INNOVATIVE APPLICATIONS OF IONIC LIQUIDS AS “GREEN” ENGINEERING LIQUIDS

Correlation of Macroscopic Surface Tension and Microscopic Surface Composition of Binary Ionic Liquid Mixtures with Common Cations and Anions of Different Size

We investigated the surface tension and surface composition of binary ionic liquid (IL) mixtures of ILs sharing the same cation. As model system, binary mixtures of 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc], molar volume: 154.4 cm3·mol-1 at 293 K) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2C1Im][Tf2N], molar volume: 256.2 cm3·mol-1 at 293 K), with very different surface tensions, and with anions of very different chemical structure and size were studied over the whole composition range. The surface tension was obtained by pendant-drop (PD) measurements in the presence of 0.1 MPa argon between 294 and 323 K, and the surface composition was determined by angle-resolved photoelectron spectroscopy (ARXPS) in ultrahigh vacuum at 293 K. The ARXPS results reveal a strong preferential enrichment of [C2C1Im][Tf2N] at the vacuum-liquid interface of the binary mixtures, which is more pronounced at lower [C2C1Im][Tf2N] bulk contents. This microscopic behavior is reflected in the macroscopic surface tensions, which are significantly lower than calculated assuming a linear mixing behavior based on the bulk composition. A previously developed prediction model to correlate the surface tension with the molar surface composition yields deviations of more than 5% from the measured values, which we attribute to the strongly different sizes of the anions. By accounting for the surface areas occupied by the ILs, we present an improved new model which describes the experimental data very well within 1.4%.

Thermodynamic Evaluation of Novel 1,2,4-Triazolium Alanine Ionic Liquids as Sustainable Heat-Transfer Media

Ionic liquids, which are widely recognized as environmentally friendly solvents, stand out as promising alternatives to traditional heat-transfer fluids due to their outstanding heat-storage and heat-transfer capabilities. In the course of our ongoing research, we successfully synthesized ionic liquids 1-ethyl-4-alkyl-1,2,4-triazolium alanine [Taz(2,n)][Ala], where (n = 4, 5); in this study, we present comprehensive data on their density, surface tension, isobaric molar heat capacity, and thermal conductivity for the first time. The key thermophysical parameters influencing the heat-transfer process, such as thermal expansibility, compressibility, isochoric heat capacity, and heat-storage density, were meticulously calculated from experimental data. Upon comparison with previously reported ionic liquids and commercially utilized heat-transfer fluids, [Taz(2,n)][Ala] demonstrated superior heat-storage and heat-transfer performance, particularly in terms of heat-storage density (~2.63 MJ·m-3·K-1), thermal conductivity (~0.190 W·m-1·K-1), and melting temperature (~226 K). Additionally, the presence of the alanine anion in [Taz(2,n)][Ala] provides more possibilities for its functional application.

Graphene Oxide-PAMAM Nanocomposite and Ionic Liquid Modified Carbon Paste Electrode: An Efficient Electrochemical Sensor for Simultaneous Determination of Catechol and Resorcinol

In this paper, a simple strategy was proposed for the analysis of catechol by a carbon paste electrode (CPE) modified with graphene oxide-third generation of poly(amidoamine) dendrimer (GO/G3-PAMAM) nanocomposite and ionic liquid (IL). The synthesis of GO-PAMAM nanocomposite was confirmed using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), and Fourier transform infrared spectroscopy (FT-IR) techniques. The prepared modified electrode (GO-PAMAM/ILCPE) exhibited good performance to detect catechol with a notable decrease in overpotential and increase in current compared with an unmodified CPE. Under optimum experimental conditions, GO-PAMAM/ILCPE electrochemical sensors indicated a lower limit of detection (LOD) of 0.034 μM and a linear response in the concentration range of 0.1 to 200.0 µM for the quantitative measurement of catechol in aqueous solutions. In addition, GO-PAMAM/ILCPE sensor exhibited an ability to simultaneously determine catechol and resorcinol. It can be found that catechol and resorcinol could be completely separated on the GO-PAMAM/ILCPE with the differential pulse voltammetry (DPV) technique. Finally, a GO-PAMAM/ILCPE sensor was utilized to detect catechol and resorcinol in water samples with recoveries of 96.2% to 103.3% and relative standard deviations (RSDs) of less than 1.7%.

Cation structure-dependence of the induced free charge density gradient in imidazolium and pyrrolidinium ionic liquids

We report on the structure-dependence and magnitude of the induced free charge density gradient (ρ_f) seen in room-temperature ionic liquids (RTILs) with imidazolium and pyrrolidinium cations. We characterize the spatially-resolved rotational diffusion dynamics of a trace-level cationic chromophore to characterize ρ_f in three different pyrrolidinium RTILs and two imidazolium RTILs. Our data show that the magnitude of ρ_f depends primarily on the alkyl chain length of RTIL cation and the persistence length of ρ_f is independent of RTILs' cation structure. These findings collectively suggest that mesoscopic structure in RTILs plays a significant role in allowing charge density gradients to form.

Thermal Hydraulics and Thermochemical Design of Fatty Acid Methyl Ester (Biodiesel) Esterification Reactor by Heating with High Boiling Point Phenyl-Naphthalene Liquid

FAME (biodiesel) is an alternative fuel that can be produced from vegetable oils. There is growing interest in the research and development of renewable energy sources. A possible solution is a biofuel usable in compression-ignition engines (diesel engines) produced from biomass rich in fats and oils. This paper contains a new and safer design of an esterification reactor for producing FAME (biodiesel) by utilizing high boiling point fluid (called phenyl-naphthalene). CFD simulation of biodiesel production by using methyl imidazolium hydrogen sulfate ionic liquid has been carried out. Ionic liquids (ILs) are composed of anions and cations that exist as liquids at relatively low temperatures. They have many advantages, such as chemical and thermal stability, low flammability, and low vapor pressures. In this work, the ionic liquids have been applied in organic reactions as solvents and catalysts of the esterification reaction. The great qualities of high boiling temperature fluids, along with advances in the oil and gas industries, make the organic concept more suitable and safer (water coming into contact with liquid metal may cause a steam explosion hazard) for heating the esterification reactor. The COMSOL Multiphysics code has been employed and simultaneously solves the continuity, fluid flow, heat transfer, and diffusion with chemical reaction kinetics equations. It was shown that the heat flux could provide the necessary heat flux required for maintaining the esterification process. It was found that the mass fractions of methanol and oleic acid decrease along the reactor axis. The FAME mass fraction increased along the reactor axis. The maximal biodiesel yield obtained in the esterification reactor was 86%. This value is very similar to the experimental results obtained by Elsheikh et al.

New benzyltriethylammonium/urea deep eutectic solvent: Quantum calculation and application to hyrdoxylethylcellulose modification

In this paper, a new deep eutectic solvent (DES) has been successfully synthesized that is based on benzyltriethylammonium bromide as a hydrogen bond acceptor (HBA) and urea as a hydrogen bond donor (HBD). However, its usability in modifying cellulose derivatives, especially acylating hydroxyethylcellulose (HEC) was investigated. The chemical modification (acetylation) of HEC was carried out in BTEAB/urea DES system without any additional conventional solvent or catalyst. However, the proposed structure of acetylated HEC (HECA) was confirmed according to the structural spectra analyses FTIR-ATR, ¹H, ¹³C, and APT-NMR. The crystalline behavior of acetylated and unmodified HEC in the DES system has been evaluated using XRD patterns, where the thermal stability was evaluated basing on the TD-TGA thermograms. Hence, SEM images and EDX spectra were recorded to prove the changes that are expected at the morphological level and elemental profile. Yet, the nanometric sheets aspect was observed. The Functional Density Theory (DFT) was investigated as a useful computational tool to understand mechanism and donor-acceptor interactions. The topological parameters (electron density Laplacian, kinetic energy density, potential energy density, and energy density) at the bond critical points (BCP), between TBEAB and urea, are deducted according to Quantum Bader's theory, and Atoms-in-molecules (AIM). The non-covalent interactions and steric effect in the DES system were studied using the reduced density gradient isosurface (RDG). Theoretical and computational calculations revealed that the H-bonds and the electrostatic coexist, as predominant interactions in the BTEAB-based DES resulting chemical structure, and mechanism formation. The physical interactions between the component entities of DES lead to a new equilibrium that is more stable than that of HBA and HBD in their separate states.

Polymer-Grafted Porous Silica Nanoparticles with Enhanced CO2 Permeability and Mechanical Performance

Three different types of polymer ligands, poly(methyl methacrylate) (PMMA), poly(methyl methacrylate-random-poly(ethylene glycol)methyl ether methacrylate) (PMMA-r-PEGMEMA), and poly(ionic liquid)s (PIL), were grafted onto the surface of 15 nm solid and large hollow porous silica nanoparticles (average particle size ∼60 nm) by surface-initiated atom transfer radical polymerization (SI-ATRP) to demonstrate the enhanced carbon dioxide (CO₂) permeability as well as mechanical properties. After characterizing the purified products, free-standing bulk films were fabricated by the solvent-casting method. The poly(ionic liquid) nanocomposite films exhibited a much higher carbon dioxide permeance than PMMA and PMMA-r-PEGMEMA systems with a similar silica content. Also, the hollow silica-mixed matrix membranes showed a significant enhancement in CO₂ permeability compared to the 15 nm solid silica films because of the pore structure. Despite the transparency loss due to the scattering of larger particle sizes, the hollow silica particle brush films exhibited the same mechanical properties as the 15 nm solid silica-derived ones.

Strongly diluted dimethyl-imidazolium chloride–alcohol solutions: solvents are structurally different but dynamic heterogeneities are similar

Based on the analysis of dynamic properties of ionic liquid solutions, the descriptions of diffusion mechanisms are built for dimethylimidazolium chloride (dmim⁺/Cl⁻)–alcohol solute systems and the influence of the monohydric alcohols' molecular structure on their diffusion mechanisms in dmim⁺/Cl⁻–alcohol at T = 400 K by molecular dynamics simulations are studied. From the analysis of radial distribution functions, MSDs, velocity autocorrelation function, and autocorrelation functions of dispersion we found that the motion of all components in IL dmim⁺/Cl⁻–alcohol (ethanol, propanol) systems at T = 400 K occurs in the sub-diffuse regime and that the dynamics of the dmim⁺/Cl⁻–alcohol (ethanol, propanol) systems is heterogeneous. The increase of the alkyl chain length of the alcohol molecule does not affect the motion of the ionic liquid components; instead, it increases the characteristic times describing the model representation of alcohol molecule diffusion at short and medium times, without affecting diffusion mechanisms.

The increase of the alkyl chain length of the alcohol molecule does not affect the motion of the ionic liquid components.

A review on tribological performance of ionic liquids as additives to bio lubricants

All the moving components in an internal combustion engine require a lubricant that allows smooth sliding and/or rolling of interacting surfaces. Lubricant not only minimizes the friction and wear but also dissipates the heat generated due to friction and removes debris from the area of contact. Environmental concerns, decreasing mineral oil reserves and difficult disposal of nonbiodegradable conventional lubricants have urged the researchers to shift towards environmental-friendly lubricants. Number of tribological studies carried out in the past have proved that ionic liquid-based bio-lubricants are sustainable and biodegradable alternative to mineral oils. This paper presents a brief review of properties of ionic liquids and their ability to reduce friction and wear between the interacting surfaces. Tribological performance and compatibility of ionic liquids with various base-oils have been compared under boundary lubrication. The results reveal that phosphonium-based ionic liquids namely tetra-decyl tri-hexyl phosphonium bis(2,4,4-trimethylpentyl) phosphinate (P66614)i(C8)2PO2 and tri-hexyl tetra-decyl phosphonium bis(2-ethylhexyl) phosphate (P-DEHP) are more suitable for tribological applications. Since, ionic liquids can be tailored according to the application and millions of combinations are possible therefore, there is a need to summarize the published data in a more systematic and logical way.

Green Solvent: Green Shadow on Chemical Synthesis

The natural beauty and purity of our planet has been contaminated deeply due to human selfish activities such as pollution, improper waste management, and various industrial and commercial discharges of untreated toxic by-products into the lap of nature. The collective impact of these hazardous suspensions into the natural habitat is very deadly. Challenges due to human activity on the environment have become ubiquitous. The chemical industry has a major role in human evolution and, predictably, opened gates of increased risk of pollution if the production is not done sustainably. In these circumstances, the notion of Green Chemistry has been identified as the efficient medium of synthesis of chemicals and procedures to eradicate the toxic production of harmful substances. Principles of Green Chemistry guide the scientist in their hunt towards chemical synthesis which requires the use of solvents. These solvents contaminate our air, water, land and surrounding due to its toxic properties. Even though sufficient precautions are taken for proper disposal of these solvents but it is difficult to be recycled. In order to preserve our future and coming generation from the adverse impacts associated with solvents it is very important to find alternative of this which will be easy to use, reusable and also eco-friendly. Solvents are used daily in various industrial processes as reaction medium, as diluters, and in separation procedures. As reaction medium, the role of solvent is to bring catalysts and reactants together and to release heat thus affecting activity and selectivity. The proper selection of the solvent considering its biological, physical and chemical properties is very necessary for product separation, environmental, safety handling and economic factors. Green solvents are the boon in this context. They are not only environmentally benign but also cost effective. The biggest challenge faced by the chemists is adaptation of methods and selection of solvents during chemical synthesis which will give negligible waste product and will remain human and nature friendly. During designing compounds for a particular reaction it is difficult to give assurance regarding the toxicity and biodegradability of the method. Chemists are still far away from predicting the various chemical and biological effects of the compounds on the back of the envelope. To achieve that point is formidable task but it will definitely act as inspiration for the coming generation of chemists. The green solvents are undoubtedly a far better approach to eliminate the negative impacts and aftermath of any chemical synthesis on the environment. Our study in this review covers an overview of green solvents, their role in safer chemical synthesis with reference to some of the important green solvents and their detail summarization.

Changes in the gut microbiota of mice orally exposed to methylimidazolium ionic liquids

Ionic liquids are salts used in a variety of industrial processes, and being relatively non-volatile, are proposed as environmentally-friendly replacements for existing volatile liquids. Methylimidazolium ionic liquids resist complete degradation in the environment, likely because the imidazolium moiety does not exist naturally in biological systems. However, there is limited data available regarding their mammalian effects in vivo. This study aimed to examine the effects of exposing mice separately to 2 different methylimidazolium ionic liquids (BMI and M8OI) through their addition to drinking water. Potential effects on key target organs-the liver and kidney-were examined, as well as the gut microbiome. Adult male mice were exposed to drinking water containing ionic liquids at a concentration of 440 mg/L for 18 weeks prior to examination of tissues, serum, urine and the gut microbiome. Histopathology was performed on tissues and clinical chemistry on serum for biomarkers of hepatic and renal injury. Bacterial DNA was isolated from the gut contents and subjected to targeted 16S rRNA sequencing. Mild hepatic and renal effects were limited to glycogen depletion and mild degenerative changes respectively. No hepatic or renal adverse effects were observed. In contrast, ionic liquid exposure altered gut microbial composition but not overall alpha diversity. Proportional abundance of Lachnospiraceae, Clostridia and Coriobacteriaceae spp. were significantly greater in ionic liquid-exposed mice, as were predicted KEGG functional pathways associated with xenobiotic and amino acid metabolism. Exposure to ionic liquids via drinking water therefore resulted in marked changes in the gut microbiome in mice prior to any overt pathological effects in target organs. Ionic liquids may be an emerging risk to health through their potential effects on the gut microbiome, which is implicated in the causes and/or severity of an array of chronic disease in humans.

Analysis of mobile chemicals in the aquatic environment-current capabilities, limitations and future perspectives

Persistent and mobile water contaminants are rapidly developing into a focal point of environmental chemistry and chemical regulation. Their defining parameter that sets them apart from the majority of regularly monitored and regulated contaminants is their mobility in the aquatic environment, which is intrinsically tied to a high polarity. This high polarity, however, may have severe implications in the analytical process and thus the most polar of these mobile contaminants may not be covered by widely utilized trace-analytical methods, and thus, alternatives are required. In this review, we infer the physical and chemical properties of mobile water contaminants from a set of almost 1800 prioritized REACH chemicals and discuss the implications these substance properties may have on four integral steps of the analytical process: sampling and sample storage, sample pre-treatment, separation and detection. We discuss alternatives to widely utilized trace-analytical methods, examine their application range and limitations, highlight potential analytical techniques on the horizon and emphasize research areas we believe still offer the most room for further improvement. While we have a comprehensive set of analytical methods to cover a large portion of the known mobile chemicals, these methods are still only infrequently utilized. Graphical abstract.

Synthesis of novel functional ionic liquids and their application in biomass

A series of dicationic ionic liquids (ILs) including [PF6][(PYR)C4(MIM)][Cl], [PF6][(PYR)C4(PYR)][Cl], [PF6][(PYR)C5(MIM)][Cl], and [PF6][(PYR)C5(PYR)][Cl], and monocationic ILs including [(PYR)C4Cl][PF6], [(PYR)C5Cl][PF6], [(MIM)C2COOH][PF6] and [(PYR)C2COOH][PF6] were synthesized. Their thermal stability and melting points were determined. Their solubility with organic solvents and the miscibility with water were investigated. These functional ILs are hydrophilic at high temperatures and they are hydrophobic at low temperatures, which enable the effective isolation of the resulting reducing sugar. High yields of reducing sugar were obtained for corn stalk after 8 h (20.73%) and potato starch after 6 h (72.50%) by the treatment with the mixture of [PF6][(PYR)C4(PYR)][Cl] and [(PYR)C2COOH][PF6]. The reuse of dicationic and monocationic ILs was successfully performed and no significant reduction in yields of reducing sugar was observed. These functional ILs have important implications in the design of homogeneous and heterogeneous systems with water and organic solvents, which could be used to satisfy some specific applications.

Enzymatic polymerization to polyesters in nonaqueous solvents

Aliphatic polyesters are thermoplastic and biodegradable polymers with promising potentials to substitute synthetic polymers derived from petrochemicals. In particular, polylactides (PLAs) and other polylactones can be renewable and biocompatible. A more benign approach for polyester synthesis is the enzymatic polycondensation or ring-opening polymerization (ROP) reactions, whose outcomes largely depend on the reaction conditions including solvents, water content and temperature. This chapter illustrates several examples of enzymatic polymerization to polyesters using various solvents (i.e., organic solvents, supercritical fluids, ionic liquids, and aqueous biphasic systems). Hydrophobic solvents containing little water tend to promote the enzymatic polymerization and lead to high molecular masses of polyesters. Since some enzymatic polymerization reactions are performed at high temperatures (such as ring-opening polymerization of lactide at >100°C), these processes demand solvents with high boiling points (such as many ionic liquids). Supercritical fluids (such as supercritical CO₂) can be "green" solvents, but their compatibility with enzymes and their practicability of scaling up remain as challenges. On the other hand, ionic liquids can be tailored to be compatible with enzymes and to have high thermal stability although the studies of their uses in enzymatic polycondensation and ROP reactions are still at an early stage.

Ionic liquid-based nanofluids (ionanofluids) for thermal applications: an experimental thermophysical characterization

Heat transfer fluids materials are manufactured for the purpose of transfer, distribution and storage of heat. Several of their important properties can be listed (for example flash point, thermal expansivity or technical safety). However, to assess the thermal exchange performance of these fluids, a prior knowledge of their heat capacity, density, viscosity and thermal conductivity is obligatory. The most popular heat transfer fluids are based on organic liquids, such as ethylene glycol. However, new technologies and development require more efficient materials. Ionanofluids, mixtures of ionic liquids and nanoparticles, were proposed as a viable replacement for those commonly used fluids due to the properties of ionic liquids (wide liquid range or low vapour pressure and flammability) combined with enhanced thermophysical properties of nanofluids caused by the dispersion of nanoparticles (mainly thermal conductivity and heat capacity). Very few authors reported the extensive analysis of those systems thermophysical properties and impact on the heat exchange efficiency. Moreover, the availability of published data is very limited. The aim of this work is to investigate ionanofluids based on the trihexyl(tetradecyl)phosphonium cation paired with the acetate, butanoate, hexanoate, octanoate or decanoate anion, mixed with carbon nanotubes, boron nitride, graphite or mesoporous carbon as nanoparticles with concentration up to 3 wt %. The density, heat capacity, thermal stability, thermal conductivity and viscosity of selected ionanofluids were determined experimentally as functions of the temperature (up to 363.15 K) and compared with theoretical tools to evaluate the predictive capability. Based on the experimental results, lubrication, heat storage potential and economic analysis were also discussed and compared to commercial heat transfer fluids.

Evidence of CT complex formation between a probe and unreacted methylimidazole in imidazolium cation based ionic liquids: sensing by functionalised 2-benzyledinemalononitrile

A new sensor-based detection and estimation of unreacted methylimidazole in ionic liquids, which can corrupt the photophysical data, is presented.

Extraction of ferulic acid and vanilla acid by hydrophobic ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate

The study was carried out to evaluate the extraction efficiency of ferulic acid (FA) and vanilla acid (VA) from aqueous phase into IL phase. To achieve the highest extraction efficiency, the influence of varying key parameters was evaluated and optimized by response surface methodology based on Box-Behnken design, including phase volume ratio, extraction temperature and extraction time. FA (or VA) extraction under the optimal conditions were: phase volume ratio of 1.38 (1.28), extraction temperature of 66.34 °C (49.28 °C) and extraction time of 33.83 min (36.64 min) under optimum conditions an average extraction efficiency of 97.11 ± 1.05% for FA was achieved, while VA was 85.43 ± 1.62%. This was very close to the predicted value from the model, 98.05% (86.16%). Additionally, recycling and utilization of ILs were performed well with the recovery ratio for 81.0%. Based on thermodynamic analysis, FTIR and ¹H NMR analysis, the combination of hydrophobic interaction and hydrogen-bond interaction resulted in the real extraction result above. It is desirable to provide a useful reference for the separation and purification of FA, VA, and extend the potential application of ionic liquid in the separation of natural active compounds with great prospects.

Sub-μL measurements of the thermal conductivity and heat capacity of liquids

We present the analysis of the thermal conductivity, κ, and heat capacity, C_p, of a wide variety of liquids, covering organic molecular solvents, ionic liquids and water-polymer mixtures. These data were obtained from ≈0.6 μL samples, using an experimental development based on the 3ω method, capable of the simultaneous measurement of κ and C_p. In spite of the different type and strength of interactions, expected in a priori so different systems, the ratio of κ to the sound velocity is approximately constant for all of them. This is the consequence of a similar atomic density for all these liquids, notwithstanding their different molecular structures. This was corroborated experimentally by the observation of a C_p/V ≈ 1.89 × 10⁶ J K^-1 m^-3 (≈3R/2 per atom), for all liquids studied in this work. Finally, the very small volume of the sample required in this experimental method is an important advantage for the characterization of systems like nanofluids, in which having a large amount of the dispersed phase is sometimes extremely challenging.

Acoustic cavitation in 1-butyl-3-methylimidazolium bis(triflluoromethyl-sulfonyl)imide based ionic liquid

In this work, a comparison between the temperatures/pressures within acoustic cavitation bubble in an imidazolium-based room-temperature ionic liquid (RTIL), 1-butyl-3-methylimidazolium bis(triflluoromethyl-sulfonyl)imide ([BMIM][NTf₂]), and in water has been made for a wide range of cavitation parameters including frequency (140-1000kHz), acoustic intensity (0.5-1Wcm^-2), liquid temperature (20-50°C) and external static pressure (0.7-1.5atm). The used cavitation model takes into account the liquid compressibility as well as the surface tension and the viscosity of the medium. It was found that the bubble temperatures and pressures were always much higher in the ionic liquid compared to those predicted in water. The valuable effect of [BMIM][NTf₂] on the bubble temperature was more pronounced at higher acoustic intensity and liquid temperature and lower frequency and external static pressure. However, confrontation between the predicted and the experimental estimated temperatures in ionic liquids showed an opposite trend as the temperatures measured in some pure ionic liquids are of the same order as those observed in water. The injection of liquid droplets into cavitation bubbles, the pyrolysis of ionic liquids at the bubble-solution interface as well as the lower number of collapsing bubbles in the ionic liquid may be the responsible for the lower measured bubble temperatures in ionic liquids, as compared with water.

Teratogenic, cardiotoxic and hepatotoxic properties of related ionic liquids reveal the biological importance of anionic components

Whole organism assays in zebrafish reveal novel biological activities of ionic liquids.

Synthesis, characterization, and application of 1-butyl-3-methylimidazolium thiocyanate for extractive desulfurization of liquid fuel

1-Butyl-3-methylimidazolium thiocyanate [BMIM]SCN has been presented on extractive desulfurization of liquid fuel. The FTIR, (1)H-NMR, and C-NMR have been discussed for the molecular confirmation of synthesized [BMIM]SCN. Further, thermal, conductivity, moisture content, viscosity, and solubility analyses of [BMIM]SCN were carried out. The effects of time, temperature, sulfur compounds, ultrasonication, and recycling of [BMIM]SCN on removal of dibenzothiophene from liquid fuel were also investigated. In extractive desulfurization, removal of dibenzothiophene in n-dodecane was 86.5 % for mass ratio of 1:1 in 30 min at 30 °C under the mild process conditions. [BMIM]SCN could be reused five times without a significant decrease in activity. Also, in the desulfurization of real fuels, multistage extraction was examined. The data and results provided in the present paper explore the significant insights of imidazolium-based ionic liquids as novel extractant for extractive desulfurization of liquid fuels.

Chemical–mechanical properties of tribofilms and their relationship to ionic liquid chemistry

Hardness as a function of indentation depth for tribofilms formed from ZDDP and N_DEHP ionic liquid. Superimposed on the data is the corresponding phosphate chain length information acquired from XANES.

Study on the growth of wheat seedlings under acetic acid ionic liquids [Cnmim][OAc] (n = 2, 4, 6)

A transmission electron microscope (TEM) was used to observe the cellular structure of wheat leaf under the effects of ionic liquids (ILs).

A mechanism for solvent extraction of first row transition metals from chloride media with the ionic liquid tetraoctylammonium oleate

The extraction mechanism of cobalt, nickel and zinc with the ionic liquid tetraoctylammonium oleate is reported.