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Soil fulfils vital functions for life on Earth and so, just like water and air, its protection from all sources of contamination is a major concern. However, the extensive use of petroleum derived products, either as energy sources or as commodities, leads to important environmental liabilities. Ex situ soil washing is a technology to concentrate contaminants, allowing soil cleaning and the reuse of extracted petroleum derived products. This work focuses on the optimization of ex situ soil washing process using surfactants, introducing an evaluation of the washing solution recycling and its after use safe disposal, promoting the reduction of raw materials, energy and water resources costs. Two surfactants, sodium dodecyl sulphate (SDS) and polyoxyethylene sorbitan monooleate (Tween 80), were tested in the decontamination of an artificially contaminated soil with engine lubricant oil waste. The optimization of the washing conditions, such as stirring speed, liquid-solid ratio, number of washing stages, and surfactant concentration, was carried out using a design of experiments (DOE) software , so that the maximum extraction efficiency of total petroleum hydrocarbons (TPHs) was achieved. A TPH removal efficiency of (80.7 ± 3.2)% was obtained with Tween 80 after 5 h of washing and (90.7 ± 2.8)% with SDS after 2 h at 200 rpm on an orbital shaker with a liquid to solid ratio (L/S) of 15. The potential for reuse of the washing solutions was evaluated. Finally, the discharge of the washing solution was considered using activated carbon to remove the surfactants and ensure its safe disposal.

The formulation of magnetic ionic liquids (MILs) or organic salts based on lanthanides as anions has been explored. In this work, a set of choline-family-based salts, and two other, different cation families, were combined with Gadolinium(III) and Terbium(III) anions. Synthetic methodologies were previously optimized, and all organic salts were obtained as solids with melting temperatures higher than 100 °C. The magnetic moments obtained for the Gd(III) salts were, as expected, smaller than those obtained for the Tb(III)-based compounds. The values for Gd(III) and Tb(III) magnetic salts are in the range of 6.55-7.30 MB and 8.22-9.34 MB, respectively. It is important to note a correlation between the magnetic moments obtained for lanthanides, and the structural features of the cation. The cytotoxicity of lanthanide-based salts was also evaluated using 3T3, 293T, Caco2, and HepG2 cells, and it was revealed that most of the prepared compounds are not toxic.

This work aims to explore the gas permeation performance of two newly-designed ionic liquids, [C 2 mim][CF 3 BF 3 ] and [C 2 mim][CF 3 SO 2 C(CN) 2 ], in supported ionic liquid membranes (SILM) configuration, as another effort to provide an overall insight on the gas permeation performance of functionalized-ionic liquids with the [C 2 mim] + cation. [C 2 mim][CF 3 BF 3 ] and [C 2 mim][CF 3 SO 2 C(CN) 2 ] single gas separation performance towards CO 2 , N 2 , and CH 4 at T = 293 K and T = 308 K were measured using the time-lag method. Assessing the CO 2 permeation results, [C 2 mim][CF 3 BF 3 ] showed an undermined value of 710 Barrer at 293.15 K and 1 bar of feed pressure when compared to [C 2 mim][BF 4 ], whereas for the [C 2 mim][CF 3 SO 2 C(CN) 2 ] IL an unexpected CO 2 permeability of 1095 Barrer was attained at the same experimental conditions, overcoming the results for the remaining ILs used for comparison. The prepared membranes exhibited diverse permselectivities, varying from 16.9 to 22.2 for CO 2 /CH 4 and 37.0 to 44.4 for CO 2 /N 2 gas pairs. The thermophysical properties of the [C 2 mim][CF 3 BF 3 ] and [C 2 mim][CF 3 SO 2 C(CN) 2 ] ILs were also determined in the range of T = 293.15 K up to T = 353.15 K at atmospheric pressure and compared with those for other ILs with the same cation and anion's with similar chemical moieties.

Deep eutectic solvents (DES), a new class of alternative solvents, have recently been used in the pre-treatment of lignocellulosic biomass. Due to the ability to dissolve phenolic compounds, they have been efficiently applied as delignification agents. However, to extend DES application to bioprocesses, such as Anaerobic Digestion (AD), their toxicity to microbial consortia must be evaluated. In this work, an effective delignifying DES, composed of choline chloride (ChCl) and oxalic acid (OA) (1:1) was prepared and its effect evaluated, for the first time, in biogas production. Results show that the presence of DES had both beneficial and detrimental effects on the anaerobic consortium, depending on its concentration. In the concentration range of 0.3-12.5 g/L, the presence of DES led to a lag-phase of 1 to 8 d as the DES concentration increased. However, after the lag-phase has been surpassed, DES up to a concentration of 12.5 g/L improved the biogas production, reaching an accumulated biogas volume three times higher than the control assay for the concentration of 12.5 g/L. For the highest DES concentrations (19.8-78.1 g/L), the biogas production was inhibited. The assays performed with DES components alone have indicated that OA at 3.2 g/L was the main responsible for the inhibition of biogas production (50% less biogas produced than the control). ChCl at 4.9 g/L has not presented a lag-phase and produced an accumulated biogas volume like the control assay (1200 mL for 30 d incubation). This work points out that ChCl:OA DES may be used in the delignification of biomass further submitted to AD, provided the inhibitory concentrations of OA are not achieved., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Several organic salts based on the combination of two different choline derivative cations and MnCl3-, GdCl4- and TbCl4- as anions were immobilized in mesoporous silica nanoparticles (MSNs) by a two-step synthetic method. Firstly, MSNs were functionalized with choline derivative cations with chloride anions and then the metals were incorporated by the reaction of the chloride with the respective metal chloride salts. These nanomaterials were fully characterized by different characterization techniques such as 1H-NMR, FT-IR, elemental analysis, TEM, TGA, N2 adsorption, XRD and DLS. These characterization data were important to confirm the successful functionalization of the nanomaterials and to access their textural properties and colloidal stability. The final materials were also characterized by ICP-MS that indicated the metal contents. The cytotoxicity profile was evaluated in four different cell lines (3T3, 293T, HepG2 and Caco-2), which shows some relevant differences between the metal organic salts and their immobilized analogues.

Liquid-liquid phase behavior measurements were performed for binary mixtures of water and ionic liquids (ILs) containing the same 1-ethyl-3-methylimidazolium ([C 2 mim] + ) cation and different imide-based anions, having symmetric (bis(fluorosulfonyl)imide ([FSI] - )) or asymmetric structures (2,2,2-trifluoromethylsulfonyl-N-cyanoamide ([TFSAM] - ) and 2,2,2-trifluoro-N-(trifluoromethylsulfonyl)acetamide ([TSAC] - )). An inversion of phase behavior was observed: while below ∼298 K, the miscibility of water in the studied ILs increases according to the order [C 2 mim][TSAC] < [C 2 mim][FSI] < [C 2 mim][NTf 2 ], for temperatures above ∼303 K, the reverse trend is observed [C 2 mim][NTf 2 ] < [C 2 mim][FSI] < [C 2 mim][TSAC]. In turn, above ∼306 K the [C 2 mim][TFSAM] is completely miscible with H 2 O in all ranges of concentrations. The obtained results also revealed an unusual water solubility variation of 11% in [C 2 mim][FSI], and 20% in [C 2 mim][TSAC], when the system temperature was changed by less than 1 K, around 298 K and 301 K, respectively. Molecular Dynamics (MD) simulations were used to understand the IL-water interactions and rationalize the experimental observations. These results suggested that the miscibility trends are mainly related to the ability of the water molecules to form water-anion and water-water aggregates in solution.

Since their discovery, deep eutectic solvents (DES) have been explored in multiple applications. However, the complete physicochemical characterization is still nonexistent for many of the proposed and used DES. In particular, vapor pressure, which is a crucial property for the application of DES as solvents, is very rarely available. In this work, the measurement of the total and partial pressures of two sulfolane-based DES, tetrabutylammonium bromide:sulfolane and tetrabutylphosphonium bromide:sulfolane, in several proportions, from 40 to 100 °C and atmospheric pressure, was performed using headspace gas chromatography mass spectrometry, HS-GC-MS. A large decrease on the total pressure was recorded which, together with the finding that total pressures showed negative deviations from Raoult's law, is indicative of the favorable, strong interactions between the two components within the DES. Additionally, the study of vapor pressure change with DES molar composition was carried out, and surprisingly, the existence of inflection points in the pressure curve was observed. Experimental results were modeled using the PC-SAFT equation of state, and in addition, MD simulations were performed to provide a molecular understanding of the pressure data. Considering the different results and insights obtained from the used strategies, it can be concluded that both DES systems have especially strong interactions between salt and sulfolane, at high sulfolane content, due to the different structural rearrangement of the liquid state.

The aim of this work is to develop an optimized enzymatic assisted extraction methodology to extract carotenoids and phenolic compounds from sunflower wastes (petals and florets) using natural hydrophobic green solvents. Several natural green hydrophobic solvents were used as well as natural hydrophobic eutectic solvents composed of d,l-menthol and different acids, with different hydrophobicity. The multi-enzyme complex Viscozyme ® was used to disrupt the cell wall of petals and disc florets. The extracted carotenoids content into the hydrophobic phase was quantified using UV-Vis spectrophotometry and the carotenoids profile was studied using high-performance liquid and thin layer chromatography. The amount of total sugars in the aqueous phase was also analyzed using the dinitrosalicylic acid (DNS) method to infer about the enzymatic action in cell wall. Phenolic compounds also in the aqueous phase were analyzed by Folin Denis method. The eutectic solvent d,l-menthol:d,l-lactic acid (M:HLac) (1:2) was the best solvent for extraction of carotenoids from sunflower wastes, with 147 ppm of carotenoids extracted, in comparison to 115 ppm obtained with the standard solvent, n -hexane. In what concerns phenolic compounds, M:HLac was again better than the standard solvent. The use of the multi-enzyme complex Viscozyme ® had different responses, depending on the solvent tested. For the green solvent M:HLac, the enzyme improved the carotenoids extraction, achieving 335 ppm of carotenoids in the extract. The role of enzyme, solvent, water and sunflower quantity in the carotenoid extraction was evaluated and optimized through a central composite rotatable design (CCRD), using the M:HLac as solvent. According to the analysis of CCRD, the most efficient extractions were carried out using more solvent and less raw material, whose best result reached 1449 mg carotenoids/100 g biomass ppm of carotenoids. This work emphasizes the possibility of developing more sustainable enzyme-assisted separation processes, through the substitution of toxic solvents with natural, environmentally friendly, solvents., Competing Interests: Conflict of interestThe authors declare that they have no conflicts of interests., (© King Abdulaziz City for Science and Technology 2020.)

In recent times, deep eutectic solvents (DES) have received attention as an extractive media for separations. In this work, the water stability of eight menthol-based DESs and two tetrabutylammonium chloride (N 4444 Cl) based DESs with organic acid-based hydrogen bond donors (HBD) at a temperature of 298.15 K and atmospheric pressure were studied. dl-Menthol and N 4444 Cl were considered as the hydrogen bond acceptors (HBA). Molecular dynamics simulation (MD) was used as a tool to examine the distribution of molecules of DES and water in either phase. The intermolecular nonbonded interaction among the species of the systems was analyzed with radial distribution function, interaction energy, and hydrogen-bonding analysis to understand the stability of DESs in an aqueous medium. The results showed that the strong hydrogen bond plays a crucial role in the water stability of the DES. The degree of hydrogen bonding in HBD-water in terms of HBDs obtained by MD simulation can be presented in the order of acetic acid > levulinic acid > butanoic acid > pyruvic acid > hexanoic acid > octanoic acid > decanoic acid > dodecanoic acid. The strength of the hydrogen bond was attributed to the structure of solvents and the alkyl chain length of the HBD group. Overall, the order of stability of DES in water based on a "relative stability factor" was found as dl-menthol:acetic acid (1:1) < dl-menthol: levulinic acid (1:1) < dl-menthol:butanoic acid (1:1) < dl-menthol:pyruvic acid (1:2) < dl-menthol:hexanoic acid (1:1) < dl-menthol:octanoic acid (1:1) < dl-menthol: decanoic acid (1:1) < dl-menthol:dodecanoic acid (2:1). The transfer of molecules in the system from the aqueous phase to the DES rich phase was analyzed with the help of mean-square displacement and diffusion-coefficients. dl-Menthol and organic acids starting from octanoic acid and higher ones can be used in aqueous systems as solvents. Finally, dl-menthol:octanoic acid (1:1) -based DES was used to benchmark and predict the extraction efficiency of a pesticide (nitenpyram) from an aqueous feed. Hydrogen bond analysis demonstrated higher interactions of nitenpyram with dl-menthol and octanoic acid as compared to water. The MD simulation of the ternary system consisting of DES, water, and nitenpyram showed encouraging results, and gave an excellent agreement with experimental literature data in terms of extraction efficiency (∼42 to 46.7%) and distribution ratio (0.72).

In this contribution, thin poly(ionic liquid) (PIL) coatings with a well-defined pore structure built up from interpolyelectrolyte complexation between a PIL and poly(acrylic acid) (PAA) were successfully used for enhanced solid phase microextraction (SPME). The introduction of porosity with tunable polarity through the highly versatile PIL chemistry clearly boosts the potential of SPME in the detection of compounds at rather low concentrations. This work will inspire researchers to further explore the potential of porous poly(ionic liquid) materials in sensing and separation applications.

As the development of novel antibiotics has been at a halt for several decades, chemically enhancing existing drugs is a very promising approach to drug development. Herein, we report the preparation of twelve organic salts and ionic liquids (OSILs) from ciprofloxacin and norfloxacin as anions with enhanced antimicrobial activity. Each one of the fluoroquinolones (FQs) was combined with six different organic hydroxide cations in 93-100% yield through a buffer-assisted neutralization methodology. Six of those were isomorphous salts while the remaining six were ionic liquids, with four of them being room temperature ionic liquids. The prepared compounds were not toxic to healthy cell lines and displayed between 47- and 1416-fold more solubility in water at 25 and 37 °C than the original drugs, with the exception of the ones containing the cetylpyridinium cation. In general, the antimicrobial activity against Klebsiella pneumoniae was particularly enhanced for the ciprofloxacin-based OSILs, with up to ca. 20-fold decreases of the inhibitory concentrations in relation to the parent drug, while activity against Staphylococcus aureus and the commensal Bacillus subtilis strain was often reduced. Depending on the cation-drug combination, broad-spectrum or strain-specific antibiotic salts were achieved, potentially leading to the future development of highly bioavailable and safe antimicrobial ionic formulations.

The present study explores the preparation of dual nanofibrillar-based bio-sorbent films composed of cellulose nanofibrils (CNFs) and lysozyme nanofibrils (LNFs) for application in the removal of Hg(II) from aqueous solutions. The free-standing films were fabricated via simple vacuum filtration of water suspensions of CNFs and LNFs and disclose good mechanical and thermal properties. The Hg(II) removal efficiency was evaluated by atomic fluorescence spectroscopy in ultra-pure and natural spring waters contaminated with environmental realistic levels of mercury (50 μg L -1 ). The removal efficiency is pH-dependent reaching a maximum of 99 % after 24 h at a pH value close to the isoelectric point of the protein. Under the experimental conditions, the sorption kinetics are well described by the pseudo-second-order and Elovich models, suggesting a chemisorption mechanism. These results demonstrate the ability of the dual nanofibrillar-based films to remove Hg(II) from water samples reaching a residual concentration lower than the guideline value for water intended for human consumption (1 μg L -1 ). Therefore, the CNFs/LNFs bio-sorbents might be a solution to treat low-concentrated mercury-contaminated waters., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Simple mixtures of ionic liquids (IL-IL mixtures) can become a promising approach for the substitution of task-specific ILs. Such a concept was explored in this article by comparison of the thermophysical properties of neat 1-ethyl-3-methylimidazolium 2,2,2-trifluoromethylsulfonyl-N-cyanoamide, [C 2 mim][TFSAM], and equimolar mixtures of two structurally similar ILs having more common ions. Molecular dynamics (MD) simulations were additionally used to further highlight structural aspects of these systems at a molecular level.

In this work, a facile preparation of SPME fibers with increased surface area is presented. The SPME fibers were prepared by grinding poly(ionic liquids) (PILs) to obtain particles of 1-16 µm and, with the aid of a silicon adhesive, attach these particles to a steel wire support. Three different PILs, poly(1-vinyl-3-benzylimidazolium-co-styrene bromide) [poly(ViBnIm-co-Sty Br)], poly(1-vinyl-3-benzylimidazolium-co-styrene bis(trifluoromethanesulfonyl)imide) [poly(ViBnIm-co-Sty TFSI)] and poly(diallyldimethylamine bis(trifluoromethanesulfonyl)imide) [poly(Pyrr 11 TFSI)], were used. The first two PILs were obtained by reversible addition-fragmentation chain transfer polymerization followed by metathesis reactions. The thicknesses of the prepared fibers were found to be 19 ± 4 µm and 85% of the particles used have diameters between 2 and 10 µm. The prepared fibers were tested by performing the headspace extraction of two standard solutions, one containing a mixture of alcohols with different chain lengths, and the other a mixture of aromatic compounds, leading to sorption times of 10 - 15 min due the large surface area attained with this method. PILs with aromatic moieties containing the bromide anion showed high selectivity towards polar compounds, due to the hydrogen basicity of the anion, and also towards aromatic analytes, due to the aromatic nature of styrene moieties and the cation pendant groups. The limits of detection fall in the sub ppb level, while relative standard deviations and reproducibility from fiber-to-fiber found maximums of 16.2% and 22.5%, respectively. Furthermore, the PIL based fibers showed up to 90% higher extraction efficiencies compared to the commercial fibers of polydimethylsiloxane and polyacrylate., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Deep eutectic solvents (DESs) consist of a mixture of two or more solid components, which gives rise to a lower melting point compared to the starting materials. Until recently only hydrophilic DESs were available, and despite their revolutionary role in the alternative-solvents field, important issues in chemistry, and chemical engineering (such as water-related problems and the replacement of toxic volatile organic compounds) could not be tackled. Hydrophobic (deep)-here in parenthesis due to the different depths of the eutectic melting points-eutectic solvents are a subclass of DESs where both components are hydrophobic. The low toxicity, high biodegradability, and straightforward preparation without further purification steps of naturally occurring low-cost compounds are among the key advantages. Although research on hydrophobic DESs is scarce (the first report was only published in 2015), some interesting features and applications have been reported and deserve to be evaluated and comparisons established. This Minireview is divided into two parts: The first part provides a brief general introduction to DESs and the second part discusses the nomenclature using solid-liquid phase diagram analysis, chemical stability, thermophysical properties comparison, and finally the most important emerging fields of application., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Considering the high potential of hydrogen (H₂) as a clean energy carrier, the implementation of high performance and cost-effective biohydrogen (bioH₂) purification techniques is of vital importance, particularly in fuel cell applications. As membrane technology is a potentially energy-saving solution to obtain high-quality biohydrogen, the most promising poly(ionic liquid) (PIL)⁻ionic liquid (IL) composite membranes that had previously been studied by our group for CO₂/N₂ separation, containing pyrrolidinium-based PILs with fluorinated or cyano-functionalized anions, were chosen as the starting point to explore the potential of PIL⁻IL membranes for CO₂/H₂ separation. The CO₂ and H₂ permeation properties at the typical conditions of biohydrogen production ( T = 308 K and 100 kPa of feed pressure) were measured and discussed. PIL⁻IL composites prepared with the [C(CN)₃] - anion showed higher CO₂/H₂ selectivity than those containing the [NTf₂] - anion. All the membranes revealed CO₂/H₂ separation performances above the upper bound for this specific separation, highlighting the composite incorporating 60 wt% of [C₂mim][C(CN)₃] IL., Competing Interests: The authors declare no conflict of interest.

Deep eutectic solvents (DESs), a novel generation of solvents, have recently been described as efficient and timesaving fibrillation agents for proteins. In this context, the present work aims at assessing the effect of the hydrogen bond donor (HBD) of cholinium chloride ([Ch]Cl):carboxylic acid based DESs on the dimensions (length and width) of lysozyme nanofibers (LNFs). Mono-, di- and tri-carboxylic acids (acetic, lactic, levulinic, malic and citric acids) were used to prepare different DES formulations, which were successfully used on the fibrillation of lysozyme. The results showed that the carboxylic acid (i.e. the HBD) plays an important role on the fibrillation efficiency and on the length of the ensuing LNFs with aspect-ratios always higher than those obtained by fibrillation with [Ch]Cl. The longest LNFs were obtained using lactic acid as the HBD with an average length of 1004 ± 334 nm and width of 31.8 ± 6.8 nm, and thus an aspect-ratio of ca. 32. The potential of these protein nanofibers as reinforcing additives was evaluated by preparing pullulan (PL)-based nanocomposite films containing 5% LNFs with different aspect-ratios, resulting in highly homogenous and transparent films with improved mechanical performance., (Copyright © 2018. Published by Elsevier B.V.)

A supramolecular hydrogel based on a metal-containing deep eutectic solvent (DES) is presented here for the first time. The phase diagram of the DES-based hydrogel was drawn and its rheological properties were determined.

M13 is a filamentous, non-lytic bacteriophage that infects Escherichia coli via the F pilus. Currently, phage M13 is widely used in phage display technology and bio-nanotechnology, and is considered a possible antibacterial therapeutic agent, among other applications. Conventional phage purification involves 5-7 operational steps, with high operational costs and significant product loss (approximately 60%). In this work, we propose a scalable purification process for M13 bacteriophage using a novel stationary phase based on a polymeric ionic liquid (PIL) with a positively charged backbone structure. Poly (1-vinyl-3-ethyl imidazolium bis(trifluoromethylsulfonyl) imide) - poly(VEIM-TFSI) predominantly acted as an anion exchanger under binding-elution mode. This revealed to be a rapid and simple method for the recovery of phage M13 with an overall separation yield of over 70% after a single downstream step. To the best of our knowledge, PILs have never been used as separation matrices for biological products and the results obtained, together with the large number of cations and anions available to prepare PILs, illustrate well the large potential of the proposed methodology., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Deep eutectic solvents (DESs) constitute a new class of ionic solvents that has been developing at a fast pace in recent years. Since these solvents are commonly suggested as green alternatives to organic solvents, it is important to understand their physical properties. In particular, polarity plays an important role in solvation phenomena. In this work, the polarity of different families of DESs was studied through solvatochromic responses of UV-vis absorption probes. Kamlet-Taft α, β, π* and E T N parameters were evaluated using different solvatochromic probes, as 2,6-dichloro-4-(2,4,6-triphenyl-N-pyridino)-phenolate (Reichardt's betaine dye 33), 4-nitroaniline, and N,N-diethyl-4-nitroaniline for several families of DESs based on cholinium chloride, dl-menthol and a quaternary ammonium salt ([N 4444 ]Cl). In addition, a study to understand the difference in polarity properties between DESs and the corresponding ILs, namely ILs based on cholinium cation and carboxylic acids as anions ([Ch][Lev], [Ch][Gly] and [Ch][Mal]), was carried out. The chemical structure of the hydrogen bond acceptor (HBA) in a DES clearly controls the dipolarity/polarizability afforded by the DES. Moreover, Kamlet-Taft parameters do not vary much within the family, but they differ among families based on different HBA, either for DESs containing salts ([Ch]Cl or [N 4444 ]Cl) or neutral compounds (dl-menthol). A substitution of the HBD was also found to play an important role in solvatochromic probe behaviour for all the studied systems.

Herein, seven anions including four imide-based, namely bis[(trifluoromethyl)sulfonyl]imide (TFSI), bis(fluorosulfonyl)imide (FSI), bis[(pentafluoroethyl)sulfonyl]imide (BETI), 2,2,2-trifluoromethylsulfonyl-N-cyanoamide (TFSAM) and 2,2,2-trifluoro-N-(trifluoromethylsulfonyl) acetamide (TSAC), and two sulfonate anions, trifluoromethanesulfonate (triflate, TF) and nonafluorobutanesulfonate (NF), are considered and compared. The volumetric mass density and dynamic viscosity of five ionic liquids containing these anions combined with the commonly used 1-ethyl-3-methylimidazolium cation (C 2 C 1 im), [C 2 C 1 im][FSI], [C 2 C 1 im][BETI], [C 2 C 1 im][TFSAM], [C 2 C 1 im][TSAC] and [C 2 C 1 im][NF] are measured in the temperature range of 293.15 ≤ T/K ≤ 353.15 and at atmospheric pressure. The results show that [C 2 mim][FSI] and [C 2 mim][TFSAM] exhibit the lowest densities and viscosities among all the studied ionic liquids. The experimental volumetric data is used to validate a more consistent re-parameterization of the CL&P force field for use in MD simulations of ionic liquids containing the ubiquitous bis[(trifluoromethyl)sulfonyl]imide and trifluoromethanesulfonate anions and to extend the application of the model to other molten salts with similar ions.

The CO 2 and N 2 permeation properties of ionic liquids (ILs) based on the 1-ethyl-3-methylimidazolium cation ([C 2 mim] + ) and different fluorinated anions, namely 2,2,2-trifluoromethylsulfonyl-N-cyanoamide ([TFSAM] - ), bis(fluorosulfonyl) imide ([FSI] - ), nonafluorobutanesulfonate ([C 4 F 9 SO 3 ] - ), tris(pentafluoroethyl)trifluorophosphate ([FAP] - ), and bis(pentafluoroethylsulfonyl)imide ([BETI] - ) anions, were measured using supported ionic liquid membranes (SILMs). The results show that pure ILs containing [TFSAM] - and [FSI] - anions present the highest CO 2 permeabilities, 753 and 843 Barrer, as well as the greatest CO 2 /N 2 permselectivities of 43.9 and 46.1, respectively, with CO 2 /N 2 separation performances on top of or above the Robeson 2008 upper bound. The re-design of the [TFSAM] - anion by structural unfolding was investigated through the use of IL mixtures. The gas transport and CO 2 /N 2 separation properties through a pure [C 2 mim][TFSAM] SILM are compared to those of two different binary IL mixtures containing fluorinated and cyano-functionalized groups in the anions. Although the use of IL mixtures is a promising strategy to tailor gas permeation through SILMs, the pure [C 2 mim][TFSAM] SILM displays higher CO 2 permeability, diffusivity and solubility than the selected IL mixtures. Nevertheless, both the prepared mixtures present CO 2 separation performances that are on top of or above the Robeson plot.

Fluoroquinolones (FQs) and Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) are two classes of Active Pharmaceutical Ingredients (APIs), widespreadly used in human healthcare and as veterinary drugs, and that have been found throughout the water cycle in the past years. These two classes of APIs are commonly present in aqueous streams in concentrations ranging from ng.L -1 to µ g.L -1 . Despite such low concentrations, these contaminants tend to bioaccumulate, leading to serious environmental and health issues after chronic exposure. The low concentrations of FQs and NSAIDs in aqueous media also render their difficult identification and quantification, wich may result in an unefficient evaluation of their environmental impact and persistence. Therefore, the development of alternative pre-treatment techniques for their extraction and concentration from aqueous samples is a crucial requirement. In this work, liquid-liquid systems, namely ionic-liquid-based aqueous biphasic systems (IL-based ABS), were tested as simultaneous extraction and concentration platforms of FQs and NSAIDs. ABS composed of imidazolium-, ammonium- and phosphonium-based ILs and a citrate-based salt (C 6 H 5 K 3 O 7 ) were evaluated for the single-step extraction and concentration of three FQs (ciprofloxacin, enrofloxacin and norfloxacin) and three NSAIDs (diclofenac, naproxen and ketoprofen) from aqueous samples. Outstanding one-step extraction efficiencies of APIs close to 100% were obtained. Furthermore, concentration factors of both FQs and NSAIDs were optimized by an appropriate manipulation of the phase-forming components compositions to tailor the volumes of the coexisting phases. Concentration factors of 1000-fold of both FQS and NSAIDs were obtained in a single-step, without reaching the saturation of the IL-rich phase. The concentration of APIs up to the mg.L -1 allowed their easy and straightforward identification and quantification by High-Performance Liquid Chromatography (HPLC) coupled to an UV detector, as shown either with model aqueous samples or real wastewater effluent samples.

Crosslinked pyrrolidinium-based poly(ionic liquids) (Pyrr-PILs) were synthesized through a fast, simple, and solventless photopolymerization scheme, and tested as solid phase microextraction (SPME) sorbents. A series of Pyrr-PILs bearing three different alkyl side chain lengths with two, eight, and fourteen carbons was prepared, characterized, and homogeneously coated on a steel wire by using a very simple procedure. The resulting coatings showed a high thermal stability, with decomposition temperatures above 350 °C, excellent film stability, and lifetime of over 100 injections. The performance of these PIL-based SPME fibers was evaluated using a mixture of eleven organic compounds with different molar volumes and chemical functionalities (alcohols, ketones, and monoterpenes). The Pyrr-PIL fibers were obtained as dense film coatings, with 67 μm thickness, with an overall sorption increase of 90% and 55% as compared to commercial fibers of Polyacrylate (85 μm) (PA85) and Polydimethylsiloxane (7 μm) (PDMS7) coatings, respectively. A urine sample doped with the sample mixture was used to study the matrix effect and establish relative recoveries, which ranged from 60.2% to 104.1%., Competing Interests: The authors declare no conflict of interest.

In the current era of human life, we have been facing an increased consumption of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs). Nevertheless, NSAIDs are not completely metabolized by humans and are further excreted into domestical effluents. Several studies have been showing that a wide variety of pharmaceuticals are present in water effluents and are thus a matter of serious concern in the public health. Although treatment plants use sophisticated technologies for pollutants/contaminants removal, none of these processes was particularly designed for NSAIDs. In this perspective, this work addresses the use of a liquid-liquid extraction approach, employing ionic liquids (ILs), for the removal of NSAIDs from aqueous media. In particular, aqueous biphasic systems (ABS) composed of ILs and aluminium-based salts, which are already used in water treatment plants, were tested for the removal of diclofenac, ibuprofen, naproxen and ketoprofen. With these systems, extraction efficiencies of NSAIDs up to 100% were obtained in a single-step. The recovery of NSAIDs from the IL medium and the recyclability of the IL-rich phase were then ascertained to guarantee the development of a more sustainable and cost-effective strategy. Based on the remarkable increase in the solubility of NSAIDs in the IL-rich phase (from a 300- to a 4100-fold when compared with pure water), water was then studied as an effective anti-solvent, and where single-step recovery percentages of NSAIDs from the IL-rich phase up to 91% were obtained. After the "cleaning" of the IL-rich phase by the induced precipitation of NSAIDs, the phase-forming components were recovered and reused in four consecutive cycles, with no detected losses on both the extraction efficiency and recovery of NSAIDs by induced precipitation. Finally, an integrated process is here proposed, which comprises the (i) removal of NSAIDs from aqueous media, (ii) the cleaning of the IL-rich phase by the recovery of NSAIDs by induced precipitation, and (iii) the phase-forming components recycling and reuse, aiming at unlocking new doors for alternative treatment strategies of aqueous environments.

Amyloid fibrils have recently gained a lot of attention due to their morphology, functionality and mechanical strength, allowing for their application in nanofiber-based materials, biosensors, bioactive membranes and tissue engineering scaffolds. The in vitro production of amyloid fibrils is still a slow process, thus hampering the massive production of nanofibers and its consequent use. This work presents a new and faster (2-3h) fibrillation method for hen egg white lysozyme (HEWL) using a deep eutectic solvent based on cholinium chloride and acetic acid. Nanofibers with dimensions of 0.5-1μm in length and 0.02-0.1μm in thickness were obtained. Experimental variables such as temperature and pH were also studied, unveiling their influence in fibrillation time and nanofibers morphology. These results open a new scope for protein fibrillation into nanofibers with applications ranging from medicine to soft matter and nanotechnology., (Copyright © 2016 Elsevier B.V. All rights reserved.)

During the past decade, significant advances in ionic liquid-based materials for the development of CO2 separation membranes have been accomplished. This review presents a perspective on different strategies that use ionic liquid-based materials as a unique tuneable platform to design task-specific advanced materials for CO2 separation membranes. Based on compilation and analysis of the data hitherto reported, we provide a judicious assessment of the CO2 separation efficiency of different membranes, and highlight breakthroughs and key challenges in this field. In particular, configurations such as supported ionic liquid membranes, polymer/ionic liquid composite membranes, gelled ionic liquid membranes and poly(ionic liquid)-based membranes are detailed, discussed and evaluated in terms of their efficiency, which is attributed to their chemical and structural features. Finally, an integrated perspective on technology, economy and sustainability is provided.

In the past few years, the improvement of advanced analytical tools allowed to confirm the presence of trace amounts of metabolized and unchanged active pharmaceutical ingredients (APIs) in wastewater treatment plants (WWTPs) as well as in freshwater surfaces. It is known that the continuous contact with APIs, even at very low concentrations (ng L -1 -μg L -1 ), leads to serious human health problems. In this context, this work shows the feasibility of using ionic-liquid-based aqueous biphasic systems (IL-based ABS) in the extraction of quinolones present in aqueous media. In particular, ABS composed of imidazolium- and phosphonium-based ILs and aluminium-based salts (already used in water treatment plants) were evaluated in one-step extractions of six fluoroquinolones (FQs), namely ciprofloxacin, enrofloxacin, moxifloxacin, norfloxacin, ofloxacin and sarafloxacin, and extraction efficiencies up to 98% were obtained. Despite the large interest devoted to IL-based ABS as extractive systems of outstanding performance, their recyclability/reusability has seldomly been studied. An efficient extraction/cleaning process of the IL-rich phase is here proposed by FQs induced precipitation. The recycling of the IL and its further reuse without losses in the ABS extractive performance for FQs were established, as confirmed by the four consecutive removal/extraction cycles evaluated. This novel recycling strategy supports IL-based ABS as sustainable and cost-efficient extraction platforms.

In this work, we explore the interactions between the ionic liquid 1-ethyl-3-methylimidazolim acetate and different inorganic salts belonging to two different cation families, those based on ammonium and others based on sodium. NMR and Raman spectroscopy are used to screen for changes in the molecular environment of the ions in the ionic liquid + inorganic salt mixtures as compared to pure ionic liquid. The ion self-diffusion coefficients are determined from NMR data, allowing the discussion of the ionicity values of the ionic liquid + inorganic salt mixtures calculated using different methods. Our data reveal that preferential interactions are established between the ionic liquid and ammonium-based salts, as opposed to sodium-based salts. Computational calculations show the formation of aggregates between the ionic liquid and the inorganic salt, which is consistent with the spectroscopic data, and indicate that the acetate anion of the ionic liquid establishes preferential interactions with the ammonium cation of the inorganic salts, leaving the imidazolium cation less engaged in the media.

Aqueous biphasic systems (ABSs) provide a sustainable and efficient alternative to conventional liquid-liquid extraction techniques with volatile organic solvents, and can be used for the extraction, recovery, and purification of diverse solutes. In this work, and for the first time, ABSs composed of poly(ionic liquid)s (PILs) and inorganic salts were measured at 25 °C and atmospheric pressure. New PILs having pyrrolidinium polycations combined with different counter-anions, namely acetate [Ac](-), trifluoroacetate [TFAc](-), hexanoate [Hex](-), adipate [Adi](-), and citrate [Cit](-) were synthesized, by a simple and environmentally-friendly procedure, and characterized. The effect of the PIL features, namely molecular weight and anionic character, and other experimental variables, such as temperature, on the phase splitting ability was researched. The aptitude of the studied ABS to be implemented as separation technologies was also evaluated through the use of a model biomolecule, tryptophan.

Significant antiproliferative effects against various tumor cell lines were observed with novel ampicillin salts as ionic liquids. The combination of anionic ampicillin with appropriate ammonium, imidazolium, phosphonium, and pyridinium cations yielded active pharmaceutical ingredient ionic liquids (API-ILs) that show potent antiproliferative activities against five different human cancer cell lines: T47D (breast), PC3 (prostate), HepG2 (liver), MG63 (osteosarcoma), and RKO (colon). Some API-ILs showed IC50 values between 5 and 42 nM, activities that stand in dramatic contrast to the negligible cytotoxic activity level shown by the ampicillin sodium salt. Moreover, very low cytotoxicity against two primary cell lines-skin (SF) and gingival fibroblasts (GF)-indicates that the majority of these API-ILs are nontoxic to normal human cell lines. The most promising combination of antitumor activity and low toxicity toward healthy cells was observed for the 1-hydroxyethyl-3-methylimidazolium-ampicillin pair ([C2 OHMIM][Amp]), making this the most suitable lead API-IL for future studies., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this work, novel and nontoxic fluorinated ionic liquids (FILs) that are totally miscible in water and could be used in biological applications, where fluorocarbon compounds present a handicap because their aqueous solubility (water and biological fluids) is in most cases too low, have been investigated. The self-aggregation behavior of perfluorosulfonate-functionalized ionic liquids in aqueous solutions has been characterized using conductometric titration, isothermal titration calorimetry (ITC), surface tension measurements, dynamic light scattering (DLS), viscosity and density measurements, and transmission electron microscopy (TEM). Aggregation and interfacial parameters have been computed by conductimetry, calorimetry, and surface tension measurements in order to study various thermodynamic and surface properties that demonstrate that the aggregation process is entropy-driven and that the aggregation process is less spontaneous than the adsorption process. The novel perfluorosulfonate-functionalized ILs studied in this work show improved surface activity and aggregation behavior, forming distinct self-assembled structures.

In this work, we demonstrate that the presence of fluorinated alkyl chains in Ionic Liquids (ILs) is highly relevant in terms of their thermophysical properties and aqueous phase behaviour. We have measured and compared the density and viscosity of pure 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate, [C2C1im][FAP], with that of pure 1-ethyl-3-methylimidazolium hexafluorophosphate, [C2C1im][PF6], at atmospheric pressure and in the (288.15 to 363.15) K temperature range. The results show that the density of [C2C1im][PF6] is lower than that of [C2C1im][FAP], while the viscosity data reveal the opposite trend. The fluid phase behaviour of aqueous solutions of the two ILs was also evaluated under the same conditions and it was found that the mutual solubilities of [C2C1im][FAP] and water are substantially lower than those verified with [C2C1im][PF6]. The experimental data were lastly interpreted at a molecular level using Molecular Dynamics (MD) simulation results revealing that the interactions between the IL ions and the water molecules are mainly achieved via the six fluorine atoms of [PF6](-) and the three analogues in [FAP](-). The loss of three interaction centres when replacing [PF6](-) by [FAP](-), coupled with the bulkiness and relative inertness of the three perfluoroethyl groups, reduces its mutual solubility with water and also contributes to a lower viscosity displayed by the pure [FAP]-based IL as compared to that of the [PF6]-based compound.

Ionic liquids have been explored as attractive alternative media for CO2 separation not only due to their low volatility but also due to their highly tuneable nature. Aiming at designing highly efficient liquid phases for flue gas separation and natural gas purification, this work focuses on the use of binary ionic liquid mixtures containing sulfate and/or cyano-functionalized anions. Several mixtures were prepared and their gas transport properties through supported ionic liquid membranes (SILMs) were investigated. The thermophysical properties of these mixtures, namely viscosity and density (data presented and discussed in ESI), were also measured so that trends between transport properties and thermophysical properties could be evaluated. The results obtained indicate that depending on the anions mixed, membranes with fine-tuned gas permeabilities, diffusivities and solubilities can be obtained. Additionally, SILMs prepared with these ionic liquid mixtures are on the upper bound of the CO2/N2 separation, or even may surpass it, indicating their potential for separating CO2 in low-pressure post-combustion processes. Overall, the use of ionic liquid mixtures combining the most selective anions with the least viscous anions is a highly promising strategy to design advanced engineered liquid phases for CO2 separation membranes.

In order to overcome the problems associated with low water solubility, and consequently low bioavailability of active pharmaceutical ingredients (APIs), novel organic salts containing fluoroquinolones (e.g. ciprofloxacin and norfloxacin) were prepared, using an optimized synthetic procedure based on direct protonation, with different biocompatible counter ions such as mesylate, gluconate and glycolate. All the prepared organic salts were characterized by spectroscopic techniques, mass spectrometry and thermal analysis. Solubility studies in water and simulated biological fluids at 25°C and 37°C were also performed. Additionally, octanol-water and phospholipid-water partition coefficients were measured at 25°C. The cytotoxicity and anti-inflammatory efficacy using an human cell model of intestinal epithelia (Caco-2 cells) were also evaluated and compared to those of the parent APIs. The adequate selection of the biocompatible anions allows the tuning of important physical, thermal and toxicological properties., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Proteins display an essential role in numerous natural systems due to their structural and biological properties. Given their unique properties, proteins have been thoroughly investigated in the last few decades, offering a myriad of solutions for the development of innovative biomaterials, including films, foams, composites and gels, in particular for biomedical applications such as drug delivery systems, biosensors and scaffolds for tissue regeneration. In this context, this review intends to give a general overview of the potential of protein based materials within the sustainable polymers context, covering aspects ranging from protein types, selection/isolation to properties of protein based (nano)materials and biomedical applications, passing through preparation methodologies of materials.

In the past several years, ionic liquids (ILs) have been at the cutting edge of the most promising science and technology. ILs not only have found applications in classical areas of knowledge but also are important candidates to solve classical problems within several societal challenges, such as clean and efficient energy, through the development of a broad swath of energy technologies, such as advanced batteries, dye-sensitized solar cells, double-layer capacitors, actuators, fuel cells, thermo-cells, and water splitting, essentially related to highly efficient carbon capture and storage technologies and resource efficiency to date. This review focuses on the application of IL methodologies to solve critical pharmaceutical problems, in particular, the low solubility and thus bioavailability of pharmaceutical compounds and the presence of polymorphs, which severely hamper the efficacy of important commercially available drugs. The development of strategies to use ILs as carriers of pharmaceutical active compounds is an extremely promising and wide avenue. Further, the synthesis of liquid salts through the discerning combination of cations and anions with several distinct pharmaceutical roles provides answers to some of today's pharmaceutical industrial challenges.

Aiming at full sustainability of CO2 separation processes, a series of supported ionic liquid membranes based on environmentally friendly cholinium carboxylate ionic liquids were successfully prepared. Their gas permeation properties were measured and high permselectivities were obtained for both CO2 /CH4 and CO2 /N2 ., (Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Cholinium-based ionic liquid methacrylic monomers having halide, lactate and acetate counter-anions were synthesized and polymerized by using conventional free radical polymerization. The polymer properties were characterized by NMR, SEC/GPC, TGA, and DSC and compared among eight different cationic polymethacrylic analogs. Polycations with different methacrylic alkylammonium backbones having lactate anion displayed comparatively better thermal stability than those having the acetate counter-anions and they also exhibited lower glass transition temperatures than their counterparts having acetate and halide counteranions. As an application, cholinium lactate methacrylate ionic liquid monomer was used to prepare ion gels by photopolymerization. Interestingly, these are the first examples of ion gels which are fully composed of low toxicity and biocompatible cholinium ionic liquids. Furthermore, the same ionic liquid monomer, cholinium lactate methacrylate, showed the ability to dissolve cellulose. This facilitated the preparation of transparent poly(ionic liquid)/cellulose composite coatings by photopolymerization.

In order to overcome the problems associated with low water solubility, and consequently low bioavailability of active pharmaceutical ingredients (APIs), herein we explore a modular ionic liquid synthetic strategy for improved APIs. Ionic liquids containing L-ampicillin as active pharmaceutical ingredient anion were prepared using the methodology developed in our previous work, using organic cations selected from substituted ammonium, phosphonium, pyridinium and methylimidazolium salts, with the intent of enhancing the solubility and bioavailability of L-ampicillin forms. In order to evaluate important properties of the synthesized API-ILs, the water solubility at 25 °C and 37 °C (body temperature) as well as octanol-water partition coefficients (Kow's) and HDPC micelles partition at 25 °C were measured. Critical micelle concentrations (CMC's) in water at 25 °C and 37 °C of the pharmaceutical ionic liquids bearing cations with surfactant properties were also determined from ionic conductivity measurements., (Copyright © 2013 Elsevier B.V. All rights reserved.)

The subject of ionicity has been extensively discussed in the last decade, due to the importance of understanding the thermodynamic and thermophysical behaviour of ionic liquids. In our previous work, we established that ionic liquids' ionicity could be improved by the dissolution of simple inorganic salts in their milieu. In this work, a comparison between the thermophysical properties of two binary systems of ionic liquid + inorganic salt is presented. The effect of the ammonium thiocyanate salt on the ionicity of two similar ionic liquids, 1-ethyl-3-methylimidazolium ethylsulfonate and ethylsulfate, is investigated in terms of the related thermophysical properties, such as density, viscosity and ionic conductivity in the temperature range 298.15-323.15 K. In addition, spectroscopic (NMR and Raman) and molecular dynamic studies were conducted in order to better understand the interactions that occur at a molecular level. The obtained results reveal that although the two anions of the ionic liquid exhibit similar chemical structures, the presence of one additional oxygen in the ethylsulfate anion has a major impact on the thermophysical properties of the studied systems.

The study of solid-fluid transitions in fluorinated ionic liquids using differential scanning calorimetry, rheology, and molecular modeling techniques is an essential step toward the understanding of their dynamics and the thermodynamics and the development of potential applications. Two fluorinated ionic liquids were studied: 1-hexyl-3-methylimidazolium perfluorobutanesulfonate, HMIm(PFBu)SO3, and tetrabutylammonium perfluorobutanesulfonate, NB4(PFBu)SO3. The experimental calorimetric and rheological data were analyzed taking into account the possible mesoscale structure of the two fluorinated ionic liquids. The simulation results indicate the possible formation of three nanosegregated domains-polar, nonpolar, and fluorous-that may have a profound impact on ionic liquid research. In the case of HMIm (PFBu)SO3 the three types of mesoscopic domains can act as interchangeable jigsaw pieces enabling the formation of multiple types of crystals and inducing the observed calorimetry and rheological trends.

In the past few years, ionic liquids (ILs) with cyano-functionalized anions have shown to be improved candidates for electrochemical and separation applications. Nevertheless, only scattered data exist hitherto and a broad analysis of their structure-property relationship has yet to be attempted. Therefore, in this work, a systematic study of the densities, viscosities and refractive indices of imidazolium-based ILs with cyano-functionalized anions was carried out at 0.1 MPa within a broad temperature range (from 278 to 363 K). The ILs under study are based on 1-alkyl-3-methylimidazolium cations (alkyl = ethyl, butyl and hexyl) combined with the [SCN](-), [N(CN)2](-), [C(CN)3](-) and [B(CN)4](-) anions. The selected matrix of cation/anion combinations allows us to provide a detailed and comprehensive investigation of the influence of the -CN group through an analysis of the thermophysical properties of the related ILs. The results show that, regardless of the cation, the densities decrease with an increase in the number of cyano groups or anion molecular weight. Moreover, for a fixed cation and temperature, the refractive index of the ILs decreases according to the rank: [SCN](-) > [N(CN)2](-) ≈ [C(CN)3](-) > [B(CN)4](-). On the other hand, no clear trend was observed for the viscosity of ILs and the respective number of -CN groups. The viscosity dependence on the cyano-functionalized anions decreases in the order: [SCN](-) > [B(CN)4](-) > [N(CN)2](-) > [C(CN)3](-). The isobaric thermal expansion coefficient, the derived molar refraction, the free volume, and the viscosity energy barrier of all compounds were estimated from the experimental data and are presented and discussed. Finally, group contribution models were applied, and new group contribution parameters are presented, extending these methods to the prediction of the ILs properties.

Recently, efforts have been put on the development of new drug formulations using ionic liquid framework. In this work, two different species of abroad-spectrum polyketide antibiotic, tetracycline, are studied in terms of some important properties for antibiotics such as solubility in water and hydrophilic-hydrophobic balance. Tetracycline was used as cation, whereas docusate, a biocompatible anion, which enables the tailoring of the hydrophilicity of salts, was chosen as the anion. The developed innovative ion pair, tetracycline docusate, was characterized in terms of its thermal stability, water solubility, octanol-water, and liposome-water partition coefficients, using UV-vis spectrophotometry because of the absorbance of tetracycline around 270 nm. Egg yolk phosphatidylcholine liposomes were used as cell membrane models, and the interactions of both tetracycline hydrochloride and tetracycline docusate with the liposomes were quantified by determination of the partition coefficient using derivative spectrophotometry. A theoretical model based on simple partition drugs between two different media was used to determine the partition coefficient in liposomes., (Copyright © 2013 Wiley Periodicals, Inc.)

The dissolution of uracil-a pyrimidine nucleic acid base-in the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][CH3COO]) has been investigated by methods of (1)H and (13)C NMR spectroscopy, (1)H-(1)H NOESY NMR spectroscopy, and quantum chemical calculations. The uracil-[C2mim][CH3COO] interactions that define the dissolution mechanism comprise the hydrogen bonds between the oxygen atoms of the acetate anion and the hydrogen atoms of the N1-H and N3-H groups of uracil and also the hydrogen bonds between the most acidic aromatic hydrogen atom (H2) of the imidazolium cation and the oxygen atoms of the carbonyl groups of uracil. The bifunctional solvation nature of the ionic liquid can be inferred from the presence of interactions between both ions of the ionic liquid and the uracil molecule. The location of such interaction sites was revealed using NMR data ((1)H and (13)C chemical shifts both in the IL and in the uracil molecule), complemented by DFT calculations. NOESY experiments provided additional evidence concerning the cation-uracil interactions.

The liquid-liquid equilibria of mixtures of cholinum-based ionic liquids (N-alkyl-N,N-dimethylhydroxyethylammonium bis(trifluoromethane)sulfonylimide, [N(11n2OH)][Ntf(2)], n = 1, 2, 3, 4, and 5) plus water or 1-octanol were investigated at atmospheric pressure over the entire composition range. The experiments were conducted between 265 and 385 K using the cloud-point method. The systems exhibit phase diagrams consistent with the existence of upper critical solution temperatures. The solubility of [N(1 1 n 2OH)][Ntf(2)] in water is lower for cations with longer alkyl side chains (larger n values). The corresponding trend in the octanol mixtures is reversed. The ([N(1 1 1 2OH)][Ntf(2)] + water + octanol) ternary system shows triple liquid-liquid immiscibility at room temperature and atmospheric pressure. A combined analytic/synthetic method was used to estimate the corresponding phase diagram under those conditions. Auxiliary molecular dynamics simulation data were used to interpret the experimental results at a molecular level.

During the past decade, ionic-liquid-based Aqueous Biphasic Systems (ABS) have been the focus of a significant amount of research. Based on a compilation and analysis of the data hitherto reported, this critical review provides a judicious assessment of the available literature on the subject. We evaluate the quality of the data and establish the main drawbacks found in the literature. We discuss the main issues which govern the phase behaviour of ionic-liquid-based ABS, and we highlight future challenges to the field. In particular, the effect of the ionic liquid structure and the various types of salting-out agents (inorganic or organic salts, amino acids and carbohydrates) on the phase equilibria of ABS is discussed, as well as the influence of secondary parameters such as temperature and pH. More recent approaches using ionic liquids as additives or as replacements for common salts in polymer-based ABS are also presented and discussed to emphasize the expanding number of aqueous two-phase systems that can actually be obtained. Finally, we address two of the main applications of ionic liquid-based ABS: extraction of biomolecules and other added-value compounds, and their use as alternative approaches for removing and recovering ionic liquids from aqueous media.

This work reports on the systematic investigation of the influence of the cation alkyl side-chain length of 1-alkyl-3-methylimidazolium chloride ionic liquids ([C(n)C(1)im]Cl, with n = 1-14), as well as the substitution of the most acidic hydrogen in the imidazolium core by a methyl group, in the formation of aqueous biphasic systems. Ternary phase diagrams, tie-lines, tie-line slopes, tie-line lengths, and critical points for the several systems (ionic liquid + water + K(3)PO(4)) were determined and reported at 298 K and atmospheric pressure. It is shown that the increase of the cation alkyl chain length enhances the formation of aqueous biphasic systems if alkyl chain lengths until the hexyl are considered. The results for longer alkyl side chains show, nevertheless, that the phenomenon is more complex than previously admitted and that the capacity of the ionic liquid to self-aggregate also governs its ability to phase separate. The effect of the alkyl side-chain length on the phase-forming ability of the studied systems was quantitatively evaluated based on their salting-out coefficients derived from a Setschenow-type behavior. The aptitude of each ionic liquid for liquid-liquid demixing as a function of the cation alkyl side-chain length clearly follows three different patterns. The results obtained for the trisubstituted cation indicate that the hydrogen-bonding interactions between the ionic liquid cation and water are not a relevant issue in the formation of aqueous two-phase systems. In general, for the [C(n)C(1)im]Cl series, a multifaceted ratio between entropic contributions and the ability of each ionic liquid to self-aggregate in aqueous media control the phase behavior.

Density and viscosity data of the N-alkyl-N,N-dimethyl-N-(2-hydroxyethyl)ammonium bis(trifluoromethylsulfonyl)imide ionic liquids homologous series [N(1 1 n 2(OH))][Ntf(2)] with n=1, 2, 3, 4 and 5 have been measured at atmospheric pressure in the 283