Conductor-like Screening Model For Real Solvents Research Articles

Liquid-liquid extraction of phenolic compounds from aqueous solution using hydrophobic deep eutectic solvents

This work evaluates the efficiency of extracting phenolic compounds (phenol, guaiacol, eugenol and pyrocatechol) from aqueous solution using Hydrophobic Deep Eutectic Solvents (HDESs). Four solvents were selected by screening HDESs database using the predictive model COSMO-RS (Conductor like Screening Model for Real Solvent): menthol: dodecanoic acid [2:1], decanoic acid: dodecanoic acid [2:1], octanoic acid: menthol [2:1] and thymol: menthol [1:1]. Experimental liquid–liquid equilibria of ternary systems {water – HDESs – phenolic compounds} measured at 298.15 K under atmospheric pressure were used to determine the distribution coefficient and selectivity values. Experimental data were used to determine the interaction parameters of the thermodynamic Non-Random Two-Liquid model (NRTL). NRTL model represents with good accuracy experimental data. COSMO-RS model predicts well the ternary systems containing phenolic compounds except those containing pyrocatechol. Finally, extraction of the four phenolic compounds from synthetic oil and kinetics study were performed. The extraction process using HDES: octanoic acid: menthol [2:1] exhibits the highest efficiency and more than 85 % of phenolic compounds are extracted after 5 min.

Theoretical Study on the Photoacidity of Hydroxypyrene Derivatives in DMSO Using ADC(2) and CC2.

This work applies the thermodynamic Förster cycle to theoretically investigate the pKa*, i.e., excited-state pKa values of pyranine-derived superphotoacids developed by Jung and co-workers. The latter photoacids are strong enough to transfer a proton to the aprotic solvent dimethyl sulfoxide (DMSO). The Förster cycle provides access to pKa* via the ground-state pKa and the electronic excitation energies. We use the conductor-like screening model for real solvents (COSMO-RS) to compute the ground-state pKa and the correlated wavefunction-based methods ADC(2) and CC2 with the continuum solvation model COSMO to calculate the pKa change upon excitation. A comparison of the calculated UV/Vis absorption and fluorescence emission energies to the experimental results leads us to infer that this approach allows for a proper description of the electronic excitations. In particular, implicit solvation by means of the COSMO model appears to be sufficient for the treatment of these photoacids in DMSO. The calculations confirm the presumption that a charge redistribution from the hydroxy group to the aromatic ring and the electron-withdrawing substituents is the origin of photoacidity for these photoacids. Moreover, the calculations with the continuum solvation model predict that the pKa jump upon excitation decreases with increasing solvent polarity, as rationalized based on the Förster cycle.

Screening of ionic liquids as sustainable greener solvents for the capture of greenhouse gases using COSMO-RS approach: Computational study

As the world's population, urbanization, and industrialization grow, so does the production of greenhouse gases (GHGs). Considering the harmful impact of these gases on the environment and livelihood, capturing them is necessary to reduce their levels in the atmosphere. Conventional solvents for capturing greenhouse gases, mainly CO2, CH4, and N2O, are toxic, expensive, and result in the generation of additional waste. To overcome these limitations, Ionic liquids (ILs), a class of “green solvents,” are a sustainable alternative for greenhouse gas capture because of their excellent properties. The only restriction is that screening for millions of ILs is time-consuming and inconvenient. Conductor-like screening model for real solvents (COSMO-RS) is an efficient technique to prescreen ILs. This study outlines eight cations and thirty anions, forming 240 ILs combinations for each GHGs CO2, CH4, and N2O. All in total, 720 ILs combinations were screened. COSMO-RS results suggest that phosphonium, choline, and ammonium cations, electronegative and food-grade anions such as [F−], [SO42−], [Gly], [Lys] will be suitable for capturing greenhouse gases.

A Prediction for the Conversion Performance of H2S to Elemental Sulfur in an Ionic-Liquid-Incorporated Transition Metal Using COSMO-RS

In the present study, the conversion performance of hydrogen sulfide (H2S) to elemental sulfur in ionic-liquid-incorporated transition metals (ILTMs) is predicted using a conductor-like screening model for realistic solvents (COSMO-RS). The predictions were made via the establishment of a correlation between the conversion performance and solubility of H2S in ionic liquids (ILs). All molecules involved were optimized at the DFT/TZVP/M06 computational level and imported on the COSMOtherm program at equimolar conditions. For validation purposes, the solubility of ILs was predicted at 1 bar pressure. Simple regression analysis was used to establish a relationship between the solubility and conversion performance of H2S. The results indicate that the solubility prediction of ILs is accurate (R2 = 93.40%) with a p-value of 0.0000000777. Additionally, the conversion performance is generally found to be dependent on the solubility value. Furthermore, 1-butyl-3-methylimidazolium chloride [bmim][Cl] was chosen as the base IL for incorporating the transition metal, owing to its solubility and selectivity to H2S. The solubility trend of ILTMs is found to follow the following order: [bmim][NiCl3] > [bmim][FeCl4] > [bmim][CoCl3] > [bmim][CuCl3]. According to the viscosity measurements of ILTMs, [bmim][NiCl3] and [bmim][FeCl4] exhibited the highest and lowest viscosity values, respectively. Therefore, [bmim][FeCl4] is a promising ILTM owing to its higher solubility and low viscosity for the application studied.

Multiscale Molecular Simulation Strategies for Understanding the Delignification Mechanism of Biomass in Cyrene

In recent years, the cellulose-derived solvent Cyrene has piqued considerable interest in the green chemistry community despite only recently being available in the quantities required for solvent applications. Deconstruction of cellulose is an essential step in the production of fuel and value-added chemicals from lignocellulosic biomass. However, the high recalcitrance and heterogeneity of lignin hinder this process, necessitating the need to solubilize lignin. To understand the dissolution of lignin in Cyrene and Cyrene–cosolvent systems, multiscale molecular simulation approaches have been employed. Initially, the conductor-like screening model for real solvent (COSMO-RS) model was used to assess the thermodynamic properties of lignin in Cyrene and Cyrene–cosolvent systems. From the COSMO-RS calculations, the correlation between the predicted activity coefficient and the experimental lignin solubility was excellent. Further, classical molecular dynamics (MD) simulations were performed to evaluate the delignification of biomass by predicting structural and dynamic properties of lignin–solvent systems. The microscopic properties such as interaction energies, radius of gyration, solvent-accessible surface area, radial and spatial distribution functions (RDFs/SDFs), and hydrogen bonds were assessed to characterize lignin dissolution in these solvent mixtures and were validated with experimental data. From the MD simulations, it was observed that lignin adopts a coil-like structure in Cyrene and Cyrene:water mixtures, thereby dissolving the lignin, while lignin adopts a collapsed-like structure in the presence of water. The occupancy density of Cyrene is highly surrounded by the aryl and hydroxyl groups of lignin polymer rather than by water. The interaction energies between lignin and Cyrene and Cyrene–cosolvent were much stronger than that between lignin and water, explaining the higher biomass delignification in Cyrene-based solvents.

Evaluation of deep eutectic solvents for the extraction of fucoxanthin from the alga Tisochrysis lutea – COSMO-RS screening and experimental validation

Fucoxanthin is a carotenoid in algae with purported beneficial health-related properties including antioxidant, anti-photoaging, anti-metastasis, anti-hypertensive activity and more. These properties give fucoxanthin the potential to be used in cosmetic, dietary, and medicinal applications. This study evaluates the use of deep eutectic solvents (DESs) to extract fucoxanthin from the microalgae Tisochrysis lutea. Conductor-like Screening Model for Real Solvents (COSMO-RS) was used to screen the performance of 24 different types of DESs in the extraction of fucoxanthin based on their calculated capacities. Experimental extraction validation was then carried out using the 6 top-ranked DESs. The experimental results revealed that the extraction capacity of the thymol: dodecanoic acid DES (1.25: 1 molar ratio) for fucoxanthin was the most efficient (7.69 mg/g dry biomass weight (DW)) among the DESs explored under the screening conditions and was higher than the capacity of the conventional solvents methanol (6.29 mg/g DW) and ethanol (6.75 mg/g DW). This corresponded with COSMO-RS screening results. Then, the optimisation of extraction conditions for fucoxanthin using thymol: dodecanoic acid DES was further investigated, revealing that the highest yield of fucoxanthin (22.03 mg/g DW) was extracted at optimum experimental conditions at a temperature of 36.2 °C, stirring time of 2.58 h, and the biomass percentage of 11.36 %. Additionally, fucoxanthin showed good stability in thymol: dodecanoic acid DES over eleven days of storage. After seven extraction cycles, the final fucoxanthin concentration (13.06 mg/mL DES) resulted in a good reusability of the terpene-based food safe DES.

Ultrasonic-Assisted Extraction of Toxic Acidic Components from Acidic Oil Using 1,8-Diazobicyclo[5.4.0]undec-7-ene-Based Ionic Liquids.

Ionic liquids (ILs) show remarkable performance in enhancing the naphthenic acid extraction efficiency and decreasing the extraction time. However, the ultrasonic-assisted IL-based extraction of naphthenic acid is merely addressed previously. Therefore, this study investigated the impact of essential ultrasonic parameters, including amplitude and time, on naphthenic acid extraction using different ILs, and the system was optimized for maximum extraction. The IL 1,8-diazobicyclo[5.4.0]-undec-7-ene (DBU) with thiocyanate anions revealed the highest efficiency in extracting naphthenic acid from a model oil (dodecane) at optimized conditions, and the experimental liquid–liquid equilibrium data were obtained at atmospheric pressure for the mixture of dodecane, [DBU], thiocyanate, and naphthenic acid. In addition, the influence of the chain length of the cation (hexyl, octyl, or decyl) on the extraction efficiency was also evaluated by determining the distribution coefficients, and the conductor-like screening model for real solvents (COSMO-RS) study was carried out at infinite dilution. It was found that [DBU-Dec] [SCN] gives the best extraction efficiency and has a distribution coefficient of 9.2707 and a performance index of 49.48. Based on these values, ILs can be ordered as follows: [DBU-Dec] [SCN] > [DBU-Oct][SCN] > [DBU-Hex][SCN] in the decreasing order of performance index 49.48, 41.58, and 28.13. Moreover, non-random two liquid and Margules thermodynamic models were employed to investigate the interaction parameters between the components. Both models showed excellent agreement with the experimental results and could successfully be used for ultrasonic-assisted IL extraction of naphthenic acid.

Using COSMO-RS to Predict Hansen Solubility Parameters

Hansen solubility parameters (HSP) provide essential information on the nature of solvents, being a useful tool in their selection for product and process design. In this work, linear models were developed to estimate HSP based on the use of COSMO-RS (conductor-like screening model for realistic solvents) descriptors. Hansen solubility parameters for 195 compounds were obtained from the literature and classified into two categories: training set (133 compounds) and testing set (62 compounds). Then a factorial regression was carried out to predict dispersion, hydrogen-bonding interaction, and polar contribution of HSP (δD, δH, and δP, respectively) based on σ-moments and energy COSMO-RS descriptors. The description of the dispersion contribution was the least successful due to the low variability of the experimental data, despite the database containing compounds of a widely different chemical nature. The models obtained proved to be more than simple mathematical equations since a physical meaning is achieved when COSMO-RS descriptors are used. The models developed were then applied to the test database. An excellent performance was observed, with δH showing the highest R2 (0.90), and the MAE obtained were 0.98, 1.74, and 1.44 MPa1/2 for δD, δH, and δP, respectively, which are lower than those found in previous works. Finally, HSP data for caffeine, nicotine, paracetamol, and d-camphor were estimated. The results were close to the literature data and those predictive by the HSPiP software. Moreover, it was shown that δP and δH drive the molecules’ polarity, impacting their log Kow (a quantitative measure of polarity). This work shows that COSMO-RS descriptors are a tool to predict HSP through linear models, opening new doors in the screening, design, and selection of solvents to be used in chemical processes.

Deep removal of chlorobenzene based volatile organic compounds from exhaust gas with ionic liquids

Taking chlorobenzene (C6H5Cl) and o-dichlorobenzene (C6H4Cl2) as representatives of chlorobenzene based volatile organic compounds (CBs), a novel deep-purification technology of absorbing with ionic liquids (ILs) as absorbent was proposed and systematically investigated. Based on conductor-like screening model for real solvents (COSMO-RS) model, the suitable IL 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4]) for absorbing CBs was screened out from 289 kinds of commonly used ILs. Removal experiments of C6H5Cl and C6H4Cl2 by [EMIM][BF4] were carried out at different temperatures, pressures and IL flow rates. Results suggested that [EMIM][BF4] had excellent absorption properties, and deep removal of CBs can be achieved that the content of C6H5Cl/C6H4Cl2 in the purified gas can be decreased down to 13.6 ppm/9.9 ppm (in molar fraction). Absorption capacity of [EMIM][BF4] to CBs was almost unchanged after absorbing and desorbing for up to 20 times, proving the repeatability of the absorption performance. Characterization by NMR and FT-IR showed that there was no chemical bond formed between [EMIM][BF4] and CBs, proving that the absorption process was physical absorption. Moreover, the structure of the regenerated [EMIM][BF4] had not been changed, which indicates that [EMIM][BF4] has strong thermal stability and chemical stability. Finally, the interaction mechanisms between [EMIM][BF4] and CBs were clarified from the aspects of interaction energy and interaction sites by quantum chemical calculation and wave function analysis. This work fills the gap of removing CBs by absorption method with ILs, and proved that ILs could be employed as promising green solvents for chlorobenzene based VOCs removal.

Modeling vapor–liquid equilibrium and liquid–liquid extraction of deep eutectic solvents and ionic liquids using perturbed‐chain statistical associating fluid theory equation of state. Part II

AbstractThis study aims to use perturbed‐chain statistical associating fluid theory (PC‐SAFT) to describe the phase behavior of systems containing deep eutectic solvents (DESs) and ionic liquids (ILs). The DESs are based on tetrabutylammonium chloride and tetrabutylammonium bromide as hydrogen bond acceptors, and levulinic acid and diethylene glycol as hydrogen bond donors in the mole ratio of 1:2 and 1:4, respectively. Predictions of phase equilibria by PC‐SAFT were compared with the results of COnductor like Screening MOdel for Real Solvents (COSMO‐RS) and non‐random two‐liquid (NRTL). In this work, low viscosity ether‐ and pyridinium‐based ILs [EnPy][NTf2] and [CmPy][NTf2] were used for vapor–liquid equilibrium systems, while 1‐(2‐methoxyethyl)‐1‐methylpyrrolidinium bis(trifluoromethylsulfonyl)‐amide and 1‐propyl‐3‐methylimidazolium bis{trifluoromethylsulfonyl}imide with n‐heptane + thiophene and n‐hexane + ethylbenzene were used in the liquid–liquid extraction, respectively. In the last part, the phase behavior of the mixtures of perfluoroalkylalkanes with their linear alkane counterparts was studied and compared with the SAFT‐Mie pair potential.

An open source COSMO-RS implementation and parameterization supporting the efficient implementation of multiple segment descriptors

The model COSMO-RS (Conductor-like screening model for realistic solvation) is based on the approximation of molecular interactions by the interactions of surface segments from the molecular cavities. These segment interactions are functions of the segment properties i.e. descriptors, with the most important descriptor being the screening charge density. Whereas the inclusion of further descriptors can lead to improved accuracy for the models predictions, it also increases the computational demand due to the growth of the central nonlinear equation system of COSMO-RS. In this work, we present an algorithm that efficiently allows the introduction of further segment descriptors at moderate size increase of the central equation system. It is included into our implementation of COSMO-RS, which is provided as open source code and will be named openCOSMO-RS in the future. Different parameterizations of the model are performed, implementing an RDKit/ORCA based workflow for the required quantum chemical calculations. In this way, the implementation is open for evaluation and refinement for a large range of academic users.

Searching for Sustainable Refrigerants by Bridging Molecular Modeling with Machine Learning.

We present here a novel integrated approach employing machine learning algorithms for predicting thermophysical properties of fluids. The approach allows obtaining molecular parameters to be used in the polar soft-statistical associating fluid theory (SAFT) equation of state using molecular descriptors obtained from the conductor-like screening model for real solvents (COSMO-RS). The procedure is used for modeling 18 refrigerants including hydrofluorocarbons, hydrofluoroolefins, and hydrochlorofluoroolefins. The training dataset included six inputs obtained from COSMO-RS and five outputs from polar soft-SAFT parameters, with the accurate algorithm training ensured by its high statistical accuracy. The predicted molecular parameters were used in polar soft-SAFT for evaluating the thermophysical properties of the refrigerants such as density, vapor pressure, heat capacity, enthalpy of vaporization, and speed of sound. Predictions provided a good level of accuracy (AADs = 1.3–10.5%) compared to experimental data, and within a similar level of accuracy using parameters obtained from standard fitting procedures. Moreover, the predicted parameters provided a comparable level of predictive accuracy to parameters obtained from standard procedure when extended to modeling selected binary mixtures. The proposed approach enables bridging the gap in the data of thermodynamic properties of low global warming potential refrigerants, which hinders their technical evaluation and hence their final application.

Time-Resolved SAXS Study of Polarity- and Surfactant-Controlled Superlattice Transformations of Oleate-Capped Nanocubes During Solvent Removal.

Structural transformations and lattice expansion of oleate-capped iron oxide nanocube superlattices are studied by time-resolved small-angle X-ray scattering (SAXS) during solvent removal. The combination of conductor-like screening model for real solvents (COSMO-RS) theory with computational fluid dynamics (CFD) modeling provides information on the solvent composition and polarity during droplet evaporation. Evaporation-driven poor-solvent enrichment in the presence of free oleic acid results in the formation of superlattices with a tilted face-centered cubic (fcc) structure when the polarity reaches its maximum. The tilted fcc lattice expands subsequently during the removal of the poor solvent and eventually transforms to a regular simple cubic (sc) lattice during the final evaporation stage when only free oleic acid remains. Comparative studies show that both the increase in polarity as the poor solvent is enriched and the presence of a sufficient amount of added oleic acid is required to promote the formation of structurally diverse superlattices with large domain sizes.

Study of the ionic liquids’ electrochemical reduction using experimental and computational methods

Ionic liquids (ILs) as electrolytes have attracted attention because of their distinctive properties. Numerous studies on the electrochemical stability of the ILs have been published. However, a deep understanding of the parameters that affect the reduction stability is highly required. In this study, the reduction potentials of five ILs including two novel ILs that contain 1,2,4-triazolium as cation were evaluated experimentally using cyclic voltammetry (CV) and compared with computational modeling using Tmolex software and Conductor like Screening Model for Real Solvents (COSMO-RS). We investigate the parameters that affect the ILs’ reduction stability such as the lowest unoccupied molecular orbital (LUMO) energy levels of the cations and anions, as well as the effect of the molecular interaction between them. We conclude that while using the computational method, the individual values of the LUMO of the cations or anions without taking into consideration the molecular interaction might misguide the prediction of the ILs reduction stability.

Prediction of acid pKa values in the solvent acetone based on COSMO-RS.

In this contribution we extent the use of the conductor-like screening model for realistic solvation (COSMO-RS) to the prediction of pKa values in acetone, a commonly used dipolar aprotic solvent. For this, we calculated the Gibbs free energy of dissociation of 120 organic acids (nine acrylic acids, 87 benzoic acids, nine phenols, and 15 benzenesulfonamides) using COSMO-RS at the two levels BP-TZVP and BP-TZVPD-FINE and determined the parameters for a linear free energy relation for the prediction by performing linear fits to experimental values. Our results suggest that the data set dissects into two groups, with the phenols being different from the other three subsets. The acrylic and benzoic acids and the sulfonamides can be treated together and yield an excellent linear correlation ( ) with an RMSD of only ~0.3. The slope is found to be significantly smaller than the theoretical value ( ), only 45% of it, which is in accordance with findings in the literature. The phenols, however, while similarly well correlated in their own subset with an RMSD of 1.7-1.9, exhibit a slope larger than one. We discuss both a higher uncertainty in the reference values as well as physical origins as possible reasons.

Carbon Dioxide Solubility in Nonionic Deep Eutectic Solvents Containing Phenolic Alcohols.

Deep eutectic solvents (DES) are a new class of green solvents that have shown unique properties in several process applications. This study evaluates nonionic DES containing phenolic alcohols as solvents for carbon dioxide (CO2) capture applications. Potential phenolic alcohols and the molar ratio between DES constituents were preselected for experimental investigations based on the conductor-like screening model for realistic solvation (COSMO-RS). CO2 solubility was experimentally determined in two different DES, namely, L-menthol/thymol in 1:2 molar ratio and thymol/2,6-xylenol in 1:1 molar ratio, at various temperatures and pressures. CO2 solubility in the studied systems was higher than that reported in the literature for ionic DES and ionic liquids. This study demonstrates that nonionic DES containing phenolic alcohols can be excellent, inexpensive, and simple solvents for CO2 capture.

Systematic method of screening deep eutectic solvents as extractive solvents for m-cresol/cumene separation

Deep eutectic solvents (DESs) have been widely applied as extractive solvents for the separation of phenolic compounds from low-temperature coal tar (LTCT). However, systematic study of screening suitable DESs from numerous candidates for this separation process is still scarce. In this work, a systematic method of screening promising DESs as extractive solvents is proposed for the separation of m-cresol/cumene, as a representative phenolic compound/neutral oil mixture in LTCT. Experimental data of DES-involved systems are collected from literature to validate the reliability of conductor-like screening model for real solvents (COSMO-RS), which serves as the foundation for thermodynamic calculation and process simulation. Then, the crucial influencing factors for DESs screening (i.e., salt and solvent, and the molar ratio) on the thermodynamic properties are investigated by COSMO-RS. After that, a systematic DESs screening method combining the calculation of infinite dilution thermodynamic properties, the estimation of melting point and viscosity, the calculation of liquid-liquid equilibria, and the evaluation of process performance is proposed. The results indicate that chlorocholine chloride (CChC): acetic acid (AA) (1:2) and choline chloride (ChCl): ethylene glycol (EG) (1:3) are identified as the optimum DESs for m-cresol/cumene separation. Finally, the high separation performances of CChC:AA (1:2) and ChCl:EG (1:3) are confirmed by extraction experiments.

Multitask Quantum Study of the Curcumin-Based Complex Physicochemical and Biological Properties.

Density functional theory (DFT), time-dependent density functional theory (TDDFT), quantum theory of atoms in molecules (QTAIM), and extended transition state natural orbitals for chemical valence (ETS-NOCV) have all been used to investigate the physicochemical and biological properties of curcumin and three complexes, i.e., Cur-M (M = Ni, Cu, and Mg). Based on DFT calculations, the enolic form (Cur-Enol) is more stable than the anti-diketone form (Cur-Anti diketone) favored for complexation. This enolic form stability was explained by the presence of three intramolecular hydrogen bonds according to the QTAIM analysis. Furthermore, the ETS-NOCV technique revealed that the enolic form had more significant antioxidant activity compared with the anti-diketone form. The calculations from the COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) showed that the dimethyl sulfoxide (DMSO) solvent could dissolve all the curcumin tautomers Cur-Enol, Cur-Anti-diketone and Cur-Cu, Cur-Mg, and Cur-Ni complexes in contrast to benzene, acetone, octanol, ethanol, methanol, and water. Furthermore, except for Cur-Mg, which had a relatively low solubility (14 g/L), all complexes were insoluble in water. Cur-Anti-diketone was considerably more soluble than Cur-Enol in the examined solvents.

Amino Acid Ionic Liquids as a Potential Adjuvant for Fungicide Formulations: COSMO-RS Prediction and Dissolution Mechanism Elucidation

Screening green solvents to improve the solubility of insoluble pesticides in water is a significant development direction for pesticide formulations in the future. Amino acid ionic liquids (AAILs) have strong dissolution properties and are widely used in dissolution. In this work, the conductor-like screening model for real solvents (COSMO-RS) as a solvent screening tool was used to screen AAILs with good solubility for two insoluble fungicides (fludioxonil and cyprodinil) and the physicochemical properties (viscosity, density, and CMC) of AAILs were characterized. The results showed that the selected AAILs had good solubility effects on fungicides, wherein the solubility of fludioxonil and cyprodinil in 1-ethyl-1-methyl-pyrrolidinium glycinate ([Empy][Gly]) was 115.78 and 67.17 g/L, respectively. The mechanism of the AAIL dissolving the fungicide was explored by theoretical calculation and IR characterization, indicating that the hydrogen bond interaction was the main driving force for AAILs to dissolve fungicides. The solubilization effects of AAILs in different systems were explored, and the results showed that the solubilization effect in aqueous solution was positively correlated with the content of AAILs, which was not only related to the interaction between fungicides and AAILs, but also the formation of micelles as an essential factor. Moreover, the impact of the biosurfactant rhamnolipid (Rha) and AAILs on the solubilization effect was explored, and most AAILs demonstrated a synergistic solubilization effect after adding Rha, which was expected. Finally, the inhibitory effects of organic solvent adjuvant methanol and eight AAILs on wheat growth were measured. Three [Empy] ILs showed less inhibitory effects on wheat than methanol under the same concentration. The research results indicated that AAILs had a promising research prospect as cosolvents in pesticide formulations.

Solubility determination and prediction for FOX-7 in three binary solvents at different temperatures

ABSTRACT The solid–liquid equilibrium and thermodynamic properties of FOX-7 in three binary mixed solvents (N-methyl pyrrolidone-water, N,N-dimethylacetamide-water and 1,4-Butyrolactone-water) are studied by focused beam reflectance measurement (FBRM) dynamic detection method and the solubility is predicted by conductor-like screening model for real solvents (COSMO-RS) under atmospheric pressure from 298.15 to 343.15 K. The results show that the solubility of FOX-7 increase with the increasing temperature and the mole fraction of N-methyl pyrrolidone, N,N-dimethylacetamide and 1,4-Butyrolactone. The solubility data can be well correlated by Apelblat, van’t Hoff and Yaws equation. The data of hybrid thermodynamic parameters (including the hybrid enthalpy, entropy, and Gibbs energy) show that the dissolution process is endothermic, non-spontaneous and enthalpy driven. In addition, COSMO-RS can accurately predict the increasing trend of solubility with increasing of temperature and mole fraction of solvent. However, the COSMO-RS overestimates solubility in three binary solvents except for x NMP = 0.1575, the average mean squared quadratic error becomes larger with an increasing mole fraction of water. Solubility data and thermodynamic parameters can lay a foundation for the crystallization and spheroidization modification of FOX-7.