Journal of Solution Chemistry最新文献

The investigation carried out in this study focused on exploring the hydrogen bonding structure of liquid solutions of methyl lactate and 1-alkanols include 1-butanol, 1-pentanol, 1-hexanol, and 1-heptanol. To analyze the interactions between the molecules, the researcher utilized the cubic-plus-association (CPA) model, which takes into account both the physical and association interactions. The maximum deviation observed in the density of the liquid solutions of methyl lactate with 1-heptanol was 0.28%, indicating the effectiveness of the CPA model in accurately modeling the density. Additionally, the researchers calculated the excess molar volumes and deviation in viscosity for the studied liquid mixtures. The analysis of these measurements revealed that the solutions of methyl lactate with 1-alkanols exhibited positive excess molar volumes across the entire concentration range. On the other hand, negative viscosity deviations were observed for the mentioned alkanols. These findings suggest that there are weak intermolecular associations within the liquid solutions, with weaker bond strength observed in higher alkanols.

An aqueous two-phase system (ATPS) composed of PEG35000, Na₂CO₃, K₂CO₃, and their mixtures at 298 K was studied. The liquid–liquid equilibrium (LLE) of these systems, including binodal curves, tie-lines, tie-line length, and slope of the tie-line, were obtained. Additionally, for the first time, salt mixtures with different initial mass ratios of 1:3, 1:1, and 3:1 were used to prepare the aqueous two-phase systems. The effect of electrolyte and salting-out power for these systems was examined and compared. Consistent with the literature, it was found that the salting-out power of Na⁺ is higher than that of the K⁺ cation. Furthermore, in Na₂CO₃ and K₂CO₃ mixtures, increasing the amount of sodium ions resulted in stronger salting-out power. The LLE data was correlated with the Othmer-Tobias, Bancroft, and Setschenow models, and good agreement was found with all three models.

This review article provides an overview of the fundamental background and application of aqueous two-phase systems (ATPSs) in protein and enzyme extraction. The types of ATPSs, including polymer/salt, polymer/polymer, alcohol/salt, surfactant-based, and ionic liquid-based ATPSs, are discussed, along with the unconventional ATPSs. Factors affecting partitioning in ATPSs, such as molecular weight and polymer concentration, pH, temperature, hydrophobicity, and affinity, are also examined. The article then focuses on the application of ATPSs in protein and enzyme extraction, including continuous processing and scaling-up. The future prospects, challenges, and limitations of ATPSs in this field are discussed, along with the challenges associated with their use in industry. The results section highlights the potential of citrate green salts as an alternative to sulfate and phosphate salts in salt-based ATPSs and the need for more research on using ionic liquids as an additive in ATPS types for protein and enzyme extraction. Overall, this review suggests combining cheap and environmentally friendly materials in ATPSs can be a practical solution for using ATPSs in the industry.

Ciprofloxacin (CIPH) was classified as one of the most effective quinolone antibiotics, which is commonly used to cure a wide range of infections resulting from Gram-negative and Gram-positive microorganisms. The complexes which formed due to the interaction of Ni(II), Zn(II), Cu(II), Gd(III) and Sm(III) with ciprofloxacin were characterized by CHN% analysis, conductivity, FTIR, electronic spectra, fluorescence measurements, and magnetic susceptibility, besides studying the complex–DNA interaction. Meanwhile, the molar conductance values (0.001 mol·L⁻¹ in DMSO) revealed the electrolytic behavior of the complexes and could be designated with the A⁻B⁺ formula. In addition, the geometry of the compounds was confirmed from the electronic transitions as well as the μ_eff values as octahedral for all complexes. The postulated formula could be generally assigned as [M(CIP)_a(CIPH)_b(H₂O)_c](NO₃)(H₂O)_n(C₂H₅OH)_m. Moreover, the interaction between metal complexes and DNA revealed that the Cu complex had the highest binding constant. Nanotechnology was applied to synthesized compounds using silica nanoparticles (SiNPs), which were prepared using a sol–gel process. The silica nanoparticles were chemically functionalized for binding the ligand and its metal complexes; this enables the as-prepared compounds to enhance their features as a drug delivery platform. Meanwhile, the antimicrobial activity was tested for the free complexes and SiNPs composites. Collectively, Sm complex gave the largest zone of inhibition, while the Cu(II)–SiNPs composite showed the strongest potential to reduce the bacterial activity. Furthermore, the fluorescence data of CIPH, ligand–metal mixture and the effect of silica nanoparticles on them were studied.

The use of experimental parameters to quantify solvent properties, for example in linear free energy relationships, is well established and several scales of solvent acidity, basicity and polarity/polarizability have been developed. The success of this approach raises questions of which molecular properties contribute to particular solvent parameters and whether these contributions are found in all parameters representing a particular solvent property. In the present study, Catalan’s hydrogen bond basicity and acidity parameters, SB and SA, and Gutmann’s acceptor number, AN, a measure of a solvent’s Lewis acidity, are correlated with molecular properties derived from computational chemistry. The results are compared with the results of similar correlations with Kamlet and Taft’s β and α Solvent Scales, Gutmann’s donor number DN) and Abraham’s B and A solute scales. The results show that measures of solvent basicity, SB, β and DN all correlate strongly with the partial charge on the most negative atom in the solvent molecule and the energy of the donor orbital and, in all cases, the parameter values for hydrogen-bonded solvents are anomalous. Abraham’s B, a measure of solute hydrogen basicity, depends only on the partial charge on the most negative atom and there is no anomaly in the values for solutes that, in the pure state, form hydrogen-bonded liquids. Similarly, all measures of solvent acidity, SA, α and AN, and Abraham’s A, a measure of solute hydrogen bond acidity, depend on the partial charge on the most positive hydrogen on the molecule.

Two novel hydrophobic deep eutectic solvents (HDESs), composed of alkyl (=Hexyl, Nonan) ethylenediaminium and menthol (Men), namely Hexen/Men and Nonen/Men, were synthesized. Hexen and Nonen primarily act as hydrogen bond acceptors, with Men serving as the principal hydrogen bond donor. After the formation of HDES, the IR absorption peaks of Hexen, Nonen's–NH₂, and Men–OH fused into a wider peak, the ¹H-NMR spectra of Men–OH, shifted to a lower field. Furthermore, a significant redshift approximately 300 cm⁻¹ was detected in the vibrational frequency of the Men–OH functional group when performing density functional theory (DFT) calculations for the HDESs. These results support the development of stronger O–H···N bonds between Hexen/Nonen–NH₂ and Men–OH, and the calculated sum of hydrogen bonding energy was approximately 56 mol·kg^–1, categorizing it as an intermediate-strength hydrogen bond. Both HDESs have ethylenediamine polar heads in their hydrogen bond acceptors, which have chelating characteristics that help them coordinate with transition metal ions. Metal ions such as Cu(II), Co(II), and Ni(II) were successfully extracted from aqueous solutions at a concentration of 10 mmol·L^–1using HDESs. The Cu(II) and Ni(II) extraction efficiencies exceeded 90%, indicating their effectiveness. Notably, even at higher metal ion concentrations (100 mmol·L^–1), the extraction efficiencies of all three metal ions remained consistently below 80%. This indicates that the HDESs can suitably collect trace metal ions.

In this work, thermodynamic properties of ternary (NaNO₃ + DMF + water) system were reported using the potentiometric method. The electromotive force measurements were performed on the galvanic cell of the type: ({text{NO}}_{{3}} {text{ - ISE}}left| {{text{NaNO}}_{{3}} left( m right),{text{DMF}}left( {w% } right),{text{H}}_{{2}} {text{O }}({1} - w)% } right|{text{Na - ISE}}), in various mixed solvent systems containing 0, 5, 10, 15 and 20% mass fractions of DMF over total ionic strengths from 0.0100 to 2.500 mol·kg⁻¹ at T =  (298.2, 303.2 and 308.2) K and P = 0.1 MPa. The experimental activity coefficients of NaNO₃ were analysed using extended Debye–Hückel equation, Pitzer ion interaction model and Scatchard equation. The Pitzer adjustable parameters were used to calculate (gamma_{ pm } ,varphi , , {{G^{{text{E}}} } mathord{left/ {vphantom {{G^{{text{E}}} } {n{text{R}}T}}} right. kern-0pt} {n{{R}}T}}, , {{H^{{text{E}}} } mathord{left/ {vphantom {{H^{{text{E}}} } {n{{R}}T}}} right. kern-0pt} {n{{R}}T}},{text{and}},{{S^{{text{E}}} } mathord{left/ {vphantom {{S^{{text{E}}} } {n{text{R}}}}} right. kern-0pt} {n{{R}}}}). Also, Scatchard parameters were used to calculate ({{{gamma_{N}^{{left( {2} right)}} } mathord{left/ {vphantom {{gamma_{N}^{{left( {2} right)}} } {gamma_{N}^{{left( {1} right)}} }}} right. kern-0pt} {gamma_{N}^{{left( {1} right)}} }}}) for the whole series of under investigation system.