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As green solvents, ionic liquids (ILs) are quite suitable for the absorption of volatile organic compounds (VOCs) such as benzene and its homologues. However, solvent selection is the key to the VOC absorption process. In the present study, a rapid solvent screening tool, Conductor-like Screening Model for Real Solvents (COSMO-RS), was used to predict the solubility of toluene in 816 ILs. The effects of four structure characters, namely, the type and alkyl chain length of the cations and anions on the solubility of toluene were discussed. The following conclusions were drawn from the results: (1) ILs with pyrrolidinium-based cations showed better solubility than pyridinium- and imidazolium-based ones. (2) The solubility of toluene in PF6-based ILs increased with the increasing alkyl chain length, while its solubility in Ac-based ILs exhibited the opposite trend. (3) Toluene showed greater solubility in Cl-based ILs than those based on other anions. (4) The solubility of toluene increased with the anion alkyl chain length. Ac-based ILs were chosen as the most promising potential solvents, and further studied to determine the relationship between various interaction energy parameters and toluene solubility. The results showed that the misfit energy played a dominant role during the absorption process. Furthermore, several ILs were selected for experimental verification of the predicted solubility behavior using liquid and gaseous toluene. The results demonstrated that COSMO-RS could be used to semi-quantitatively and qualitatively predict the solubility of toluene, and this model had promising prospects in screening ILs for VOCs absorption. In summary, this study provided a fundamental basis and practical data for the control and treatment of VOCs.

2-Ethylhexyl acrylate (2-EHA) is one of the most widely used acrylates in the polymer industry, which is synthesized via Fisher esterification that is limited by chemical equilibrium. To intensify the esterification process, in this work, reactive extraction concept is proposed, with halogen-free deep eutectic solvent (DES [Im:2PTSA]) as dual solvent-catalyst that consists of imidazole (Im) and p-toluenesulfonamide (PTSA). The bifunctional effects of the DES [Im:2PTSA] are evaluated by thermodynamic analysis and experimental study. Favorable phase splitting is verified by σ-potential analysis predicted by COSMO-RS theory, combined with experiments, and the optimal acid-to-alcohol molar ratio is set to 1.2. The esterification kinetics is then experimentally determined and fitted using the molar-based and activity-based pseudo-homogeneous (PH) models, respectively. The activity-based PH model, that considers the bifunctional roles of the DES, proves to be more accurate with small RMSD of 0.0344. The stability of DES after recycling is validated to further confirm the industrial prospects of DES [Im:2PTSA] in 2-EHA production.

A suitable ionic liquid for methyl chloride drying experiment was screened out from 210 ionic liquids by COSMO-RS model. Moreover, the experimental mechanism of ionic liquids drying is further explained by the COSMO-RS model, and it is further confirmed by analyzing the binding energy. The solubility of methyl chloride in [EMIM][BF4] and TEG and [EMIM][BF4]+H2O was completed, and the experimental results well proved the reliability of the UNIFAC-Lei model. The unknown interaction parameters were obtained through the solubility data of this work and the experimental data in the literatures. The methyl chloride drying experiment was completed in the laboratory, and the water content of the methyl chloride can be reduced to below 200 ppm. The simulation of the methyl chloride drying process using [EMIM][BF4] or TEG as absorbents was carried out by ASPEN software on an industrial scale. The final simulation results show that the [EMIM][BF4] drying process has lower energy consumption and better drying effect.

For the design of eutectic solvents (ESs, usually also known as deep eutectic solvents), the prediction of the solid–liquid equilibria (SLE) between candidate components is of primary relevance. In the present work, the SLE prediction of binary eutectic solvent systems by the COSMO-RS model is systematically evaluated, thereby examining the applicability of this method for ES design. Experimental SLE of such systems are first collected exhaustively from the literature, following which COSMO-RS SLE calculations are accordingly carried out. By comparing the experimental and predicted eutectic points (eutectic temperature and eutectic composition) of the involved systems, the effects of salt component conformer and COSMO-RS parameterization as well as the applicability for different types of components (specifically the second component paired with the first salt one) are identified. The distinct performances of COSMO-RS SLE prediction for systems involving different types of components are further interpreted from the non-ideality and fusion enthalpy point of view.

1,5-Pentanediamine (PDA) produced by biological fermentation becomes popular, but the separation of PDA from the broth is a typical difficult problem. In this work, the performance of 200 ionic liquids (ILs), formed by combining 25 cations and 8 anions, in the extraction of PDA from aqueous solution were evaluated using COSMO-RS model. The extraction mechanism was investigated with the help of σ-profile and interaction energy analyses. Both the cation and anion have impacts on the extraction efficiency, where cation mainly influences the interaction of IL with PDA and anion affects the hydrophobicity of IL. The IL composed of long alkyl-chain in cation and the anion of [PF6]- or [TF2N]-, which has the σ-profile more likely distributed in the nonpolar region but less distributed in the polar region, is favorable for extraction. The experimental liquid–liquid equilibrium demonstrated the effects of cation and anion on extraction performance, which validated the reliability of COSMO-RS model in IL screening for PDA extraction. The IL [IM-1,8][PF6] could serve as a promising extractant for the downstream separation process of the biological production of PDA.

The availability of property data is one of the major bottlenecks in the development of chemical processes and products, often requiring time-consuming and expensive experiments or limiting the chemical space to a small number of known molecules. This bottleneck has been the motivation behind the continuing development of predictive property models. For the property prediction of novel molecules, group contribution methods have been groundbreaking. In recent times, machine learning has joined the more established property prediction models. However, even with recent successes, the integration of physical constraints into machine learning models remains challenging. Physical constraints are vital to many thermodynamic properties, such as the Gibbs-Dunham relation, introducing an additional layer of complexity into the prediction. Here, we introduce SPT-NRTL, a natural language processing model to predict thermodynamically consistent activity coefficients and provide NRTL parameters for easy use in process simulations.SPT-NRTL can be classed as an advanced group contribution model that uses characters of the SMILES code as atom groups and then dynamically constructs higher-order groups. The results show that SPT-NRTL achieves higher accuracy than UNIFAC in the prediction of activity coefficients across all functional groups and is able to predict many vapor–liquid-equilibria with near experimental accuracy, as illustrated for multiple exemplary mixtures. To ease the application of SPT-NRTL, NRTL-parameters of 100 000 000 mixtures are calculated with SPT-NRTL and provided online., Fluid Phase Equilibria, 568, ISSN:0378-3812

Lignocellulose is one of the most promising renewable bioresources for the production of chemicals. For sustainable and competitive biorefineries, effective valorization of all biomass fractions is crucial. However, current efforts in lignocellulose fractionation are limited by the use of either toxic or suboptimal solvents that do not always allow producing clean and homogeneous streams. Here, we present a computational screening approach that covers more than 8000 solvent candidates for the processing of lignocellulosic biomass. The automated screening identified highly effective, non-intuitive solvents based on physico-chemical properties, solubilities of the biomass fractions, and environmental, health and safety properties. Solubility experiments for the lignin and cellulose fraction confirmed the applicability of the proposed framework in biomass processing. In addition to the traditional "lignin-first'' approaches, we identified solvents applicable for the complete dissolution of biomass. Furthermore, we elucidated particular structural patterns in solvents featuring high lignin solubility. The most promising solvents attained lignin solubilities of more than 33 wt%.

The solubility and involved energies of organic acids in green solvents are relevant to the design of sustainable biorefinery downstream processes. In this work, the solubility of two important bio-based organic acids such as succinic acid and fumaric acid, in water and four bio-based solvents (i.e., ethyl acetate, 1,8-cineole, cyclopentyl methyl ether, and 2-methyl tetrahydrofuran) were measured within a temperature range of [283 – 313] K. A gravimetric methodology was adopted, previously validated using the organic acid aqueous solubilities available in the literature. The reported data present an average estimated uncertainty of measurement, with a level of confidence of 95%, of 5.2·10-4 mol·mol−1. Experimental results were correlated with the van’t Hoff equation, and the Buchowski–Ksiazaczak λh model, where the root mean squared deviations were, This work was funded by the CONICYT PFCHA/DOCTORADO BECAS CHILE/2017 – 72180306. P. Gorgojo acknowledges her Ramón y Cajal fellowship RYC2019-027060-I funded by MICIN/AEI/10.13039/501100011033 and by “ESF Investing in your future”. M. González-Miquel also acknowledges Comunidad Autónoma de Madrid (Spain) for funding through “Programa de Excelencia para el Profesorado Universitario”.

Dispersion of asphaltene in crude oil using ionic liquids (ILs) is being considered as a viable solution, in extraction and transportation processes. In this work, the interplay between asphaltene and ILs has been studied systematically to understand the effect of structural variation of ILs on asphaltene solubility. The activity coefficient of the total of 1517 ILs with different combinations of cation and anion of ILs for representative asphaltene molecule (asphaltene) was estimated via COSMO-RS (Conductor-like Screening Model for Real Solvents). COSMO_RS predictions were validated using experimental data on asphaltene solubility. Among the studied ILs, asphaltene showed high solubility in imidazolium-based ILs with hydrophobic anions. The present approach paved a way forward to rationally understand the impact of structural variation of ILs on their interaction with asphaltene molecule and to design new ILs for the dispersion and stabilization of asphaltene.

In this work a new method for inclusion of pressure effects in COSMO-type activity coefficient models is proposed. The extension consists in the direct combination of COSMO-SAC and lattice-fluid ideas by the inclusion of free volume in form of holes. The effort when computing pressure (given temperature, volume, and mole numbers) with the proposed model is similar to the cost for computing activity coefficients with any COSMO-type implementation. For given pressure, computational cost increases since an iterative method is needed. This concept was tested for representative substances and mixtures, ranging from light gases to molecules with up to 10 carbons. The proposed model was able to correlate experimental data of saturation pressure and saturated liquid volume of pure substances with deviations of 1.16% and 1.59%, respectively. In mixture vapor-liquid equilibria predictions, the resulting model was superior to Soave-Redlich-Kwong with Mathias-Copeman α-function and the classic van der Waals mixing rule in almost all cases tested and similar to PSRK method, from low pressures to over 100 bar. Good predictions of liquid-liquid equilibrium were also observed, performing similarly to UNIFAC-LLE, with improved responses at high temperatures and pressures.

Quercetin is known as a bioflavonoid compound that has been successfully optimized to be a chemosensor probe for Fe3+ recognition. The sensitivity of quercetin towards Fe3+ increased in DMSO:deionized water with a 9:1 ratio at pH 4. There was also no significant interference from other metal ions, such as K+, Cr3+, Ag+, Cd2+, Mg2+, Pb2+, Co2+, Ni2+, Zn2+ and Cu2+ in the selectivity optimization. The detection limit of the probe was 20.5 μM. The stoichiometry of 1:1 quercetin:Fe3+ was calculated using the Job plot method. The sigma profile was calculated using COSMO-RS, which showed that quercetin formed stronger hydrogen bonds with the DMSO solvent. Density functional theory (DFT) calculations, such as molecular electrostatic potential (MEP) and the Fukui function, were performed to visualize and clarify the region of interaction between quercetin and Fe3+. The TD-DFT method was successfully used to investigate the electronic properties of quercetin and quercetin–Fe3+ and it showed good agreement between experimental and theoretical results.

International audience; In recent years, the preparation of deep eutectic solvents (DESs) using amines as hydrogen bond donors (HBD) has been reported by several research groups. One of the potential use of this type of DESs is in the field of CO2 capture, where the viscosity of the solvent before and after the absorption is of paramount importance. Since the number of possible combinations of DESs is huge, a mathematical model for the predicting of the viscosity of DESs at different temperatures is very important.In this work, a new mathematical model for the prediction of amine-based DESs viscosities using the quantitative structure property relationships (QSPR) approach is presented. A combination of multilinear regression (MLR) and artificial neural networks (ANN) methods is used for the development of the model. A data set of 108 experimental measurements of viscosity of five amines-based DESs, taken from the literature, is used for the development and subsequent verification of the model. The more appropriate model is determined by a dedicated statistical analysis, in which the most significant descriptors are preliminary determined. The results show that the proposed models are able to predict the DESs viscosities with very high accuracy, i.e. with a R2 value of 0.9975 in training and 0.9863 for validation using the ANN model and R2 value of 0.9305 for the MLR model. The retrieved model can be considered as a very reliable tool for the prediction of DESs viscosity when experimental data are absent. In turn, this can provide useful guidelines for the synthesis of low-viscosity DESs able to minimize energy requirements associated to their processing (e.g. power required for pumps), thus fostering their industrial-scale implementation.

In this study, the bamboo dissolution capability of six amino acid-based ionic liquids (AAILs) with two different cations, i.e. 1-ethyl-3-methylimidazolium (Emim) and Tetrabutylphosphonium (P4444) and three anions derived from amino acids were investigated by Conductor-like screening model for real solvents (COSMO-RS) prediction and hydrogen bond basicity (β) of Kamlet–Taft parameters. COSMO-RS was used for calculating sigma profile, activity coefficients (γi) and aqueous base dissociation constant of corresponding acids of the anions (pKa) of AAILs. The trends in sigma profile, γi and pKa for AAILs were compared with β values and the effect of structure moiety of ionic liquids was also discussed. The trend of COSMO-RS prediction for anions was noted similar to the β values of AAILs with the exception of serinate anion. Similarly, the trend predicted by COSMO-RS and β values was also found same while changing the cations of AAILs. To investigate, the correlation of the above-mentioned properties with experimental dissolution ability, tetrabutylphosphonium aminoethanic acid ([P4444]Gly) and 1-ethyl-3-methylimidazolium aminoethanic acid ([Emim]Gly) ionic liquids were synthesized and evaluated. The trend predicted by COSMO-RS and the β values were not correlating with efficiency of AAILs for bamboo dissolution. Both AAILs were able to dissolve the bamboo. However, material of [P4444]Gly treated sample was evaluated through XRD analysis where change in crystallinity of cellulose was identified after dissolution and regeneration of bamboo. Scanning Electron microscopy also showed homogenous structure for regenerated materials.

The solubility of 9 sparingly soluble pesticide active ingredients (PAIs) was predicted in 133 deep eutectic solvents (DESs) based on 7 hydrogen bond acceptors and 19 hydrogen bond donors, using a COSMO-RS model. 13 DESs with superior solubility of water-insoluble PAIs were screened out and verified with experiments. The actual measurement results agree well with the forecasting results. When compared with the solubility in pure water, some PAIs can even be mutually dissolvable with tetraethylammonium chloride: decanoic acid (1:2), tetrabutylammonium chloride: decanoic acid (1:3), and tetrabutylammonium chloride: phenol (1:5), such as butachlor, acetochlor, and metolachlor. IR and 1H NMR spectra suggested that hydrogen bonding between DESs and PAIs molecules played a crucial role in solvation. Crucially, the study indicated that it’s feasible to replace toxic organic solvents with DESs in emulsifiable concentrates formulations. The effects of different concentrations of tetraethylammonium chloride: decanoic acid (1:2) on the growth of wheat seedlings were also explored. The results showed that it did not affect the germination rate of wheat seeds, but with the increase of concentration, the growth indexes such as the lengths of shoots and roots grew shorter, the fresh weight of aboveground and underground decreased. This study not only provides COSMO-RS as a useful and reliable tool to screen DESs but also highlights that DESs can be an alternative to replace toxic and harmful organic solvents in emulsifiable concentrates (EC) formulations, which provide ideas and a basis for designing new green pesticide formulations.

Keratin, which extracted from human hair, has great potential in biomedical applications because of its excellent biocompatibility. Efficient dissolution of human hair in the solvent is the key step for its extraction. In this work, 143 kinds of ILs and three model compounds were used to predict the dissolving ability of ILs for human hair dissolution by using COSMO-RS. Moreover, five-imidazole based ILs were screened out from 143 kinds of ILs to verify the predicted dissolving ability for human hair. The results shown that ILs with cation [Emim]+ and anions OAc-, DEP- have the strong dissolving ability of human hair. Furthermore, the effect of dissolving temperature, mass ratio, water content and the recycle performance of ILs have also been investigated systematically. It can be concluded that the 9 wt % human hair can be complete dissolved in [Emim]DEP at 130 ℃ for 90 min, and the dissolution capability of [Emim]DEP after 5 recycles is same as the fresh [Emim]DEP. The structure of regenerated keratin was characterized by FT-IR, XRD and TGA, and the results indicated that the structure of regenerated keratin is similar with the human hair.

As the second most abundant terrestrial polymer, lignin has emerged as a major sustainable source for the production of fuels, chemicals, and materials. However, efficient screening of solvents for lignin dissolving faces great challenges. In this work, COSMO-RS was used to screen 3886 ionic liquids (ILs) composed of 58 cations and 67 anions, to find out the most effective ones for lignin dissolving by considering the critical items of logarithmic infinite dilution activity coefficient (lnγ∞) and σ-profiles. The substantial improvement of lignin dissolution was achieved in [PMpyrr][OAc] IL by both simulations and experiments validations. Moreover, it was found that the anions dominate the dissolution process and the strongly polar anions exhibit better dissolution ability. Furthermore, the underlying mechanism originated from the hydrogen bond (H-bond) between ILs and lignin was also revealed and systemically analyzed from donor and acceptor ability, indicating that high lignin solubility is reached in the ILs with stronger ability to form H-bond acceptors. This work leads to possible ways toward developing more selective and efficient lignin dissolution methods based on solvent properties.

In this work, the factors that determine a high or low extraction performance when using ionic liquids (ILs) as diluents in the solvent extraction of Rhenium (Re(VII)) from aqueous solutions were studied by means of experiments, quantum chemical (QC) calculations, and COSMO-RS. For this purpose, kerosene and the ionic liquids (ILs) 1-butyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide [C4C1im][Tf2N], or 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [C8C1im][Tf2N] were used as diluents to determine de effect of alkyl chain of ILs, and two high molecular weight amines: trioctylamine (TOA) and Alamine 336 (Al336) were used as the extractants. The results indicated that the so-called reference extracting phase TOA in kerosene achieved 99% extraction percentages. On the contrary, a lower performance was observed when replacing kerosene with any of both ILs. This reduction was mainly due to two reasons. First, the IL dissociates where the cation takes part in the formed complex, hindering the TOA-perrhenate bonding, and second, the formed complex that contains IL cations shows poor dissolution in the diluent phase. This could be avoided by means of long alkyl chain imidazolium bis(trifluoromethylsulfonyl)imide-based ILs. Additionally, operating parameters such as equilibrium stages and concentration of the stripping agent were studied. Promising results were obtained by replacing TOA with Al336 dissolved in the IL [C8C1im][Tf2N], showing very similar results with the reference extracting phase.

The current investigation is aimed to find the effective Task-Specific Ionic Liquid (TSIL) for the extraction of the calcium ion through the quick screening method based on the Conductor-like Screening Model for Real Solvents (COSMO-RS). From the several prescreened cations and anions with different functional groups, a set of appropriate combinations were preliminarily selected to be examined for their efficiency of the calcium ion extraction. With the aid of the COSMO-RS model, the values of the octanol-water partition coefficient (Kow), melting point, and viscosity of the selected TSILs, as well as the infinite dilution chemical potential of the CaCl2 and Ca(NO3)2 salts in the studied TSILs were computed. Analysis of the obtained results led to the conclusion that phosphate anions in combination with tetrabutylammonium [N4444]+ and tetrabutylphosphonium [P4444]+ cations would form more effective TSILs for the Ca2+ extraction. Among these, TSILs tetrabutylammonium bis(2-ethylhexyl) phosphate [N4444][DEHP] and tetrabutylphosphonium bis(2-ethylhexyl) phosphate [P4444][DEHP] were synthesized to verify the computational results, and the extraction of calcium ion was measured as a function of various diluent and concentration of TSILs. The synthesized TSILs represented high calcium extraction efficiency, which was in agreement with the computational result. The mechanism of calcium extraction was studied using the slope analysis method. The stripping of calcium ion from the organic phase and recyclability of TSILs were also investigated.

The forecast of an increase in the consumption of petroleum products, together with the growing scarcity of new deposits, makes it necessary to take full advantage of existing ones. The main problem faced by the petrochemical industry is high acid crude oils, which produce corrosion in equipment and high monetary losses. Crude oil acidity is usually calculated by making use of the total acid number (TAN). Current operations for the elimination of naphthenic acid (NA) have several drawbacks so at present this has led to new lines of research, among which the application of ionic liquids (ILs) in the extraction of this compound stands out. In this work, the extractive behavior of 6 different ILs has been analyzed with simulations of molecular dynamics (MD), a technique based on classical mechanics that allows visualizing the movement of molecules while they interact. This allows us to study the extraction mechanism of NA by ILs, as well as transport properties such as diffusion coefficients. In addition, it will be experimented in the laboratory with the same cases to contrast the results obtained, making use of a synthetic crude oil (SC, 150 g/mol, TAN equal to 3.8), which was treated with every IL at four different temperatures (30, 70, 90 and 120 °C). The IL/NA ratio implemented was 1:1 mol/mol, which corresponded more or less with the IL/crude ratio of 0.015 g/g. To support (MD) results and experimental results, the COSMO-RS model was used to characterize ILs analyzing the results obtained by the σ-profile. COSMO-Therm was put into practice to study the theoretical predictions of the TAN in the liquid/liquid phase equilibria where results were in agreement with the experimental ones except for acetate, whose extraction mechanism is supposed to be different (neutralization). Computer simulation suggests that a longer alkyl chain of [BMIm] respect [EMIm] behaves better in extraction, and it seems that the anion plays a major role in the extraction process of the NA than the cation of the ILs. This tendency has been correlated with the experimental results.

With more stringent standards regarding the emission of greenhouse gases, capturing or removal of these detrimental pollutants has become of significant importance in industrial plants. In this presented investigation, e∗-modified Sanchez–Lacombe equation of state and COSMO-RS-Lei and COSMO-RS-ADF models have been employed in order to estimate the solubility of sulfur dioxide (SO2) in different ionic liquids (ILs) as chemical sorbents with different cations and anions. The experimental data of Imidazolium, Pyridinium, Guanidinium and Ammonium based ionic liquids such as experimental data of density and the amount of SO2 solubility into ionic liquids in a wide range of temperature and pressure have been obtained from the literature. The characteristic parameters of the e∗-modified Sanchez–Lacombe EOS have been adjusted by applying a database including 580 experimental data points of ILs density for 4 SO2/IL systems. In order to confirm the accuracy of the mentioned models, the phase equilibrium (PTx) diagrams of the SO2/ILs systems have been drawn and predicted data are compared with experimental data. According to the figures and also reported tables which contain the amount of calculated errors, It can be claimed that presented models in this study are capable to predict the amount of SO2 solubility into ionic liquids within the value of AARD% around 5%, 63% and 62% for e∗-modified Sanchez–Lacombe EOS, COSMO-RS-Lei and COSMO-RS-ADF respectively.

In this work the synthesis of five new Bronsted acidic ionic liquids (BAILs) bearing same anion (camphorsulfonate) but different cations; 3-(3-sulfopropyl)-imidazolium, 1-methyl-3-(3-sulfopropyl)-imidazolium, 1-methyl-3-(4-sulfobutyl)-imidazolium, 1-ethyl-3-(3-sulfopropyl)-imidazolium, 1-butyl-3-(3-sulfopropyl)-imidazolium) were synthesized and characterized. The characterization of BAILs was carried out using NMR, FTIR and elemental analysis (CHNS). The thermophysical properties of these ILs such as density, refractive index, viscosity and thermal stability were analyzed in wide temperature window. Furthermore, the effect of alkyl chain length of cations on thermophysical properties was well studied. The experimental values of density were further used to calculate other significant properties such as molar volume, standard molar entropy, lattice energy and thermal expansion coefficients. The Bronsted acidities of investigated ILs were determined using Hammett method. Furthermore, COSMO-RS study was performed to determine δ-surface, and δ-profile of the studied ILs.

Conductor-like screening model for real solvents (COSMO-RS) is presented as thermodynamic predictive tool for calculating liquid-liquid equilibrium (LLE) phase diagrams in ternary mixtures {ionic liquid (IL) + 2-phenylethanol (PEA) + water} — a model system of extractive recovery of PEA bioproduced using yeast. Overview of the performance of the model is demonstrated by using the experimental LLE data available in the literature. An effect of quantum chemical theory level (BP-TZVP-COSMO vs. BP-TZVPD-FINE) on accuracy of thermodynamic data prediction is discussed. Capacity of the COSMO-RS approach in capturing effect of chemical structure of IL on LLE as well as LLE-derived properties (distribution ratio of PEA and PEA/water selectivity) is presented. Infinite dilution PEA/water selectivity is adopted to carry out the COSMO-RS-based screening of approximately 9000 ILs to find possibly the most effective extracting agent. On the basis on presented methodology, some general guidelines on a proper selection of IL for extraction of PEA form aqueous solutions are proposed and discussed.

As a contribution to the 9th Industrial Fluid Property Simulation Challenge on predicting interfacial tension between water and a set of non-polar oils at temperatures up to 170 °C we have used our first-principles based model, which is based on density functional theory and uses COSMO-RS implicit solvent model thermodynamics. Our calculations predict that the oil-water interfacial tension starts to drop significantly for alkanes at temperatures above ∼100 °C, and the oil-water interfacial tension drops significantly with increased temperature already above ∼25 °C for aromatic oils. In the range 110–170 °C, the interfacial tension drops almost linearly with temperature at a rate of about −0.082 mN/m/K for dodecane and −0.147 mN/m/K for toluene. Our method predicts that for any mix of dodecane and toluene, a linear interpolation of the interfacial tension with respect to the composition is a good approximation. The agreement of our predictions with the experimental data was overall satisfying, apart from a significant difference in the temperature dependence of the dodecane-water interfacial tension. We provide results derived from other experimental measurements suggesting that the large decrease measured by the challenge organizers may be erroneous.

In this study, the densities of formaldehyde (FA) + water (H2O) binary systems with formaldehyde fractions ( x F A ) of 0.05–0.27 at temperatures (T) of 293.15, 298.15, and 313.15 K were measured at 0.1 MPa, as well as those of a formaldehyde + water + methanol (MeOH) ternary system with x F A of 0.05–0.27 and x M e O H of 0.09–0.64. A thermodynamic model was combined with the conductor-like screening model for real solvents (COSMO-RS) coupled with a chemical reaction equilibrium and mass balance to describe the species distribution in the above solutions containing poly (oxymethylene) glycols ((HO(CH2O)nH, MGn n ≥ 1) and poly (oxymethylene) hemiformals (CH3O(CH2O)nH, HFn, n ≥ 1) produced by the reactions of FA with H2O and MeOH, respectively. The densities and volumes of these unknown oligomers, MGn and HFn, were computed by the COSMO-RS method and were correlated with the polymerization degree, n, and temperature, T. Furthermore, the densities of the FA + H2O and FA + H2O + MeOH solutions were calculated based on the species distribution and COSMO-RS simulations, which reproduced the experimental data well. Finally, the excess molar volumes of the FA + H2O and FA + H2O + MeOH systems were studied for the first time.

The separation of benzene and cyclohexane from their mixture is difficult to perform via conventional distillation because of their close boiling points. In this work, liquid-liquid extraction using ionic liquids (ILs) is suggested for this purpose and 16 cations and 13 anions were selected to form 208 possible ILs screened with the Conductor-like Screening Model for Real Solvents (COSMO-RS) module. The screening result was experimentally validated by liquid–liquid extraction using four of the top ranked ILs, namely 1-ethyl-3-methylimidazolium acetate ([C2mim][Ac]), 1-ethyl-3-methylimidazolium dicyanamide ([C2mim][N(CN)2]), 1-ethyl-3-methylimidazolium thiocyanate ([C2mim][SCN]) and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C2mim][Tf2N]). The ternary liquid–liquid equilibria for these ILs with benzene and cyclohexane were investigated at 25 °C and 1 atm with feed concentration of benzene ranging from 10 to 60 wt%. Good agreement was achieved between the tie-lines obtained from the COSMO-RS model and those obtained experimentally. The performance of ILs used in this study was compared with organic solvents, other ILs, and deep eutectic solvents reported in literature. The results of selectivity and distribution ratio confirmed that COSMO-RS was a reliable method for solvent screening and demonstrated the suitability of the selected ILs as extracting solvents. In all ternary systems, no IL was detected in the cyclohexane layer and the concentration of cyclohexane in the IL layer was very low. This observation indicated that there was minimum cross-contamination between the phases and therefore less energy will be required for the solvent recovery.

Experimental isobaric molar heat capacities at atmospheric pressure have been determined for the mixture {p-cymene + propan-1-ol} every 10 K in the temperature interval (298.8–328.5) K and over the entire composition range with a Calvet type calorimeter. Densities, necessary for calculating heat capacities, have been also measured in similar conditions. Excess molar volumes have been calculated from densities. They are positive at (318.15 and 328.15) K and sigmoidal at (298.15 and 308.15) K with negative values in the zone very rich in propan-1-ol. Excess molar heat capacities have been calculated from the molar heat capacities and show positive values. Both excess molar properties increase as the temperature rises at a given molar fraction. Excess properties are discussed in terms of intermolecular interactions. The solvation model COSMO-RS has been applied to predict the excess molar heat capacities, being the quantitative predictions rather poor.

Protic ionic liquids (ILs) with seven-membered azepanium cation were synthesized and characterized. The molecular structure of the synthesized ILs was confirmed using 1H NMR and 13C NMR spectroscopy. In one hand, sulfonic acid ( SO3H) group was tethered to the azepanium moiety combined with HSPO4 or H2PO4−anion and on the other hand azepanium based alkyl sulfate ILs were synthesized by reacting azepane with corresponding dialkyl sulfates. Thermo-physical properties (density, viscosity, glass transition temperature, thermal decomposition temperature) of the synthesized ILs were measured. All the studied ILs showed good thermal stability. From the viscosity and density data of alkyl sulfate ILs, the volumetric properties such as molar volume, lattice energy and standard molar entropy were calculated. COSMO-RS was used to predict hydrogen bonding energy, interaction energy, Van der Waals energy and H-bond accepting and H-bond donating nature of these pure ILs. Activity coefficient values have also predicted for these ILs with cellulose.

In the presented study, COSMO-RS sigma moments were utilized in a nonlinear multivariate QSPR model for the estimation of the temperature dependent surface tension of various ionic liquids in wide surface tension (15.5–65.1 mN m−1) and temperature (268–533 K) range. The developed model is supposed to be a generally applicable, robust and accurate method for the prediction of ionic liquid's surface tension. 880 data points ensure its reliability, which values were used to establish, validate and test the method. An artificial neural network was developed, optimized and used as regression model. The prediction power of the proposed model was validated with an external data set, with a squared correlation coefficient R2 = 0.97 and a mean absolute error MAE = 1 mN m−1. The estimation ability of the model was compared against widely known methods. Furthermore, the factor sensitivity analyses of the utilized molecular descriptors allowed shedding light on the intermolecular basis of ionic liquid's surface tension. Results showed that the kind of skewness of the sigma profile, the electrostatic interaction energy and the hydrogen bonding acceptor function play the most important roles in the formation of ionic liquid's surface tension.

Guggenheim proposed a theoretical expression for the combinatorial entropy of mixing of unequal sized and linear and branched molecules to improve the Flory-Huggins model. Later the combinatorial activity coefficient equation, which was derived from Guggenheim's model, was applied in the UNIQUAC, UNIFAC, and COSMOSAC models. Here we derive from Guggenheim's entropy theory a new function for the number of nearest neighbors of a compound in a multicomponent mixture for which the knowledge of the coordination number and a reference area are not needed. This new relation requires only the mole, volume and surface fraction of the compounds in the mixture. The benefit of the new relation is that both the combinatorial and the residual term in the aforementioned models can be made lattice-independent. We demonstrate that the proposed relation simplifies the Staverman-Guggenheim combinatorial model and can be applied with success to the UNIQUAC and COSMOSPACE model in the description of vapor-liquid phase equilibria and excess enthalpy. We also show that the new expression for the number of nearest neighbors should replace the relative surface area and the number of surface patches in the residual part of the UNIQUAC and the COSMOSPACE model, respectively. As a result a more rigorous version of the UNIQUAC and the COSMOSPACE model is obtained. This could serve as a better basis for predictive models like UNIFAC, COSMO-RS and COSMOSAC.

Ionic liquid (ILs) have been attracting significant attention as an alternative solvent for DNA extraction/purification and stabilization/storage. In this work, we investigated the interaction between DNA nucleotides and bio-base ILs to get insight into the effect of structural variations of the ILs on the ILs-DNA complex formations. COSMO-RS based quantum calculations and molecular simulation were used to investigate the interaction between the bio-base ILs and DNA nucleotides. Deoxyadenosine 5′ monophosphate (A), Deoxythymidyine 5′ monophosphate (T), Deoxycytidine 5′ monophosphate (C), Deoxyguanosine 5′ monophosphate (G) and their dimers were used to model DNA. 260 ILs (13 cations and 20 amino acid based anions) were evaluated. Activity coefficients at infinite dilution of the DNA nucleotides and excess enthalpy of mixing of the systems were predicted using COSMO-RS model. Solvation free energies of the DNA nucleotides were estimated employing molecular dynamics simulations. The activity coefficients of DNA nucleotides decrease with increasing nucleotides chain length. This implies solubility of the nucleotides is higher for longer DNA nucleotide chain. Piperidinium and pyrrolidinium based ILs show lower activity coefficient than choline and morpholinium based ILs. ILs with anions containing nonpolar side chain amino acids show lower activity coefficient compared to those with polar side chains. This implies strong interaction between the nucleotides and ILs with anions containing nonpolar side chain amino acids compared to anions with polar side chains. Moreover, ILs based on anions with nonpolar side chain show higher negative excess enthalpy of mixing compared to those with polar side chain. Further, solvation free energies of DNA nucleotides in the ILs are negative. Solvation free energy is more negative for dimers compared to monomer nucleotides. ILs based on anions with nonpolar side chain show more negative solvation free energies compared to those with polar side chains.

Production of bio-butanol from biomass by fermentation in an aqueous phase needs new solutions and entrainers for the separation of product. Ionic liquids (ILs) are attractive significant attention as novel, low pressure solvents alternative to conventional organic solvents for biphasic solvent extraction. Ternary liquid-liquid equilibrium data are presented for mixtures of {ionic liquid (1) + butan-1-ol (2) + water (3)} at T = 298.15 K and ambient pressure to analyze the performance of the IL in the extraction of butan-1-ol from aqueous phase. The bis{(trifluoromethyl)sulfonyl}amide-based ILs have been studied: octyltriethylammonium bis{(trifluoromethyl)sulfonyl}amide, [N8,2,2,2][NTf2], methyltrioctylammonium bis{(trifluoromethyl)sulfonyl}amide, [N8,8,8,1][NTf2], 1-dodecyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide, [DoMIM][NTf2] and 1-hexyloxymethyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}amide, [C6H13OCH2MIM][NTf2]. The results are discussed in terms of the selectivity and the solute distribution ratio of separation for the related systems. The IL with three octyl alkyl chains, [N8,8,8,1][NTf2] at the ammonium-based cation shows higher selectivity and the same distribution ratio in comparison to the other ILs in this process. Additionally, the viscosity of [N8,2,2,2][NTf2], and density and viscosity of the best IL, [N8,8,8,1][NTf2] were measured for the collection of physico-chemical properties of the ILs used in this work. The non-random two liquid NRTL model was used successfully to correlate the experimental tie-lines. The prediction of ternary compositions was shown with good precision using COSMO RS for the ILs used in this work and for data from literature. The data and calculations presented here indicate the possible use of the model COSMO RS for the prediction of ternary LLE and of the use of [N8,8,8,1][NTf2], as a good solvent for the separation of butan-1-ol from water using solvent extraction.

A new COSMO-RS based electrolyte model (COSMO-RS-ES) was applied to the prediction of the solubility of CO2 in aqueous MDEA solutions. For this purpose, the model was combined with the Soave-Redlich-Kwong equation of state to describe the gas phase non-ideality. First, it was shown that the model can successfully describe the phase equilibria in the CO2 + water, as well as in alkanolamine + water systems. Using a region specific interaction parameter for the amine, the accuracy of the model for the prediction of the phase equilibrium in alkanolamine + water systems was further improved. Additionally, a detailed investigation of different amine + water systems based on the calculation of the partial molar enthalpies and entropies provided valuable insights on the properties of the systems. The description of the ternary CO2 + MDEA + H2O system was successful after a readjustment of selected interaction energy equations of the model using few parameters. The model was then applied to the prediction of the species distribution as well as the prediction of the partial pressure of CO2 at low gas loading.

Petroleum industry encounters a challenge to search prospective solvents for asphaltene species which is the main cause of arterial blockage in oil pipelines that results in flow assurance problem. Recently, ionic liquids (ILs) have received significant attention as green oilfield solvents due to their tunable physicochemical properties. In this study, COSMO-RS (Conductor like Screening Model for Real Solvents) was used to screen ILs to be used as the potential extractant for asphaltene. For benchmarking and validation purpose, the estimated activity coefficient at infinite dilution (ACid) of 3 ILs with various organic solvents (125 data points) at different temperatures were used and the Root Mean Square Deviation (RMSD) value was found to be 0.14 which indicated the good reliability and the prediction capability of COSMO-RS. Henceforth, 240 ILs of different combinations, containing 6 types of cations namely: 1-butyl-3-methyl imidazolium [BMIM], 3-methyl-1-propyl pyridinium [MPPy], n-butyl-iso-quinolinium [C4isoQ], 1-butyl-1-methyl-pyrrolidinium [BMPYRO], 1-butyl-1-methyl piperidinium [BMPIP] and Tetra methyl ammonium [TMAm] combined with 40 anions were investigated. ACid data of all cation and anion combinations were used for selectivity, capacity and performance index calculations to evaluate the effectiveness of ILs. Results showed that among the investigated combinations, ILs containing hetero-atomic aromatic cations combined with sterically hindered anion e.g. [C6F18P] is favorable for asphaltene removal at ambient temperature and atmospheric pressure.

Screening deep eutectic solvent (DES) is significant for separation process, due to its large number of potential combinations. In this work, 49 DESs were screened for the extractive desulfurization based on the COSMO-RS model. The distribution coefficient, selectivity, and performance index were derived from the mass-based liquid–liquid equilibrium of DES involved systems. DES TBPB:DMF(1:3) showed the highest performance index and was screened as the extractive solvent. Its performance was interpreted from the analysis of its σ-profile and σ-potential, and its desulfurization ratio can reach up to 82.1%, determined by experiment, when the initial sulfur content in the model fuel was 500 ppm. After 3 stages of extraction, the sulfur content was remarkably reduced to

A COSMO-based/Aspen HYSYS methodology has been used to perform an extensive thermodynamic evaluation of potential application of ionic liquids (ILs) to absorption refrigeration cycles. By applying this a priori methodology, 7200 systems, formed by 900 ILs and 8 refrigerants, representative of available commercial/cation and refrigerant, were evaluated, which would be otherwise unviable due to the lack of experimental data. Firstly, COSMO-RS analysis was carried out for the preliminary selection of suitable ILs as absorbents for each refrigerant, by means of predicted values of Henry’s Law constants of refrigerants in ILs. Selected ILs were then introduced in Aspen HYSYS simulator database by using the molecular information by COSMO-RS method. The reliability of COSMO-based/Aspen HYSYS calculations was successfully validated by comparison to available experimental data (>2700 points) of pure and mixture properties of absorbent-refrigerant systems. Then, the performance of selected ILs (and other proposed in the bibliography) in absorption refrigeration cycles was evaluated by process simulations (>230 refrigerant/IL pairs studied at 60 different operating conditions) using COSMO-based/Aspen HYSYS methodology. Cycle efficiency was analyzed in terms of the coefficient of performance (COP), solution circulation ratio (f ratio) and the total mass flow pumped from the absorber to the generator, a new parameter proposed to compare the results obtained with different refrigerants. COSMO-based/Aspen HYSYS methodology allowed the selection of adequate refrigerant-absorbent pairs (refrigerant with high cooling capacities and IL with absorption capacity) competitive to conventional systems as H2O/LiBr or NH3/H2O. Furthermore, the analysis of operating condition effects by COSMO-based/Aspen HYSYS methodology allows selecting refrigerant/IL pairs with maximum efficiency in the cycle for a fixed cooling temperature, revealing additional advantage of the applications of IL in absorption refrigeration technologies., The authors are grateful to Comunidad Autónoma de Madrid for the Project S2013/MAE-2800 and to Ministerio de Economía y Competitividad (MINECO) of Spain for financial support of Project CTQ2017-89441-R. Marcos Larriba also thanks MINECO for awarding him a Juan de la Cierva-Formación Contract (Reference FJCI-2015-25343).

Ionic liquids (ILs) have been proposed as promising extractants to broaden the potential utility of liquid–liquid extraction process for lithium, but developing an attractive IL from numerous available ILs remains challenging. In this work, a rapid preliminary predicting and screening method based on COSMO-RS was proposed. The design strategy was to collocate anions that had intensive affinity to lithium ion with high hydrophobic cations. Based on it, a series of candidate ILs were prepared and characterized by 1H and 13C NMR spectroscopy, including [P4444]-based and [N4444]-based ILs with phosphate, phosphinate and long-chain carboxylate anions. The further extraction experiments indicated that the tetrabutylammonium mono-2-ethylhexyl(2-ethylhexyl)phosphate ([N4444][EHPMEH]) had the highest Li+ extraction efficiency. The extraction mechanism was investigated by slope analysis method and ATR-IR spectroscopy. It was determined that every Li+ associated with 1.33 molecule [N4444][EHPMEH] to form the extracted species. The stripping study showed that the Li+ was able to be stripped by only 0.5 mol/L HCl without additional agents. The extraction experiments of Li+ from multi-metal-ion solution were also carried out, and the distribution ratio of Li+ was nearly twice those of Na+, K+, and Rb+, indicating that [N4444][EHPMEH] was available to separate lithium ion from the other alkali metal ions.

To progress the understanding of molecular interaction for the binaries of an IL, [Emim][triflate] with 2-methoxyethanol (ME) or N-methylpyrrolidone (NMP), thermo acoustic and volumetric properties such as speeds of sound (u) and densities (ρ) were measured as a function of temperature between (298.15–318.15) K over the entire composition range at ambient pressure. The combined volumetric and quantum-chemical (COSMO-RS) calculations have been utilized. These excess properties were fitted to Redlich-Kister type equation for acquiring the binary coefficients and standard deviations. Simultaneously, the COSMO-RS studies exhibited qualitative analysis of ion-pair formation, interactions of ion–dipole and hydrogen bonding between IL with the studied molecular solvents. The experimentally obtained excess molar volumes are further analyzed with the help of Prigogine–Flory–Patterson (PFP) theory.

The ionic liquids (ILs) have been widely studied as potential replacements of conventional solvents in the extraction of aromatic hydrocarbons from alkanes. However, most of the literature is focused in obtaining liquid-liquid equilibria experimental data without studying the complete extraction and IL regeneration process. In this paper, a computer-aided methodology combining COSMO-based molecular simulations and Aspen Plus process simulations has been used to study the extraction process of aromatic hydrocarbons from pyrolysis gasoline employing a binary mixture of 1-ethyl-4-methylpyridinium bis(trifluoromethylsulfonyl)imide ([4empy][NTf2]) and the 1-ethyl-3-methylimidazolium dicyanamide ([emim][DCA]) ILs as solvent. An extensive comparison (more than 600 points) between experimental data and the predictions obtained by the COSMO-based thermodynamic model of liquid–liquid and vapor–liquid equilibria and ILs physical properties was made for validation purposes. Process simulations were performed in three system configurations: with one, two, or three flash distillations in the IL recovery section. The potential advantage of using binary IL-IL mixture as extracting solvent was studied in the whole range of composition. The configuration with three flash distillations and the binary IL-IL mixture with a 75% of [4empy][NTf2] were selected as the optimal conditions to increase aromatic recovery and purity, improving the separation performance respect to the neat ILs, The authors are grateful to Ministerio de Economía y Competitividad (MINECO) of Spain for financial support of Projects CTQ2014-52288-R and CTQ2014–53655-R and to Comunidad Autónoma de Madrid for the Project S2013/MAE-2800. Noemí Delgado-Mellado also thanks MINECO for awarding them an FPI grant (Reference BES–2015–072855) and Marcos Larriba also thanks MINECO for awarding him a Juan de la Cierva-Formación Contract (Reference FJCI-2015-25343). Pablo Navarro thanks Fundação para a Ciência e a Tecnologia for awarding him a postdoctoral grant (Reference SFRH/BPD/117084/2016).

Aqueous solubility and reactivity of four azo dyes were investigated by DMol3/COSMO-RS calculation to examine the effects of global orbital cut-off and COSMO segment variation on the accuracies of theoretical solubility and reactivity. The studied dyes are (E)-2,2′-((4-((2-chloro-4-nitrophenyl)diazenyl)-3-methylphenyl)azanediyl)diethanol [D1], (E)-2,2′-((4-((2,4-dinitrophenyl)diazenyl)-3-methylphenyl)azanediyl)diethanol [D2], (E)-2,2′-((4-((2,6-dichloro-4-nitrophenyl)diazenyl)-3-methylphenyl)azanediyl)diethanol [D3] and (E)-2,2′-((4-((2-chloro-4,6-dinitrophenyl)diazenyl)-3-methylphenyl)azanediyl)diethanol [D4]. The VWN-BP level of theory in conjunction with the double numerical basis set containing polarization function (DNP) was employed for the calculations. The aqueous solubility was calculated from the COSMO-RS data using the Cramer et al. solubility equation (CSE) and the general solubility equation (GSE) by Yalkowsky. The results showed that GSE calculated solubility (SGSE) increases with orbital cut-off and reached optimum value at 5.5 A orbital cut-off. SGSE values obtained at 5.5 A orbital cut-off for D1 and D3 are comparable to experimental values, while the best results were obtained for D2 and D4 at 4.5 A cut-off. The CSE calculated solubility (SCSE) showed no definite trend with cut-off variation but the best CSE cut-off for the dyes seemed to exhibit an inverse linear relationship with the molecular weights of the dyes. The reactivity of the dyes was enhanced in water and the minimum cut-off value for the reactivity study was 4.5 A. Both the calculated solubility and reactivity indices generally showed low sensitivity to change in COSMO segment. We conclude that the DMol3/COSMO-RS model is appropriate for predicting the aqueous solubility and reactivity of azo dyes and that the CSE and the GSE are reliable for solubility determination using COSMO-RS data, but their dependence on orbital cut-off differ.

The use of ionic liquids (ILs) as solvent in the liquid-liquid extraction of aromatic compounds is one of their most studied applications. Nevertheless, the recovery of the extracted hydrocarbons has been much less investigated, being a required task to complete the global separation process. Taking into account the negligible vapor pressure of the ILs, this step could be easily carried out by flash distillation, which requires the study of vapor-liquid equilibrium (VLE). In order to study this topic deeper, in this work a systematic analysis of the VLE and vapor-liquid-liquid equilibrium (VLLE) data for {aromatic hydrocarbon + IL} binary mixtures was carried out, from both an experimental and computational point of view. For that, new experimental VLE and VLLE data of 24 {toluene + IL} binary mixtures were measured at 323.15 K using a technique based on the static headspace gas chromatography (HS-GC), providing relevant information on the toluene retained in the liquid depending on the cation/anion structure of the IL in the mixture. Furthermore, the quantum chemical Conductor-like Screening Model for Real Solvents (COSMO-RS) method was applied to better understand the structure-property relationship determining the phase behavior of {aromatic hydrocarbon + IL} binary systems. First, the suitability of COSMO-RS to predict VLE and VLLE data of {toluene + IL} binary mixtures was evaluated by comparison to 225 experimental data at 323.15 K, including 24 different ILs over the whole composition range. Valuable conclusions were achieved respect to the molecular model of IL needed to adequately predict VLE and VLLE data of the {aromatic hydrocarbon + IL} binary mixtures. Once the computational approach was stated, COSMO-RS methodology was used to analyze the influence of the intermolecular interactions between the toluene and the IL component on the phase behavior of their mixtures. As a result, COSMO-RS was demonstrated as a useful tool for the rational design of ILs with optimized properties for the separation of aromatic + aliphatic hydrocarbon binary mixtures, considering both liquid-liquid extraction and solvent regeneration steps, The authors are grateful to Ministerio de Economía y Competitividad (MINECO) of Spain for financial support of Projects CTQ2014-52288-R and CTQ2014–53655-R and to Comunidad Autónoma de Madrid for the Project S2013/MAE-2800. Pablo Navarro thanks Fundação para a Ciência e a Tecnologia for awarding him a postdoctoral grant (Reference SFRH/BPD/117084/2016). Marcos Larriba also thanks MINECO for awarding him a Juan de la Cierva-Formación Contract (Reference FJCI-2015-25343).

A green, simple, and effective vortex-assisted dispersive liquid–liquid microextraction method that utilizes a menthol-based low transition temperature mixture (menthol-LTTM-VADLLME) was developed to extract and preconcentrate four types of pyrethroids, namely bifenthrin, deltamethrin, fenpropathrin, and permethrin from water samples. In addition, quantum chemical-based conductor-like screening model for realistic solvents (COSMO-RS) software was used to predict the molecular interaction between low transition temperature mixtures (LTTMs) and pyrethroids based on their σ-profile, σ-potentials, and activity coefficient at infinite dilution. High performance liquid chromatography (HPLC) was employed for the further separation of the pyrethroids and their quantification. Several key parameters that affect pyrethroid extraction efficiency are identified as the vortex time, type of LTTM, volume of LTTM, type of dispersive solvent, dispersive solvent volume, type of salt, and amount of salt. The extraction time of 90 s and 150 µL of menthol: sesamol at ratio 1:1 were selected as the best conditions, while ionic strength and type of dispersant solvent were not relevant for the extraction of the target compounds. After optimization, the menthol-LTTM-VADLLME method was found to be able to detect pyrethroids in the range of 0.5–1000.0 μg/L with good linearity (correlation coefficient = 0.9988–0.9995). The method detection limit and quantification limit were found to be in the range of 0.05–0.11 μg/L and 0.18–0.35 μg/L, respectively. The relative standard deviation of inter-day and intra-day precisions were 2.2–5.0% (n = 5) and 1.2–1.9% (n = 7) respectively. The optimized method can successively determine pyrethroids in tap, drinking and river water samples with good recoveries of 73–111%. Hence, this method presents a good approach for determining pyrethroid content in water samples.

In this work, the solubility of curcumin, gallic acid, and caffeine was measured in aqueous solutions of deep eutectic solvents (DES) and its constituents individually (HBA: cholinium chloride, and HBD: ethylene glycol and 1,2-propanediol) at 298.2 K. The solubility behavior was evaluated by experimental and in silico (by COSMO-RS model) approaches. Additionally, the solubilization kinetics of the curcumin was also evaluated. The finds of this work showed that the use of proper additives can favor the solubility of hydrophobic biomolecules, such as curcumin, in aqueous media. When the gallic acid solubility curves were determined, the hydrotropic effect was observed. This fact allows manipulating the solubilization or precipitation of this biomolecule according to the target application. For the caffeine, in its turn, all additives reduced the solubility of caffeine in relation to pure water. To support the understanding of the experimental data, the biomolecules and additives polarity were calculated by COSMO-RS, through their σ-profile. The in silico approach reinforces the postulate that there is a set of factors involved in solubilization processes, being some of them: the non-polar charges, size, and linearity of the chemical chain, of both solvent and solute. Finally, the dissolution kinetics of curcumin was determined demonstrating the DES' viscosity effect on the mass transfer processes which are the basis of the solubility mechanism. The results here explored reinforces the importance of understanding the role of the polarity, size, and linearity of the chemical chain of all compounds involved in the solubility assay. The comprehension of these facts is of great importance to process development for the food and pharmacist industry, allowing to tune the solubility of the target biomolecule.

This paper presents an experimental and theoretical study for a perstraction system to recover diluted vanillin from aqueous solutions using an organophilic and hydrophobic membrane of polydimethylsiloxane (PDMS), and the hydrophobic ionic liquids (ILs) 1-butyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide ([bmim][Tf2N]), 1-octyl-3-methylimidazolium bis((trifluoromethyl)sulfonyl)imide ([omim][Tf2N]) and trihexyl tetradecyl phosphonium cyanamide ([P6,6,6,14][DCA]) as the extractant phase. The proposed mass transfer model was established as suitable for describing the extraction of vanillin from the aqueous phase in the perstraction system using ILs. According to this model, it was determined that the main mass transfer resistances were offered by the PDMS membrane, followed by the IL. [P6,6,6,14][DCA] experimentally showed a 13% increase in the transmembrane flux in comparison with the [Tf2N] anion based ILs, but also showed higher water transmembrane flux. In this regard, [omim][Tf2N] was found to exhibit better vanillin/water selectivity. The perstraction system gives better transmembrane fluxes than the data reported in the literature for vanillin extraction using pervaporation system. On the other hand, according to the screening in COSMO-RS, the combination of the anions DCA, SCN, TCC, Otf, PFBS, Tf2N, Pf2N y PF6 with pyrrolidinium, piperidinium and phosphonium base cations, are suitable to increase the performance of vanillin extraction.

Eutectic solvents (ESs) have been extensively explored in polymer chemistry. Nevertheless, studies utilizing ESs as a constituent of biodegradable poly(diol-co-citrate) (PDCA) polyesters are lacking in the literature. In this work, we propose utilizing benzalkonium chloride (BAC) based hydrophobic eutectic solvents (HESs) as a constituent of PDCAs. Spotting the light on the molecular-level interactions and mechanisms, a theoretical computational study was conducted to evaluate the feasibility of the process by exploiting a combination of geometrical optimizations, COSMO-RS quantum chemical calculations, density functional theory (DFT) calculations, reactivity calculations, and a blends compatibility study. The studied HES is comprised of dodecyldimethylbenzyl ammonium chloride (DDBAC) as an HBA and 1,10-decanediol (D10DO) as the diol HBD at a 1:3 M ratio. Based on the obtained results, it was found that DDBAC-based HESs can be considered as potential solvents for antimicrobial PDCAs. Additionally, the modeling framework reported in this work can be utilized for screening new types of ESs promoting an efficient design approach of new PDCAs with tailored properties based on the choice of the ES’s HBA.

Organic solvents are usually used to extract artemisinin from Artemisia annua L., and they can also be the solvents for the subsequent purification or derivatization to produce compounds with more efficient antimalarial effect. However, these solvents are volatile, explosive and toxic. The designable material ionic liquids (ILs) are alternative solvents to replace traditional ones. In this work, a reliable method for screening ILs with high solvation capability for artemisinin was developed. The infinite dilution activity coefficients of artemisinin in 903 ILs, composed by 43 cations and 21 anions, were calculated by COSMO-RS, and the results implied that the solubility of artemisinin in ILs mainly depends on the anions. Solubilities of artemisinin in 14 representative ILs were tested, and the results were in good accordance with those obtained in COSMO-RS calculation. The stability of artemisinin in some typical ILs was also studied, which indicated that this drug was stable in [EMIM][BF4], [EMIM][CF3Ac], [EMIM][NTF2], [BPY][NTF2], [EMIM][SCN], and [EMIM][Ac]. The excess enthalpy analysis demonstrated that artemisinin interacted with ILs mainly through hydrogen bond. Extraction of artemisinin using the optimal IL indicated that more artemisinin could be extracted from the leaves when compared with petroleum ether (254.73 mg/mol IL vs. 14.16 mg/mol solvent), further verifying accuracy of the simulation results. Therefore, structures of ILs with high solvation capacity for artemisinin can be obtained by the COSMO-RS method.

Eutectic solvents (ESs) have been extensively studied in the literature for the purification of fuels. Nevertheless, most studies investigated the extraction of a single type of aromatic from n-alkanes. In this work, aiming to provide insights about the performance of ESs in a process that mimics the multicomponent dearomatization used industrially, a salt-acid-based ES, comprised of methyltriphenyl-phosphonium bromide and acetic acid, was applied in simultaneously extracting toluene, thiophene, quinoline, and pyrrole from n-decane. First, the DES was characterized for its eutectic composition, physicochemical, and critical properties. Then, an initial screening to determine the molecular-level interactions and extraction mechanism were studied experimentally and using COSMO-RS screening charge density profiles and potentials. A physical mechanism was confirmed for the extraction of pyrrole, thiophene, and toluene while for quinoline, an acid-base reaction was the predominant extraction mechanism. The phase diagrams of each impurity were also experimentally determined, predicted using the COSMO-RS model, and correlated using the NRTL model in Aspen Plus. Lastly, a parametric investigation studying the impact of key parameters including stirring time, initial concentration, mixing effects, solvent-to-feed ratio, multi-stage extraction, and repetitive usage of solvent was conducted. On multi-stage extraction, full recovery of pyrrole and quinoline ( ≈ 99.9%) was achieved in only 2-stages, whereas for thiophene and toluene efficiencies of 82.2% and 58.4% were reached after the 5th stage, respectively.

Hypothesis Anionic surfactants can form stable monolayers around oil droplets via interactions with macromolecules thereby physically stabilizing high fish oil enriched emulsions (50–70% fish oil) while phenolic acids have antioxidant properties to prevent lipid oxidation. COSMO-RS (Conductor-like Screening Model for Real Solvents) is a powerful tool for the rational design of molecules with multi-functionalities. Therefore, it should be possible to assemble segments of natural molecules into a single multifunctional molecule using COSMO-RS to confer both physical and oxidative stability to fish oil enriched systems. Experiments COSMO-RS was used to predict the thermodynamic properties of series phenoleoyl malic acid esters of monoglycerides in comparison with commercial emulsifiers. A novel series of amphiphilic lipids, equipped with multi-functional groups from natural building blocks (fatty-acyl, glycerol, malic & phenolic acids), were then synthesized in a facile approach and characterized by various spectroscopy techniques. Oil-in-water emulsions stabilized by the amphiphilic lipids were formulated and characterized by dynamic light scattering measurements and fluorescence imaging. Findings An elaborate integration of multi-functions into a single molecule was achieved, displaying superior or comparable emulsion stability and antioxidant property, compared to a commercial emulsifier, phenolic acids and their combinations. This is the first report to holistically integrate the rational design, synthesis and functional characterization of natural-based multifunctional molecules for high capacity fish oil delivery systems.

Deep eutectic solvents (DESs) have received much attention as a potential extracting agent in recent years due to favorable characteristic such as low cost, non-toxic, non-flammable and availability. In this research, the solubility of different gases including CO 2 , CO, CH 4 , H 2 and N 2 in Choline Chloride/Urea as a deep eutectic solvent at the temperature ranging from 308 and 333 K and pressure up to 5 MPa is determined. Furthermore, the effect of different molar ratios of Choline Chloride to Urea (1:1.5, 1:2.0 and 1:2.5) on the solubility of CO 2 is elucidated. In this regard, two thermodynamic models (NRTL and COSMO-RS) are used. The performance of the proposed models is validated with the experimental data. The adjustable parameters of NRTL model are computed by local optimization. In order to comprise the results of two thermodynamic models precisely, the absolute relative errors (ARDs) are computed. The results indicate that NRTL model predicts the solubility data superior than COSMO-RS model. This is rationalized because COSMO-RS model does not use any adjustable parameters in solubility calculation.

Two multi–walled Carbon Nanotubes (MWCNTs) adsorbents, chemically functionalized by either OH (MWCNTs–OH) or COOH (MWCNTs–COOH), were adopted to study the adsorption of Crystal Violet (CV) dye from aqueous solutions. A series of CV dye adsorption isotherms was recorded at different temperatures ranging from 298 to 328 K. Experimental results demonstrated that the adsorbents have similar performances, even if the sample functionalized by COOH (MWCNTs–COOH) shows slightly higher adsorption capacity. In light of the statistical physics, a model was developed and applied to explain the adsorption mechanism and to describe the role of adsorbent functionalization through model parameters. Mathematically, this model was defined by three parameters reflecting the main physicochemical aspects of the adsorption process such as, the number of dye molecules linked per site of adsorbent (nd), an energetic coefficient (w) and the number of occupied receptor site (Km). A very good accordance between the experimental results and the proposed model was observed. The difference in nd values for the two adsorbents can be attributed to the intensity of interactions between dye and the specific functional groups of the adsorbents. An energetic characterization of the systems was carried out by calculating three specific interaction energies of CV dye with the functionalized carbon nanotubes (the electrostatic misfit energy; EMF, the hydrogen–bonding energy; EHB and the Van der Waals energy; EvdW) by application of conductor–like screening model for real solvents (COSMO–RS). The COSMO–RS model clearly indicated that the hydrogen–bonding interaction is the dominant energetic factor in CV dye adsorption. Finally, a good complementarity was retrieved between the results of statistical physics and COSMO–RS models.

In this work, methyl isopropyl ketone (MIPK) was studied to extract o-, m-, p-cresol from water at 333.2 and 343.2 K. The liquid–liquid equilibrium (LLE) data for the ternary systems, MIPK + o-, m-, p-cresol + water, were determined at 101.3 kPa. The extraction performance of MIPK for cresols was evaluated by the distribution coefficient and selectivity. High distribution coefficients and selectivity values indicate MIPK is a promising extractant to separate cresols from wastewater. The experimental LLE data were accurately correlated by using the NRTL and UNIQUAC activity coefficient models, with root mean square deviation (RMSD) values below 1%. The conductor-like screening model for real solvent (COSMO-RS) model was used to predict the phase diagrams of the studied systems, and the RMSD from the experimental data are ∼5% (o-cresol), ∼3% (m-cresol), ∼2.5% (p-cresol) respectively. Furthermore, molecular dynamics (MD) simulations were employed to study the effect of temperature on the hydrogen bonds in the studied systems. The results were used to adjust the hydrogen-bonding parameter of the COSMO-RS model, yielding phase diagram closer to the experiments.