Binary Aqueous Solvent Research Articles

Oiling out and solubility measurement, molecular simulation and thermodynamic properties of d-tagatose in four aqueous binary solvent systems at 283.15 to 323.15 K

Solubility of D-Tagatose in four aqueous binary solvent systems from 278.15 K to 323.15 K was determined using the anti-solvent assisted gravimetric method. The solubility increases with temperature in all four binary solvents, with water, a good solvent, exhibiting a similar trend. In addition, the dissolution process generally follows the ’like dissolves like’ rule. The study indicates that the oiling out occurs when water exhibits a high molar fraction in water + 1-propanol, and water + isopropanol. Furthermore, we study the charge of the molecule using the molecular electrostatic potential surface (MEPS), aiming to analyze the molecular interactions. Then, to explain the dissolution behaviors of D-tagatose, the radial distribution function (RDF) by molecular dynamics simulations (MD) revealed a strong correlation between solute–solvent interactions and solubility, with significant solvent–solvent interactions. The solubility data was correlated using the modified Apelblat equation, Van’t Hoff equation, λh equation, and Jouyban-Acree model, with demonstrating the high consistency in the data. Finally, the thermodynamic properties revealed that the dissolution process of D-Tagatose is endothermic, and entropy-driven based on all positive values for ΔsolHo, ΔsolSo, ΔsolGo.

Solubility of 2,5-Furandicarboxylic Acid in Pure and Mixed Organic Solvent Systems at 293 K Predicted Using Hansen Solubility Parameters.

Central to the production of polyethylene furanoate (PEF), a bioplastic that could potentially replace petroleum-derived plastics, is 2,5-furandicarboxylic acid (FDCA). FDCA is a chemical derived from biomass that has low solubility in traditionally used solvents such as water. Thus, identifying solvents that can solubilize significant amounts of FDCA could allow for lower PEF production costs. In this study, FDCA solubility was investigated in nine pure solvents including H2O, acetonitrile (ACN), γ-valerolactone (GVL), γ-butyrolactone (GBL), ethanol (EtOH), methanol (MeOH), dimethyl sulfoxide (DMSO), sulfolane (SULF), and tetrahydrofuran (THF), eight binary, and three ternary solvent blends at 293 K. For all binary systems excluding DMSO and MeOH, the solubility of FDCA increased 1.5-65 times compared to the pure organic solvent, and the FDCA solubility was at least 10 times higher when compared to pure water. Specifically, the 20/80 w/w H2O/DMSO system solubilized 23.1 wt % FDCA, the highest of any binary blend studied, and 190 times more solubility than in pure water. In 20/80 w/w H2O/THF, the FDCA solubility was 60 times higher than pure water. In ternary blends that included DMSO, H2O, and either GVL, THF, or SULF, solubility increased by at least 6.6 times relative to the pure secondary organic component and 54 times relative to pure water. Using Hansen solubility parameters (HSPs), the radius of interaction (R i,j ) was found to be more strongly correlated to FDCA solubility than individual HSPs or the total solubility parameter. A MATLAB-based optimization code was developed and successful in minimizing the R i,j of a solvent blend to maximize FDCA solubility in binary and ternary aqueous solvents.

Alcohol-Induced Denaturation of Hen Egg White Lysozyme Studied by Infrared, Circular Dichroism, and Small-Angle Neutron Scattering.

In aqueous binary solvents with fluorinated alcohols, 2,2,2-trifluoroethanol (TFE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), and aliphatic alcohols, ethanol (EtOH) and 2-propanol (2-PrOH), the denaturation of hen egg white lysozyme (HEWL) with increasing alcohol mole fraction xA has been investigated in a wide view from the molecular vibration to the secondary and ternary structures. Circular dichroism (CD) measurement showed that the secondary structure of α-helix content of HEWL increases on adding a small amount of the fluorinated alcohol to the aqueous solution, while the β-sheet content decreases. On the contrary, the secondary structure does not significantly change by the addition of the aliphatic alcohols. Correspondingly, the infrared (IR) spectroscopic measurements revealed that the amide I band red-shifts on the addition of the fluorinated alcohol. However, the band remains unchanged in the aliphatic alcohol systems with increasing alcohol content. To observe the ternary structure of HEWL, small-angle neutron scattering (SANS) experiments with H/D substitution technique have been applied to the HEWL solutions. The SANS experiments were successful in revealing the details of how the geometry of the HEWL changes as a function of xA. The SANS profiles indicated the spherical structure of HEWL in all of the alcohol systems in the xA range examined. The mean radius of HEWL in the two fluorinated alcohol systems increases from ∼16 to ∼18 Å during the change in the secondary structure against the increase in the fluorinated alcohol content. On contrast, the radius does not significantly change in both aliphatic alcohol systems below xA = 0.3 but expands to ∼19 Å as the alcohol content is close to the limitation of the HEWL solubility. According to the present results, together with our knowledge of the alcohol cluster formation and the interaction of the trifluoromethyl (CF3) groups with the hydrophobic moieties of biomolecules, the effects of alcohols on the denaturation of the protein have been discussed on a molecular scale.

Thermodynamic analysis for the dissolution of two similar amino acids in sodium sulfate aqueous solution

In the current work, the analyti cal static gravimetric technique was used to assess the solubilities of DL-α-amino butyric acid and DL-valine in an aqueous binary solvent mixture of sodium sulfate (Na2SO4) under equilibrium saturation conditions in between temperature range 288.15 and 308.15 K. Different thermodynamic factors along with transfer Gibbs energetics and entropies under standard conditions were estimated by using computational as well as theoretical method by using the experimental solubilities. Several modes of interactions that occur during solvation were also explained. The manner that solvent molecules of solute amino acids are surrounded in the aforementioned medium employed during the process is taken into consideration. Amino acids become more soluble as the temperature rises. The study also helps us to reach the conclusion that physical properties of electrolyte (Na2SO4), mixed solvent, and the size of the amino acids’ molecules are the main governing factors for the chemical stability as well as other thermodynamic and physical property like solubility of solute amino acids.

Ether-type co-solvents of excellence for aqueous base-free Pt-catalyzed oxidation of concentrated 5-(hydroxymethyl)furfural to 2,5-furandicarboxylic acid

The biomass-derived 5-(hydroxymethyl)furfural (5-HMF) is readily converted in water to 2,5-furandicarboxyl acid (FDCA) that is well known as a renewable diacid monomer. However, the limited solubility of FDCA in water posed serious challenges to process development. Herein, the base-free Pt-catalyzed oxidation of 5-HMF was explored in aqueous binary solvent systems containing organic co-solvents such as dimethyl sulfoxide, N,N-dimethylformamide, gamma-valerolactone, dioxane, diethylene glycol dimethyl ether, and 1,2-dimethoxyethane (DME). The FDCA solubility and 5-HMF oxidation performance were investigated in co-solvent/H2O systems with different co-solvent fractions. When correlated with the solvatochromic parameters of co-solvents, the FDCA yield appeared to be in harmony with their polarizability and hydrogen bonding acceptance ability. Thus, infrared spectra were collected with three systems such as co-solvent/H2O, 5-HMF in co-solvent, and 5-HMF in co-solvent/H2O. The employed co-solvent was found to have different abilities to interact with the O–H and C=O moieties of 5-HMF via H-bonding and dipole-induced dipole attraction (related with the polarizability), respectively. Consequently, a high FDCA yield was achieved using three ether-type co-solvents in which these interactions are relatively weak. In a continuous-flow pattern for the base-free oxidation of 3 wt% 5-HMF solution, a FDCA yield of >98 % was achieved with 60 wt% DME/H2O under the optimized conditions.

Determination and Correlation of Solubility of N-Acetylglucosamine in Four Aqueous Binary Solvents from 283.15 to 323.15 K.

N-Acetylglucosamine (NAG) is a significant novel functional monosaccharide with a wide range of potential applications, such as in the medical and cosmetic fields. A gravimetric technique was used to assess the solubility of NAG in water, methanol, N,N-dimethylformamide, water + methanol, water + n-propanol, water + N,N-dimethylformamide, and water + acetonitrile at temperatures ranging from 283.15 to 323.15 K. The outcomes of the experiment demonstrated that the temperature and water content were positively correlated with the solubility of NAG in four experimental binary solvents. The order of solubility in the four aqueous solvent mixtures is water + DMF > water + methanol > water + n-propanol > water + acetonitrile. The solubility data was well correlated using the modified Apelblat model, the CNIBS/R-K model, and the Apelblat-Jouyban-Acree model. Experimental data from NAG will help guide the design of cooling and dissolution in crystallization processes.

CONDUCTIVITY STUDY OF SODIUM BROMIDE AND SODIUM CHLORIDE SALTS IN BINARY MIXTURES OFAQUEOUS AND ORGANIC SOLVENTS

The effect of solvent composition on the conductivity behaviour of sodium bromide (NaBr) and sodium chloride (NaCl) salts in binary mixed aqueous and organic solvents was evaluated using conductivity measurement. The specific conductivities of the salts in methanol-water, ethylene glycol-water and ethylene glycol-methanol mixtures were determined at different solvent compositions (0, 0.1, 0.4, 0.7 and 1) and concentrations (0.01, 0.02, 0.03, 0.04 and 0.05 M) of the salts with JENWAY 4510 conductivity meter at room temperature. The results show that the conductivities of the solutions of both salts in the mixed solvent systems were higher at lower organic solvent compositions and gradually decreased with increasing composition of the solvents. It was also observed that conductivity decreased as the hydrocarbon character of the organic solvent increased in all the binary mixtures. These results have been discussed on the basis of free-ion and ion-pair interactions as well as other chemical and physical properties of the single component solvents.

Solubility and solvation thermodynamics of l-tryptophan in aqueous methanol solvent mixtures

This article presents mole fraction solubilities of l-tryptophan in binary aqueous methanol solvent systems and applied them to estimate thermodynamical parameters like transfer Gibbs free energetics and entropies of solutions. The estimated thermodynamic energies were linked with interaction parameters like dipole–dipole interactions, enthalpy due to transfer of l-tryptophan from water to binary water–methanol solvent mixtures. The transfer Gibbs free energetics for chemical interactions and entropies for solvent–solvent interaction were calculated by mathematical relations. The chemical transfer energetics was applied to explain the probable stability of l-tryptophan in the mixed solvents. Many associated thermophysical parameters were also calculated at standard temperature (298.15 K).

Continuous Crystallization Process of Cefminox Sodium in MSMPR Crystallizer

Continuous crystallization technology has attracted rising attention from chemists and material scientists. In this paper, cefminox sodium is selected as a model drug for consecutive antisolvent crystallization using a multistage mixed suspension mixed product removal (MSMPR) crystallizer. The effects of operating parameters on the product crystal particle size, crystal habit, and yield under steady-state conditions are investigated in detail: operating parameters such as the initial concentration of the crystallization solution, the volume ratio of the crystallization solution to antisolvent, the total flow rate, the amount of seed crystals added, the crystallization temperature, and the mixing rate. The kinetic solubility data of cefminox sodium in two binary aqueous mixed solvents at 278.15–303.15 K are determined by laser dynamic method, and two empirical models are subsequently borrowed to fit the obtained data. This work provides a new crystallization process for cefminox sodium. After optimization, the mass yield is increased to 89.11%, the average particle size Dv(50) is about 164 µm.

A comparative analysis of volumetric, viscometric and conductometric properties of Triethylmethylammonium Tetrafluoroborate (TEMABF4) and Tetraethylammonium Tetrafluoroborate (TEABF4) in pure propylene carbonate (PC) and binary aqueous propylene carbonate solvents

Electrolytes play a major role in electrochemical energy storage devices and specifically organic electrolytes are used predominantly over aqueous electrolytes due to wide electrochemical window, high energy density and efficiency. However, aqueous electrolytic systems for energy storage applications still need to be explored as these are non-flammable, environment friendly, non-toxic, carrying high ionic conductivity and low cost as compared to organic counterparts. In this study, an effort has been made in doing a comparative analysis of the physicochemical properties of Triethylmethylammonium Tetrafluoroborate (TEMABF4) and Tetraethylammonium Tetrafluoroborate (TEABF4) in pure propylene carbonate (PC) and binary aqueous mixtures of PC (0.01 &0.02 m) at different temperatures and concentrations. From this data, various volumetric, viscometric, and conductometric parameters have been calculated and the results obtained are analysed and compared in terms of solute–solute and solute–solvent interactions. From the analysis of thermo physical parameters, we have found that both the salts act as structure breaker in PC whereas structure maker in binary aqueous mixtures of PC (0.01 & 0.02 m). FTIR studies have also been done to see the intermolecular interactions and structural alterations. Furthermore, results from Cyclic Voltammetry (CV) studies suggested that a binary aqueous organic electrolytic system can also be a potential electrolytic system as its electrochemical window is comparable to that of pure electrolytic organic solvents.

Effects of solvent extraction on phenolic concentration and antioxidant capacity of the Oedogonium sp. (Chlorophyta) using a simplex-centroid mixture design

Among the freshwater benthic macroalgae found in Brazilian rivers and streams, species of Oedogonium (Chlorophyta) have shown great ability to produce high biomass in several environmental conditions. Their resilience to eutrophic habitats provides an opportunity to assess the use of Oedogonium biomass for applications in different fields, especially those related to the extraction of biologically active compounds of interest for health, food, and cosmetic applications. Thus, this study assessed the effects of different organic solvents (acetone, ethanol, and methanol) and their mixtures when combined with water (20% v/v), on the extraction efficiency of total phenolic compounds (TPC), and their antioxidant capacity (AC), from Oedogonium sp. biomass, using simplex-centroid mixture design. TPC ranged from 90 to 150 mg of gallic acid equivalent per 100 g dry weight (DW), while AC ranged from 1 to 8 µM of Trolox equivalent per gram (DW). The highest TPC and AC were found for extracts using an ethanol/acetone (50:50) binary aqueous solvent mixture, while the lowest values for both TPC and AC were found for the methanolic aqueous solvent. Considering the relatively low-cost and less adverse environmental impacts of the ethanol and acetone aqueous mixture, our results suggest that the use of this specific mixture of organic solvents may have significant advantages in an eventual industrial process for the extraction of phenolic compounds from Oedogonium species.

Explorations on thermophysical properties of nitrogenous bases (uracil/thymine) in aqueous l-histidine solutions at various temperatures

Thermophysical properties for varied compositions of uracil and thymine (nitrogenous bases) in H2O and in (0.1, 0.2 and 0.3) mol kg−1 binary aqueous l-histidine solvent media have been determined at temperatures ranging (293.15–313.15) K. The experimentally assessed data has been employed to enumerate numerous densimetric, acoustic and rheological parameters such as apparent molar volume (Vϕ), limiting apparent molar expansibility (E0ϕ), limiting apparent molar volume (V0ϕ), apparent molar isentropic compression (Kϕ,s), limiting apparent molar isentropic compression (K0ϕ,s), hydration number (nH), solvation number (Sn), transfer properties, viscosity B-coefficients etc. Moreover, the chaotropic behavior of each examined solute has been investigated using dB/dT (temperature derivative of Jones Dole coefficient) and Hepler’s constant (∂E0ϕ/∂T)P i.e. temperature derivative of limiting apparent molar expansibility at constant pressure. Besides, cosphere overlap model has been utilized to access various sorts of predominant interactions in the deliberated systems.

Taurine in several aqueous binary solvents: Solubility prediction, measurement, modeling, solvent effect, and thermodynamics

The crystallization of taurine in pure water results in a low yield. Introducing anti-solvents during the cooling crystallization process would increase the yield. Therefore, measuring and evaluating the solubility of taurine in different binary aqueous solvents is necessary. In this work, the qualitative trend of the solubility of taurine in the binary solvent systems of 1,2-propanediol-water, acetonitrile–water, and ethylene glycol–water was first predicted using Hansen Solubility Parameters (HSPs), and then experimentally determined using isothermal gravimetric method. The experimentally obtained solubility is correlated with the modified Apelblat model as a linear model, and NRTL, UNIQUAC, Wilson, and λh model as nonlinear models. The solubility of taurine in binary solvents is further analyzed using the KAT-LSER model to investigate the solvent effect on solubility. For all researched systems, the standard molar enthalpy and the standard molar Gibbs energy changes are computed and found to be positive, indicating the dissolution of taurine is an endothermic process.

Solubility measurement, correlation and dissolution thermodynamics properties of marbofloxacin in binary solvents

Marbofloxacin (MAB) is a broad-spectrum veterinary antibacterial drug with the great application prospects. The solid-liquid equilibrium solubility of MAB in three kinds of aqueous binary solvent systems (ethanol + water, acetonitrile + water, and methanol + water) was determined between 283.15 and 323.15 K using a dynamic laser-monitoring method at atmospheric pressure. The experimental results revealed that the solubility of MAB increased with increasing temperature and mole fraction of water in the three binary solvent systems. The modified Apelblat, λh, and (non-random two-liquid) NRTL models were used to correlate the experimental data. For the ethanol + water system, the modified Apelblat model provided a better correlation with the experimental results than the other two models. However, for the acetonitrile + water and methanol + water systems, the most favorable correlation was obtained using the NRTL model. Furthermore, the van’t Hoff equation was used to study the thermodynamic properties of MAB. The obtained solubility data and thermodynamic properties of MAB can provide theoretical guidance for selecting the appropriate solvent system for the reaction, crystallization, and purification of MAB.

Interaction of methylene blue with SDS in the premicellar solution of CPC in the aqueous and methanol-water system

Interactions between sodium dodecyl sulfate (SDS) and methylene blue (MB) have been studied in presence of cetylpyridinium chloride (CPC) in aqueous and methanol-water binary solvents via conductometric and tensiometric methods. The experiment was conducted to see the possibility of a synergistic effect of the SDS+CPC system and changes in the interactional behavior of SDS with MB in presence of CPC. The value of the molecular interaction parameter for micellization (βM) was found to be negative from the experimental results and the value of |βM| was found to be greater than ln(CMCSDS / CMCCPC), which didn’t describe synergism completely but indicated the strong striking interactions between the oppositely charged surfactants. However, the CMC of the SDS+CPC system was found to be very low as compared to the CMC of SDS alone. This result of CMC based on striking interactions between oppositely charged surfactants was used to calculate various parameters like Gibb’s free energy of micellization (∆Gmo), surface excess(Γmax), minimum surface area (Amin), surface pressure πCMC, standard free energy of adsorption (∆Gadso), pC20, minimum surface free energy (Gmins), packing parameter (P) and association equilibrium constant (K). The addition of methanol as a cosolvent enhances the CMC and α value of the SDS+CPC as well as the SDS+CPC-MB system. Correlation of ∆Gmo with different solvent parameters namely Gordon parameter (G), Reichardt's parameter (ET (30)), viscosity (ηo), and solvophobic parameter (SP) has also been evaluated.

Determination and Correlation of Solubility of Metformin Hydrochloride in Aqueous Binary Solvents from 283.15 to 323.15 K.

Metformin hydrochloride (MET·HCl) is one of the most widely used oral hypoglycemic drugs in the world. In addition to hypoglycemic effects, MET·HCl also has anti-inflammatory, anti-tumor, anti-aging, and other effects, showing good efficacy and safety of single and combined treatment. The solubility of MET·HCl in water, water + N,N-dimethylformamide, water + acetonitrile, and water + n-propanol was measured by the gravimetric method under atmospheric pressure at temperatures ranging from 283.15 to 323.15 K. The solubility of MET·HCl has a positive correlation with temperature and water content. The experimental solubility data in binary solvents was correlated by the modified Apelblat model, CNIBS/R-K model, Apelblat–Jouyban–Acree model, and λh model. By comparing the average ARD % values of the four models, it is found that the modified Apelblat model (ARD % = 1.26) provides better correlation. Hansen solubility parameters and apparent thermodynamic parameters were calculated to analyze the solubility behavior, indicating that the dissolution process is endothermic and entropically favorable.

Catalytic Oxidation of Ethylene in Solutions of Palladium(II) Cationic Complexes in Binary and Ternary Aqueous Organic Solvents

Catalytic Oxidation of Ethylene in Solutions of Palladium(II) Cationic Complexes in Binary and Ternary Aqueous Organic Solvents

Experimental and Theoretical Screening for Green Solvents Improving Sulfamethizole Solubility.

Solubility enhancement of poorly soluble active pharmaceutical ingredients is of crucial importance for drug development and processing. Extensive experimental screening is limited due to the vast number of potential solvent combinations. Hence, theoretical models can offer valuable hints for guiding experiments aimed at providing solubility data. In this paper, we explore the possibility of applying quantum-chemistry-derived molecular descriptors, adequate for development of an ensemble of neural networks model (ENNM), for solubility computations of sulfamethizole (SMT) in neat and aqueous binary solvent mixtures. The machine learning procedure utilized information encoded in σ-potential profiles computed using the COSMO-RS approach. The resulting nonlinear model is accurate in backcomputing SMT solubility and allowed for extensive screening of green solvents. Since the experimental characteristics of SMT solubility are limited, the data pool was extended by new solubility measurements in water, five neat organic solvents (acetonitrile, N,N-dimethylformamide, dimethyl sulfoxide, 1,4-dioxane, and methanol), and their aqueous binary mixtures at 298.15, 303.15, 308.15, and 313.15 K. Experimentally determined order of decreasing SMT solubility in neat solvents is the following: N,N-dimethylformamide > dimethyl sulfoxide > methanol > acetonitrile > 1,4dioxane >> water, in all studied temperatures. Similar trends are observed for aqueous binary mixtures. Since N,N-dimethylformamide is not considered as a green solvent, the more acceptable replacers were searched for using the developed model. This step led to the conclusion that 4-formylmorpholine is a real alternative to N,N-dimethylformamide, fulfilling all requirements of both high dissolution potential and environmental friendliness.

The Solubility Profile of 3,4,5-Trimethoxybenzaldehyde in Aqueous Binary Solvent Mixtures at Several Temperatures

The Solubility Profile of 3,4,5-Trimethoxybenzaldehyde in Aqueous Binary Solvent Mixtures at Several Temperatures

Solubility Measurement and Data Correlation of Metformin Hydrochloride in Four Aqueous Binary Solvents and Three Pure Solvents from 283.15 to 323.15 K

Solubility Measurement and Data Correlation of Metformin Hydrochloride in Four Aqueous Binary Solvents and Three Pure Solvents from 283.15 to 323.15 K