Volume Of Ionic Liquid Research Articles

Kinetic modeling and mechanistic evaluation of oxidative-extractive desulfurization of actual diesel fuel using ionic liquids: Engineering aspects with parametric study

In the present research, oxidative-extractive desulfurization (OEDS) of actual diesel fuel is executed by utilizing coordinated ionic liquid (IL), and a novel kinetic model is put forward to explain the OEDS process. A series of ILs synthesized by the coordination of three solvents [N,N dimethyl-formamide (DMF), N-methyl-pyrrolidone and dimethyl sulfoxide] with three salts (CaCl2, ZnCl2, and MgCl2) were tested for OEDS of diesel fuel. The best-performing IL i.e., DMF.ZnCl2 was utilized to investigate the impact of oxidant-to-sulfur (O/S) molar ratio, diesel-to-IL volume ratio, temperature, and time. Thermal analysis; thermogravimetric analysis-differential thermogravimetric analysis (TGA-DTG), and differential scanning calorimetry (DSC) were conducted to understand their thermal stability. 1HNMR was used to examine the interactions between their components. To understand the mechanism of removal, Fourier transform infrared (FTIR) spectra and UV–visible spectra of IL were studied. The kinetic model used in the present investigation presumed the extraction of non-oxidized as well as oxidized sulfur compounds. Compared to earlier reported models, the present novel kinetic model provided an improved representation of the kinetic data. At the optimized conditions (O/S ratio = 6:1, diesel to IL volume ratio = 3:1, and temperature = 50 °C), a maximum of 86 % sulfur removal was estimated from actual diesel fuel.

Transformative strategies for heavy metals extraction: Ionic liquid-boosted fizzy capsule for distributive solid-phase microextraction in aquatic environments

Within this work, an innovative ionic liquid-coated sulphonyl silanized graphene oxide-supported fizzy capsule-enhanced ionic liquid distributive solid-phase micro-extraction (MGO@SO3H-IL-DSPM) was successfully prepared for enriching and extracting lead [Pb(II)], cadmium [Cd(II)], and cobalt [Co(II)] ions from water samples. The MGO@SO3H hybrid was investigated using Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscope (SEM), Zeta potential and surface area. Exploration and optimization were conducted on various parameters including solution pH, dosages of extractant, volume of ionic liquid, and the type and concentration of eluent. The optimized experimental conditions for achieving high extraction efficiencies of the targeted metals were determined as follows: a mixture of Na2CO3 and NaH2PO4 (0.12 g) each, at a 1:1 M ratio); utilization of 0.03 g of MGO@SO3H nanocomposites; addition of 10 μL of ionic liquid as the extractant; pH adjustment to approximately 5 for Pb(II), and 4.18 for both Co(II) and Cd(II); and elution using HNO3 as the eluent (at a concentration of 1.5 M, with a volume of 3 ml). Under the ideal circumstances, the extraction yield efficiencies of the target metal ions in four authentic water samples were in the range (96.09 % − 100 %) for Cd(II), (99.99 % − 102 %) for Pb(II), and (99.99 % − 103 %) for Co(II), the RSDs were lower than 1.7 %. The content of Cd(II), Pb(II), and Co(II) ions in four actual samples of water were determined within the range of 1.25 – 3.75 μg/L, 6 – 15 μg/L, and 29.15 – 70 μg/L, respectively.

Use of magnetic nanoparticles in an Ionic liquid (BMIM-PF6) based vortex‐assisted dispersive liquid–liquid microextraction (VSLLME) for measuring the traces amounts of cadmium in environmental, biological and nutritional samples

In the present project, the magnetic nanoparticles were used in a type of an ionic liquid based micro-extraction to measure trace amounts of cadmium in different real samples containing environmental water samples, saliva and human hair. In the optimum condition, the recovery percentages for the real sample were about 94.5% to 101.3%, showing the designed method is suitable to be used for analyzing the real environmental and biological samples. The main parameters were evaluated and optimized as follows: pH was 2.5, the volume of ionic liquid was 150 µl, the amount of Fe3O4 magnetic nanoparticles was 50mg, the volume of the complexing agent was 12 µl, and the vortex time was 1 min and 2 min for ionic liquid, and magnetic nanoparticle distribution steps, respectively. Also, the volume of the medium was 10 to 20 ml.

Comparing π-complexation capabilities of ionic liquids containing silver(I) and copper(I) ions by headspace single drop microextraction in combination with high-performance liquid chromatography.

Selective π-complexation capabilities of silver(I) and copper(I) ions can be effectively facilitated in ionic liquids. To understand the effects of environmental factors that influence the π-complexation of these metal ions with analytes, techniques that employ small volumes of ionic liquid that can be readily analyzed are desired. In this study, headspace single drop microextraction coupled with HPLCis used to investigate a diverse set of environmental factors on the metal ion-mediated complexation with aromatic compounds in ionic liquid media. Silver(I) and copper(I) bis[(trifluoromethyl)sulfonyl]imide salts were both studied by dissolving them in the 1-decyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ionic liquid and employing the mixture as extraction media for aromatic compounds. Water and acetonitrile within the sample solution were observed to interfere with the complexation of silver(I) ions and aromatic compounds, while ethylene glycol and triethylene glycol did not. The temperature and extraction times were optimized to fully facilitate the π-complexation capabilities of metal ions in ionic liquid media. Partition coefficients between the sample headspace and metal ion were determined using a three-phase equilibria model. Although no discernable difference in analyte partitioning between the headspace and ionic liquid solvent was observed, analyte partition coefficients to silver(I) ion tended to be greater compared to copper(I) ion.

Vortex-assisted microextraction of melamine from milk samples using green short chain ionic liquid solvents coupled with high performance liquid chromatography determination

Melamine is added illegally to milk and dairy products to increase the amount of apparent protein. This organic nitrogen rich chemical compound has been of great challenge in food safety based on its adverse effect on health. Therefore, the extraction and determination of melamine from milk is necessary. Recently, ionic liquid (ILs) as solvent usage has been noticeable for low melting point, low toxicity, high thermal stability, and high extraction capabilities in a wide range of separation processes. ILs are introduced as organic–inorganic salts and green solvents in microextraction preparation. Therefore, in this study, three ionic liquids ([C6mim][NTF2], [C4mim][NTF2] and [C2mim][NTF2] ILs) were prepared and employed as an extraction solvent in dispersive liquid–liquid microextraction (DLLME) of melamine from milk samples followed by HPLC-UV. The selected ILs were designed using three types of alkyl-imidazolium (as the short organic cations) and bis (tri fluoro methyl sulfonyl) imide as anion and characterized by ATR-FTIR spectra, carbon, and hydrogen Nuclear Magnetic Resonance spectroscopy (H&C-NMR) and energy-dispersive X-ray spectroscopy (EDX). These techniques confirmed the formation of functional groups, the structure of hydrogen and carbon atoms, and various elements of ionic bond between imidazolium and bis (tri fluoro methyl sulfonyl) imide. In the next step, the effect of significant parameters, including type and volume of ILs, adsorption time, pH of the sample solution, and sample volume, were optimized. Under the optimal conditions, the limits of detection (LOD), limits of quantification (LOQ), and linearity range were obtained 63.64 µg kg−1, 210.03 µg kg−1, and 210.03–1000 µg kg−1, respectively, for as prepared [C6mim][NTF2] as the best ILs. Notably, the achieved LOQ was lower than the maximum residue level (MRL) for the melamine residue in dairy products. Eventually, the proposed method was applied to detect melamine in milk samples, and the relative recoveries were examined as 79.6–105.0 %.

Electronic-Control Friction Behavior of Porous Metal-Organic Framework@Ag Nanocrystals as Self-Repairing Lubricant Additive.

The low conductivity and poor antifriction performance of lubricants are the main causes of wear failure in mechanical equipment under electronic-control friction. Metal-organic framework (MOF) nanocomposites can be used to fabricate a new kind of lubricant additive. Herein, porous Cu-BTC@Ag MOF nanocrystals were successfully synthesized via an in situ generation method. Transmission electron microscopy results showed that the nano-Ag element was evenly dispersed throughout the Cu-BTC matrix. Cu-BTC@Ag nanocrystals can significantly improve the electrical conductivity of the EMI-BF4 ionic liquid, which increased by 38.8%. The average coefficients of friction (COF) and wear volume of EMI-BF4 ionic liquid with 0.5 wt % Cu-BTC@Ag decreased by 8.3 and 16% without applied voltage, respectively. This finding was due to the continuous extrusion of the EMI-BF4 stored in the Cu-BTC@Ag pores under external load. It entered the contact zone, thereby maintaining the continuous supply of lubricant. At 20 V applied voltage in the friction process, the COF of the EMI-BF4/2.0wt %Cu-BTC@Ag lubricant decreased by 18.8%, and its wear volume decreased by 32.7%. The Cu-BTC@ Ag nanocrystals adsorbed onto the metal surface to form a friction reaction film by the action of electric fields, which can repair the wear defects on the friction interface. Therefore, Cu-BTC@Ag nanocrystals acting as an additive in lubricant have remarkable prospects in the area of electronic-control friction.

Transport Properties of Protic Ionic Liquids Based on Triazolium and Imidazolium: Development of an Air-Free Conductivity Setup.

The dynamical properties of four protic ionic liquids, based on the ethyltriazolium ([C2HTr124]) and the ethylimidazolium ([C2HIm]) cation, were investigated. The associated anions were the triflate ([TfO]) and the bistriflimide ([TFSI]). Ionic conductivity values and self-diffusion coefficients were measured and discussed, extending the discussion to the concept of fragility. Furthermore, in order to allow the measurement of the ionic conductivity of very small volumes (<0.5 mL) of ionic liquid under an inert and dry atmosphere, a new setup was developed. It was found that the cation nature strongly affected the transport properties, the [C2HTr124] cation resulting in slower dynamics than the [C2HIm] one. This was concluded from both conductivity and diffusivity measurements while for both properties, the anion had a lesser effect. By fitting the conductivity data with the Vogel-Fulcher-Tammann (VFT) equation, we could also estimate the fragility of these ionic liquids, which all fell in the range of very fragile glass-forming materials. Finally, the slower dynamics observed in the triazolium-based ionic liquids can be rationalized by the stronger interactions that this cation establishes with both anions, as deduced from the frequency analysis of relevant Raman signatures and density functional theory (DFT) calculations.

Ionic Liquid Meets MOF: A Facile Method to Optimize the Structure of CoSe2-NiSe2 Heterojunctions with N, P, and F Triple-Doped Carbon Using Ionic Liquid for Efficient Hydrogen Evolution and Flexible Supercapacitors.

The rational design of catalysts' spatial structure is vitally important to boost catalytic performance by exposing the active sites and increasing specific surface area. Herein, the heteroatom doping and morphology of CoNi metal-organic frameworks(MOF) are modulated by controlling the volume of ionic liquid used in synthesis and generating CoSe2 -NiSe2 heterojunction structures wrapped by N, P, F tri-doped carbon(NPFC) after a selenisation process. Notably, the unique cubic porous structure of CoSe2 -NiSe2 /NPFC results in a specific surface five times that of the sheet-like hollow structure produced without ionic liquid. Moreover, the charge redistribution during heterojunction formation is verified in detail using synchrotron radiation. Density functional theory calculations reveal that the formation of heterojunctions and doping of heteroatoms successfully lower the ΔGH* and ΔGOH* values. Consequently, CoSe2 -NiSe2 /NPFC exhibits excellent activity for HER in both acidic and alkaline solutions. Meanwhile, CoSe2 -NiSe2 /NPFC as a cathode material exhibits excellent performance in a flexible solid-state supercapacitor, with a superior energy density of 55.7Wh kg-1 at an extremely high-power density of 15.9kW kg-1 . This material design provides new ideas for not only using ionic liquids to modulate the morphology of MOFs but also deriving heterojunctions and heteroatom-doped carbon from MOFs.

Commercialization of Ionic Liquids in Pursuit of Green Chemistry: Must we Each Become an Entrepreneur?

There will be common challenges to scaling-up any ionic liquids separations technologies which require very large volumes of ionic liquid. Some of these challenges are illustrated in this personal account which chronicles the extraction of chitin from shrimp shell from discovery to current commercialization efforts. The road being taken from discovery in an academic laboratory, through attempts to navigate the scaling-up to commercial scale using the vehicle of a faculty startup company is rewarding, but fraught with roadblocks, detours, and unexpected challenges. The differences in 'technically feasible' and 'commercially viable' are not always evident from the beginning of the journey, however, one wonders what achievements we miss as a Society because it was assumed to not be commercially viable.

Regenerative low‐cost ionic liquids: Synthesis, characterization, and application in desulphurization of flue gases

AbstractThree ionic liquids (ILs) containing the same cation but different anions were synthesized and used to separate SO2 from its mixture with air in a semi‐batch bubble column absorber. Desulphurization efficiency was determined using a state‐of‐the‐art experimental set‐up relevant to chemical process industries concerning the important process variables. The virgin and exhausted ILs were characterized using TGA, FTIR, and 1H NMR analyses. The concentrations of SO2 at the inlet to and exit from the absorber were measured using a ZRJFAY36, Fuji, Japan infrared SO2 analyzer. A maximum of 92 percent removal efficiency (PRE) was achieved from a feed gas containing 250–1500 ppm SO2 with the use of 2‐hydroxyethyl ammonium lactate [MEA][L] or tri (2‐hydroxyethyl) ammonium lactate ([TEA][L]), as the absorbents. This could be further enhanced by the interactive effect of the simultaneous increase in the superficial velocity of the gas and the volume of IL fed into the absorber. However, PRE was about 20% less with tri (2‐hydroxyethyl) ammonium salicylate ([TEA][S]). It was observed that the ILs, [MEA][L] and [TEA][L], were fairly suitable for flue gas desulphurization in industrial situations. A design criterion for continuous operation using two semi‐batch absorbers has been proposed.

Preparation of nano-magnesium oxide in ionic liquid by microwave irradiation

Nano-MgO was prepared by microwave irradiated ionic liquid method. The influence of the volume of ionic liquid ([BMIM]Ac), microwave radiation power and microwave radiation temperature on the morphology of nano-MgO were investigated. The prepared nano-MgO was characterized by TG, XRD, EDS and SEM. The results showed that the nano-MgO prepared by this method has a short rod-like shape, uniform particle size, and good dispersibility. The average diameter of the prepared rod-shaped nano-MgO was 25 nm, the length was 67 nm, and the specific surface area was 48.27 m2/g. During the preparation process with microwave radiation, [BMIM]Ac is a good dispersant, which effectively reduces the agglomeration of nano-MgO and is easy to remove.

Generating intense electric fields in 2D materials by dual ionic gating

The application of an electric field through two-dimensional materials (2DMs) modifies their properties. For example, a bandgap opens in semimetallic bilayer graphene while the bandgap shrinks in few-layer 2D semiconductors. The maximum electric field strength achievable in conventional devices is limited to ≤0.3 V/nm by the dielectric breakdown of gate dielectrics. Here, we overcome this limit by suspending a 2DM between two volumes of ionic liquid (IL) with independently controlled potentials. The potential difference between the ILs falls across an ultrathin layer consisting of the 2DM and the electrical double layers above and below it, producing an intense electric field larger than 4 V/nm. This field is strong enough to close the bandgap of few-layer WSe2, thereby driving a semiconductor-to-metal transition. The ability to apply fields an order of magnitude higher than what is possible in dielectric-gated devices grants access to previously-inaccessible phenomena occurring in intense electric fields.

Determination of Trace Sudan I in Spices by Novel, Green Ionic Liquid Based Microextraction with Spectrophotometry

A new, green method has been developed for the determination of the trace Sudan I prior to spectrophotometric determination. The ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), was used as an extraction solvent for Sudan I. The analytical parameters which influence the recovery of Sudan I, such as the pH, ionic liquid volume, and sample volume, were optimized. Sudan I was quantitatively extracted at pH 6.0. The influences of matrix components upon the analysis were investigated. The limits of detection (LOD) and quantification (LOQ) were 0.039 µg/L and 0.108 µg/L, respectively. The method was employed to determine Sudan I in food.

Magnetic effervescent tablet-assisted ionic liquid dispersive liquid–liquid microextraction employing the response surface method for the preconcentration of basic pharmaceutical drugs: Characterization, method development, and green profile assessment

This study demonstrated magnetic effervescent tablet-assisted (META) ionic liquid (IL) dispersive liquid–liquid microextraction (DLLME) as a procedure for extracting pharmaceutical drugs from water samples. An effervescent tablet (ETA) comprising precursors, citric acid and sodium bicarbonate; iron oxide nanoparticles; and IL, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]), was utilized for the dispersion of the extractant in the aqueous phase. A flat-face radius edge tablet was prepared via wet granulation, and its properties were characterized by analyzing its morphology, magnetism, and functional groups. Further, pharmaceutical drugs, namely acetaminophen, atenolol, metoprolol, gliclazide, metformin, lovastatin, nifedipine, and caffeine were utilized as model analytes. Seven variables, namely the tablet weight (1–2 g), the volume of IL (100–500 µL), pH solution adjustment (5–9), the effect of the extraction temperature (15 °C–75 °C), no. of ETAs (2–4 pieces), the effect of the solidification time (3–13 min), and effect of the reconstituting solvent (250–1250 µL), that affected the extraction efficiency were screened and optimized via the Plackett–Burman design (PBD) and central composite design (CCD), respectively. The values of the optimum extraction condition were set, as follows: tablet weight, 1 g; the volume of IL, 500 µL; solution pH, pH 9; extraction temperature, 45 °C; no. of ETAs, 2 pieces; solidification time, 7.5 min; and reconstituting solvent, 750 µL. Combined with high-performance liquid chromatography with diode-array detection (HPLC–DAD) analysis, the developed method demonstrated good linearity (r2 > 0.990), extraction recovery range (75 %–104 %), and detection limits (0.2–6.6 ng mL). The calculated intra- and inter-day precisions, which were expressed as relative standard deviations (RSD, n = 3), were < 10 %. The developed method exhibited greenness, satisfying six green criteria and 0.61 (Analytical GREEnness (AGREE) with metric score).

Influence of water and ethanol in the physical properties of choline glycinate at several temperatures

In this study, a physical characterization (density (ρ), refractive index (nD), speed of sound (u) and dynamic viscosity (η)) as a function of temperature (298.15–343.15 K) of choline glycinate (ChGly) and its binary mixtures with water or/and methanol over the entire composition range was performed from 298.15 K to 323.15 K. Several derived properties of the pure ionic liquid and excess molar volume (VmE) changes of refractive index on mixing (ΔnD), deviations in isentropic compressibility (ΔκS) and viscosity deviations (Δη) have been calculated using the experimental data in the selected temperature range. These experimental data of ChGly have been positively correlated using polynomial equations and the derived magnitudes were successfully fitted to Redlich-Kister equation. Finally, different models have been implemented for the first time to predict the density of the selected binary mixtures as a function of the temperature.

Molecular dynamics simulations and COSMO-RS method for CO2capture in imidazolium and pyrrolidinium-based room-temperature ionic liquids.

The solubility of CO2 in different ionic liquids (ILs) was determined using molecular dynamics (MD) simulations and quantum calculations. MD simulation was used to study the interaction between IL and CO2 molecules at the interface. The solubility of CO2 is found to be higher in ILs containing [TF2N]- anion. The COSMO-RS model was used to determine the Henry's law constants for CO2 in different ILs. With increasing molar volume of ILs, the Henry's law constant of CO2 drops, which is in good accord with the solubility data obtained from MD simulations. The Henry's law constants follow the sequence of [BMIM][PF6] > [PMIM][TF2N] > [BMIM][TF2N] > [BMPY][TF2N] > [HMIM][TF2N] > [OMIM][TF2N]. The MD simulations and quantum calculations have shown that [TF2N]- has a higher impact on CO2 solubility than [PF6]-; this information is useful for screening and designing of ILs for CO2 absorption.

ATR-FTIR Studies of pH and Propylammonium Acetate Ionic Liquid Molecules Coordination on Polyethylene Glycol/Water Mixtures

In our research described here attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy was applied to investigate the O–H stretching band for various solutions of the polyethylene glycol 400 (PEG400) in water under the effects of pH and the concentration of propylammonium acetate ionic liquid (IL) volume added to the solution. The Gaussian deconvolution of the O–H stretching band into five sub-bands to describe the frequency components related to each coordination type was carried out. We have shown that the coordination type found depended on the interaction between water molecules and PEG400 chains for the three pHs tested and the IL are the same types as those present in pure bulk water. Therefore, we associated and classified the coordination n types as follows: the tri-coordinated double-donor type (3DD), the 4-coordinated molecules (4), the two coordinated single-donor type (2SD), and the tri-coordinated single-donor type (3SD), from low to high frequencies, respectively. We note that the integrated intensity and the full width at half maximum of individual sub-bands associated with each coordination type depended on the local environment of the hydrogen bonds and thus the physical properties of the mixtures studied.

Application of Thermo Acoustical Parameters for the Evaluation of the Available Volume of Ionic Liquid, 1-Butyl-3-Methylimidazolium Chloride in Mixed Solvents at Different Temperatures

The available volume of 1-Butyl-3-methyl imidazolium chloride, [bmim][Cl] in pure water and aqueous solutions of potassium citrate and sodium citrate at different concentrations of solute and T = (298.15 to 318.15) K have been evaluated by making use of ultrasonic velocity and thermo acoustic parameters followed by a comparative study. The thermo acoustic parameters have been used to determine available volume, V a for the solutions under analysis. For well understanding, the values of found from the thermo acoustic methods were tallied with the values found from the well-defined ultrasonic method (Schaaff’s method). The decrease of the available volume with an increase of the mass fraction of ionic liquid and temperature shows the existence of ion-solvent interactions of IL in the studied solutions. To the best of our knowledge, this study is a pioneering effort in the evaluation of available volume present in the investigated solutions by making use of the ultrasonic approach.

Comments on “Density modeling and apparent molar volume of ionic liquid 1-butyl-3-methylimidazolium bromide in water”

Comments on “Density modeling and apparent molar volume of ionic liquid 1-butyl-3-methylimidazolium bromide in water”

Development of SPME fiber coatings with tunable porosity for physical confinement of ionic liquids as an extraction media

Extending the use of ionic liquids in sample preparation techniques remains a challenge. This paper presents procedures enabling the easy application of ionic liquids to the SPME technique. For this purpose, two approaches for producing a porous silica coating on a metal rod were investigated. Two silica precursor and porogen systems were used in the research: K2SiO3 + Formamide and Tetramethyl-orthosilicate + Polyethylene oxide. The procedure was optimized concerning its operational parameters: the possibility of immobilization of a possibly large volume of ionic liquid and mechanical strength and thermal resistance. In the course of the research, it was shown that the optimal parameters are ensured by using K2SiO3 with Formamide. The obtained material had an average pore diameter equal to 0.326 μm with a surface area of the pores similar to 6.33 m2/g. The size of the pores allows for the quantitative introduction of the ionic liquid and its immobilization to the extent of enabling the extraction of VOC and their subsequent thermal desorption. Finally, the conducted experiments showed that the dominant mechanism of retaining analytes in the IL-silica hybrid material is their dissolution in the ionic liquid, while adsorption on the silica surface plays a lesser role.