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In this paper, two new amino acid imidazole ionic liquids IL‐3 and IL‐4 were synthesized for the first time, and their separation performance as the stationary phase for capillary gas chromatography (GC) was tested. The statically coated IL‐3 and IL‐4 capillary columns exhibited moderate to high polarity, and achieved the column efficiency of 2242 plates/m and 2487 plates/m respectively determined by n‐octanol at 120 °C. Importantly, the IL‐3 and IL‐4 columns exhibited excellent separation capability for analytes with varying polarity, including n‐alkanes, arenes, esters, alcohols, bromoalkanes, halogenobenzenes, and halogenated anilines. In addition, the IL‐3 and IL‐4 columns presented high selectivity and separation capability for positional, structural and cis‐/trans‐isomers. In particular, they showed high separation performance of the chloroaniline, bromaniline, iodoaniline and xylidine isomers as an important environmental pollutant. The IL‐3 and IL‐4 columns displayed advantageous resolving capability over the commercial HP‐35 column for aromatic amine isomers, and the separation performance of IL‐4 with long carbon chain was better than that of IL‐3. Moreover, it was applied to determine isomer impurities in real samples, and showing huge potential in GC applications. This work demonstrates the potential of the amino acid imidazole ionic liquids as a new type of stationary phase in GC separations. [ABSTRACT FROM AUTHOR]

This paper studied the adsorption characteristics and mechanism of four kinds of ionic liquids (ILs) with different carbon chain lengths in montmorillonite (Mt). The results of isothermal adsorption at 25 °C show that the adsorption of four kinds of IL in Mt conforms to the Modified‐Langmuir model, and the adsorbance of IL in Mt is positively correlated with the dosage and the carbon chain length of IL. The dynamics research results show that the adsorption of IL in Mt fits well with the quasi‐second‐order dynamics equation. The reaction constant k is negatively correlated with the dosage of IL but positively correlated with the carbon chain length. The thermodynamics results show that the adsorption of IL in Mt is exothermic. The carbon chain length and the dosage of IL have a cross effect on the adsorption capacity of Mt for IL and the structure of the adsorption products. The adsorption capacity of Mt increases first and then decreases with the increase of dosage, and it increases with the increase of carbon chain length. The dosage of IL has little effect on the d(001) of IL/Mt with the short carbon chain, but the d(001) of IL/Mt with the long carbon chain increases with the increase of the dosage of IL. The carbon chain length has little effect on the d(001) of IL/Mt with a low dosage of IL, however, when the dosage of IL is high, the d(001) of IL/Mt increases with the increase of carbon chain length. The specific surface area, pore volume and the most probable radius of IL/Mt decrease with the increase of the dosage and carbon chain length, but excessive amounts of IL will still increase the most probable radius. Molecular dynamics simulation results show that when the dosage of IL is 0.3CEC, four ILs with different carbon chain lengths are arranged in a monolayer between Mt layers, N (N in IL) coordinates with Ot (O on the tetrahedral surface) at a distance of 3.0 Å, and the coordination strength increases with the increase of the carbon chain length of IL. [ABSTRACT FROM AUTHOR]

This paper explores an interconnection between timescales of dynamic heterogeneity (DH) in a neat ionic liquid (IL), 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF6]), and slow solvation of a dipolar solute, coumarin 153 (C153) in it at 298 K and 450 K. Molecular dynamics simulations employing realistic interaction potentials for both the IL and the solute have been performed. DH timescales have been obtained from non-Gaussian and new non-Gaussian (NNG) parameters, and four-point dynamic susceptibilities (χ4(k, t)) and overlap functions (Q(t)). Simulated ion displacement distributions exhibit pronounced deviations from Gaussian behaviour and develop bimodality in the timescale of structural relaxation, Τa, indicating ion hopping at long-time. DH timescales from x4(k, t) and Q(t) have been found to be longer than ΤNNG although Τα ≈ ΤNNG. Maximum cation jump length detected here corresponds to ~50% of the ion diameter and agrees well with experimental estimates. DH length-scale (f ) extracted from x4(k, t) spans about an ion diameter and shows correct temperature dependence. Our simulated solvation response functions for C153 in [Bmim][PF6] are tri-exponentials with fast time constants in good agreement with the available experimental and/or simulation data. The slow solvation rate at 298 K, however, is ~ 4 times slower than that found in experiments, although the same at 450 K corroborates well with simulation data at similar temperature from different sources. Importantly, our simulated slow solvation rates at these temperatures strongly correlate to longer DH timescales, suggesting DH as a source for the slow solvation at long-time in IL. Moreover, ion jumps at long-time suggests viscosity decoupling of long-time solvation rate in ILs. [ABSTRACT FROM AUTHOR]

All R s values become larger with adsorbed counterions, however, organic counterions adsorbed onto micelles can decrease the SASA, which is contrary to the inorganic Cl− ions. [Display omitted] • Absorbed PO− and BZ− ions lead to the decrease in SASA. • The Cl− ions are adsorbed on micelle surface while PO− and BZ− ions penetrate deeper into the micellar interior. • Water molecules penetrate into the deepest position in [C 14 mim][Cl] micelle. Self-assembly of ionic liquids (ILs) in solution has attracted wide attention due to their potential applications in various fields. The nature of counterions, especially aromatic counterions, will significantly affect the aggregation and morphological properties of ILs surfactants. In this paper, molecular dynamics (MD) simulations are applied to study the influence of three organic and inorganic counterions (phenolate (PO−), benzoate (BZ−), and Cl−) on the micellar structure of imidazolium (C 14 mim+) based ILs surfactant in aqueous solutions. Three micelles all possess prolate shape. The PO−, BZ−, and Cl− ions hardly affect the orientation and length of hydrophobic chains in micellar interior. Hydration numbers and average radial density distributions analyses show that interactions between micelles and water molecules are different in studied micelles. Surrounding water molecules penetrate into the deepest region in [C 14 mim][Cl] micelle. However, adsorbed Cl− ions are mainly located on micellar surface, not penetrating into micellar interior. Due to the intrinsic hydrophobicity of organic ions, both PO− and BZ− ions enter into deeper positions in micelles. Unlike Cl− ions, there exist π-interactions between adsorbed PO− and BZ− ions themselves. One interesting finding is that adsorbed PO− and BZ− ions can make micelle radius (R g) increase but make solvent accessible surface area (SASA) decrease. Conversely, adsorbed Cl− ions make both R g and SASA increase. Three MD models for different C 14 mim+ based micelles are proposed. [ABSTRACT FROM AUTHOR]

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. [Display omitted] • The solubility of CEES in ILs is clarified from the molecular level. • The cationic alkyl chain length affects the solubility of CEES within a specific limit. • The anion–cation IEs play a dominant role in the solubility of ILs to CEES. • Anion more significantly affects the solubility of CEES than cationic alkyl chain. Mustard gas (HD) is one of the most dangerous chemical warfare agents, which can cause serious injuries and even deaths. The rapid and efficient degradation of HD is crucial to protect people from hurting by its high toxicity. However, the widely used water-based decontaminants always have limited degradation efficiency for HD due to its poor solubility in water. Therefore, ionic liquids (ILs) hold great potentials as solvents for degradation of HD since they can improve HD's solubility for an effective degradation. In this study, the solubilities of 2-chloroethyl ethyl sulfide (CEES), a simulant of HD, in nine ionic liquids (ILs) were investigated. Interaction descriptors of the anions, cations, and ILs were computed using quantum mechanics and density functional theory to understand the influence of the IL properties on the solubility of CEES in ILs at the molecular level. The results indicate that CEES solubility depends on cation/anion physical properties and anion–cation and anion/cation/IL–CEES interactions. The cation electron affinity and anion ionization potential are closely related to the solubility of the Lewis acid CEES in the ILs. The anion/cation–CEES interaction energy (IE) exhibits poor correlation with CEES solubility, while the anion–cation IE plays a dominant role. A negative correlation was observed between absolute IL–CEES IEs and CEES solubility. For HCO 3 ¯ anion-based ILs, the interstitial space of the ILs increased with the cationic alkyl side chain length within a specific limit, resulting in more excellent solubility of CEES. For [BMIm]+ cation-based ILs, the anion influenced the cation–anion and cation/anion/IL–CEES IEs, thus affecting the solubility of CEES. In conclusion, this study serves as a guide for designing ILs for dissolving CEES and improving the degradation efficiency of HD by exploring cation–anion and anion/cation/IL–CEES interactions and other interaction descriptors. [ABSTRACT FROM AUTHOR]

• In this paper, we report the corrosion inhibition of amino acid imidazole ionic liquids ([CyVIm][AA]ILs) on mild steel in neutral media, which has not been studied before. • In addition, the corrosion inhibition performance of [CyVIm][AA]ILs in neutral media was evaluated comprehensively by a combination of experiments and simulations as well as an in-depth investigation of the corrosion inhibition mechanism. The corrosion inhibition properties of three amino acid imidazole ionic liquids ([CyVIm][AA]) as corrosion inhibitors for mild steel in a 3.5 wt% NaCl corrosion medium were evaluated by electrochemical measurements. The polarization experiments show that [CyVIm][AA] influences anode reaction processes, demonstrating that [CyVIm][AA] is an anodic inhibitor type corrosion inhibitor. [CyVIm]Try outperforms [CyVIm]His and [CyVIm]Pro in terms of corrosion inhibition. The results of surface analysis and quantum chemical calculations show that [CyVIm]Try can form a protective film on the surface of mild steel and inhibit surface corrosion. Furthermore, by applying molecular dynamics simulations, after investigating the corrosion inhibitor adsorption trends on the Fe (1 1 0) surface, the interaction order between the molecular framework of the Fe corrosion inhibitor and the Fe (1 1 0) surface for entanglement was determined. According to the radial distribution function, the corrosion inhibitor adsorption mode on the metal surface is composite adsorption with chemisorption as the major mode and physical adsorption as the secondary mode. [ABSTRACT FROM AUTHOR]

[Display omitted] • Solvent-free synthesis method that yields high purity and dry protic ionic liquids. • The synthesis method is described in detail, including a video tutorial. • The imidazolium compounds showed higher thermal stability when compared to the triazolium ones. • DFT was used hypothesize on the increased acidity of triazolium protic ionic liquids. A series of triazolium and imidazolium based protic ionic liquids were synthesized using a solvent-free method designed to address several limitations encountered with other commonly used methods. Using this method, pure (98–99% m/m) and dry (128–553 ppm of water) protic ionic liquids were synthesized (in a laboratory scale) without the need for purification methods that require heating the ionic liquid, hence avoiding the common issue of thermal decomposition. This method was also designed to allow for the accurate measurement of acid and base, and for the controlled mixing of both compounds, which is essential to avoid producing impure protic ionic liquids with excess of either acid or base. The system is constructed of only glass and chemically resistant polymer (PTFE and PVDF) parts, which avoid other contaminants that can result from unwanted reactions involving the reagents with common laboratory tools (metallic objects, paper, plastic, etc.). This process is described in detail in the paper as well as in a video. The resulting ionic liquids were carefully analyzed by spectroscopic and thermal methods designed to avoid water absorption, which is known to affect their properties. To complement this experimental characterization, computational chemistry tools were used to assess the ionic liquids' properties, as well as to assign vibrational modes. [ABSTRACT FROM AUTHOR]

Abstract The rheological behavior of a fluid is an important property that has a distinct impact on its flow conduct, which influence viscosity dependent phenomena and applications such as pumping, mass transfer rates, and hydrodynamics. As a result, the necessity of studying the different rheograms and the viscoelastic properties of fluids is essential. In this review, a vast number of novel imidazolium-based combinations of ionic liquids (IL) and natural deep eutectic solvents (NADES) in terms of different hydrogen bond donors (HBD) and hydrogen bond acceptors (HBA) having different molar ratios of HBA:HBD were classified. The rheological behaviors of these combinations at ambient temperature conditions and higher temperatures are critically evaluated. The influence of different parameters such as the effect of adding different polymers, metal oxides, and water on the rheological behaviors and eventually on the flow assurance of these solvents are investigated. Moreover, an intensive overview of all the key research papers, mainly highlighting the initial apparent viscosity and steady-state viscosity for both IL & NADES solvents with different scenarios was conducted by collecting the different trends in rheograms using different measuring devices from several experimental efforts. Also, the relatively few studies on the oscillatory measurement was also highlighted, as it has shown to be a useful analysis method to determine the elastic properties. In addition, oscillatory mode measurements were best to describe and enhance studies on IL and NADES with high viscosities, which can aid their potential uses in challenging applications such as in pumping of liquid material in many industrial processes, through the study of their elasticity behaviors under the effect of several field operation conditions. Furthermore, eight different rheological regression models from different polynomial degrees were used to describe and physically interpret the viscous and viscoelastic behaviors of the studied solvents. Highlights • Different rheograms and the viscoelastic behaviors of IL and NADES are highlighted. • IL and NADES structures have clear effect on the overall flow behavior. • Rheology of IL and NADES are important in many applications such as pumping, mass transfer rates, and hydrodynamics. [ABSTRACT FROM AUTHOR]

Abstract Increasing demand and dwindling supply of crude oil have spurred efforts towards enhancing heavy oil recovery. Recently, applications of ionic liquids (ILs) for heavy oil recovery and catalytic upgrading have been intensively studied due to their novelty as green surfactants. This paper presents the effects of different carbon chain lengths (n = 0, 2, 4, 6, 8, 10, 12) and concentrations from 1000 to 8000 ppm of imidazolium-based ILs on the oil-sand detachment efficiency at room temperature. Overall, the longest carbon chain length (n = 12), 1-dodecyl-3-methylimidazolium chloride ([DODmim][Cl]), showed highest oil-sand detachment efficiency of approximately 80% at 4000 ppm and beyond, indicating that a CMC point has been achieved. In contrary, the IL without carbon chain length (n = 0), 1-methylimidazolium chloride ([Mmim][Cl]), showed lowest oil-sand separation of a mere 5.7% at all concentrations. Interfacial tension (IFT) and zeta potential measurements further verified the above oil-sand detachment efficiencies, whereby the high oil-sand detachment efficiencies correlated to low IFT of approximately 9.78 mN/m for [DODmim][Cl] at 8000 ppm and high net zeta potential measurements of positively charged oil and sand particles. It is interesting to note that while the zeta potential measurements were all positive for oil particles in IL, the zeta potential measurements of sand particles in IL turned to negative for low concentrations of [Omim][Cl] and shorter carbon chain lengths (n ≤ 6), thus resulting in a mild attraction between the oil and sand particles. Further analysis using the Derjaguin-Landau, Verwey Overbeek (DLVO) theory which showed the inter-particle forces further validated the former oil-sand detachment efficiencies whereby repulsive forces between oil and sand particles occurred only for longer carbon chain lengths of [DODmim][Cl] and [Dmim][Cl]. Highlights • Maximum oil-sand detachment efficiency of 80% is achieved at longest carbon chain length (n = 12). • Oil-sand detachment efficiency increases with decreasing interfacial tension (IFT). • Oil-sand detachment efficiency correlates to net zeta potential measurements. • Zeta potential of sand particles turn negative in shorter carbon chain length ILs. • Repulsion forces between oil and sand particles occur at shorter separation distances with increase in carbon chain length. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract In this paper, we aimed to develop a reversible and effective method to control the surface activity and self-assembled morphology of amphiphilic imidazolium-type ionic liquids (G) in water. For this purpose, a series of pillar[5]arene/imidazolium supramolecular complexes were designed and prepared. Before the formation of the host-guest complex, the surface activity of G7 worked well, and foams could be generated easily. However, after the addition of water-soluble pillar[5]arene (WP5), the rigid WP5 platform caused steric hindrance that prevented the hydrophobic chains on G7 from getting close to each other, inducing the change in surface activity. On the other hand, because paraquat (PQ) has a larger association constant with WP5 than G7 , the surface activity of the solution can be recovered after the addition of PQ. TEM confirmed that self-assembled morphologies of this reversible system transformed from nanoparticles to nanosheets then to nanoparticles. It is anticipated that this supramolecular method for controlling the surface activity of amphiphiles in a reversible way may find application in fields where fast foaming and defoaming are needed. [ABSTRACT FROM AUTHOR]

An analytical method for the simultaneous determination of iodide and iodate by reversed phase liquid chromatography with ultraviolet detection using imidazolium ionic liquids as mobile phase additives was developed in this paper. Imidazolium ionic liquids, pyridinium ionic liquids, and common ion pair reagent tetrabutylammonium hydroxide as mobile phase additives were compared. The results indicated that imidazolium ionic liquids as the mobile phase additives were better than any tetrabutylammonium hydroxide or pyridinium ionic liquids. The relevant mechanisms of separation and detection for the anions were discussed. Imidazolium ionic liquids acted as ion pair reagents and ultraviolet absorption reagents in the separation and detection of the anions. The optimized mobile phase of methanol/0.3 mmol/L 1-hexyl-3-methylimidazolium tetrafluoroborate aqueous solutions (12/88, v/v), detection wavelength of 210 nm, and column temperature of 35 °C were used for the determination of iodide and iodate. Under these conditions, the detection limits of iodide and iodate were 0.02 and 0.03 mg/L, respectively. To evaluate the practicability of the method, the determination of iodide and iodate in medicines and beverages was performed by this method. The results are that the spiked recoveries were greater than 95% and RSD was less than 3.0%. The method was simple, accurate, and reliable and could provide a reference for the analysis of iodide and iodate.The simultaneous determination of iodide and iodate by reversed phase liquid chromatography with ultraviolet detection using imidazolium ionic liquids as mobile phase additives [ABSTRACT FROM AUTHOR]

For the possible application in high safety lithium ion batteries, nano-particle decorated poly(methyl methacrylate-acrylonitrile-ethyl acrylate) (P(MMA-AN-EA)) based gel polymer electrolyte (GPE) using 1-ethyl-3-methylimidazolium bis(trifluoromethanesolfonyl) imide (EMITFSI) ionic liquid as plasticizer was developed in this paper for the first time. Characterization of thermal stability indicated that the MS5 (SiO 2 : Al 2 O 3  = 5:5 in weight) membrane presented better property of anti-thermal shrinkage, which in turn exhibited the excellent flame retardation performance for the corresponding GPE when incorporated with ionic liquid. The developed MS5 membrane had the strongest fracture strength of 160 MPa, much higher than that of polyethylene (PE) separator (138 MPa). Electrochemical analysis suggested that the GPE exhibited the enhanced ionic conductivity of 3.2 × 10 −3  S cm −1 at ambient temperature, caused by its better porous structure with the highest porosity of 70%. The temperature dependence of ionic conductivity followed Vogel-Tamman-Fulcher (VTF) behavior. Oxidative potential of MS5 based GPE was significantly improved from 4.7 V (vs. Li + /Li) (PE saturated with ionic liquid) to 5.7 V. Theoretical calculation results showed that the stronger interaction between lithium ions and TFSI − anions was responsible for the better compatibility of GPE with the electrodes. Thus, MS5 based GPE exhibited excellent cyclic stability, which kept 95.1% capacity retention after 100 cycles under 0.2C rate in LiFePO 4 /GPE/Li type coin cell at room temperature, while retained 88.4% of initial discharge capacity at high temperature of 55 °C. Due to the enhanced transference number of lithium ion of the GPE, LiFePO 4 cathode in LiFePO 4 /GPE/Li coin cell also presented superior rate performance. [ABSTRACT FROM AUTHOR]

This paper reports on the synthesis and characterization of novel dicationic ionic liquid electrolytes based on asymmetrical imidazolium-trialkylammonium ionic liquids. The results obtained indicate that the length of the alkyl chain attached to the nitrogen atom has a significant influence on the thermal and electrochemical properties of the electrolytes, as well as on parameters such as lithium ion coordination number and lithium ion transport number. All synthesized dicationic ionic liquids and the corresponding electrolytes are liquid at room temperature being thermally stable up to 300 °C; well above battery operation temperature. Room temperature ionic conductivities of the electrolytes are in the range of 0.8–7.2 × 10 −5  S cm −1 , with an electrochemical stability window of 1.5 V–5.0 V vs. Li/Li + . Synthesized electrolytes have been tested in Li half-cells using LiMn 2 O 4 (LMO) spinel as cathode material. Cyclic voltammetry, rate capability and galvanostatic cycling studies at 60 °C have been performed. Again, the alkyl chain length attached to the nitrogen atom plays a significantly role in the electrochemical performance of the LMO cells. Among the cells studied, the one assembled with the electrolyte 1M LITFSI doped IMI 1,6 -TEA exhibits the best rate capability and the high cycling performance. [ABSTRACT FROM AUTHOR]

Abstract: Ruthenium‐containing organometallic ionic liquids with the B(CN)4 anion were developed that generate microporous amorphous coordination polymers upon UV irradiation. UV light irradiation of [Ru(C5H5)(C6H5R)][B(CN)4] (R=butyl, ethyl, octyl) quantitatively generated a yellow powder of a coordination polymer with the formula [Ru(C5H5){B(CN)4}]n. In this reaction, the arene ligand is eliminated by UV irradiation and coordination polymer is formed by coordination of the cyano groups of the anion to the Ru ion. The photogenerated solids exhibited nitrogen absorption properties due to their microporous structure. This paper proposes a method to fabricate functional coordination polymers by photoirradiation of liquids. [ABSTRACT FROM AUTHOR]

Аbstract This paper describes Quantitative Structure-Activity Relationships (QSAR) studies, molecular docking and in vitro antibacterial activity of several potent imidazolium-based ionic liquids (ILs) against S. aureus ATCC 25923 and its clinical isolate. Small set of 131 ILs was collected from the literature and uploaded in the OCHEM database. QSAR methodologies used Associative Neural Networks and Random Forests (WEKA-RF) methods. The predictive ability of the models was tested through cross-validation, giving cross-validated coefficients q 2  = 0.82–0.87 for regression models and overall prediction accuracies of 80–82.1% for classification models. The proposed QSAR models are freely available online on OCHEM server at https://ochem.eu/article/107364 and can be used for estimation of antibacterial activity of new imidazolium-based ILs. A series of synthesized 1,3-dialkylimidazolium ILs with predicted activity were evaluated in vitro . The high activity of 7 ILs against S. aureus strain and its clinical isolate was measured and thereafter analyzed by the molecular docking to prokaryotic homologue of a eukaryotic tubulin FtsZ. [ABSTRACT FROM AUTHOR]

Tri-n-butylphosphate (TBP) in an ionic liquid (IL) has been proposed as a suitable alternative for the solvent extraction of actinides from nitric acid solutions. This paper reports the detailed investigations on the physicochemical and hydrodynamic properties of the solvent system containing TBP in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide ([C4mim][NTf2]) IL. The properties such as density, viscosity, phase separation time (PST), etc., were measured for irradiated and unirradiated solvent phases composed of TBP, [C4mim][NTf2] and 1.1 mol.L-1 TBP in [C4mim][NTf2]. The results are compared with the values obtained in acid-equilibrated IL phases. ATR- FTIR spectroscopy and dynamic light scattering measurement of the IL phase were employed to characterize the interactions among the IL, TBP and nitric acid medium, and the aggregate size of the adduct formed in the IL phase. [ABSTRACT FROM AUTHOR]

This paper focuses on the use of ionic liquids (1-butyl-3-methylimidazolium methylsulphate, [bmim + ][MeSO 4 − ], and 1-ethyl-3-methylimidazolium acetate, [emim + ][Ac − ]) to extract organic compounds involved in the racemic resolution of rac -2-pentanol ( rac -2-pentanol, vinyl butyrate, rac -2-pentyl butyrate or butyric acid) from a mixture of one of these organic compounds with n -hexane. Liquid–liquid equilibrium data were experimentally obtained for seven ternary systems comprising an ionic liquid + rac -2-pentanol, vinyl butyrate, rac -2-pentyl butyrate or butyric acid + n -hexane at T = 303.15 K and atmospheric pressure. Binodal curves were measured applying the well-known procedure based on the observance of the cloud point while the compositions of the tie lines were calculated from refractive index and density measurements (the phase rich in the ionic liquid) and by gas cromatography (the phase rich in n -hexane). Selectivity values and the solute distribution ratio were utilized to test the possibility of the use of these ionic liquids as extractive solvents of the organic compounds implicated in the kinetic separation of the R - and S -enantiomers of rac -2-pentanol. The liquid-liquid equilibrium data of the ternary systems examined here have not previously been described in the literature. [ABSTRACT FROM AUTHOR]

In this paper, photosensitive materials for information storage devices are presented. The polymers were prepared using surface relief-grating (SRG) fabrication with a diode-pumped solid-state (DPSS) laser of 532 nm and the diffraction efficiency (DE) of the polymers were assessed with a low-power DPSS laser at 633 nm. However, the diffraction efficiency of the azo-functionalized epoxy-based polymer was low, even after 15 min of exposure. To improve the efficiency and reduce the time it takes for the DE measurements of the photosensitive polymer, the polymer was combined ionic liquids (ILs). Various ILs, i.e., 1-methylimidazolium chloride ([Mim]Cl) from the imidazolium family of ILs and diethylammonium dihydrogen phosphate (DEAP), triethylammonium 4-aminotoluene-3-sulfonic acid (TASA) and tributylmethylammonium methyl sulphate (TBMS) from the ammonium family of ILs, were investigated. For the first time, it was observed that DE dramatically increased the DEAP-polymer mixture in 4 min compared to the polymer (alone) and other polymer-IL mixtures. Therefore, DEAP IL could help improve the efficiency of DE measurements in a shorter time. [ABSTRACT FROM AUTHOR]

Self-assembling and interactional behavior of a trisubstituted imidazolium based surface active ionic liquid (SAIL), 1-dodecyl-2,3-dimethylimidazolium chloride [C 12 bmim][Cl], with anesthetic drugs lidocaine hydrochloride (HCl) and procaine hydrochloride (HCl) have been screened using surface tension and fluorescence measurements at 298.15 K and from conductance at 288.15, 298.15 and 308.15 K. Critical aggregation concentration ( CAC ), ionization degree ( α ), and various thermodynamic parameters were achieved using conductivity measurements. The various associated interfacial parameters of IL at different compositions of the drugs have been evaluated using surface tension. A detailed analysis of the microenvironment of the aggregates and the size of the aggregates was done by using fluorescence spectroscopy technique. The CAC values decreases as the concentration of the drug increases, which is due to the balancing between hydrophobic and electrostatic interactions. This study confirms the presence of strong synergistic interactions between SAIL and drugs and formation of highly stable drug-SAIL complexes by a conjunction of hydrophobic, hydrophilic, electrostatic and cation-π interactions with 1:1 stoichiometry. A comparative study between disubstituted and trisubstituted SAILs with lidocaine HCl have also been discussed in this paper. Surface activity of trisubstituted SAIL has been found better than their disubstituted analogue due to the high hydrophobicity and hydrophilicity of the former. [ABSTRACT FROM AUTHOR]

We report on the aggregation behavior of the mixed systems composed of sodium oleate (NaOl) with various imidazolium based ionic liquids (ILs) using tensiometry, rheometry and small angle neutron scattering (SANS). The effect of alkyl chain in 1-alkyl-3-methylimidazolium chloride, ([C n mim][Cl], where n = 4 to 10) showed that ILs with long chain length (~ C 10 ) exhibit spontaneous transition of micelles into vesicles. The comparison in ILs with same alkyl chain (C 8 ) but with different counterions viz. chloride [Cl − ], tetrafluoroborate [BF 4 − ] and hexafluorophosphate [PF 6 − ] showed that IL with hydrophilic ion Cl − exerts micellar transition while hydrophobic PF 6 − showed no noticeable effect. However, an interesting finding in this paper is the unusual behavior of IL with moderately hydrophobic BF 4 − that transforms micelles into vesicles. Moreover, mixed micellar systems of NaOl and IL transform into vesicular solution when pH condition turns into acidic. Tensiometric measurements disclosed strong synergistic interactions between the oppositely charged ILs and NaOl. The information on the modification of micellar characteristics of NaOl/ILs mixed system is useful for industrial applications. [ABSTRACT FROM AUTHOR]

N,N -dihexyloctanmide (DHOA) in ionic liquid medium has been proposed for the solvent extraction of actinides from nitric acid solutions. This paper reports the physicochemical and hydrodynamic properties of the solvent system containing N,N -dihexyloctanmide (DHOA) in 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C 4 mim][NTf 2 ]) ionic liquid, for the first time. The properties such as density, viscosity, phase disengagement time etc. were measured for irradiated and unirradiated liquids composed of DHOA, [C 4 mim][NTf 2 ] and 1.1 M solution of DHOA in [C 4 mim][NTf 2 ]. The results were compared with the values obtained for the nitric acid equilibrated–organic phases. ATR-FTIR spectroscopy and dynamic light scattering (DLS) measurement of the ionic liquid phase was employed for characterizing interaction between the ionic liquid-DHOA-nitric acid, and the aggregate size of the adduct formed in the solution. [ABSTRACT FROM AUTHOR]

In this paper, 1,3-bis(carboxymethyl)imidazolium nitrate was prepared, and its structure was also determined by a single-crystal X-ray diffraction. Its FT-infrared and Raman spectra were measured and reported. The crystal structure and the type of O H…O hydrogen bonds were analyzed on the basis of the vibrational spectroscopy and Density Functional Theory (DFT) calculation. Additionally, thermal stability of 1,3-bis(carboxymethyl)imidazolium nitrate and its decomposition process were discussed. [ABSTRACT FROM AUTHOR]

In this paper, we have demonstrated the facile synthesis of stable gold nanoparticles (AuNPs) using imidazolium ionic liquids (ImILs) as a stabilizer as well as a surfactant and their surface plasmon resonance (SPR) in different molecular solvents with varying dielectric properties. The preparation of AuNPs capped with N,N′-dialkyl ImILs of different chain lengths (denoted as [C4,Cn-im]Br, n = carbon number of the alkyl chain) has been investigated. With one long alkyl chain (n≥ 14), these AuNPs could be stably dispersed in solution over a month. The amphiphilic nature of the imidazolium salt dictates the stability and dispersion of these AuNPs in organic or aqueous solvents. Alkyl chain lengths (n≥ 14) and the amount of ImILs have insignificant effect on the size of AuNPs and they possess an average size of 5 nm. These ionic liquid stabilized AuNPs were exploited to examine their optical properties when exposed to various solvent systems by measuring the change in the SPR spectrum. It was seen that the position of the SPR band of AuNPs is greatly influenced by the solvents under consideration. The shift in the SPR absorption band is observed to be in the range of 520 nm to 605 nm for AuNP@[C4,C16-im]Br from nonpolar to highly polar solvents. The considerable discovery presented here is that the λSPR of the SPR shifts to the blue with the increase of carbon atom in the alcohol chain from methanol to 1-decanol. Also for polyethylene glycols (PEGs), the λSPR shifts to the blue with the increase in molecular weight from PEG 200 to PEG 600. In above both cases, the variation in SPR of AuNPs is observed according to the dielectric properties of the medium in addition to the steric factor of alcohols and PEGs during their interaction with AuNP surfaces. [ABSTRACT FROM AUTHOR]

This work presents a comparative study of the electrochemical behaviour, on a glassy carbon electrode, of dissolved EuCl 3 in two chlorobasic ionic liquids, the 1-ethyl-3-methylimidazolium chloride, C 2 mimCl, and the 1-buthyl-3-methylimidazolium chloride, C 4 mimCl, over the temperature ranges 363–398 K and 343–363 K respectively. In both media, the electro-reduction of EuCl 6 3 − takes place via only one electrochemical step EuCl 6 3 − /EuCl 6 4 − . The electrochemical system EuCl 6 4 − /Eu(0) has not been observed within the electrochemical window of both ILs, due to the prior reduction of the respective imidazolium cation from the solvents, which inhibits the electro-extraction of Eu(0) from the media on the GC electrode. The paper describes how several electrochemical techniques (e.g. cyclic voltammetry (CV), convolutive potential sweep voltammetry (CPSV), steady state voltammetry (SSV), chronopotentiometry (CP) and chronoamperometry (CA)) have been used experimentally: i) verifying assumptions used in their theoretical analysis, and ii) ensuring reproducible conditions at the electrode/electrolyte interface, with the aim to obtain high-precision measurements of the diffusion coefficient of EuCl 6 3 − . In order to know if there are discrepancies between the obtained data, a two-way analysis of variance, ANOVA, has been carried out. The analysis has shown that with a 95% confidence level there are no significant differences between the diffusion coefficients obtained by the different techniques. On the other hand, the diffusion coefficient of EuCl 6 3 − increases with the temperature following the Arrhenius law, being the activation energy for diffusion 40.4 ± 2.6 and 60.2 ± 1.8 kJ mol − 1 in C 2 mimCl and C 4 mimCl respectively. The dimensionless Schmidt numbers, defined as the ratio between solvent viscosity and solute diffusivity ( Sc = ν/D), have also been calculated to characterise the solute global mass transport through its environment. On the GC electrode, the electro-reduction of EuCl 6 3 − to EuCl 6 4 − is a quasi-reversible process. Accurate values of the kinetic parameters (i.e. the intrinsic rate constant of charge transfer, k 0 , and the charge transfer coefficient, α), as well as the reversible half wave potential, E r 1/2 , have been obtained for the first time in the mentioned ionic liquids, by simulation of the cyclic voltammograms and logarithmic analysis of the voltammograms and convoluted curves. [ABSTRACT FROM AUTHOR]

In this paper spectrally resolved white light interferometry is applied for measuring the refractive index of different ionic liquids over a wide spectral band from 400 to 1000 nm. The measuring device is compound by a Michelson interferometer whose output is analyzed by means of two spectrometers. The first one is a homemade prism spectrometer which provides the interferogram produced by the sample over a wide continuum spectrum. The second one is a commercial diffraction grating spectrometer used to make high precision measurements of the displacement between the Michelson mirrors by interferometry. Both instruments combined allow the retrieval of the refractive index of the sample over a wide visible-near infrared continuum spectrum with deviations on the fourth decimal. A group of 14 different ionic liquids based on the 1-alkyl-3-methylimidazolium cation have been studied through this technique. The measured refractive index of the ionic liquids is used to calculate their electronic polarizability. This makes possible to gain insight into the microscopic behavior of the compounds. To give a better picture, the liquids have been classified in four groups and their refractive indices and polarizabilities are compared in order to find correlations between these magnitudes and the structure of the liquids. [ABSTRACT FROM AUTHOR]

This paper reports the preparation of two protic ionic liquids (PILs) 2-methylimidazolium lactate and 2-methylimidazolium acetate through simple proton-transfer reaction by microwave irradiation method. This work further improves the influences of semiconductor metal oxides like CuO (p-type), ZnO (n-type) [two transition metal oxides] and SnO 2 (n-type a non-transition metal oxide) over the synthesized PILs. These metal oxides were prepared by sol-gel method and doped over the synthesized ILs by making thin films by spin coating method. The focus of the present study is to learn how the band gap of p-type and n-type metal oxide varies when it is incorporated over the PILs. Their structure, optical properties and morphology were studied through FT-IR, UV-Visible, photoluminescence and XRD spectral studies. [ABSTRACT FROM AUTHOR]

In this paper we report a simultaneous one-step extraction of five pesticides (acetamiprid, imidaclopride, simazine, linuron and tebufenozide) of different polarity using aqueous biphasic system based on 1-butyl-3(methyl or ethyl) substituted imidazolium or pyrrolidinium ionic liquids with bromide or dicyanamide anion and potassium carbonate as a salting-out agent. Experimentally data obtained for the ternary system {ionic liquid + K 2 CO 3 + H 2 O} were fitted and correlated by Merchuk equation with satisfactory high correlation factor. The effect of the cation alkyl chain length and the variation of anions of the ionic liquid on the aqueous biphasic system formation and the efficiency of pesticide extraction were investigated. Complete extraction of all studied pesticides was obtained applying aqueous biphasic system based on 1-butyl-3-ethyl imidazolium dicyanamide. It was shown that simultaneous extraction of the different polarity pesticides is achieved in a single-step procedure applying properly tailored ionic liquids in the aqueous biphasic system formulation. In order to explain excellent extraction of the polar pesticides in the studied aqueous biphasic systems, molecular dynamics was applied and the binding energies and non-covalent interactions were calculated. It was found that 1-butyl-3-ethyl imidazolium dicyanamide achieves the strongest interactions with the polar pesticides (acetamiprid and imidaclopride) leading to the highest partition coefficients. It was shown that combination of experimental and computational approach can be successfully applied for the selection and design of suitable ionic liquids for efficient extraction of various polarity pesticides using simple aqueous biphasic ionic liquid based systems. [ABSTRACT FROM AUTHOR]

The paper discusses the nonlinear response of disordered systems. In particular we show how the nonlinear response can be interpreted in terms of properties of the potential energy landscape. It is shown why the use of relatively small systems is very helpful for this approach. For a standard model system we check which system sizes are particular suited. In case of the driving of a single particle via an external force the concept of an effective temperature helps to scale the force dependence for different temperature on a single master curve. In all cases the mobility increases with increasing external force. These results are compared with a stochastic process described by a 1d Langevin equation where a similar scaling is observed. Furthermore it is shown that for different classes of disordered systems the mobility can also decrease with increasing force. The results can be related to the properties of the chosen potential energy landscape. Finally, results for the crossover from the linear to the nonlinear conductivity of ionic liquids are presented, inspired by recent experimental results in the Roling group. Apart from a standard imidazolium-based ionic liquid we study a system which is characterized by a low conductivity as compared to other ionic liquids and very small nonlinear effects. We show via a real space structural analysis that for this system a particularly strong pair formation is observed and that the strength of the pair formation is insensitive to the application of strong electric fields. Consequences of this observation are discussed. [ABSTRACT FROM AUTHOR]

Imidazolium-based ionic liquids (ILs) are usually synthesized using non-ionic imidazole compounds as precursors. While the ILs have been extensively studied in the past, the precursors was not paid much attention to. The structural analysis of the precursors, however, may offer an opportunity to better understand the behavior of the ionic compounds of interest. In this paper, a comparative study of two ionic liquids and their imidazole precursors is presented. The precursors 1-methylimidazole [1-MIM] and 1,2-dimethylimidazole [1,2-DMIM] are compared in order to explain the influences of the methyl group at the C(2) position (methylation). Since the imidazole compounds are non-ionic, the spectroscopic properties of [1-MIM] and [1,2-DMIM] are not affected by cation-anion interactions. In addition, the products obtained by alkylation using propyl iodide leading to the corresponding IL compounds 1-methyl-3-propylimidazolium iodide [1-MPrIM + ][I − ] and 1,2-dimethyl-3-propylimidazolium iodide [1,2-DMPrIM + ][I − ] were studied. For this purpose, vibrational spectroscopy in terms of FT-Raman and FTIR in the wavenumber range from [45 to 3500 cm −1 ] and from [600 to 4000 cm −1 ], respectively, was performed. Moreover, to aid the spectral assignment, density functional theory (DFT) calculations were carried out. The aim was to investigate the vibrational structure, to understand the effects of the propyl group at the N(3) and of the methyl group at the C(2) position, and to analyze the resulting cation-anion interactions. The data indicate that the iodide ion predominantly interacts with the C(2) H group via hydrogen bonding. Upon methylation, the C(4/5) H moiety becomes the main interaction site. However, an interaction takes place only with one of the two hydrogen atoms resulting in a split of the initially degenerate CH stretching modes. [ABSTRACT FROM AUTHOR]

We demonstrate a controllable doping technique of few-layer black phosphorus (BP) via surface charge transfer using an ionic liquid mixture of EMIM(C6H11N2+):TFSI(C2F6NO4S2-) [EMIM:TFSI, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl) imide]. A wide range of hole carrier densities, from 1011 cm-2 (nondegenerate) to 1013 cm-2 (degenerate), can be obtained by controlling the weight percentage of the ionic liquid mixture. The doping method we proposed in this paper can be applied to make a multifunctional homogeneous lateral p-n junction device. By doping a fraction of the BP sample and by applying a gate voltage to the other fraction of the BP, we obtain homogeneous lateral p+-p, p+-n, p+-n+ junction diodes in a single BP channel. The homogeneous lateral BP p+-p and p+-n junctions display ideal rectifying behavior and a much stronger photoresponse due to the built-in potential. Furthermore, at high positive gate voltages, the interband tunneling enables the homogeneous lateral p+-n+ junction transistors to provide both a negative differential resistance (NDR) and a negative transconductance (NTC) in the current-voltage characteristics at room temperature. On the basis of our results, it is possible to build novel devices utilizing the large NDR and NTC in BP such as amplifiers, oscillators, and multivalued logic systems. [ABSTRACT FROM AUTHOR]

In this paper, the pulping process of wheat straw using ionic liquid 1-ethyl-3-methylimidazolium bromide ([Emim]Br) as the digestion liquor is presented. The influence of pulping conditions on the pulp yield are analysed by single- factor and orthogonal experiments, and optimum pulping conditions are obtained. The average pulp yield reaches 44 %, and the average recovery rate of ionic liquid is 93.5 %. The XRD pattern shows no obvious change in the crystal structure of the wheat straw cellulose. Additionally, the SEM image illustrates that there are many fine fibres in the pulp and the spaces between the fibres are large. [ABSTRACT FROM AUTHOR]

Ternary liquid-liquid equilibria were experimentally determined for eight systems composed of an ionic liquid + n -hexane + an organic compound implicated in the racemic resolution of rac -2-pentanol ( rac -2-pentanol, vinyl butyrate, rac -2-pentyl butyrate or butyric acid) at a temperature of 303.15 K and pressure of 0.1 MPa. The following ionic liquids were used: 1-ethyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide, [emim + ][NTf 2 − ], and 1-hexyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide, [hmim + ][NTf 2 − ]. The binodal curves and the tie line of the conjugate phases compositions were determined through measurement of the refractive index for the ionic liquid-rich phase and by using gas chromatography for the hexane-rich phase, enabling their potential to be assessed for selective extraction of organic compounds from a mixture of ionic liquid reaction media for the resolution of rac -2-pentanol. Liquid phase activity coefficients were calculated using the Non-Random Two-Liquid equation and the tie line theoretical data calculated from the model are in good agreement with the experimental data. As yet, the literature contains no data for the systems studied in this paper. [ABSTRACT FROM AUTHOR]

The ionic liquids (ILs) are green solvents with numerous applications in technology and science. Among the physical properties of the ILs which have a great effect on their application, thermal stability is an important issue which has been discussed in this paper. Kinetics aspect of thermal decomposition of the ILs is considered as a scale of thermal stability. The ILs which have been studied here are composed of 1-hexyl-3-methylimidazolium cation with halide anion [Hmim][X], (X = F, Cl, Br). Three probable paths for thermal decomposition of ILs have been proposed. The first and second paths are the SN2 mechanism in which there are two possible sites on the imidazolium ring position, methyl and hexyl chain. Third path is E2 mechanism which is initiated from hexyl chain. In the case of [Hmim][X] (X = Cl, Br), since the first path has a lower activation energy, it occurs faster than the second path, while in the case of [Hmim][F], path B has a lower barrier than path A and occurs faster. Energy analysis for three studied ILs, showed that [Hmim][Br] with E a = 137.5 kJ mol − 1 is decomposed faster than other ILs. [ABSTRACT FROM AUTHOR]

Extraction behaviour of trivalent actinides and lanthanides was studied using solutions of 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP), a beta-diketone, in a room temperature ionic liquid, 1-methyl-3-octyl-imidazolium bis(trifluoromethylsulphonyl) imide (C 8 mim·Tf 2 N). The complex extracted into C 8 mim·Tf 2 N differs in its composition than those observed in molecular diluents such as benzene. Whereas, neutral ML 3 complex is predominant in molecular diluents, a positively charged complex, [ML 2 ·HL] + (where M = La 3 + , Eu 3 + , Lu 3 + and Am 3 + ; L = PMBP − ; HL = HPMBP), was identified to be extracted into the ionic liquid medium. Luminescence spectroscopic studies suggested presence of four inner-sphere water molecules in the extracted species. This paper reports for the first time the stability constant of a lanthanide (Nd 3 + ) complex with HPMBP in C 8 mim·Tf 2 N which are significantly larger than those reported in molecular diluents. Thermodynamic parameters were also determined to throw light on the nature of complexation. [ABSTRACT FROM AUTHOR]

This paper reports experimental values of dynamic viscosity for four binary systems of 1-ethyl-3-methylimidazolium tetrafluoroborate, [Emim][BF4], with dimethyl sulfoxide (DMSO), acetonitrile (ACN), ethylene glycol (EG) and 1,4-dioxane over the temperature ranges from 293.15 K to 353.15 K at p = 0.1 MPa. All binary mixtures were completely miscible over the entire range of mole fraction, except the system with 1,4-dioxane. The viscosity results have been correlated by the one parameter Grunberg–Nissan and Fang and He equations and the two-parameter McAllister, Eyring-UNIQUAC, Eyring-NRTL and Eyring-Wilson models and the results were compared. Additionally, the viscosity deviations, Δ η , and the excess Gibbs energy of activation for viscous flow, G ∗ E , were calculated and fitted to the Redlich–Kister equation. The results show that all Δ η values are negative over the whole composition range and the G ∗ E values are positive, except for the system with EG. The results of the excess functions are discussed in terms of molecular interactions. [ABSTRACT FROM AUTHOR]

The production of 2-phenylethanol (PEA), an important flavor and fragrance compound, with a rose-like odor has been significantly increased last decade. The aim of this study was to propose a new ionic liquids (ILs) and Deep Eutectic Solvents (DES) as an entrainers in a biphasic systems in possible bioproduction of PEA. ILs and DESs reveal many unique properties which make them very interesting for applications in modern ‘green’ technologies. In present contribution we have reported new experimental results on (solid, or liquid + liquid) phase equilibrium (SLE/LLE) measurements of eight binary systems composed of pyrrolidinium-based, imidazolium-based and phosphonium-based ILs (namely: 1-butyl-1-methylpyrrolidinium tricyanomethanide, [BMPYR][TCM], 1-butyl-1-methylpyrrolidinium tetracyanoborate, [BMPYR][TCB], 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate), [BMPYR][CF 3 SO 3 ], 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, [BMPYR][FAP], and 1-butyl-1-methylpyrrolidinium dicyanamid, [BMPYR][DCA], 1-butyl-1-methylimidazolium tricyanomethanide, [BMIM][TCM] and trihexyl-tetradecyl-phosphonium tricyanomethanide, [P 6,6,6,14 ][TCM] with PEA and water. The complete miscibility with PEA was observed for [BMPYR][FAP], [BMPYR][DCA] and [BMIM][TCM]. The best solubility of solid IL in PEA was found for [BMPYR][TCM]. Complete miscibility with water was observed for [BMPYR][CF 3 SO 3 ] and [BMPYR][DCA]. Moreover, new results on SLE/LLE of six binary systems of DES: {choline chloride + resorcinol (1:4), or phenylacetic acid (1:1), or phenylacetic acid (1:2), or oxalic acid (1:1), or malonic acid (1:1)} and {acetylocholine chloride + 1,10-decanediol} are shown. The initial information of the eutectic temperature and composition was found for {acetylocholine chloride + 1,10-decanediol}. Complete miscibility with PEA was observed only for {choline chloride + malonic acid (1:1)}. Simple eutectic systems of phase behavior with complete miscibility in the liquid phase for all the later mixtures were observed. The solubility of DES in water reveals SLE/LLE phase equilibrium. The best solvent was {choline chloride + malonic acid (1:1)}. The modeling of liquidus curves of ILs in PEA was proposed with excess Gibbs energy model, NRTL. It correlates the solubility with the average root mean square deviation, σ T = 0.78 K. To our best knowledge this is the very first paper when the SLE/LLE of PEA and water have been tested for systems with ILs and DESs. [ABSTRACT FROM AUTHOR]

This paper presents the computational assessment of the electrochemical stability of a series of alkyl methylimidazolium-based ionic liquids for their use as lithium battery electrolytes. The oxidation and reduction potentials of the constituent cation and anion of each ionic liquid with respect to a Li+/Li reference electrode were calculated using density functional theory following the method of thermodynamic cycles, and the electrochemical stability windows (ESW)s of these ionic liquids were obtained. The effect of varying the length of alkyl side chains of the methylimidazolium-based cations on the redox potentials and ESWs was investigated. The results show that the limits of the ESWs of these methylimidazolium-based ionic liquids are defined by the oxidation potential of the anions and the reduction potential of alkyl-methylimidazolium cations. Moreover, ionic liquids with [PF6]- anion have a wider ESW. In addition to characterizing structure-function relationships, the accuracy of the computational approach was assessed through comparisons of the data against experimental measurements of ESWs. The potentials calculated by the thermodynamic cycle method are in good agreement with the experimental data while the HOMO/LUMO method overestimates the redox potentials. This work demonstrates that these approaches can provide guidance in selecting ionic liquid electrolytes when designing high-voltage rechargeable batteries. [ABSTRACT FROM AUTHOR]

The pyrolysis behaviors of Shengli lignite (SL) pretreated with ionic liquid 1-butyl-3-methyl-imidazolium dihydrogen phosphate ([Bmim]H 2 PO 4 ) was studied in this paper. The effect of pretreatment temperature and the ratio of [Bmim]H 2 PO 4 to SL on the pyrolysis behaviors of lignite were mainly investigated. Also the mechanism of the influence of [Bmim]H 2 PO 4 pretreatment on the pyrolysis of lignite was investigated by FTIR analysis. It is found that [Bmim]H 2 PO 4 pretreatment results in the drastical increase of the yield of tar, especially the yield of oil fraction. The yield of tars obtained from pyrolysis of SL treated in [Bmim]H 2 PO 4 at 200 °C with the ratio of [Bmim]H 2 PO 4 to SL at 1 increases by 1.7 times compared to that of SL. [Bmim]H 2 PO 4 pretreatment results in the increase of yield of oil fraction, especially the yield of arenes and phenolics. The FT-IR analysis shows that [Bmim]H 2 PO 4 pretreatment results in the increase of the content of carbonyl group and ether bond in SL. [ABSTRACT FROM AUTHOR]

Description of the local microscopic structure in ionic liquids (ILs) is a prerequisite to obtain a comprehensive understanding of the influence of the nature of ions on the properties of ILs. The local structure is mainly determined by the spatial arrangement of the nearest neighboring ions. Therefore, the main interaction patterns in ILs, such as cation-anion H-bond-like motifs, cation-cation alkyl tail aggregation, and ring stacking, were considered within the framework of the nearest-neighbor approach with respect to each particular interaction site. We employed classical molecular dynamics (MD) simulations to study in detail the spatial, radial, and orientational relative distribution of ions in a set of imidazolium-based ILs, in which the 1-butyl-3-methylimidazolium (C4mim+) cation is coupled with the acetate (OAc-), chloride (Cl-), tetrafluoroborate (BF4 -), hexafluorophosphate (PF6 -), trifluoromethanesulfonate (TfO-), or bis(trifluoromethanesulfonyl)amide (TFSA-) anion. It was established that several structural properties are strongly anion-specific, while some can be treated as universally applicable to ILs, regardless of the nature of the anion. Namely, strongly basic anions, such as OAc- and Cl-, prefer to be located in the imidazolium ring plane next to the C-H2/4-5 sites. By contrast, the other four bulky and weakly coordinating anions tend to occupy positions above/below the plane. Similarly, the H-bond-like interactions involving the H² site are found to be particularly enhanced in comparison with the ones at H4-5 in the case of asymmetric and/or more basic anions (C4mimOAc, C4mimCl, C4mimTfO, and C4mimTFSA), in accordance with recent spectroscopic and theoretical findings. Other IL-specific details related to the multiple H-bond-like binding and cation stacking issues are also discussed in this paper. The secondary H-bonding of anions with the alkyl hydrogen atoms of cations as well as the cation-cation alkyl chain aggregation turned out to be poorly sensitive to the nature of the anion. [ABSTRACT FROM AUTHOR]

To improve the solubility of cellulose at lower temperatures, several polar organic solvents were examined as cosolvents in imidazolium ionic liquid (IL). All tested cosolvents increased the solubilization efficiency of ILs at lower temperatures. Among these, N-methylimidazole, N-methyl-2-pyrrolidone, and dimethyl sulfoxide (DMSO) were notably efficient; in case of Avicel the solubility was increased, with 12-15% cellulose dissolution in 1-allyl-3-methylimidazolium chloride ([Amim]Cl) at 30°C. IR spectra of the regenerated celluloses from IL/cosolvent systems showed characteristic features of cellulose II and/or amorphous cellulose. Thermogravimetric analyses showed significantly higher thermal stability of regenerated cellulose from [Amim]Cl/DMSO compared with that without DMSO. Moreover, dimethylacetamide (DMAc) increased the solubility of filter paper pulp in 1-ethyl- 3-methylimidazolium acetate ([Emim]OAc), with 12% pulp dissolution at 30°C. No decrease in the degree of polymerization (DP) of cellulose was observed with [Emim]OAc/ DMAc, whereas 8-9% DP decrease was observed with [Emim]OAc, even at 30°C. These results indicate that some cosolvents including DMSO and DMAc increase solubilization efficiency and have superior cellulose-protective effects during enhanced dissolution in ILs. [ABSTRACT FROM AUTHOR]

This paper seeks to address the potential of using ionic liquids as nanolubricants on Polyether-ether-ketone (PEEK) surface. We characterize the tribological properties of two ionic liquids, namely1-ethyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium tetrafluoroborate. The tribological data are compared with those of perfluoropolyether (PFPE) and Multiply Alkylated Cyclopentanes (MAC) data obtained from previous study. Ionic liquids at lower concentration of 0.4wt% (in solution prior to deposition) showed lower wear lives as compared to those for PFPE and MAC. However, at higher concentration of 4wt%, these ionic liquids have the same wear lives as those of PFPE and MAC, but show considerably lower coefficients of friction. Mechanisms of nanolubrication for ionic lubricantsvis-a-visthose of PFPE and MAC are explained. [ABSTRACT FROM AUTHOR]

Over the past several years, the Modified Quasichemical Model for short-range ordering has been used successfully to obtain a quantitative thermodynamic description of various multicomponent high temperature inorganic molten salt systems. In the present paper, it was applied to the (LiN(FSO 2 ) 2 + KN(FSO 2 ) 2 + CsN(FSO 2 ) 2 ) ternary system and the ([C 2 mim]Cl + AlCl 3 ) binary system (where [C 2 mim]Cl refers to 1-ethyl-3-methyl-imidazolium chloride), which both involve some ionic liquid compounds. Those two systems were selected as prototypes since experimental data were available for them in the literature. The (LiN(FSO 2 ) 2 + KN(FSO 2 ) 2 + CsN(FSO 2 ) 2 ) liquid displays relatively little short-range ordering, and the experimental ternary eutectic at T = 309 K or 312 K was satisfactorily reproduced by using solely the optimized binary parameters along with a standard symmetric interpolation method. The ([C 2 mim]Cl + AlCl 3 ) liquid displays strong negative deviations from ideality, and two different compositions of maximum short-range ordering (near the [C 2 mim]AlCl 4 and [C 2 mim]Al 2 Cl 7 compositions) were introduced. All available experimental data (phase diagram, emf measurements, partial enthalpies of mixing) were satisfactorily reproduced by the model. The Volume-based Thermodynamics (VBT) from Glasser and Jenkins was used to assess the missing thermodynamic data for [C 2 mim]Cl, and it was also tested on several ionic liquid compounds of the methyl-imidazolium type. [ABSTRACT FROM AUTHOR]

This paper demonstrates the synthesis of nanopetals-assembled copper oxide thin film by simple and inexpensive hydrothermal method using copper sulfate hexahydrate as precursor. The structural analysis from X-ray diffraction pattern showed formation of monoclinic crystal structure. Surface morphological studies by scanning electron micrograph revealed formation of uniform and crack free bunches of nanopetals. Electrochemical behavior of copper oxide was investigated at different concentrations of novel 1-(1׳-methyl-2׳-oxo-propyl)-2,3-dimethylimidazolium chloride ionic liquid as an electrolyte using cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. The results demonstrated that, the nanopetal assembled copper oxide exhibited maximum specific capacitance of 133 F g −1 in 0.2 M ionic liquid. [ABSTRACT FROM AUTHOR]

This paper presents application of the hygroscopic ionic liquids, such as 1-ethyl-3-methylimidazolium ethylsulfate, 1-ethyl-3-methylimidazolium dicyanamide and 1-ethyl-3-methylimidazolium tetrafluoroborate, for the membrane-based air dehumidification. Liquid membranes, supported by the hydrophobic porous membrane, were prepared and their dehumidification efficiency was evaluated in terms of the water recovery rate and water vapor permeability. The performance of supported liquid membranes, composed of ionic liquid, was higher when compared to that, containing triethylene glycol. Ionic liquids showed recovery of water from 80%RH humid air as high as 10 g/h. The permeabilities of water vapor through the ionic liquids were 26,000–46,000 Barrer and the separation factor to the air was over 1000. These measured permeabilities were compared to that predicted by the solution diffusion mechanism, which was supported by the adsorption, diffusivity and viscosity measurements of the liquids. It was demonstrated that solution–diffusion mechanism well describes transport of air through the ionic liquid membrane and with further considerations can be applied for the description of water vapor transport in ILs. [ABSTRACT FROM AUTHOR]

A novel aluminium silicate hydroxide additive has shown excellent anti-wear effect in practical applications and has been mainly studied on steels in laboratory conditions. In this paper, the pin-on-disk sliding wear tests were carried out to investigate the wear and worn surfaces of grey cast iron with additives in different concentration. It was found that the silicate additive showed an obvious anti-wear effect and a reliable duration, reduced the number of pits and cracks on the worn surfaces and improved the nanohardness of the worn surfaces of grey cast iron disks by 72%. Furthermore, Raman spectroscopy displayed that the carbon structure of the worn surface of grey cast iron disks with the additive had an obvious transformation from nanocrystalline graphite to amorphous carbon. Copyright © 2015 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The present paper presents the influence of the ionic liquid nature impregnated onto Florisil upon the adsorption performance of the obtained material in the removal process of Tl(I) ions from aqueous solutions. The impregnation of the studied ionic liquid onto Florisil was realized through ultrasonication which proved to be an efficient method because is not time consuming, combine the advantages of the ionic liquids with those of the solid support, is used a smaller amount of the ionic liquid and there is no risk of loss of the extractant in the aqueous phase. The FTIR, SEM, and energy dispersive EDX applied to the obtained adsorbents proved the fact that the Florisil solid support was impregnated with the studied ionic liquids and also put in evidence the morphology changes of the solid support produced by its impregnation with these ionic liquids. Equilibrium, kinetic and thermodynamic data were applied in order to determine the efficiency of the studied adsorbent in the removal process of Tl(I) ions. The phosphonium based ionic liquid impregnated onto Florisil developed a higher efficiency in the removal process of thallium ions from aqueous solution then the materials obtained through impregnation of Florisil with imidazolium based ionic liquids. [ABSTRACT FROM AUTHOR]

This paper reports the thermodynamicinhibition effect of sevenionic liquids (ILs) on methane hydrate formation. The isochoric multistepheating dissociation pressure search method is applied for experimentallydetermining the phase boundary between hydrate–liquid–vapor(H–L–V) phases and liquid–vapor (L–V)phases in the pressure and temperature ranges of 3.45–13.28MPa and 274.3–287.6 K, respectively. All the studied IL aqueoussolutions are used at a mass fraction of 0.1. A comparison of thethermodynamic inhibitory performance of various ILs is carried outand reveals the predominant role of the type of anion of ILs. Consideringthe difficulty in directly measuring the dissociation enthalpies,the values of ΔHof methane hydrate are alsocalculated using the Clausius–Clapeyron equation. It is foundthat the mean dissociation enthalpies of methane hydrate in the presenceof the seven ILs vary from 59.05 to 60.81 kJ·mol–1, and are very close to that in pure water. [ABSTRACT FROM AUTHOR]

The major objective of this paper is the application of a reliable model to describe volumetric properties of imidazolium-based ionic liquids. In this regard, we have applied the Song and Mason equation of state for [Bmim][PF 6 ], [C 2 mim][NtF 2 ], [C 3 mim][NtF 2 ], [C 6 mim][NtF 2 ], [C 7 mim][NtF 2 ], [C 2 mim][EtOSO 3 ], [Bmim][MeSO 4 ], [Bmim][OcSO 4 ], [C 4 mim][dca], [Bmim][BF 4 ], [hmim][PF 6 ], [omim][PF 6 ] and [omim][BF 4 ]. This equation of state consists of three temperature dependent parameters. These parameters have been calculated as functions of reduced temperature with the use of a law of corresponding states. It is shown that knowledge of liquid density at the normal boiling point and normal boiling temperature are sufficient to predict the volumetric properties of these ionic liquids. We have taken 2469 experimental points for 13 ionic liquid to show the reliability of the present equation of state. The overall average absolute deviation is 1.06%. A comparison of the predicted results, using the present equation of state (which needs just two input parameters) with the results of some previous equations of state (needing 3 input parameters) indicates that this equation of state is more accurate than those. [ABSTRACT FROM AUTHOR]

In this paper we describe the electro-oxidation of methyl-substituted aromatic compounds to the corresponding aldehydes in aqueous imidazole ionic liquid (IL) solutions and using a platinum electrode. The electro-oxidative behavior of p -methoxy toluene ( p -MT) was studied in the ILs using cyclic voltammetry (CV), and the oxidation was shown to be an irreversible process. Increasing the acid strength of the ILs led to further oxidation to the corresponding acid. The controlled potential electrolysis of methyl-substituted aromatic compounds was also investigated under the optimized reaction conditions and the products were detected by NMR, IR and gas chromatography/mass spectrometry (GC/MS). The method represents a promising way to prepare aromatic aldehydes. In order to detect intermediates, in-situ Fourier transform infrared spectroscopy (in-situ FTIR) data was acquired during the oxidation processes. The results further confirmed that the procedure provides a selective approach to the synthesis of aromatic aldehydes. The selectivity toward formation of the corresponding aromatic aldehydes was 21–92% when using the optimized reaction conditions. Excellent electrochemical stability of the ILs was demonstrated and they could be recycled at least 35 times. [ABSTRACT FROM AUTHOR]

The aim of the paper is the selective extraction and stripping of Cd(II) from acidic iodide solutions containing Cd(II) and Ni(II) by liquid–liquid solvent extraction technique using synthesized and characterized imidazolium salts as carriers, which are 3-butyl-1-methyl-1H-imidazol-3-ium bromide (IM1), 1,3-dibutyl-1H-midazol-3-ium bromide (IM2), 3-isobutyl-1-methyl-1H-imidazol-3-ium bromide (IM3), 1,3-diisobutyl-1H-midazol-3-ium bromide (IM4), in dichloromethane. The important parameters affecting extraction and stripping behavior of Cd(II) were studied experimentally. Complex formation and its stoichiometric rate between IMs and CdI 4 2− was explained with comparison of ATR-FTIR spectrums of pure and CdI 4 2− (aq) loaded IMs and slope analysis. According to these evaluations, the adduct formation was confirmed as IM 2 CdI 4(org) . In the light of obtained results, the symmetric IMs substituting n -butyl group on nitrogen atoms have been determined as the best appropriate IMs to transport of Cd(II). Under optimum conditions, 99.24% of Cd(II) has been extracted from acidic iodide solution containing 500 mg/L of Cd(II) and Ni(II). Ni(II) extraction percentages were observed as negligible throughout experiments. The extraction selectivity of Cd(II) over the other metal ion impurities has been identified in the order β Cd/Ni > β Cd/Co > β Cd/Zn > β CdCu . [ABSTRACT FROM AUTHOR]