Chloride Ionic Liquid Research Articles

Highly Transparent All‐Polysaccharide Composite Films with Tailored Transmission Haze for Light Manipulation

AbstractLow‐cost light management films that completely originate from natural polymers for biodegradable optoelectronics are a growing trend with great demand in the near future, for example, highly transparent and hazy films. Herein, a novel green method simply based on the solubility difference between cellulose and chitosan in ionic liquid is proposed to cast all‐polysaccharide transparent films with customized transmission haze. The dissolved cellulose in 1‐Allyl‐3‐methylimidazolium chloride (AmimCl) ionic liquid serves as matrix. The insoluble chitosan is deliberately dispersed in the matrix, which can maintain its original particle size due to its poor solubility in AmimCl and can significantly increase the surface roughness of the composite film and hence functions as the light scatterer. Eventually, an all‐polysaccharide composite film (Cel/CS) with high transmittance (>84.8%) and tunable haze (10–93%) is prepared using different coagulating bath and drying methods. The film is highly suitable for large‐scale continuous production and sufficient to satisfy the varying haze requirements of different applications, including flexible lighting and displays, antireflection and anti‐glare coatings, and privacy protection.

Preconcentration and spectrophotometric determination of mercury in water, food and hair samples through ionic-liquid induced micelle-mediated extraction

A new, eco-friendly, and rapid micelle-mediated preconcentration technique was described for trace mercury in water, food and hair samples perior to its spectrophotometric determination. The developed method depended on cloud point extraction supported with ionic liquid (IL-CPE) for extraction of mercury utilizing a nonionic surfactant (Triton X-114) and 1-hexadecyl-3-methylimidazolium chloride (C16MeImCl) ionic liquid, as an extracting phase in the presence of 5-benzyl-4-[4-methoxybenzylideneamino)-4H-1,2,4-triazole-3-thiol (BMBATT) as a new chelating agent at pH 7.0. The influence of varous analytical variables on improving the extraction performance was tested. In the range of 2.0-600 µg L−1, the calibration curve was linear with correlation coefficient of 0.9997. The detection limit and preconcentration factor were 0.4 µg L−1 and 100, respectively. The reliability and precision of the developed IL-CPE system as the relative standard deviation (RSD %) of 100 and 400 µg L−1 mercury were in the range 1.0 and 2.4%, respectively (n=10). The validity of the developed IL-CPE approach was confirmed by the analysis of certified reference materials (NIST-1641d mercury in natural water and NCS ZC81002B human hair). The applicability of proposed IL-CPE technique was demonstrated successfully by estimation of trace mercury in real water, food and hair samples.

Activity Coefficient at Infinite Dilution Study of Molecular Interaction-Selectivity in Separation Processes

The activity coefficient at infinite dilution for 47 selected organic solutes in 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) ionic liquid (IL) was determined at 303.15 K to 343.15 K through inverse gas chromatography (IGC). The partial molar excess enthalpy, entropy, Gibbs free energy at infinite dilution, and Hildebrand solubility parameters were obtained from the values of activity coefficient at infinite dilution. The selectivity and capacity of heptane/thiophene, heptane/benzene and benzene/thiophene separation problems were also calculated based on the activity coefficient at infinite dilution values. The selectivity of three separation problems of [AMIM]Cl was 85.36, 30.65 and 2.79, which indicated that [AMIM]Cl is an ideal solvent for the separation of heptane/thiophene.

A two-phase reaction system for selective oxidative degradation of lignin model compounds

Lignin depolymerization through an oxidation method could provide value-added products, but it is challenging in terms of recovering catalysts or separating products in time to avoid over-oxidation. In this study, a process of selectively oxidative degradation of lignin model compounds was operated in a two-phase reaction system. Lignin model compounds of 4-benzyloxyphenol (PBP) or guaiacylglycerol-β-guaiacyl ether (GGE) in a bottom phase of 1-butyl-3-methylimidazole chloride ([BMIM]Cl) ionic liquid were selectively oxidized by H2O2 in the presence of a solid acid (SO42-/Fe2O3-ZrO2), and the degradation products immediately diffused into the upper organic solvent phase (butyl acetate). In this kind of reaction system, the yield of the products was improved due to the prolonged life of ∙OH in ionic liquid, and the product selectivity was maintained due to the timely product separation, and the ionic liquid and the catalyst were easily recycled.

Using a Microchannel Reactor to Optimize the Production of 1-Alkyl-3-Methylimidazolium Chlorides

The possibility of using microchannel flow reactors to obtain the kinetic and technological parameters of the synthesis of 1-butyl-3-methylimidazolium chloride (BMIMCl) ionic liquid is demonstrated for the reaction of 1-methylimidazole (MIm) with 1-chlorobutane with no solvents. BMIMCl is produced with high selectivity and specific output in a microchannel flow reactor at temperatures of 120–180°C a contact time of 2–45 min, and a pressure of 20 bar. A positive result is obtained, due to the laminar profile of the flow and a uniform distribution of the reagents concentration over the microchannel cross section. Studying the kinetics of the process in a microchannel flow reactor reveals a shift of the reaction to the mode of diffusive inhibition at temperatures above 150°C. The kinetic data obtained for BMIMCl synthesis are used to develop ways of producing 1-ethyl-3-methylimidazolium and 1-hexyl-3-methylimidazolium chlorides (EMIMCl and HMIMCl, respectively) under the conditions of a microchannel flow reactor. The approach proposed in this work is of interest in developing flow and periodic facilities for the low-tonnage production of dialkylimidazolium, ammonium, and pyridinium salts via quaternization of the corresponding alkyl chlorides and nitrogen-containing bases.

Catalytic Performance of Sulfonated Carbon Catalysts for Hydrolysis of Palm Oil Empty Fruit Bunch

Utilizing lignocellulosic biomass into valuable products, such as chemicals and fuels, has attracted global interest. One of lignocellulosic biomass, palm oil empty fruit bunch (EFB), has major content of cellulose (30-40%), which is highly potential to be a raw material for fermentable sugar production. In this research, a series of sulfonated carbon catalysts with various concentrations of sulfuric acid (H2SO4, 10-30 v/v%) solutions have been successfully prepared and applied for a single stage of heterogeneous acid-catalyzed hydrolysis over microcrystalline cellulose and EFB under moderate temperature condition and ambient pressure. The catalysts’ physical and chemical properties were characterized by using a Thermogravimetric Analyzer (TGA), X-ray diffractometer, surface area analyzer, and Fourier-transform infrared spectrophotometer. The characterization results showed that sulfonated carbon had relatively similar physical properties with the parent of active carbon. The hydrolysis activity of sulfonated carbon catalysts gave various Total Reducing Sugar (TRS). The effects of sulfate loading amount in catalyst samples and various ionic liquids were investigated. The hydrolysis of pure microcrystalline cellulose powder (Avicel) using 30%-sulfonated carbon (30-SC) catalyst in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) ionic liquid at 150°C yielded the highest TRS of 16.11%. Subsequently, the catalyst of 30-SC was also tested for hydrolysis of EFB and produced the highest TRS of 40.76% in [BMIM]Cl ionic liquid at 150°C for 4 h. The obtained results highlight the potential of sulfonated carbon catalysts for hydrolysis of EFB into fermentable sugar as an intermediate product for ethanol production.

Evaluation of polymer inclusion membrane efficiency in selective separation of lithium ion from aqueous solution

In regards to the unique properties of lithium, lithium separation with high purity is crucial in various industries. Due to the close radii of alkali and alkaline earth metals, this is important to choose a technique with appropriate properties for ion separation in aqueous medium. Among the available methods for lithium enrichment, polymer inclusion membrane (PIM) system has features that meet the needs. In this study, a PIM containing green polyol as the base polymer, 12-Crown-4 (12C4) as the carrier and 1-butyl-3-methylimidazolium chloride (BMIMCl) ionic liquid was synthesized to separate lithium ion from an aqueous solution of Li+, Na+, K+, Ca2+, and Mg2+. Also, the zeolitic imidazolate framework type ZIF-8 was employed in the membrane structure to improve Li+ enrichment process. Characterization techniques such as FTIR, AFM and SEM, verified that ZIF-8 was added to the PIM structure. The results showed that ZIF-8 nanoparticles increased the hydrophobicity and the roughness of PIM that resulted in more selectivity. In addition, this type of MOF has regular porosity that is a suitable pathway for ion transport across the membrane. This feature increases the ion flux of synthesized PIMs. In the optimum combination of membranes, lithium ion flux was 45.7 × 10−3 mmol⋅cm−2⋅h−1 and 63 × 10−3 mmol⋅cm−2⋅h−1 without ZIF-8 and with ZIF-8 nanoparticles, respectively. Also, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), and cellulose acetate (CA) were employed as base polymer of PIM to evaluate the effect of polymer on the ion flux. The lithium flux of these polymers was 47.2 × 10−3 mmol⋅cm−2⋅h−1, 44.3 × 10−3 mmol⋅cm−2⋅h−1, and 24.98 × 10−3 mmol⋅cm−2⋅h−1 that are respectively related to PVDF, PVC and CA base PIMs.

Preparation of AgCl with enhanced photocatalytic activity using ionic liquid as chlorine source

In this study, Ag/AgCl photocatalysts were prepared by using chloride ionic liquid (IL) as a chlorine source. The structure, composition, morphology, light response ability and surface properties of IL-AgCl were characterized by X-ray diffraction, scanning electron microscope, X-ray photoelectron spectroscopy, Raman spectroscopy, UV–Vis diffuse reflection spectra, specific surface area and surface photovoltage spectrum. The photocatalytic activity of the samples was investigated by measuring the residual concentration of rhodamine B used as a simulated pollutant. The experimental results show that the ionic liquid can promote the stability of AgCl, furthermore, all the IL-AgCl photocatalysts have a higher separation rate of photogenerated charge pairs than the reference AgCl. The surface properties and photocatalytic activity of AgCl prepared tightly relate to the type of IL used, among all the AgCl prepared, AgCl prepared by 1-carboxyethyl-3-methyl-imidazolium chloride has the best catalytic activity.

Niobium chloride in 1−n−butyl−3−methylimidazolium chloride ionic liquid as a catalyst for biginelli reaction

In this study, NbCl5 in a liquid ionic medium was evaluated as a catalyst for Biginelli reaction. Firstly, the ionic species found in mixtures of NbCl5 and 1−butyl−3−methylimidazolium chloride (BMImCl) at various molar ratios (x) were determined. Samples with x ranging from 0.2 up to 0.4 were constituted of BMIm+, Cl− and [NbCl6]− ions in different proportions. When x was 0.5, BMIm+ and [NbCl6]− were the only species. When the molar ratio was 0.6 a mixture of BMImNbCl6 and Nb2Cl10 was observed. The identification of the ionic species provides useful information about the chemical nature of the niobium catalyst in the Biginelli reaction and other chemical or electrochemical transformations. The Biginelli reaction carried out using ethyl acetoacetate, benzaldehyde and urea in the presence of NbCl5 and xNbCl5_BMImCl mixtures with x varying from 2 to 5 yielded almost 90% of 3,4-dihydropyrimidinone, which means the acid C (2) hydrogen in the BMIm+ with [NbCl6]- as the counterion acted as Brønsted acid capable of bonding to the CO of benzaldehyde and ethyl acetoacetate, following the iminium mechanism.

Lignocellulosic hydrogel from recycled old corrugated container resources using ionic liquid as a green solvent

Lignocellulosic hydrogels are valuable bio-products that have been considered widely in recent investigations. Also, application of low value recycled fibers for high value added products can be of much interest. In this respect, current research has focused on producing hydrogel from recycled old corrugated container (OCC) resources, using 1-butyl-3-methyl-imidazolium chloride ionic liquid (IL) as a green solvent. The results indicated that the IL successfully dissolved OCC fibers, allowing the production of lignocellulosic hydrogel. Considering total water absorption amount as a main criterion for evaluation of hydrogels, the fabricated hydrogel showed promising results (up to 4700% water absorption). X-ray diffraction analysis confirmed obvious reduction in cellulose material crystallinity and crystallite size as a result of the process. Field emission scanning electron microscopy also demonstrated the microstructure of the hydrogel, pore size and shape in the hydrogel, which well supported the laboratory research results. Furthermore, the effect of processing parameters showed that specimens washed with distilled water as the anti-solvent resulted in the highest water absorption. Infrared spectroscopy can be used to suggest the presence of more lignin content in the hydrogel washed with ethanol. Moreover, the best water re-absorption results were observed for the hydrogel washed with distilled water.

Electrochromic Device Composed of a Di-Urethanesil Electrolyte Incorporating Lithium Triflate and 1-Butyl-3-Methylimidazolium Chloride

A di-urethane cross-linked poly(oxyethylene)/silica hybrid matrix (di-urethanesil, d-Ut(600)), sinthesized by the sol-gel process, was doped with lithium triflate (LiCF3SO3) and the 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid. The as-produced xerogel film is amorphous, transparent, flexible, homogeneous, hydrophilic, and has low nanoscale surface roughness. It exhibits an ionic conductivity of 3.64×10−6 and 5.00×10−4 S cm-1 at 21 and 100 oC, respectively. This material was successfully tested as electrolyte in an electrochromic device (ECD) with the glass/ITO/a-WO3/d-Ut(600)10LiCF3SO3[Bmim]Cl/c-NiO/ITO/glass configuration, where a-WO3 and c-NiO stand for amorphous tungsten oxide and crystalline nickel oxide, respectively. The device demonstrated attractive electro-optical performance: fast response times (1-2 s for coloring and 50 s for bleaching), good optical memory (loss of transmittance (T) of only 41% after three months, at 555 nm), four mode modulation (bright mode (+3.0 V, T = 77% at 555 nm), semi-bright mode (−1.0 V, T = 60% at 555 nm), dark mode (−1.5 V, T = 38 % at 555 nm), and very dark mode (−2.0 V, T = 11% and −2.5 V, T = 7% at 555 nm )), excellent cycling stability denoting improvement with time, and high coloration efficiency (CEin = −6727 cm2 C−1 (32th cycle) and CEout = +2794 cm2 C−1 (480th cycle), at 555 nm).

Fesipmim]Cl as highly efficient and reusable catalyst for solventless synthesis of dihydropyridine derivatives through Hantzsch reaction

In the present investigation, magnetic ferrite nanoparticles (ferrite NPs) were synthesized and coated with silica (ferrite@SiO2NPs) by using the sol-gel method. After that, silica propylmethylimidazolium chloride ionic liquid [Sipmim]Cl was prepared and linked with the above-prepared ferrite@SiO2NPs to synthesize ferrite silica propylmethylimidazolium chloride [Fesipmim]Cl catalyst. The formation of [Fesipmim]Cl catalyst was confirmed by Fourier-transform infrared (FT-IR) spectroscopy analysis. X-ray diffraction (XRD) analysis confirmed the structure of ferrite NPs and ferrite@SiO2 NPs. Transmission electron microscopy (TEM) evidenced the successful formation of ferrite NPs and ferrite@SiO2 NPs. Scanning electron microscopy (SEM) results revealed the change in morphology of ferrite NPs, ferrite@SiO2NPs and [Fesipmim]Cl. The magnetic properties of [Fesipmim]Cl catalyst were measured by vibrating sample magnetometer (VSM). The efficiency of the [Fesipmim]Cl catalyst was checked by using it for the synthesis of different derivatives of dihydropyridine through Hantzsch reaction via a three-component coupling reaction of substituted benzaldehydes, ethyl/ methyl acetoacetate and ammonium acetate. The formation and structures of all the synthesized compounds were confirmed by FT-IR, 1HNMR, 13C NMR spectral analyses. The reusability of the catalyst [Fesipmim]Cl was checked up to seven cycles and found to have excellent activity up to five cycles.

Sequential use of ionic liquid functionalized Zn-Al layered double hydroxide as adsorbent and photocatalyst

Studies regarding the recovery of palladium ions from aqueous solutions through adsorption onto ionic liquid functionalized Zn-Al layered double hydroxides and the subsequent use of the exhausted adsorbent as photocatalysts in the degradation process of methylene blue are presented. For this purpose, three materials were synthesized: unmodified Zn3Al layered double hydroxide (LDH), a layered double hydroxide modified with methyl tri-alkyl ammonium chloride ionic liquid (IL) by ultrasonic impregnation and by co-synthesis. After sample characterization using XRD, FTIR, SEM and EDX techniques, the studied materials were employed as adsorbents in the Pd(II) ions recovery from aqueous solutions. It was proved that the presence of IL in the structure of the Zn3Al – LDH lead to an enhancing of the adsorption efficiency, especially when the co-synthesis method was used for the LDH functionalization. The resulted exhausted adsorbents were efficiently capitalized as photocatalysts in the degradation process of MB from aqueous solutions. The presence of ionic liquid in the structure of raw material Zn3Al and the presence of adsorbed Pd(II) ions onto the surface of the spent adsorbents, led to efficiencies of the photocatalytic methylene blue degradation above 90%.

Anodic Dissolution of Copper in the Aluminum Chloride-1-Ethyl-3-Methylimidazolium Chloride Ionic Liquid

The ever popular AlCl3-1-ethyl-3-ethylimidazolium chloride (EtMeImCl) ionic liquid (IL) system offers a unique solvation environment for many metal ions. In fact, the use of these chloroaluminate ionic liquids for the electrochemical surface finishing of metals was recently reviewed.1 These ionic liquids display adjustable Lewis acidity that depends directly on the mole ratio of the AlCl3 to the organic salt. The basic AlCl3-EtMeImCl mixture, which contains coordinately unsaturated Cl-, provides a solvation environment similar to aqueous HCl and NaCl, except of course without the complications due to the H2O solvent or H3O+. The opposite situation prevails in the Lewis acidic ionic liquid because the main chemically active ionic component of the ionic liquid is the coordinately unsaturated species, [Al2Cl7]-. Thus, there are no “hard” ligands available to form stable, isolable anionic complexes with the anodization product. Recently, both composition regions of the AlCl3-EtMeImCl IL system have been explored for the electrodissolution/electropolishing of Al.2 The advantages afforded by anodic dissolution of metals in this ionic liquid relative the aqueous acids and salt solutions commonly used for this purpose are quite obvious, i.e., the avoidance of the oxide surface films that invariably complicate the metal electropolishing process. In this paper, we report the thermodynamics and kinetics of the anodic dissolution of copper metal in the acidic and basic compositions of the AlCl3-EtMeImCl ionic liquid. In the former, the dissolution of copper at a Cu-RDE exhibits mixed control. No limiting current or passivation due to the formation of an insoluble surface film was apparent. In the basic composition region, mixed control was observed at small overpotentials, but as the overpotential was increased, a limiting current was obtained that scaled linearly with the Cl- concentration in the ionic liquid. The connection between these results and the mechanism of the dissolution process will be discussed.____________________________________________ 1. T. Tsuda, G. R. Stafford and C. L. Hussey, J. Electrochem. Soc., 164, H5007 (2017).2. C. Wang and C. L. Hussey, J. Electrochem. Soc., 163, H1186 (2015).

A computational chemistry approach to modelling conducting polymers in ionic liquids for next generation batteries

An overview of modern quantum chemical methods is presented followed by a discussion of their application in the field of conducting organic polymers (COPs), with a view towards modelling the cathodic half-cell of a poly(3,4-ethylenedioxythiophene) (PEDOT) cathode in an AlCl3-1-ethyl-3-methylimidazolium chloride (EMImCl) ionic liquid electrolyte. The most popular combination of hybrid DFT functional and polarized moderate basis set has been broadly and successfully applied to COPs in the literature. However, in the presence of anions and intermolecular interactions, diffuse functions and dispersion corrections must also be included. A comprehensive specification of these elements appears well suited to the determination of many relevant parameters including molecular geometry, bandgap of oligomers and energies for systems including multiple chains and chloroaluminate anions. However, range-separated hybrid functionals may be more suitable for determining electron transport properties of very long chains. The clearest benefit of DFT to this system is the ability to visualize charge distribution and the interaction between charged PEDOT and the active species, which will help to explain the specific capacity, voltage and charge/discharge characteristics — insights that may help identify further improvements.

Computational NMR Spectroscopy of Ionic Liquids: [C4C1im]Cl/Water Mixtures.

In this work, I have analyzed the structure of binary mixtures of 1-butyl-3-methylimidazolium chloride ionic liquid, [C4C1im]Cl, and water, using computational NMR spectroscopy. The structure of the complex fluid phase, where the ionic and hydrophobic nature of ionic liquids is further complicated by the addition of water, is first generated by classical Molecular Dynamics (MD) and then validated by calculating the NMR properties with DFT at the ONIOM(B3LYP/cc-pVTZ//B3LYP/3-21G) on clusters extracted during the MD trajectories. Three ionic liquid/water mixtures have been considered with the [C4C1im]Cl mole fraction of 1.00, 0.50, and 0.01, that is the pure ionic liquid [C4C1im]Cl, the equimolar [C4C1im]Cl/water mixture, and a diluted solution of [C4C1im]Cl in water. A good agreement is obtained with published experimental data that, at the same time, validates the structural features obtained from the MD and the force field used, and provides an example of the power of NMR spectroscopy applied to complex fluid phases.

Iron oxide nanoparticles modified with ionic liquid as an efficient adsorbent for fluoride removal from groundwater

Abstract A promising ionic liquid modified iron oxide was synthesized with a co-precipitation method using trihexyltetradecylphosphonium chloride ionic liquid as a multi-functionalized material. The removal of fluoride was investigated by batch study. Ionic liquid with iron oxide nanoparticle characterization was conducted by Ultraviolet–visible spectroscopy, Fourier-transform infrared spectroscopy, Scanning electron microscope, X-ray powder diffraction, Raman spectroscopy, and Brunauer–Emmett–Teller. Batch adsorption was analyzed by varying parameters namely pH (8), contact time (30 min), adsorbent dosage (0.06 g/L), temperature (30 °C), initial concentration (10 mg/L), and stirring rate (400 rpm). The regression coefficient (R2) was the best fit at pseudo-second-order which was 0.99. The best isotherm model was Langmuir model which showed an adsorption capacity of 67.9 mg/g with maximum fluoride removal 96%. However, iron oxide modified with ionic liquid showed an efficient fluoride removal capacity and it can also be considered as an excellent adsorbent from aqueous solution.

Fiber fines for fabricating lignocellulose films and the effect of lignin

Excess lignocellulose fines in some fiber processing mills cause issues and hurt product quality. To use this type of biomaterial as a resource, surplus fines can be separated and dissolved with solvents for further transformation. Therefore, 1-butyl 3-methyl imidazolium chloride ionic liquid (IL) was used as a powerful green solvent for a rapid dissolution process. However, a low degree of polymerization (DP) of the cellulose in fines and the effects of lignin content and its structure on the process and film properties are controversial subjects. This study demonstrated that the three dimensional structure of lignin did not permit the raw bagasse fines (prior to pulping) to dissolve in the IL even after several hours. However, following decomposition of the lignin structure by pulping, the fiber fines were readily dissolved. Further, all the fabricated films from the fiber fines exhibited satisfactory strength properties, despite the fact that the cellulose had a low DP. The films from bleached fiber fines showed higher tensile strength than those containing lignin, although the cellulose chain was longer and had a higher DP for the latter. Lignin resulted in reduced transparency, and higher absorption of ultraviolet radiations, but it did not affect the surface roughness of the films.

Fluorescence quenching of the SYBR Green I-dsDNA complex by in situ generated magnetic ionic liquids.

Magnetic ionic liquids (MILs) with metal-containing cations are promising extraction solvents that provide fast and high efficiency extraction of DNA. Hydrophobic MILs can be generated in situ in a methodology called in situ dispersive liquid-liquid microextraction. To consolidate the sample preparation workflow, it is desirable to directly use the DNA-enriched MIL microdroplet in the subsequent analytical detection technique. Fluorescence-based techniques employed for DNA detection often utilize SYBR Green I, a DNA binding dye that exhibits optimal fluorescence when bound to double-stranded DNA. However, the MIL may hinder the fluorescence signal of the SYBR Green I-dsDNA complex due to quenching. In this study, MILs with metal-containing cations wereselected and their fluorescence quenching effects evaluated using Fӧrster Resonance Energy Transfer and quantified using Stern-Volmer models. The MILs were based on N-substituted imidazole ligands (with butyl- and benzyl- groups as substituents) coordinated to Ni2+ or Co2+ metal centers as cations, and paired with chloride anions. The effects of NiCl2 and CoCl2 salts and of the 1-butyl-3-methylimidazolium chloride ionic liquid on the fluorophore complex were also studied to understand the components of the MIL structure that are responsible for quenching. The metal within the MIL chemical structure was found to be the main component contributing to fluorescence quenching. Fӧrster critical distances between 11.9 and 18.8Å were obtained for the MILs, indicating that quenching is likely not due to non-radiative energy transfer but rather to spin-orbit coupling or excited-state electron transfer. The MILs were able to be directly used in qPCR and fluorescence emission measurements using a microplate reader for detection, demonstrating their applicability in fluorescence-based detection methods. Graphical abstract.

Cobalt Extraction from Sulfate/Chloride Media with Trioctyl(alkyl)phosphonium Chloride Ionic Liquids.

The application of phosphonium-based ionic liquids (ILs) on the selective extraction of cobalt is presented. The extraction mechanism is established, and different parameters of the process are evaluated. It has been found that it is possible to extract cobalt from aqueous solutions in sulfate media, with the addition of sodium chloride, using phosphonium ILs. The cobalt extraction was selective with respect to nickel and strongly dependent on the chloride concentration in the aqueous solution. The cobalt extraction is given by an anion exchange mechanism through an endothermic process. Cobalt extractions greater than 98% were obtained using the proposed methods. Cobalt stripping from the loaded IL phase using water was proved. Therefore, an alternative extraction process to traditional organic solvents is proposed. This alternative has additional advantages such as easy handling, lower costs in reagents and equipment, and risk reduction.