Search Results (233)

The photocatalytic reduction of CO₂ in aqueous media offers a sustainable route for solar-to-fuel conversion, yet remains challenged by CO₂’s thermodynamic stability and kinetic inertness, low solubility, and competitive hydrogen evolution. Here, we investigate the interplay between ionic liquids (ILs), photocatalyst supports, and additive composition in directing product selectivity among CO, CH₄, and H₂. Using imidazolium acetate as a benchmark, we demonstrate that ILs not only pre-activate CO₂ but can also undergo decomposition pathways under illumination, notably Kolbe-type reactions leading to methane formation from acetate rather than from CO₂. Comparative studies of Pd-decorated TiO₂ and g-C₃N₄ nanosheets reveal distinct behaviors driven by their interfacial interactions with the imidazolim-based ionic liquid: weak interaction with TiO₂ strongly promotes hydrogen evolution, whereas strong coupling with g-C₃N₄ synergizes with C₁C₄ImOAc to trigger acetate-derived Kolbe reactivity. The systematic evaluation of alternative salts confirms the determinant role of anion basicity and medium-pH-basic anions facilitate CO₂ activation, whereas weakly basic or non-coordinating anions favor water splitting. Overall, these results clarify the dual role of ionic liquids as both CO₂ activators and sacrificial agents, and highlight design principles for improving product selectivity and efficiency in aqueous CO₂ photoreduction systems. Full article

1-Butyl-3-methylimidazolium (bmim) ionic liquids (ILs) are widely used for lignocellulose fractionation, yet their role extends beyond mere solvents. This study revealed that bmim-based ILs act as active chemical reagents, modifying the lignin structure in an anion-dependent manner. Thermal treatment (80–150 °C) of spruce dioxane lignin with [bmim]OAc, [bmim]Cl, and [bmim]MeSO₄ resulted in two distinct transformation pathways. In [bmim]MeSO₄, acidic catalysis dominates, leading to lignin condensation (increase in weight-average molecular weight, M_w, to 15.2 kDa at 150 °C) and intense sulfur incorporation (up to 9.9%) via anion-derived methylation/sulfation. Conversely, [bmim]OAc promotes depolymerization (decrease in M_w to 3.6 kDa) and efficient covalent bonding of the bmim cation to lignin (up to 10.8 cations per 100 aromatic units and a 6.5% nitrogen content at 150 °C), preventing condensation. Two-dimensional NMR and HPLC-HRMS analyses revealed the formation of a C–C bond between the C₂ atom of the imidazole ring and the α-carbon of the phenylpropane lignin fragments and allowed for the identification of a number of individual nitrogen-containing lignin oligomers in the [bmim]OAc-treated samples. Their formation likely proceeds via nucleophilic addition of the N-heterocyclic carbene (NHC), derived from the bmim cation by deprotonation with the highly basic acetate anion, to aldehyde groups. The action of [bmim]Cl primarily induces acid-catalyzed transformations of lignin with minimal covalent modification. These findings redefine imidazolium ILs as reactive media in biorefining, where their covalent interactions can influence the properties of lignin but complicate its native structure and the recyclability of the IL. Full article

In this work, the adsorption of imidazolium-based ionic liquids containing the bis(trifluoromethanesulfonyl) imide anion (NTf₂⁻) from aqueous phase was evaluated using different activated carbons (ACs). Three commercial Acs and two Acs prepared from grape seeds (one produced by pyrolysis and the other by hydrothermal carbonization (HTC), both activated with potassium hydroxide) were tested, assessing the adsorption of both the cation and the anion. For commercial ACs, similar adsorption performances were observed, with maximum adsorption capacities ranging from 0.85 to 1.08 mmol g⁻¹. These values increased under acidic conditions (pH 4), reaching 1.74 mmol g⁻¹ for the 1-butyl-3-methylimidazolium cation (Bmim⁺) and 1.87 mmol g⁻¹ for NTf₂⁻. Among the prepared ACs, the HTC-derived AC showed slightly higher capacities than the commercial samples, while the pyrolysis-derived AC exhibited the highest adsorption capacity for BmimNTf₂ (3.36 mmol g⁻¹ at pH 4). In terms of reusability, the pyrolysis-derived AC maintained 84% of its initial adsorption capacity between the third and fifth regeneration cycles. These results highlight the high adsorption performance and recyclability of grape-seed-derived activated carbons, demonstrating their potential for the removal of ionic liquids from aqueous environments. Full article

Ionic Liquids (IL) are a unique class of molten salts, with specific formulations exhibiting antimicrobial properties. Several recent studies have highlighted the ability of ILs to form micelles, permeabilize the plasma membrane, and destabilize cellular structure, ultimately initiating cell death. Moreover, while these membrane-destabilizing properties are cytotoxic to most cellular organisms at high concentrations, their membrane destabilization capability at lower concentrations may lead to improvements in drug delivery for combinatorial therapies against specific microbes. Work presented in this study aimed to identify a synergistic relationship between ILs, 1-n-Hexyl-3-methylimidazolium chloride (HMIM[Cl]) and 1-Methyl-3-n-octylimidazolium chloride (OMIM[Cl]), and antifungal drugs (AF), Clotrimazole, Ketoconazole, Fluconazole, and Itraconazole, with the hypothesis that in a combinatory setting there should be improved AF efficacy against model fungal organisms: S. boulardii, S. cerevisiae, S. pombe, and C. albicans. Several complementary assays were used to identify the combined effects of IL + AF treatment, including Kirby–Bauer tests and minimum inhibitory concentrations (MIC) assays to establish antimicrobial effects, and flow cytometry to evaluate cell wall permeability. Finally, we demonstrate that at low concentrations, the ILs tested in this study are capable of improving the effectiveness of current antifungal compounds at concentrations not cytotoxic to human cells. Full article

Imidazolium-based ionic liquids bearing a homologous series of oxychlorine anions—1-butyl-3-methylimidazolium chlorite, chlorate, and perchlorate—were synthesized and characterized to relate anion oxygenation to density, thermal expansivity, viscosity, electrical and molar conductivity, ionicity, and antimicrobial performance. Temperature-dependent measurements were carried out from 293.15 to 323.15 K: density and viscosity were recorded and modeled to obtain thermal expansion coefficients; electrical and molar conductivities were measured under identical conditions; and activation parameters were extracted by Arrhenius analysis for viscous flow and for conductivity. Ionicity was assessed from Walden plots and quantified by vertical deviation from the potassium-chloride reference (Angell approach). Complementary DFT calculations provided optimized ion-pair geometries, noncovalent contact patterns, molecular electrostatic potential maps, and frontier-orbital descriptors. In silico ADMET properties were computed to contextualize pharmacokinetic and safety flags. Antimicrobial activity was evaluated by broth microdilution against Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Candida quilliermondii; [Bmim]Cl was included as a comparator to isolate the effect of anion oxygenation. The combined experimental–computational workflow delineates how chlorite, chlorate, and perchlorate shape physicochemical behavior, ionicity, and bioactivity in [Bmim] ionic liquids, providing design guidance for future applications. Full article

Tungsten is a critical raw material with increasingly important industrial applications. It is primarily found in minerals such as scheelite and wolframite (0.5% W), which are extracted and processed at the mine site to produce a high-grade scheelite concentrate (60% W). This process results in significant tungsten losses in the form of tailings, currently not utilized at the EU level. Deep eutectic solvents and imidazolium-based ionic liquids have been shown to possess excellent utility for recovering tungsten from low-grade concentrates, achieving tungsten oxide (96% purity) at high global yields (80%). In this study, an optimized ionic liquid-based process (involving leaching, solvent extraction, crystallization, and calcination) was developed at the laboratory scale. Important issues such as solvent flammability or the commercial availability of ionic liquids were addressed to ensure the safety and industrial feasibility of the process. Furthermore, a pilot plant was designed, constructed, and operated for a significant period (3 days). Tungsten oxide was produced with improved purity (>99%) and global yield (91.6%) in continuous operation. Full article

The research presented in this manuscript aimed to conduct complex studies on epoxy composites filled with modified biowaste. This work discusses the entire process: first, the preparation and analysis of oak waste flour used as an additive to epoxy materials based on Epidian 6; then, obtaining and characterizing epoxy composites containing 5 wt.% of biowaste; and finally, the determination of the influence of wood filler and modification performed using selected ionic liquids (tetradecyltrihexylphosphonium bis(trifluoromethylsulfonyl)amide (IL-1), tetradecyltrihexylphosphonium bis(2,4,4-trimethylpentyl)phosphinate (IL-2), and 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide) (IL-3)) on the susceptibility of epoxy composite to the enzymatic degradation. The enzymatic degradation was performed for four weeks using the lipase enzymes (Porcine Pancreas and Rhizopus Oryzae). The epoxy composition EP6-WF_IL-2, containing 5 wt.% of wood flour modified with IL-2, was characterized by the best mechanical parameters in terms of bending strength and flexural modulus (65.64 MPa and 1855.3 MPa, respectively). During enzymatic biodegradation, the lowest susceptibility to enzymatic degradation, regardless of the incubation conditions, was observed in samples of EP6-WF_IL-3 epoxy composition containing wood flour modified with methyltrioctylammonium bis(trifluoromethylsulfonyl)imide. Full article

Machine learning models and web-based tools have been developed for predicting key properties of imidazolium-based ionic liquids. Two high-quality datasets containing experimental density and viscosity values at 298 K were curated from the ILThermo database: one containing 434 systems for density and another with 293 systems for viscosity. Molecular structures were optimized using the GOAT procedure at the GFN-FF level to ensure chemically realistic geometries, and a diverse set of molecular descriptors, including electronic, topological, geometric, and thermodynamic properties, was calculated. Three support vector regression models were built: two for density (IonIL-IM-D1 and IonIL-IM-D2) and one for viscosity (IonIL-IM-V). IonIL-IM-D1 uses three simple descriptors, IonIL-IM-D2 improves accuracy with seven, and IonIL-IM-V employs nine descriptors, including DFT-based features. These models, designed to predict the mentioned properties at room temperature (298 K), are implemented as interactive applications on the atomistica.online platform, enabling property prediction without coding or retraining. The platform also includes a structure generator and searchable databases of optimized structures and descriptors. All tools and datasets are freely available for academic use via the official web site of the atomistica.online platform, supporting open science and data-driven research in molecular design. Full article

Poly(ionic liquids) (PILs) show great promise as a new class of solid electrolytes for energy applications, including high-temperature polymer electrolyte fuel cells, owing to their combination of the unique electrochemical properties of ionic liquids and macromolecular architecture. In this study, we prepared and characterized PIL-based composite polymer electrolyte membranes containing silica nanofibers (SiO₂NFs). The SiO₂NFs were prepared via electrospinning, followed by calcination, and were used as a thermally and mechanically stable, porous substrate. The crosslinked protic PIL was synthesized via in situ radical polymerization of imidazolium hydrogensulfate-based reagents (one monomer and one crosslinker). It was then used as the membrane matrix. The prepared freestanding PIL membranes remained thermally stable at temperatures of up to 180 °C. Furthermore, the PIL/SiO₂NF composite electrolyte membranes demonstrated improved mechanical properties due to reinforcement by the NF framework. These composite membranes also exhibited relatively high proton conductivity (approximately 0.1 to 1 mS/cm) in the 100–150 °C temperature range. Full article

In response to the prevalent issues of short inhibition cycles and poor environmental compatibility in traditional inhibitors, this study prepared a new sepiolite-based composite inhibitor by loading imidazolium ionic liquid onto sepiolite. Through TG-DTG analysis, cone calorimeter experiments, and FTIR spectroscopy, we comparatively investigated the combustion characteristics of the composite inhibitor and its effects on the oxidation properties, inhibition performance, and active functional groups of coal samples. The results demonstrate that appropriate loading optimizes the thermal stability of sepiolite. Compared with conventional inhibitors, the composite exhibited the minimum weight loss rate at characteristic temperatures and achieved greater delays in critical temperature points of coal samples. The composite inhibitor delayed ignition time by 27–44 s compared to conventionally inhibited coal. The 3% [BMIM][BF₄]/sepiolite formulation showed CO emission peak intensity 3.02 times that of raw coal within 0–200 s, while reducing CO₂ production rate by 10.56% compared to MgCl₂-treated samples at 1000 s. The P_PFI exhibited maximum enhancement. Post-inhibition analysis revealed a 22–51% reduction in peak areas of active functional groups, indicating that the sepiolite-based composite achieves inhibition through synergistic physical and chemical interactions. Ultimately, a sepiolite-based composite inhibitor with environmental benignity was developed, whose inhibition performance is significantly enhanced compared to the traditional inhibitor MgCl₂. This research provides theoretical foundations for developing advanced inhibitor materials in coal mine applications. Full article

A theoretical study was performed using Density Functional Theory (DFT) to investigate the impact of π-conjugated aliphatic chain growth on the chemical and electronic properties of hybrid antimony pentachloride salts with pyridine- and imidazolium-based cations. Ten molecular systems were optimized to determine their ground-state geometry. Using conceptual DFT, parameters such as chemical hardness, electrophilicity index, electroaccepting power, and electrodonating power were studied. The energy gap was obtained for all ten molecular systems, ranging from −4.038 to −3.706 eV as the chain length increased, favoring intramolecular charge transfer in long-chain systems. Natural bond orbital (NBO) analysis showed charge redistribution between anion and cation as the π-conjugated aliphatic chain grows. At the same time, non-covalent interaction (NCI) studies revealed key attractions and repulsive interactions, such as H···Cl and Cl···π, which are modulated by chain length. These results demonstrate that the structural modification of the cation allows for the fine-tuning of the electronic properties of ionic liquids (ILs). Increasing the conjugated aliphatic chain length was observed to reduce the chemical hardness and electrophilicity index, as well as affecting the Egap of the molecular systems. This work demonstrates that there is an optimal size for the inorganic ion, allowing it to form an optimal IL compound. Full article

Over the past few decades, lithium-ion batteries (LIBs) have gained significant attention due to their inherent potential for environmental sustainability and unparalleled energy storage efficiency. Meanwhile, polymer electrolytes have gained popularity in several fields due to their ability to adapt to various battery geometries, enhanced safety features, greater thermal stability, and effectiveness in reducing dendrite growth on the anode. However, their relatively low ionic conductivity compared to liquid electrolytes has limited their application in high-performance devices. This limitation has led to recent studies revolving around the development of poly(ionic liquids) (PILs), particularly imidazolium-mediated polymer backbones as novel electrolyte materials, which can increase the conductivity with fine-tuning structural benefits, while maintaining the advantages of both solid and gel electrolytes. In this study, a curated dataset of 120 data points representing eight different polymers was used to predict ionic conductivity in imidazolium-based PILs as well as the emerging ionene substructures. For this purpose, four ML models: CatBoost, Random Forest, XGBoost, and LightGBM were employed by incorporating chemical structure and temperature as the models’ inputs. The best-performing model was further employed to estimate the conductivity of novel ionenes, offering insights into the potential of advanced polymer architectures for next-generation LIB electrolytes. This approach provides a cost-effective and intelligent pathway to accelerate the design of high-performance electrolyte materials. Full article

This review surveys recent advances and emerging prospects in phase-transfer catalysis (PTC) for fuel desulfurization. In response to increasingly stringent environmental regulations, the removal of sulfur from transportation fuels has become imperative for curbing SO_x emissions. Conventional hydrodesulfurization (HDS) operates under severe temperature–pressure conditions and displays limited efficacy toward sterically hindered thiophenic compounds, motivating the exploration of non-hydrogen routes such as oxidative desulfurization (ODS). Within ODS, PTC offers distinctive benefits by shuttling reactants across immiscible phases, thereby enhancing reaction rates and selectivity. In particular, PTC enables efficient migration of organosulfur substrates from the hydrocarbon matrix into an aqueous phase where they are oxidized and subsequently extracted. The review first summarizes the deployment of classic PTC systems—quaternary ammonium salts, crown ethers, and related agents—in ODS operations and then delineates the underlying phase-transfer mechanisms, encompassing reaction-controlled, thermally triggered, photo-responsive, and pH-sensitive cycles. Attention is next directed to a new generation of catalysts, including quaternary-ammonium polyoxometalates, imidazolium-substituted polyoxometalates, and ionic-liquid-based hybrids. Their tailored architectures, catalytic performance, and mechanistic attributes are analyzed comprehensively. By incorporating multifunctional supports or rational structural modifications, these systems deliver superior desulfurization efficiency, product selectivity, and recyclability. Despite such progress, commercial deployment is hindered by the following outstanding issues: long-term catalyst durability, continuous-flow reactor design, and full life-cycle cost optimization. Future research should, therefore, focus on elucidating structure–performance relationships, translating batch protocols into robust continuous processes, and performing rigorous environmental and techno-economic assessments to accelerate the industrial adoption of PTC-enabled desulfurization. Full article

Long-chain imidazolium-based ionic liquids (ILs) possess a broad-spectrum biological activity and are considered promising antifouling agents for protective coatings. A new hydrophobic IL, 1-dodecyl-3-methylimidazolium dodecylbenzenesulfonate (C₁₂C₁IM-DBS), has been synthesized, and a modified epoxy coating material containing 10, 20, and 30 wt% of this IL was prepared by dissolution of C₁₂C₁IM-DBS in commercial DER 331 epoxy resin, followed by a curing phase with diethylenetriamine. Infrared analysis revealed physicochemical interactions between the hydroxyl groups of the resin and the IL. Spectrophotometric studies showed no release of C₁₂C₁IM-DBS after 30 days of exposure of the modified coatings to water. The plasticizing effect of the IL on the epoxy resin was established by differential scanning calorimetry analysis. The introduction of 10 and 20% C₁₂C₁IM-DBS into DER 331 reduced its glass transition temperature from 122.8 °C to 109.3 and 91.5 °C, respectively. The hardness of epoxy resin decreased by approximately 26% after the introduction of the IL. Moreover, DER 331/C₁₂C₁IM-DBS coatings on steel substrates showed significantly improved impact resistance compared to neat resin. The antibiofilm efficiency of DER 331/C₁₂C₁IM-DBS coatings was evaluated by assessing the capability of two biofilm-forming model strains, Staphylococcus aureus ATCC 25923 and Pseudomonas aeruginosa PA01, to form attached biofilms on the surface. The IL effectively inhibited S. aureus surface-associated biofilm development even at the lowest content of 10%. On the contrary, an approximately 50% inhibition of biofilm metabolic activity was detected for DER 331/C₁₂C₁IM-DBS coatings containing 20% and 30% of the IL. Overall, the results of this study indicate that the hydrophobic IL C₁₂C₁IM-DBS is an efficient modifying additive for epoxy resins, which can significantly improve their operational properties for various industrial applications. Full article

Microwave-assisted ionothermal strategies offer an effective pathway for rapid zeolite crystallization under mild conditions, while conventional ionothermal approaches are still constrained by prolonged crystallization cycles that limit their industrial applicability. Herein, we report a microwave-activated, ionic liquid-mediated synthesis strategy that enables the precise modulation of crystallization kinetics and composite assembly. By introducing ZSM-5 seeds into the ionic liquid system, the nucleation and growth of AlPO₄-5 were significantly accelerated, reducing crystallization time by up to 75% (optimal condition: 60 min). Among various imidazolium-based ionic liquids, [BMMIm]Br demonstrated an optimal balance of hydrophilic and hydrophobic interactions, yielding composite zeolites with high surface area (350 m²·g⁻¹) and large pore volume (0.28 cm³·g⁻¹). Comprehensive characterization (XRD, SEM-EDX, NH₃-TPD) confirmed the formation of well-defined ZSM-5/AlPO₄-5 core–shell structures and revealed tunable acid site distributions depending on the ionic liquid used. In methanol to olefins (MTO) reactions, the composite catalyst exhibited outstanding selectivity towards light olefins (C₂=–C₄=: 72.84%), markedly outperforming the individual ZSM-5 and AlPO₄-5 components. The superior catalytic behavior is primarily attributed to the synergistic effect of hierarchical acid site tuning and the integrated core–shell architecture, which together optimize reaction selectivity. This strategy provides a promising route for the rational design of high-performance zeolites with significant industrial applicability. Full article