Imidazolium-based Ionic Liquids Research Articles

Mechanism of efficient electroreduction of CO2 to CO at Ag electrode in imidazolium-based ionic liquids/acetonitrile solution

Imidazolium-based ionic liquids (Imim-ILs) have great application potential in catalyzing the electrochemical CO2 reduction reaction (CO2RR). However, the microscopic mechanism by which imidazolium-based cations promote CO2RR remains unclear. In this study, we observe that despite the structural differences between [Bmmim]+ and [Bmim]+, both exhibit high catalytic activity during the electrochemical CO2RR. Electrochemical and in situ spectroscopic analyses, as well as Quantum Theory of Atomic in Molecules (QTAIM), reveal that the pivotal step in the CO2RR mechanism facilitated by [Bmmim]+ and [Bmim]+ involves the formation of [Bmmim]···CO2 or [Bmim]···CO2 complexes via hydrogen bond. These complexes enhance the electrochemical reduction of CO2 or ·CO2- on electrode, facilitating efficient CO production. Specifically, the [Bmmim]···CO2 complex forms at the C4-H position of the imidazole ring, while in the [Bmim]···CO2 complex, it forms at the C2-H position.

Accelerated CO2 preferential permeation using graphene oxide confined ionic liquid membranes for CO2/H2 separation

Due to the enhanced mass transfer process of nanochannels and the high affinity of ionic liquids (ILs) for carbon dioxide (CO2), the membranes combined with 2D nanosheets and ILs have attracted significant attention in carbon capture, utilization, and storage (CCUS). However, regulating the structure of IL to enhance the separation performance of CO2 remains a big challenge. Herein, we selected different imidazolium-based ILs and proposed a simple strategy to prepare nano-confined IL membranes by intercalating ILs into graphene oxide (GO). These membranes are subsequently used to remove CO2 from industrial syngases, where they display an abnormal CO2 preferential permeation process relative to the smaller H2 molecule. Meanwhile, CO2 permeation decreases gradually with the increase of alkyl chain length, whereas CO2/H2 selectivity shows a tendency to first increase and then decrease. Interestingly, all GO-confined IL membranes surpass the Robeson upper bound, achieving peak CO2 permeance of 13.85 GPU and CO2/H2 selectivity of 13.58, respectively. Further characterization of the interlayer spacing and density functional theory (DFT) calculations reveal that the high CO2/H2 separation performance mainly arises from the fact that nano-confined ILs can block the transit of H2 through the dense packing structure, simultaneously enhancing CO2 solubility and permeability through the membrane. These quantitative insights into the nanoconfined IL membrane not only deepen the scientific understanding of the abnormal transfer process within the nanochannel but also propose novel methodologies for preparing high-performance CO2 capture membranes.

IMIDAZOLIUM-BASED IONIC LIQUIDS FOR THE SELECTIVE SEPARATION OF TOCOTRIENOL HOMOLOGUES FROM PALM FATTY ACID DISTILLATE VIA LIQUID-LIQUID EXTRACTION

Objective: Tocotrienols have now stepped into the limelight of vitamin E research and have proven to have some exceptional benefits that are not shared by their “older” tocopherol siblings. Unlike tocopherols, tocotrienols are able to inhibit cholesterol biosynthesis, have specific neuroprotective activities stronger antioxidant effects, antihypertensive and anti-cancer. The purpose of this study was to carry out selective separation of tocotrienols homologues from Palm Fatty Acid Distillate (PFAD) by liquid-liquid extraction, using Ionic liquids (ILs) as extractants in the presence of diluent. Methods: Four kinds of imidazolium-based ILs that used are 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), 1-Butyl-3-methylimidazolium acetate ([Bmim]Ac), 1-Hexyl-3-methylimidazolium chloride ([Hmim]Cl) and 1-Ethyl-3-methylimidazolium chloride ([Emim]C]). The extraction is carried out by creating a two-phase system between ILs and PFAD in n-hexane. Quantification of extracted tocotrienols was performed using High-Performance liquid Chromatography (HPLC) with a C18 column, mobile phase methanol: water (97.5:2.5), flow rate 1 ml/min and Ultraviolet (UV) detector at 295 nm. Results: The results showed that the concentration (extraction efficiency) of tocotrienols extracted using ILs in order were [Bmim] Ac 1611.09 mg/Kg (75.41%) and [Hmim][Cl] 1603.39 mg/Kg (75.05%), [Bmim]Cl 1523.60 mg/Kg (71.32%) and [Emim]Cl 1174.24 mg/Kg (54.96%). Conclusion: [Bmim]Ac yielded the highest tocotrienols concentration and extraction efficiency.

Effect of ether chain and isomerism on surface and antimicrobial activity of mono- and dicationic imidazolium-based surface-active ionic liquids

A series of 16 imidazolium-based surface-active ionic liquids (SAILs) were synthesized. The designed SAILs, consisted of either one amphiphilic center, 3-alkoxymethyl-1-benzylimidazolium or 3-alkoxymethyl-1-benzyl-2-methylimidazolium, and two amphiphilic centers, 3,3′-[α,ω-(dioxaalkane)]bis(1-benzylimidazolium) or 3,3′-[α,ω-(dioxaalkane)]bis(1-benzyl-2-methylimidazolium). These compounds were investigated in terms of thermal analysis, ability to self-organize to micelles, and antimicrobial activity. The insertion of an ether moiety in the alkyl side or spacer chain favored adsorption at the air–water interface and micellization in the bulk solution when compared to commercial chloride surfactants. The results showed that attachment of a methyl group to the imidazolium ring led to lower the critical micelle concentration (CMC) than lengthening the alkyl chain or spacer in the imidazolium cation. Additionally, biological activity increased with increasing hydrophobicity of the compounds. The methylation of the imidazole ring at positions 2 and 2′ yielded in a notable increase in bacteriostatic activity, especially against Gram-positive bacteria, notably the Staphylococcus aureus strains. It has been demonstrated that minor structural modifications, specifically substituting the imidazole ring instead of elongating the alkyl chain or spacer, can modify the micellization and aggregation behavior, leading to differences in both the efficacy and variety of antimicrobial activity of amphiphilic SAILs.

Assessing the Activity and Stability of Cu-Based Gas Diffusion Electrodes for the CO2 Conversion in Different Electrolytes: Bicarbonate Vs. Ionic Liquid/Acetonitrile

In the context of sustainable strategies proposed to convert CO2 to valuable products, the electrochemical reduction of CO2 (ECR-CO2) represents one of the most promising alternatives1. Herein, the ECR-CO2 has been carried out employing for the first-time synthesised core-shell Cu2O/SnO2-based nanoparticles within a continuous flow cell both in aqueous solution and in the presence of ionic liquids (ILs), which have been known to boost CO2-derived products2. Interestingly, in aqueous potassium bicarbonate-based electrolyte, the synthesised material demonstrated a stable syngas production at -20 mA cm-2, with a CO/H2 ratio of about 10. The electrode stability and selectivity in aqueous environment has been further demonstrated for 24 hours of continuous operations at 10 cm2 scale. However, a CO/H2 ratio of about 3 was reached with 1-Butyl-3-methylimidazolium triflate ([BMIM][TfO]) in acetonitrile (ACN)3. In the aprotic media, stability issues have been faced during operations, visualized in the darkening of the gas diffusion electrodes and in colour changes of the electrolyte. Raman spectroscopy, Field Emission Scanning Electron Microscopy and Electrochemical Impedance Spectroscopy techniques have been employed for the physicochemical characterization of the electrodes and to assess the evolution of the electrochemical interfaces within the system over time. Molecular dynamics simulations have shown that the instability of the GDE could start with the displacement of Cu surface atoms from their equilibrium position by ACN molecules. Furthermore, we observed that the immobilization of ruthenium and rhenium complexes on the catalyst can be crucial to determine its suitability for either the hydroformylation or the carbonylation reaction, making this technology a promising solution for the green transition of the chemical industry. Acknowledgments The financial support of the SUNCOCHEM project (Grant Agreement No 862192) of the European Union’s Horizon 2020 Research and Innovation Action programme and of Fondazione CRT are acknowledged. References IEA. Global Energy Review: CO2 Emissions in 2021. (2021).Kunene, T., Atifi, A. & Rosenthal, J. Selective CO2 Reduction over Rose’s Metal in the Presence of an Imidazolium Ionic Liquid Electrolyte. ACS Appl. Energy Mater. 3, 4193–4200 (2020).Fortunati, A., Hernández, S., et al. Understanding the role of imidazolium-based ionic liquids in the electrochemical CO2 reduction reaction. Communications Chemistry, 6(1), 1–13 (2023).

Elucidating effect of dicarboxylate anions on nanostructural organization of dicationic imidazolium-based ionic liquids

This work reports the influence of the dicarboxylate anion (oxalate, malonate succinate, glutarate, adipate, pimelate) on the aggregation process of ionic liquids derived from 1,8-bis(3-methylimidazolium-1-yl)-octane [C8(MIM)2] and 1,10-bis(3-methylimidazolium-1-yl)-decano [C10(MIM)2] in water solution. The aggregation behavior was investigated using electrical conductivity, nuclear magnetic resonance, transmission electron microscopy, atomic force microscopy, and zeta potential. Results showed that the aggregates have a wormlike morphology. The CAC values for [C10(MIM)2]2+ increase in the following order: [Oxa] < [Suc] < [Mal] < [Glu] < [Adi] < [Pim], which indicates a direct relationship with the increase in the number of methylene groups of the dianion spacer. In the case of [C8(MIM)2]2+, there was no relationship between the CAC value and the anion’s alkyl spacer chain length, which was attributed to the flexibility and complexity of the dynamic behavior of the aggregates. Anions on the nanorganized structures of micelles are oriented in the way that carboxylate groups are at the aggregate surface (forming hydrogen bonds with cationic heads and water), and apolar alkyl chains are in the hydrophobic (downshift) region of the micelles making an arrangement where they also adopt the bend conformation of alkyl chains. The aggregation of dicationic ILs with dicarboxylate anions is a very innovative topic of investigation in the literature, and more research on different structures, system conditions, and techniques could be done to gain a better understanding of these systems.

Cation in Imidazolium-Based Ionic Liquids Promoting H-Spillover in Metal Oxide Supported Catalyst for Selective Catalytic Hydrogenolysis

Cation in Imidazolium-Based Ionic Liquids Promoting H-Spillover in Metal Oxide Supported Catalyst for Selective Catalytic Hydrogenolysis

Subcellular effects of imidazolium-based ionic liquids with varying anions on the marine bivalve Mytilus galloprovincialis

Green Chemistry involves applying a set of principles aimed at minimizing the use of hazardous substances in the design, production, and application of chemical products. In recent decades, Ionic Liquids (ILs) have emerged as more environmentally friendly substitutes for traditional organic solvents. This preference is primarily due to their low vapor pressure, which results in minimal atmospheric pollution and enhanced industrial safety. However, existing literature highlights the toxicity of ILs towards aquatic invertebrates. Consequently, this study points to assess the biochemical effects of a selection of ILs through an in vitro approach. Specifically, digestive gland and gill cellular fractions (S9) of the marine bivalve Mytilus galloprovincialis were exposed to varying concentrations (0.05–2 μM) of three ILs featuring identical cations but different anions. The ILs tested were 1-ethyl-3-methylimidazolium octanoate ([EMIM][Oct]), 1-ethyl-3-methylimidazolium acetate ([EMIM][OAc]), and 1-ethyl-3-methylimidazolium ethyl sulfate ([EMIM][EtSO4]). The results indicate that [EMIM][Oct] induces higher toxicity in both S9 tissues, highlighting a strong effect of the anion. Overall, antioxidant and biotransformation defenses were significantly altered for all three ILs assessed. While acetylcholinesterase activity was significantly inhibited of about half of control activity, indicating neurotoxic damage as part of the toxicity mode of action of these ILs, neither lipid peroxidation nor alterations to DNA integrity were observed (≥100 %). This study supports the use of in vitro techniques as important tools capable of generating reliable ecotoxicological data, which can be further considered as a screening before in vivo testing and used for in silico modeling.

Effects of imidazolium-based ionic liquids on the elasticity of DNA revealed by magnetic tweezers

The functions of DNA are related to its mechanical properties, including elasticity and conformational transitions. Ionic liquids, known as green solvents, are used for DNA separation and as a solvent medium for long-term DNA storage. This paper elucidated DNA interaction mechanisms with two imidazolium-based ionic liquids: 1-butyl-3-methylimi-dazolium chloride ([bmim]Cl) and 1-octyl-3-methylimidazolium chloride ([omim]Cl), via magnetic tweezers, bulk techniques and molecular dynamic simulation (MD). By stretching and twisting individual DNA molecules, we measured the elasticity of DNA in the presence of ILs ([bmim]Cl and [omim]Cl). As results, the persistence length, stretch modulus, torsional stiffness and twist-stretch coupling exhibited a significant decrease compared to the DNA without ILs binding. Isothermal titration calorimetry analysis indicated that the ILs in the presence of DNA were thermodynamically favored driven by enthalpy and entropy. DNA underwent size transition and conformational change induced by ILs, and the charges of DNA were neutralized by the added ILs. The binding of ILs induced unwinding and softening of DNA. Circular dichroism spectra and MD results indicated that DNA maintained B-conformation after interacting with ILs. Compared to [bmim]+, [omim]+ showed stronger binding affinity to DNA and tended to aggregate on the DNA surface. ILs binding reduced Na+ and water binding on DNA, which likely prevented the hydrolytic reactions that denatured DNA and helped stabilize DNA for the long term. This research provides a critical theoretical foundation for the utilization of ionic liquids in life sciences.

How Domain Segregation in Ionic Liquids Stabilizes Nanoparticles and Establishes Long-Range Ordering─A Computational Study.

Due to their physical properties including high thermal stability, very low vapor pressure, and high microwave absorption, ionic liquids have attracted great attention as solvents for the synthesis of nanomaterials, being considered as greener alternatives to traditional solvents. While usual solvents often need additives like surfactants, polymers, or other ligands to avoid nanoparticle coalescence, some ionic liquids can stabilize nanoparticles in dispersion without any additive. In order to quantify how the ionic liquids can affect both the aggregation thermodynamics and kinetics, molecular dynamics simulations were performed to simulate the evolution of concentrated dispersions and to compute the potential of mean force between nanoparticles of both hydrophilic and hydrophobic natures in two imidazolium-based ionic liquids, which differ from each other by the length of the cation alkyl group. Depending on the nature of the nanoparticle, structured layers of the polar and apolar regions of the ionic liquid can be formed close to its surface, and those layers lead to activation barriers for dispersed particles to get in contact. If the alkyl group of the ionic liquid is long enough to lead to domain segregation between the ionic and apolar portions of the solvent, the layered structure around the particle becomes more structured and propagates several nanometers away from its surface. This leads to stronger barriers close to the contact and also multiple barriers at larger distances that result from the unfavorable superposition of solvent layers of opposing nature when the nanoparticles approach each other. Those long-range solvent-mediated forces not only provide kinetic stability to dispersions but also affect their dynamics and lead to a long-range ordering between dispersed particles that can be explored as a template for the synthesis of complex materials.

Aqueous Ionic Liquid Mixtures as Minimal Models of Lipid Bilayer Membranes.

We introduce aqueous ionic liquid (IL) mixtures, specifically mixtures of 1-butyl-3-imidazoliumtetrafluoroborate (BMImBF4), with water as a minimal model of lipid bilayer membranes. Imidazolium-based ILs are known to form clustered nanoscale structures in which local inhomogeneities, micellar or lamellar structures, are formed to shield hydrophobic parts of the cation from the polar cosolvent (water). To investigate these nanostructures, dynamic light scattering (DLS) on samples with different mixing ratios of water and BMImBF4 was performed. At mixing ratios of 50% and 45% (v/v), small and homogeneous nanostructures can indeed be detected. To test whether, in particular, these stable nanostructures in aqueous mixtures may mimic the effects of phospholipid bilayer membranes, we further investigated their interaction with myelin basic protein (MBP), a peripheral, intrinsically disordered membrane protein of the myelin sheath. Using dynamic light scattering (DLS), continuous wave (CW) and pulse electron paramagnetic resonance (EPR), and small-angle X-ray scattering (SAXS) on recombinantly produced, "healthy" charge variants rmC1WT and double cysteine variant C1S17CH85C, we find that the size and the shape of the determined nanostructures in an optimum mixture offer model membranes in which the protein exhibits native behavior. SAXS measurements illuminate the size and shape of the nanostructures and indicate IL-rich "beads" clipped together by functional MBP, one of the in vivo roles of the protein in the myelin sheath. All the gathered data combined indicate that the 50% and 45% aqueous IL mixtures can be described as offering minimal models of a lipid mono- or bilayer that allow native processing and potential study of at least peripheral membrane proteins like MBP.

From Synthesis to Functionality: Tailored Ionic Liquid-Based Electrospun Fibers with Superior Antimicrobial Properties.

Herein, we report an efficient and facile strategy for the preparation of imidazolium-based ionic liquid (IL) monomers ([CnVIm][Br], n = 2, 4, 6, 8, 10, and 12) and their corresponding polymeric ionic liquids (PILs) with potent antimicrobial activities against Gram-negative and Gram-positive bacteria and fungi. The electrospinning technique was utilized to tailor the polymers with the highest antimicrobial potency into porous membranes that can be easily implemented into diverse systems and extend their practical bactericidal application. The antimicrobial mechanism of obtained ILs, polymers, and nanomaterials is considered concerning the bearing chain length, polymerization process, and applied processing technique that provides a unique fibrous structure. The structure composition was selected due to the well-established inherent amphiphilicity that 1-alkylimidazolium ILs possess, coupled with proven antimicrobial, antiseptic, and antifungal behavior. The customizable nature of ILs and PILs complemented with electrospinning is exploited for the development of innovative antimicrobial performances born from the intrinsic polymer itself, offering solutions to the increasing challenge of bacterial resistance. This study opens up new prospects toward designer membranes providing a complete route in their designing and revolutionizing the approach of fabricating multi-functional systems with tunable physicochemical, surface properties, and interesting morphology.

Effect of complex ionic liquid additives on the formation kinetics and separation efficiency of binary gas mixture hydrates

Rising carbon emissions worldwide have necessitated the discovery of efficient CO2 separation and capture technologies. Owing to their good CO2 selectivity, imidazolium-based ionic liquids (ILs) have been used as additives in hydrate-based gas separation (HBGS) technologies. Sodium dodecyl sulfate (SDS) can notably improve the rate of hydrate formation when used as a surfactant. However, the synergistic effect of imidazolium-based ILs and SDS remains unknown. This study aimed at investigating the synergistic effect of imidazolium-based ILs and SDS on the hydrate formation kinetics of binary gas mixtures of CO2/N2 at different temperatures. The carbon capture and storage capacity was determined, and HBGS was evaluated using pure imidazolium-based IL 1-butyl-3-methylimidazolium octyl sulfate ([BMIM] [OS]) and composites of IL and SDS as additives. Compared with pure water, [BMIM] [OS] effectively promoted gas hydrate formation and increased CO2 consumption by 107.9 %. The maximum CO2 separation factor was obtained at 273.15 K, and the mixed additive significantly enhanced gas consumption by 11.1 %. X-ray diffraction and Raman spectroscopy analysis indicated that the hydrate samples were type I structural hydrates and that [BMIM] [OS] improved the mass transfer process. The results of this study provide a theoretical basis for CO2 gas separation and capture.

Vibrational Spectra Simulations in Amino Acid-Based Imidazolium Ionic Liquids.

We present maximally localized Wannier functions and Voronoi tessellation to obtain dipole moment distributions for vibrational spectra in several important ionic liquids calculated by using ab initio molecular dynamics simulations. IR and Raman spectra of various imidazolium-based ionic liquids (ILs) paired with six amino acid anions are shown herein. For IR spectra, two approaches (Wannier and Voronoi) are in agreement with respect to the relative intensities and the overall shapes for the main peaks. Under Raman spectra, the polarizability of the covalent bonds is shown to affect the strength of the Raman scattering signal. The advantage of the Voronoi tessellation method, being that it does not have strong spikes in its time development, is demonstrated by the comparison of two theoretical methods (Wannier and Voronoi) with experimental data. We analyze the errors between theoretical and experimental spectroscopic data, with the Voronoi method shown to accurately reproduce experimental values. In addition, theoretical spectroscopy shows the ability to accurately separate components of a mixture. The combination of theoretical and experimental methods is utilized to understand the spectroscopic properties of amino acid-based imidazolium ILs.

Exploration of diverse interactions of nonionic poly(vinylpyrrolidone) (PVP) and anionic sodium carboxymethylcellulose (NaCMC) polymers in aqueous imidazolium-based surface active ionic liquid solutions

The binding interactions in complex formation between surface active ionic liquids (SAILs) and polymers (nonionic or anionic) are gaining attention because of their potential applications in novel materials. Therefore, the use of a variety of measurements is required for a better understanding of the interactions involved in polymer/SAIL formation. Here, we have investigated the interactions of nonionic poly(vinylpyrrolidone) (PVP) and anionic sodium carboxymethylcellulose (NaCMC) polymers with SAIL 1-tetradecyl-3-methylimidazolium chloride [C14mim][Cl] in aqueous solution using different measurements such as conductivity, surface tension, fluorescence spectroscopy, dynamic light scattering (DLS) and rheometric measurements. The surface tension, conductivity and fluorescence profiles for SAIL-NaCMC systems provide distinct breakpoints that correspond to four different aggregation states: the concentration at which SAIL monomers begin to attach to the polymer chain (C1), the critical aggregation concentration C2 (cac), the saturation concentration (CS) and the critical micelle concentration (cmc). In the case of SAIL-PVP systems, the surface tension and fluorescence profiles confer three transition states: C2 (cac), CS and cmc and only two transition states have been observed in conductivity curves. The cooperative binding of SAIL to the NaCMC/PVP chain at the solution interface was analyzed by calculating various thermodynamic and interfacial parameters. Strong complexation was observed between NaCMC-SAIL molecules compared to PVP-SAIL systems at the air-solution surface. This is due to the non-ionic character of the PVP chain, which shows weak interactions with SAIL in comparison to NaCMC. Furthermore, DLS and fluorescence measurements were used to investigate the interactions between SAIL and polymers.

The role of the cation and anion in aqueous liquid chromatography with sodium dodecyl sulphate and imidazolium-based ionic liquids as mobile phase reagents

BackgroundIn reversed-phase liquid chromatography, solute retention is primarily influenced by interactions between a nonpolar stationary phase and a moderately polar hydro-organic mobile phase, based on the solute lipophilicity. However, challenges regarding retention and peak tailing can arise due to ionic interactions between positively charged analytes and free silanols present on silica-based stationary phases. To address these challenges, incorporating surfactants and ionic liquids (ILs) into the mobile phase offers an effective solution. These additives synergistically enhance chromatographic performance through electrostatic and lipophilic interactions, which enable fine-tuning of selectivity and improved separation efficiency. ResultsThis study explores the chromatographic behaviour of several basic compounds in aqueous mixtures containing the anionic surfactant sodium dodecyl sulphate (SDS), above its critical micellar concentration, combined with various 1-alkyl-3-methylimidazolium-based ionic liquids (ILs) featuring chloride, tetrafluoroborate, and hexafluorophosphate anions, all without the addition of organic solvents. Specifically, this research investigates the influence of different anion types within the ILs and considers the impact of the IL cations. Analysis of solute peak profiles reveals narrow and symmetrical peaks. By introducing tetrafluoroborate and hexafluorophosphate IL anions into a mobile phase that contains an anionic surfactant, the study sheds light on the interactions occurring within the chromatographic column. This enhanced understanding of the combined effects of surfactants and ILs contributes to refining chromatographic methodologies. SignificanceThis research highlights the importance of carefully selecting the appropriate IL when incorporating it into a micellar mobile phase alongside SDS. This combination results in practical retention times that surpass the performance achieved with either the surfactant or IL alone in the mobile phase. The study particularly emphasises the impact of the IL anion, especially in the absence of SDS and organic solvents. This unveils interactions that are otherwise obscured in micellar and hydro-organic media, providing new insights into chromatographic dynamics.

Extraction of Actinides and Lanthanides from Nitric Acid Solutions with Mixtures of 1,5-N,N'-Bis[(Diphenylphosphoryl)Acetyl(Hexyl)Amino]pentane and New Asymmetrical Phosphonium- and Imidazolium-Based Ionic Liquid

Extraction of Actinides and Lanthanides from Nitric Acid Solutions with Mixtures of 1,5-N,N'-Bis[(Diphenylphosphoryl)Acetyl(Hexyl)Amino]pentane and New Asymmetrical Phosphonium- and Imidazolium-Based Ionic Liquid

Intensification Mechanism of Acidic Imidazole-Based Ionic Liquids on the Synthesis of 1,3,5-Trioxane Catalyzed by Sulfuric Acid

Intensification Mechanism of Acidic Imidazole-Based Ionic Liquids on the Synthesis of 1,3,5-Trioxane Catalyzed by Sulfuric Acid

Optimised phycoerythrin extraction method from Porphyridium sp. combining imidazolium-based ionic liquids

Phycoerythrin (PE) extraction from Porphyridium sp. was studied employing ultrasound-assisted extraction combined with aqueous mixtures of two imidazolium-based ionic liquids (ILs) simultaneously, marking a significant novelty. A face-centred central composite design and response surface optimised PE yield (EPE), considering the effects of ionic liquid concentration (IL), [Emim][EtSO4]/[Bmim][EtSO4] mass ratio (E/B), biomass concentration (BM), and time (t). Improvements in EPE by 300 % and 115 % were achieved compared to a phosphate buffer solution and the freeze-thaw method, respectively. Temperature and pH effects were examined independently, leading to the determination of optimal operating conditions: BM = 10 mg mL−1, IL = 18.6 wt%, E/B = 0.78/0.22, t = 10 min, T = 35 °C, and pH = 7.5. Results indicated the potential for reusing the ILs for at least five consecutive extraction cycles, maintaining an EPE of 94.2 % compared to fresh ones. This underscores the success and innovation of the developed technology in enhancing PE extraction from Porphyridium sp.

Imidazolium-based ionic liquids disrupt saccharomyces cerevisiae cell membrane integrity.

Ionic liquids (ILs) are interesting chemical compounds that have a wide range of industrial and scientific applications. They have extraordinary properties, such as the tunability of many of their physical properties and, accordingly, their activities; and the ease of synthesis methods. Hence, they became important building blocks in catalysis, extraction, electrochemistry, analytics, biotechnology, etc. This study determined antifungal activities of various imidazolium-based ionic liquids against yeast Saccharomyces cerevisiae via minimum inhibitory concentration (MIC) estimation method. Increasing the length of the alkyl group attached to the imidazolium cation, enhanced the antifungal activity of the ILs, as well as their ability of the disruption of the cell membrane integrity. FTIR studies performed on the S. cerevisiae cells treated with the ILs revealed alterations in the biochemical composition of these cells. Interestingly, the alterations in fatty acid content occurred in parallel with the increase in the activity of the molecules upon the increase in the length of the attached alkyl group. This trend was confirmed by statistical analysis and machine learning methodology. The classification of antifungal activities based on FTIR spectra of S. cerevisiae cells yielded a prediction accuracy of 83%, indicating the pharmacy and medicine industries could benefit from machine learning methodology. Furthermore, synthesized ionic compounds exhibit significant potential for pharmaceutical and medical applications.