Tf 2N Research Articles

Surface loaded 1-methyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM+Tf2N− ] hydrophobic ionic liquid on nano-silica sorbents for removal of lead from water samples

This paper demonstrates, for the first time, that 1-methyl-3-ethylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM + Tf 2 N − ] hydrophobic ionic liquid can be potentially used as an excellent medium for solid phase extraction of Pb(II) from water matrices. In this work, [EMIM + Tf 2 N − ] was directed to synthesize two newly modified nano-silica sorbents. The first modified sorbent was based on surface derivatization via physical adsorption of [EMIM + Tf 2 N − ] onto active nano-silica particles (10–20 nm) for the formation of [NSi- OH- EMIM + Tf 2 N − ]. The second sorbent was prepared by the direct reaction of [EMIM + Tf 2 N − ] with amino modified nano-silica particles for the preparation of [NSi- NH 2 - EMIM + Tf 2 N − ]. Surface modification of nano-silica particles was characterized and confirmed by surface coverage determination as well as instrumental analysis by using a scanning electron microscope (SEM), FT-IR and thermal analysis. The capability of newly modified nano silica sorbents for extraction of lead (II) without the need for a partition chelating intermediate was studied and optimized under different controlling variables including the effect of Pb(II) concentration, sorbent dose, pH of contact medium, shaking time, interfering anions and cations. The potential applications of [NSi- OH- EMIM + Tf 2N −] and [NSi- NH 2 - EMIM + Tf 2 N − ] for solid phase extraction of Pb(II) from real water matrices via multi-stage micro-column separation were also studied and evaluated.

Solubility of H 2S in 1-(2-hydroxyethyl)-3-methylimidazolium ionic liquids with different anions

The solubility of hydrogen sulfide in a series of 1-(2-hydroxyethyl)-3-methylimidazolium ([HOemim] +)-based ionic liquids (ILs) containing different anions, viz. hexafluorophosphate ([PF 6] −), trifluoromethanesulfonate ([OTf] −), and bis-(trifluoromethyl)sulfonylimide ([Tf 2N] −) at temperatures ranging from 303.15 to 353.15 K and pressures of up to about 1.8 MPa was measured by a volumetric based static apparatus. The solubility data were correlated using two models: (1) the Krichevsky–Kasarnovsky equation and (2) the extended Henry's law combined with the Pitzer's virial expansion for the excess Gibbs energy. Henry's law constants (at zero pressure) in mole-fraction and molality scales were obtained at different temperatures by means of these two models. Using the solubility data, the partial molar thermodynamic functions of solution, i.e. Gibbs energy, enthalpy, and entropy were calculated. Comparison showed that the solubility of H 2S is greater than that of CO 2 in the corresponding ILs studied in this work and that the solubility of both gases increases as the number of trifluoromethyl (–CF 3) groups in the anion increases, i.e. the solubility behavior of both gases follows the order [HOemim][Tf 2N] ≥ [HOemim][OTf] > [HOemim][PF 6] > [HOemim][BF 4].

α-Rhamnosidase and β-glucosidase expressed by naringinase immobilized on new ionic liquid sol–gel matrices: Activity and stability studies

Novel ionic liquid (IL) sol–gel materials development, for enzyme immobilization, was the goal of this work. The deglycosylation of natural glycosides were performed with α- l-rhamnosidase and β- d-glucosidase activities expressed by naringinase. To attain that goal ILs with different structures were incorporated in TMOS/Glycerol sol–gel matrices and used on naringinase immobilization. The most striking feature of ILs incorporation on TMOS/Glycerol matrices was the positive impact on the enzyme activity and stability, which were evaluated in fifty consecutive runs. The efficiency of α-rhamnosidase expressed by naringinase TMOS/Glycerol@ILs matrices increased with cation hydrophobicity as follows: [OMIM] > [BMIM] > [EMIM] > [C 2OHMIM] > [BIM] and [OMIM] ≈ [E 2-MPy] ≫ [E 3-MPy]. Regarding the imidazolium family, the hydrophobic nature of the cation resulted in higher α-rhamnosidase efficiencies: [BMIM]BF 4 ≫ [C 2OHMIM]BF 4 ≫ [BIM]BF 4. Small differences in the IL cation structure resulted in important differences in the enzyme activity and stability, namely [E 3-MPy] and [E 2-MPy] allowed an impressive difference in the α-rhamnosidase activity and stability of almost 150%. The hydrophobic nature of the anion influenced positively α-rhamnosidase activity and stability. In the BMIM series the more hydrophobic anions (PF 6 −, BF 4 − and Tf 2N −) led to higher activities than TFA. SEM analysis showed that the matrices are shaped lens with a film structure which varies within the lens, depending on the presence and the nature of the IL. The kinetics parameters, using naringin and prunin as substrates, were evaluated with free and naringinase encapsulated, respectively on TMOS/Glycerol@[OMIM][Tf 2N] and TMOS/Glycerol@[C 2OHMIM][PF 6] and on TMOS/Glycerol. An improved stability and efficiency of α- l-rhamnosidase and β-glucosidase expressed by encapsulated naringinase on TMOS/Glycerol@[OMIM][Tf 2N] and TMOS/Glycerol@[C 2OHMIM][PF 6] were achieved. In addition to these advantageous, with ILs as sol–gel templates, environmental friendly processes can be implemented.

Surface segregation in binary mixtures of imidazolium-based ionic liquids

Surface composition of binary mixtures of room-temperature ionic liquids has been investigated using time-of-flight secondary ion mass spectrometry at room temperature over a wide composition range. The imidazolium cations with longer aliphatic groups tend to segregate to the surface, and a bis(trifluoromethanesulfonyl)imide anion (Tf 2N −) is enriched at the surface relative to hexafluorophosphate (PF 6 −). The surface of an equimolar mixture of Li[Tf 2N] and 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF 6]) has a nominal composition of [bmim][Tf 2N] because of surface segregation and ligand exchange. The surface segregation of cations and anions is likely to result from alignment of specific ligand-exchanged molecules at the topmost surface layer to exclude more hydrophobic part of the molecules.

Effect of room temperature ionic liquid structure on the enzymatic acylation of flavonoids

Enzymatic acylation reactions of flavonoids (rutin, esculin) with long chain fatty acids (palmitic, oleic acids) were carried out in 14 different ionic liquid media containing a range of cation and anion structures. Classification of RTILs according to flavonoid solubility (using COSMO-RS) was the basis for structural selection. Overall, anion selection had a far greater influence on lipase activity than choice of cationic moiety. RTILs containing TF 2N −, PF 6 − and BF 4 − anions were most successful as reaction media while RTILs containing anions with stronger solvating properties (i.e. H-bonding ability) resulted in decreased yields, likely due to increased interactions with the protein structure of the lipase. Biosynthesis of rutin proceeded much slower than of esculin. All-in-all, judicious selection of RTILs was central to achieving high yields (>98% after 6 days for TOMA·TF 2N) since a balance must be struck that maximized flavonoid solubility with minimum negative impact on lipase activity. The process also benefitted from an increased reaction temperature which may have helped to reduced mass transfer limitations.

Butanol recovery from aqueous solution into ionic liquids by liquid–liquid extraction

Biobutanol has currently attracted considerable attention as an alternative biofuel to the petroleum-derived fuel due to several advantages including high energy content, low water absorption and easy application to the existing gasoline infrastructure. However, its production has still faced many obstacles to overcome including lack of energy-efficient butanol separation process from fermentation broth. To solve this issue, the extraction behavior of butanol from aqueous media into a variety of imidazolium-based ionic liquids (ILs) was investigated by liquid–liquid extraction. To understand the effect of ILs properties, the solvent characteristics of ILs such as mutual solubility of feed solvent (water) and extraction solvent (IL), distribution coefficient of butanol between water and IL, selectivity, and extraction efficiency were correlated with hydrophobicity and polarity of ILs. The butanol distribution between ILs and water strongly depends on the hydrophobicity of anions of ILs followed by the hydrophobicity of cations of ILs. On the other hand, butanol extraction efficiency and selectivity depend on the polarity of ILs. Considering extraction efficiency and selectivity, [Tf 2N]-based ILs among the tested ILs showed to be the best extract solvent for the recovery of butanol from aqueous media. Among the studied ILs, [Omim][Tf 2N] showed the highest butanol distribution coefficient (1.939), selectivity (132) and extraction efficiency (74%) at 323.15 K, respectively.

Molecular dynamics investigation of biomimetic ionic liquids

Ionic liquids having long alkyl chains containing 18-carbon atoms have recently been synthesized and found to have low melting points close to −50 ° C. The inspiration for this work arose from the concept of homeoviscous adaption (HVA), whereby the fluidity of phospholipid bilayers is increased by the addition of unsaturated lipids in the bilayer. In the present work, results of molecular dynamics simulations are reported for one of the low melting point ionic liquids examined in this earlier study: 1-oleyl-3-methylimidazolium (9,10-cis-octadecenyl) bis(trifluoromethanesulfonyl)imide ([C 18(1[9])mim] [Tf 2N]). This ionic liquid contains a single unsaturated bond in the cis configuration. For comparison, calculations are also performed on the saturated all-trans analogue: 1-stearyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C 18mim] [Tf 2N]). Since the melting point behavior of these ILs is analgous to HVA of phospholipid bilayers, these ILs are referred to as “biomimetic” ILs. Simulations are performed at temperatures 1.2 times the corresponding experimental melting points of the ionic liquids as well as at a common temperature to interrogate the structure and dynamics of the two liquids. Additional molecular dynamics simulations are carried out at high pressure. Results of thermophysical properties such as densities and isothermal compressibilities are reported. The local structure of the ionic liquids is examined via various orientational and radial distribution functions. Consistent with other simulation and experimental reports for ionic liquids having long alkyl groups on the cations, these ionic liquids exhibit nanoscale heterogeneity where the polar and hydrophobic regions are segregated. Subtle differences between the orientation and packing of the saturated and unsaturated alkyl chains are observed. The mean square displacement and cation rotational dynamics are also computed for both ILs. It is observed that at low pressure, the translational dynamics of the [C 18(1[9])mim] cation is greater than that of the [C 18mim] cation, consistent with experimental viscosity measurements. The simulations reveal that the motion of the ions is severely retarded at low temperatures and high pressures.

Modeling of high-pressure vapor–liquid equilibrium in ionic liquids + gas systems using the PRSV equation of state

Ionic liquids are environmentally friendly solvents composed of large organic cations and relatively small inorganic anions, whose melting point is below T = 373.15 K. This is an arbitrary limit defined in order to organize the dramatically increasing number of possible applications in chemical processes. These compounds are regarded as potentially environmentally benign solvents due to their almost negligible vapor pressure, which essentially eliminates emission to the atmosphere; besides, they present a wide range of liquid existence. Ionic liquids are applicable in separation processes, such as recovery of valuable products and remotion of polluting agents in effluents [1–4] and are a new and exciting class of compounds that have the potential to overcome many of the problems associated with current CO 2-capture techniques. In this work, high-pressure vapor–liquid equilibrium (VLE) of 17 binary mixtures ionic liquid + gas has been modeled with the Peng–Robinson/Stryjek–Vera (PRSV) [5,6] equation of state (EoS) applying the Wong–Sandler (WS) [7] mixing rules, including the van Laar (VL) model for the excess Gibbs free energy [8] for the gamma–phi approach and the one-fluid van der Waals (VDW) mixing rules for the phi–phi approach. Critical properties and acentric factor of ionic liquids [pmim][Tf 2N] and [hmmim][Tf 2N] were determined using the extended group contribution method by Lydersen–Joback–Reid [9], while, for the other ionic liquids, these properties are available in the literature [10,11]. Experimental data were obtained from literature [12–18] and the adjustable parameters were fitted by minimizing the errors between predicted and experimental bubble pressure. van Laar and binary interaction parameters were regarded as temperature-dependent. The results, in terms of main deviations between experimental and calculated pressures for the 17 binary systems, are reasonably satisfactory (3.62% and 2.59% for the gamma–phi and phi–phi approaches, respectively).

Predictions of cation and anion effects on solubilities, selectivities and permeabilities for CO 2 in ionic liquid using COSMO based activity coefficient model

The solubilities and selectivities for CO 2, N 2 and CH 4 in ionic liquid were predicted using a COSMO based activity coefficient model, COSMO-SAC method. The 1-alkyl-3-methylimidazolium cations were focused in this work. The anion species include tetrafluoroborate [BF 4], hexafluorophosphate [PF 6], triflate [OTf], dicyanamide [dca] and bis(trifluoromethane)-sulfonimide [Tf 2N]. The predicted results of the solubilities of CO 2 in the ionic liquids by COSMO-SAC method are in agreement with the experimental data within the averaged deviation of 0.0017 in mole fraction. The predicted results of selectivities for CO 2/N 2 and CO 2/CH 4 represent the effects of anion species qualitatively. Permeability through supported liquid membrane can be presented by solubility and diffusion coefficients in the liquid. The permeabilities of CO 2 through the ionic liquid membranes were also predicted by a solution-diffusion model with COSMO-SAC method. The predicted results of the CO 2 permeabilities through the ionic liquids represent the experimental data within the order of the permeabilities.

Acid activation of titanium alkoxide systems – Structural characterisation of Ti(IV) sulfonyl-imide complexes

Treatment of [Ti(O i Pr) 4] with the sulfonyl-imine systems Tos 2NH ([( p-Me-C 6H 4SO 2) 2NH]) and Tf 2NH ([(CF 3SO 2) 2NH]) results in the formation of the new Lewis acidic titanium sulfonyl-imide complexes [Ti(O i Pr) 2( O, O′-Tos 2N) 2] ( 1) and [Ti(O i Pr) 2(HO i Pr) 2( O-Tf 2N) 2] ( 2), respectively. The molecular structures of the complexes have been determined by single crystal X-ray diffraction. The reaction of [Ti(O i Pr) 3(OAr)] (Ar = 2,6-di- tert-butyl-4-methyl phenyl) with Tf 2NH results in the formation of the dimeric complex [Ti(O i Pr) 3( O, O′-Tf 2N)] 2 ( 3), which has also been structurally characterised. The ability of the complexes to catalyst the Friedel–Crafts acylation of anisole has also been assessed.

High-pressure phase behavior of ternary systems (carbon dioxide + alkanol + hydrophobic ionic liquid)

Some homogeneous liquid mixtures of an ionic liquid and a lower alkanol (e.g., methanol) can be forced to undergo a liquid–liquid phase split (resulting in a three-phase liquid–liquid–vapor (L 1L 2V) equilibrium) by pressurization with a gas. Such systems exhibit the phenomenon of “salting out by a nearcritical gas”. That phenomenon is often observed at temperatures around the critical temperature of the gas in liquid mixtures where at least one of the liquid components is a good solvent for that gas. New experimental results for both the L 1L 2V equilibrium and the corresponding critical endpoint lines of the two ternary systems (carbon dioxide + methanol + 1- n-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF 6]) and (carbon dioxide + 1-butanol + 1- n-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide [hmim][Tf 2N]) at temperatures between 293 and 333 K are reported. The experiments were performed with an “analytical method”. The liquid–liquid phase split exists only at pressures between a lower critical endpoint line (where both liquid phases become critical and coexist with a vapor phase) and an upper critical endpoint line (where one of the phases becomes critical with the vapor phase while the critical phases coexist with another liquid phase). The compositions of the coexisting three phases L 1, L 2, and V differ considerably; a high-density, ionic liquid-rich liquid phase (L 1) coexists with an alkanol-rich liquid phase (L 2) of lower density and a vapor phase (V) that is virtually ionic liquid-free. For both systems, it was observed that, at constant temperature, increasing pressure shifts the L 1 phase towards higher contents of ionic liquid and gas and less alkanol, whereas in the L 2 phase the mole fractions of ionic liquid and alkanol decrease. Higher temperatures result in a smaller difference between the pressures of both critical endpoint lines. Experimental results for both critical endpoint lines and for the compositions of the coexisting liquid phases are reported.

Performance of nitrile-containing anions in task-specific ionic liquids for improved CO 2/N 2 separation

This work explores the performance of a series of ionic liquids that incorporate a nitrile-containing anion paired to 1-alkyl-3-methylimidazolium cations in tailoring the selectivity and permeance of supported ionic liquid membranes for CO 2/N 2 separations. The permeance and selectivity of three ionic liquids, each with an increasing number of nitrile groups in the anion (i.e., two, three, and four), were measured using a non-steady-state permeation method. By predictably varying the molar volume and viscosity of the ionic liquids, we show that the solubility, selectivity, and permeance can be optimized for CO 2/N 2 separation through controlled introduction of the nitrile functionality into the anion. Of the three nitrile-based ionic liquids studied, 1-ethyl-3-methylimidazolium tetracyanoborate, [emim][B(CN) 4], showed the highest permeance with a value of 2.55 × 10 −9 mol/(m 2 Pa s), a magnitude 30% higher than that of the popular ionic liquid [emim][Tf 2N]. This same nitrile-bearing ionic liquid also exhibited a high CO 2/N 2 selectivity of approximately 53. Additionally, the carbon dioxide solubility for each ionic liquid was measured at room temperature with [emim][B(CN) 4] again exhibiting the highest CO 2 solubility. Results from our study of the nitrile-based ionic liquids can be rationalized in terms of regular solution theory wherein the selectivity and permeance of a given SILM system are largely determined by the molar volume and viscosity of the corresponding ionic liquid phase.

CO 2 absorption properties of Brønsted acid–base ionic liquid composed of N, N-dimethylformamide and bis(trifluoromethanesulfonyl)amide

The solubilities of CO 2 and the liquid densities in a Brønsted acid–base ionic liquid, [DMFH][Tf 2N], composed of N, N-dimethylformamide (DMF) and bis(trifluoromethanesulfonyl)amide (HTf 2N) have been investigated at high pressures and at different temperatures. The results were compared with those in DMF and a typical 1-butyl-3-methylimidazolium analogue with the same anion, [BMIM][Tf 2N]. The mole fraction scaled solubilities of CO 2 in the three liquids showed a slight increase in the following order, DMF < [DMFH][Tf 2N] < [BMIM][Tf 2N], whereas more remarkable difference was observed in the volume scaled concentrations of CO 2, [BMIM][Tf 2N] < [DMFH][Tf 2N] « DMF, mainly due to the bulkiness of liquid entities.

Ionic liquid structural effects on solute partitioning in biphasic ionic liquid and supercritical carbon dioxide systems

An overview of measurements of partition coefficient measurements reported in the literature is given. New infinite dilution partition coefficients for aromatic components (benzyl alcohol, phenol, acetophenone, and chlorobenzene) between ionic liquid phase and supercritical CO 2 phase are reported as determined with a chromatographic technique. Three types of solutes and six types of ionic liquids were studied. Infinite dilution partition coefficients became larger according to [bmim][Tf 2N], [bmim][PF 6], [bmim][BF 4], [bmim][Cl]. For the case of benzyl alcohol, the weight basis partition coefficient had its highest value (0.180) in [bmim][Tf 2N] at 333.2 K and 20 MPa and its lowest value (0–0.003) in [bmim][Cl] at 333.2 K and at pressures from 12 to 16 MPa. The values of the infinitely dilute partition coefficients were not sensitive to the alkyl chain length of the ionic liquids [emim][PF 6], [bmim][PF 6], and [hmim][PF 6] and could be correlated with the Sanchez–Lacombe equation of state. Trends of the infinite dilution partition coefficients for the same cation, [bmim] for the anions studied seemed to correlate with the charge per surface area of the anion.

Assessing the toxicity on [C 3mim][Tf 2N] to aquatic organisms of different trophic levels

Ionic liquids (ILs) are an exciting class of neoteric solvents that are being object of great attention as a potential replacement to conventional environmental damaging solvents in industrial applications. Despite some progress concerning ILs’ toxicity and their environmental impact, the information about these compounds is still scarce. In this work, biological tests were performed to establish the toxicity of 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide, [C 3mim][Tf 2N], in five aquatic species at different trophic levels. Freshwater algal growth inhibition ( Pseudokirchneriella subcapitata and Chlorella vulgaris), freshwater cladocerans’ immobilization and chronic traits ( Daphnia magna and Daphnia longispina) and viability of luminescent marine bacteria ( Vibrio fischeri) were investigated. The sensitivity of the different species to the IL was compared in order to determine further repercussions in trophic food web. It is shown that the studied IL is moderately toxic to the studied organisms. P. subcapitata and D. magna are the most tolerant species and C. vulgaris and D. longispina the most sensitive to its presence.

Application of a group contribution equation of state for the thermodynamic modeling of binary systems (gas + ionic liquids) with bis[(trifluoromethyl)sulfonyl]imide anion

The properties of ionic liquids (ILs) can be modified by appropriate selection of cations and anions. Even if an infinite number of ionic liquids can be generated, only a limited number of families of anions and cations are used. The group contribution equation of state (GC-EoS) is a promising method for calculating the phase behavior of systems with ILs. If the parameters of the characteristic functional group of a IL family are fitted by using data of a reduced number of ILs of the family, then the phase behavior of all the ILs of the same family can be predicted using exclusively the data of the pure components. Previously, the parameters of the IL families with an imidazolium-based cation and the anions PF 6, BF 4NO 3, and Tf 2N were fitted to experimental data [19], and some ternary systems (CO 2 + organics + ionic liquid [bmim][BF 4]) were also modeled [22]. In this work, the GC-EoS was used to calculate phase behavior of gases {(CO 2, O 2, or SO 2) + ionic liquids} with Tf 2N anion and cations of the families 2,3-dimethyl-imidazolium, 1-alkyl-1-methyl-pyrrolidinium, and 1-alkyl-3-methyl-pyridinium. The GC-EoS was able to reproduce experimental data with deviations of the same order of experimental uncertainty. With the correlated parameters it will be possible to predict the phase behavior of systems with ILs of the families considered in this work.

Thermophysical properties of 1-alkylpyridinum bis(trifluoromethylsulfonyl)imide ionic liquids

The thermophysical properties of 1-alkylpyridinium bis(trifluoromethylsulfonyl)imide, [C n py][Tf 2N] ionic liquids where n = 4, 8, 10, or 12 have been determined. Density ρ, and dynamic viscosity η, were determined at T = (293.15 to 353.15) K and refractive index n D , was measured at T = (293.15 to 333.15) K. Empirical correlations are proposed to represent the present experimental results. The values of the coefficient of thermal expansion were calculated from the experimental density values. The thermal decomposition temperature, T d was also determined using thermogravimetric analyzer (TGA) at a heating rate of (10 and 20) K · min −1.

Main-chain imidazolium polymer membranes for CO 2 separations: An initial study of a new ionic liquid-inspired platform

Three dense polymer membranes composed of main-chain, poly(imidazolium)s (imidazolium ionenes) with decyl (“C10”) spacer groups were fabricated and shown to be selective for CO 2-based separations. An imidazolium ionene with the bromide counterion (Polymer 1) exhibited good H 2/CO 2 ideal (pure component) selectivity (6.0), while H 2 permeability was slightly lower than 1 × 10 −10 cm 3(STP) cm cm (−2) s (−1) cm Hg (−1) (1 barrer). A “Robeson Plot” was used to compare the separation performance of Polymer 1 to other dense polymer membranes. Polymer 2 was structurally similar to Polymer 1 with the exception of the bulky Tf 2N anion in place of the bromide. This polymer was found to have good CO 2/CH 4 and CO 2/N 2 ideal selectivities (20 and 24, respectively), but no H 2/CO 2 separation performance with a selectivity of 1.0. A stable composite film made from an imidazolium ionene (Polymer 2) and a room-temperature ionic liquid (RTIL) was also fabricated and showed large CO 2 permeability enhancements compared to the analogous neat polymer membrane, with little or no sacrifice in CO 2/N 2 and CO 2/CH 4 ideal selectivity. The separation performance of Polymer 2 and the Polymer 2–RTIL composite films were compared to previously studied “side-chain” poly(imidazolium)s (poly(RTIL)s) and other dense polymer membranes on “Robeson Plots.” Polymer 2 and the Polymer 2–RTIL composite films exhibited CO 2 permeabilities comparable to poly(RTIL)s. This is the first known study and application of imidazolium ionenes for CO 2 light gas separation membranes.

High-pressure phase behavior of binary and ternary mixtures containing ionic liquid [C 6-mim][Tf 2N], dimethyl carbonate and carbon dioxide

High-pressure phase equilibrium data for the ternary mixtures consisting of room temperature ionic liquid, dimethyl carbonate (DMC) and carbon dioxide (CO 2) were measured using an equilibrium apparatus equipped with a variable-volume view cell. The ionic liquid studied in this work is 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [C 6-mim][Tf 2N]. Solubility data of carbon dioxide (CO 2) in the solvent mixtures of DMC and [C 6-mim][Tf 2N] with various compositions are presented at pressures up to about 7 MPa and at several temperatures between 303.15 and 333.15 K. The CO 2 solubility in the DMC + [C 6-mim][Tf 2N] solvent mixture decreased as the ionic liquid content in the mixture increased, compared at the same pressure and temperature. The equilibrium pressure increased with the increase of the content of ionic liquid in the solvent mixture.

Hydrodynamic sono-voltammetry of ferrocene in [Tf 2N] − based ionic liquid media

The present work deals with the hydrodynamic behavior of several room-temperature ionic liquids presenting the same bis(trifluoromethanesulfonyles)imide anion, associated with four different cations: 1-butyl-3-methylimidazolium, 1-octyl-3-methylimidazolium, N-trimethyl-N-propylammonium and 1-butyl-1-methylpyrrolidinium cations. Steady state voltammetry was used as an electrochemical technique to characterize mass transfer in both silent and sonicated conditions, using a rotating disk electrode. Results obtained in RTILs media are compared to those acquired in synthetic solutions of controlled viscosity, in order to develop a better understanding of the phenomena involved in such media.