Journal of Solution Chemistry最新文献

l-Aspartic acid (ASP) and l-glutamic acid (GLU) in aqueous solution of a food additive, sodium acetate (SA) have been taken for acoustic and conductometric studies. The experimental results are analysed to predict and assess the solvation behaviour and types of interactions occurring in these ternary solutions [ASP/GLU + SA + water]. Compressibility parameters like isentropic compressibility and apparent molar isentropic compressibility along with their values at infinite dilution have been computed. Transfer values and ion pair and triplet interactions have been determined. Other thermodynamic parameters like internal pressure, molar free volume, relative association and acoustic impedance, have also been derived from the acoustic data. Specific conductance values measured experimentally led to the calculation of molar conduction of electric charge. Walden product sheds light on structure building or breaking properties of the amino acids. Gibbs thermodynamic functions predict the spontaneity of ion association process. Arrhenius equation is used to calculate activation energy which is indicative of the formation of high-energy transition state required for migration of ions. Analysis of these results establishes the amino acids as water-structure forming agents and predominance of ion–solvent, ion–ion and ion–hydrophilic interactions in the studied systems.

Fourier transform infrared spectral studies have been carried out on pure 1-propanol (PrOH), pure ethyl acetate (AcOEt), and 1:1 (ethyl acetate: 1-propanol), 1:2, 1:3, 2:1 and 3:1 binary solutions at room temperature. The broad hydroxyl stretching band of pure PrOH has been deconvoluted into six Gaussian profiles which have been assigned to the O–H stretching bands of monomer, open dimer (free and bonded O–H), closed trimer, closed tetramer and closed pentamer units with the aid of density functional theory frequency calculations. The carbonyl stretching bands of monomer and closed dimer of ethyl acetate have also been discussed. The classical and non-classical H-bond interactions of n-mers of 1-propanol with ethyl acetate monomer and dimer in the solutions have been investigated using the frequency shift of the hydrogen bond donor and acceptor bond stretching bands of PrOH and AcOEt. The concentration of PrOH/AcOEt-dependent PrOH n-mer-AcOEt complexation order has been analysed.

May and Filella (J Solution Chem 52:754–761, 2023) concluded that they had verified the data in Gamsjäger et al. (Chemical thermodynamics of tin OECD, Nuclear Energy Agency Data Bank, Leoben, 2012). However, they used exactly the same primary data and not surprisingly came up with essentially the same values. They (1) provided no new data; (2) did not comment on/re-evaluate the existing experimental data (e.g., Sn–Cl complexes) that determine the accuracy of the E⁰ value for the (Sn⁴⁺/Sn²⁺) couple, but instead relied on a calculated value that is precise but of questionable accuracy; (3) disregarded extensive cassiterite (SnO₂(cass)) solubility data that is critical to (a) ascertaining the accuracy of the E⁰ value based on ({mathrm{Sn}(mathrm{Cl})}_{y}^{4-mathrm{y}}) complexes presented in Gamsjäger et al. (2012) and May and Filella (2023), (b) determining the solubility product of SnO₂(cass), and (c) determining reliable overall K⁰ values for SnO₂(s) solubility reactions involving ({mathrm{Sn}(mathrm{OH})}_{n}^{4-n}) instead of Sn⁴⁺; and (4) in no way help resolve the many orders of magnitude differences in reported K⁰ values for various Sn(IV)–OH system reactions. These issues were extensively addressed in Rai (J Solution Chem.51:1169–1186, 2022) and are briefly discussed herein, and they help to determine that, contrary to May and Filella’s (2023) conclusions, the Sn(IV)–OH system thermodynamic constants presented in Rai (2022) are indeed reliable.

The three-parameter extended Hückel equations with parameters B, b₁, and b₂ have recently been successfully tested against existing vapor pressure, electrochemical, and solubility data for aqueous NaCl solutions at temperatures from (273 to 373) K (Partanen and Partanen in J. Chem. Eng. Data 65:5226–5239, 2020). In the present study, we extend this model to the apparent and partial molar enthalpy data of these solutions. The enthalpy equations were determined using a new calculation method that gives practically the same results as that used in another previous study (Partanen et al. in J. Chem. Eng. Data 62:2617–2632, 2017), but the new method is much simpler. In the previous enthalpy study, dilute NaCl solutions up to m = 0.2 mol⋅kg⁻¹ were considered in the range from T = 273 to 353 K. Following the success of the three-parameter extended Hückel model within the whole concentration range at various temperatures, we tabulate new values for relative apparent and partial molar enthalpies for NaCl solutions at rounded molalities. The resulting values are extensively tested against the literature ones. The best agreement is obtained for temperatures below 288 K and between 313 and 353 K. Elsewhere, at least a reasonable agreement is obtained. As no enthalpy or heat capacity data were used in the estimation of our model’s parameters and as the model has excelled in explaining other high-precision thermodynamic data, we argue that the recommended enthalpy values should be preferred even for the temperatures where the agreement is only reasonable due to potential problems associated with the literature values. These problems are also considered in the study.

Graphical Abstract

Critical temperature, critical pressure and P–T–ρ–X data of acetone–water solutions with water mole fractions in a range of 0–60% were measured to provide fundamental data for CFD simulations. Critical temperatures were determined via observing critical opalescence in fused quartz capillary tubes. Meanwhile, critical pressures were measured by heating acetone–water solutions to its critical temperature in an autoclave. The standard deviations of critical temperature and critical pressure were 0.55 K and 0.029 MPa, respectively. The results indicate that only one phase exists during mixing of acetone with water. Moreover, P–T–ρ–X data under 15 and 20 MPa in the temperature range of 460–550 K were measured in the autoclave. The relative deviation of density was 0.32%. Volume-translated Peng-Robinson and Soave–Redlich–Kwong state equations were used to illustrate the P–V–T–X relationship of acetone–water solutions, and the Peng–Robinson state equation with an average absolute relative deviation of 1.19% between fitting and experimental densities was found more accurate.

The complexation between Al³⁺ ([Al(H₂O)₆]³⁺) and glycolic acid (GA, C₂H₄O₃) which has a carboxyl group and a hydroxyl group in a molecule was investigated under acidic condition using ²⁷Al NMR, ¹³C NMR and ESI–MS techniques. The five peaks including a peak due to Al³⁺ were observed in ²⁷Al NMR spectra for the mixed solution of Al³⁺ and GA, suggesting the existence of at least four Al-GA complexes. The results of NMR and ESI–MS measurements revealed that GA and Al³⁺ can form one monodentate complex (AlGA²⁺) and three bidentate complexes (AlGA⁺, AlGA₂⁻, and AlGA₃³⁻) complexes. From the deconvolution of ²⁷Al NMR spectra and pKa value of GA, the conditional formation constants (log₁₀ K) of each complex (GA/Al molar ratio of 25 in mixed solution) can be determined to be 0.94 (AlGA²⁺), − 0.96 (AlGA⁺), − 0.77 (AlGA₂⁻) and − 2.21 (AlGA₃³⁻), respectively. In addition, the overall formation constant of three bidentate complex at pH 3 was also calculated to be − 1.65.

Three imidazole anion-functionalized ionic liquids (IFILs) with tributylethylphosphonium ([P₄₄₄₂]⁺) cation and imidazolate ([Im]⁻), 4-methylimidazolate ([4-MeIm]⁻), or 4-bromimidazolate ([4-BrIm]⁻) anions were prepared to study the effect of physicochemical properties on CO₂ absorption behavior. Density (ρ), viscosity (η), and speed of sound (u) of the studied IFILs were measured, and molecular volume (V_m), standard entropy (S⁰), lattice energy (U_POT), and isentropic compressibility coefficient (κ_s) were calculated accordingly. CO₂ absorption behavior of [P₄₄₄₂][Im] at T = 313.15–333.15 K and p = 0.2 and 1 bar was investigated as an example. The results show that with the increase of temperature, ρ, η, u, and U_POT decrease, while V_m, S⁰, and κ_s increase, due to a decrease in electrostatic interaction correspondingly. The orders of ρ, u, η, V_m, and S⁰ values are as follows: [P₄₄₄₂][Im] < [P₄₄₄₂][4-MeIm] < [P₄₄₄₂][4-BrIm], while U_POT and κ_s are in reverse order. Interestingly, CO₂ capture capacity of IFILs is approximately linear with η or κ_s. Due to low η and high κ_s, CO₂ absorption capacity of [P₄₄₄₂][Im] is almost independent of temperature and partial pressure, as high as 0.90 mol CO₂/mol IL at 333.15 K and 0.2 bar, indicating that [P₄₄₄₂][Im] has potential applications for CO₂ absorption at high temperature and low pressure.

Vapor–liquid equilibrium data of binary systems (water + acetic acid, isopropanol + water, and acetic acid + isopropyl acetate), and ternary systems (water + acetic acid + 1-sulfobutyl-3-methylimidazolium hydrogen sulfate (ionic liquid, [HSO₃-bmim][HSO₄]), isopropanol + water + [HSO₃-bmim][HSO₄], and acetic acid + isopropyl acetate + [HSO₃-bmim][HSO₄]) were determined at 101.33 kPa. The nonrandom two-liquid (NRTL) model fitted well with the experimental data. The σ-profiles of water, acetic acid, isopropanol, isopropyl acetate, [HSO₃-bmim]⁺, and [HSO₄]⁻ were calculated using the COSMO-RS model. Furthermore, the binding abilities of [HSO₃-bmim][HSO₄] ionic liquid with water, acetic acid, isopropanol, and isopropyl acetate were analyzed by σ-profiles. The chemical and phase equilibrium data of acetic acid + isopropanol, and acetic acid + isopropanol + [HSO₃-bmim][HSO₄] systems were determined, meanwhile, the chemical equilibrium constant K_r was calculated. These results provided basic thermodynamic data for [HSO₃-bmim][HSO₄] as the catalyst for the esterification system of acetic acid with isopropanol.