhibit an extended operational lifespan, endowing them with significant potential for long‐term safety monitoring. The sensors are integrated into a monitoring system and demonstrate exceptional capability in differentiating the various stages of LIB thermal runaway, which paves the way for their potential applications in power storage stations and electric vehicles.

Hydrogen radical-boosted electrocatalytic CO2 reduction using Ni-partnered heteroatomic pairs.

The electrocatalytic reduction of CO2 to CO is slowed by the energy cost of the hydrogenation step that yields adsorbed *COOH intermediate. Here, we report a hydrogen radical (H•)-transfer mechanism that aids this hydrogenation step, enabled by constructing Ni-partnered hetero-diatomic pairs, and thereby greatly enhancing CO2-to-CO conversion kinetics. The partner metal to the Ni (denoted as M) catalyzes the Volmer step of the water/proton reduction to generate adsorbed *H, turning to H•, which reduces CO2 to carboxyl radicals (•COOH). The Ni partner then subsequently adsorbs the •COOH in an exothermic reaction, negating the usual high energy-penalty for the electrochemical hydrogenation of CO2. Tuning the H adsorption strength of the M site (with Cd, Pt, or Pd) allows for the optimization of H• formation, culminating in a markedly improved CO2 reduction rate toward CO production, offering 97.1% faradaic efficiency (FE) in aqueous electrolyte and up to 100.0% FE in an ionic liquid solution.

Organic-Inorganic Hybrid Solid Composite Electrolytes for High Energy Density Lithium Batteries: Combining Manufacturability, Conductivity, and Stability.

The deployment of solid and quasi-solid electrolytes in lithium metal batteries is envisioned to push their energy densities to even higher levels, in addition to providing enhanced safety. This article discusses a set of hybrid solid composite electrolytes which combine functional properties with electrode compatibility and manufacturability. Their anodic stability >5V versus Li+/Li and compatibility with lithium metal stem from the incorporated ionic liquid electrolyte, whereas the organic-inorganic hybrid host structure boosts their conductivity up to 2.7mScm-1 at room temperature. The absence of strong acids enables compatibility with porous NMC811 electrodes. Liquid precursor solutions can be readily impregnated into porous electrodes, facilitating cell assembly. Electrolytes containing TFSI- as the only anion have a superior compatibility toward high-voltage positive electrode materials, whereas electrolytes containing both FSI- and TFSI- have a better compatibility toward lithium metal. Using the former as catholyte and the latter as anolyte, NMC811/Li coin cells retain up to 100% of their initial capacity after 100 cycles (0.2C, 3.0-4.4V vs Li+/Li). Because of their unprecedented combination of functional properties, electrode compatibility, and manufacturability, these hybrid solid composite electrolytes are potential candidates for the further development of lithium metal battery technology.

Efficient Selective CO2 Composite Sorbent from Amino Acid Ionic Liquids and Silica Gel: 2H NMR Spectroscopy Provides Insight on the CO2-Binding Mechanism and in-Pore Microscopic Viscosity.

A promising CO2 sorbent based on the [Emim][Gly] (1-ethyl-3-methylimidazolium glycinate)/silica gel composite has been studied. CO2 sorption experiments have shown that the optimum loading of [Emim][Gly] ionic liquid in silica gel is 40 wt.%. The 2-step process CO2 binding mechanism in [Emim][Gly] has been proposed based on the results of sorption experiments, 2H NMR spectroscopy and ab-initio calculations. The impact of CO2 on the microscopic viscosity and the dynamical melting of ionic liquid has been thoroughly investigated. 2H NMR spectroscopy has revealed that CO2 strongly binds cation and anion in [Emim][Gly], forcing them to move in a correlated fashion.