Journal of Chemical & Engineering Data最新文献

In this work, we present new density measurements of benzyl alcohol and 1-heptanol from 283.15 to 363.15 K up to 65 MPa and ±2-octanol from 283.15 to 358.15 K up to 50 MPa. The density was obtained using a vibrating tube densimeter employing the Forced Path Mechanical Calibration method. The combined standard density uncertainty is 0.00035 g·cm^–3 for benzyl alcohol and 1-heptanol, while for ±2-octanol (racemic mixture), it is 0.00045 g·cm^–3. The density data are correlated with a multiparametric equation of state explicit in the compressibility factor. We have correlated the density with the equation of state within an average absolute percentage deviation of (0.058, 0.085, and 0.077) % for benzyl alcohol, ±2-octanol, and 1-heptanol, respectively. Isobaric expansibility and isothermal compressibility are calculated from the multiparametric equation within an average absolute percentage deviation of 6% from values reported in the literature.

The density and isobaric phase equilibria of the binary system methylcyclopentane + ethyl acetate were investigated for the first time in this work. The density of the system was measured at 101 kPa from 288.15 to 308.15 K for the entire composition range thanks to a vibrating tube densimeter. Positive excess molar volumes were observed and correlated by using a Redlich–Kister equation. New isobaric vapor–liquid equilibrium data for the system methylcyclopentane + ethyl acetate were measured by means of a recirculation ebulliometer. The phase equilibrium was measured at 25, 50, and 101.3 kPa. Equilibrium compositions were determined indirectly from density measurements of the liquid and condensed vapor phases. Some additional density and vapor–liquid equilibrium data measurements for the binary system ethyl acetate + methylcyclohexane were performed for comparison with previously published results and validation of the experimental protocol. The methylcyclopentane + ethyl acetate binary mixture displays pronounced positive deviations from ideality and a positive azeotrope. Three thermodynamic consistency tests were employed to validate the produced data set. The reported data were successfully correlated by the NRTL model, and the modified UNIFAC predictive model was also used. UNIFAC provides a very good description of the phase behavior at 101.3 kPa, whereas predictions are less accurate at low pressures (25 and 50 kPa).

Esculetin is derived from the leaves of lemons of Rutaceae and the bark of bittersweet ash, belladonna, mandala, and Rehmannia plants. In this research, the solubility of esculetin in ten solvents such as ethyl acetate, isobutyl alcohol, water, methanol, acetonitrile, n-propyl alcohol, isopropyl alcohol, n-butanol, ethanol, and acetone was determined by utilizing static equilibrium-high performance liquid chromatography (HPLC) under standard atmospheric pressure conditions and temperatures in the range of 273.15 to 318.15 K. Among the above ten pure solvents, water displayed the least solubility, while methanol exhibited the highest solubility. At the same temperature (T = 273.15 ∼ 318.15 K), the solubility of esculetin increased with the increase of the molar ratio of soluble solvents. Similarly, when the temperature increases (T = 273.15 ∼ 318.15 K), the solubility of the three binary solvents increases under the condition of a constant molar ratio. The above results suggest that the main factor affecting the solubility of esculetin in the solvent may be the polarization/bipolarity of the solvent. The experimental data was fitted by five thermodynamic models (the Buchowski–Ksiazaczak λh model, the Modified Apelblat model, the Jouyban–Acree model, the SUN model, and the CNIBS/R-K model), and the relative average deviation and root-mean-square deviation of the data were calculated, which proved that the correlation of the solubility data and the five models was relatively good. XRD and DSC were used to detect the crystal form and stability of esculetin during the experiment.

This article presents the results of equilibrium tests regarding the development of a new waste-free technology for converting ammonium nitrate(V) to potassium nitrate(V) using potassium metavanadate. To establish the best conditions for disposing of postfiltration liquor from the soda-chlorine-saltpeter (SCS) production process, a detailed analysis of the isotherm in the five-component system KNO₃ + NH₄NO₃ + KVO₃ + NH₄VO₃ + H₂O was required. Equilibrium tests were carried out by isothermal saturation of solutions method at temperatures of 293.15 and 313.15 K. The results obtained were used to plot solubility isotherms using the Jänecke method. The maximum conversion efficiencies of ammonium nitrate(V) to ammonium metavanadate are 97.53% at T = 293.15 K and 98.69% at T = 313.15 K based on the data for the triple point P₁. These results, along with literature data, were used to prepare a material balance for the proposed technological concept for the disposal of postfiltration liquor using the SCS method.

In the present study, measurements of the experimental density (ρ), speed of sound (c), and refractive index (n_D) of binary liquid mixtures of ethyl lactate (EL) with 2-aminoethanol (2-AE), 2-chloroethanol (2-CE), and ethyl acetate (EA) have been carried out within the temperature range from 298.15 to 323.15 K with an interval of 5 K and at 0.1 MPa. Excess volume (V^E), isentropic compressibility (k_s), excess isentropic compressibility (k_s^E), and excess refractive index (n_D^E) for the above liquid mixtures were calculated from the experimental measurements and they were correlated with the Redlich–Kister equation. Also, we obtained good fitting results in the computation of the density with perturbed chain statistical associating fluid theory equation of state and predictive results in the computation of the refractive index and speed of sound with several mixing rules and Nomoto’s relation, respectively. Further, we measured the Fourier-transform infrared (FT-IR) spectral data of pure liquids and their mixtures at different concentrations and simulated the molecular interactions using density functional theory (DFT) calculations for the 3 sets of binary systems with the ADF 2020.102 package at the GGA BP86-D3 level of theory with TZP. Apart from these, the type and nature of molecular interactions and structural effects were studied between the component molecules with the aid of excess thermodynamic properties, FT-IR measurements, and DFT calculations.

The thermochemical characteristics of bistetrazole dioxide salts with 7 cations were calculated for various arrangements (1.1; 1.2, and 2.2) of N-oxide groups. The volume-based thermodynamics method, the additive method (Method of Adding of Ions Contributions), and the method for determining the enthalpy of salt formation by mixing the ionic and neutral components of enthalpy (MICCM) were used, the latter of which is in good agreement with the experimental data and gives the best calculated results compared to other methods known in the literature. For an additive approach to estimating the enthalpies of salt formation, the corresponding contributions of anions have been developed, which enables a significant expansion of the range of salts currently available for calculations. The methods of quantum chemistry and atom–atom potentials were used to simulate the crystal lattices of individual compounds and cocrystals in the 11 most frequently implemented space groups for subsequent use of these results in calculations by the MICCM method. Possible previously unknown polymorphic structures of bistetrazole dioxide salts are predicted.

Single crystals of 2-tert-butyl-5-methylphenol anhydrate and 2-tert-butyl-5-methylphenol quarterhydrate were prepared and presented for the first time in this work. The structures were characterized by single-crystal X-ray diffraction and DSC analysis. The solid–liquid equilibrium (SLE) for 2-tert-butyl-4-methylphenol with 2-tert-butyl-5-methylphenol anhydrate or 2-tert-butyl-5-methylphenol quarterhydrate was studied by the cooling–heating recycling method using a synthetic visual technique at atmospheric pressure (101.6 ± 1.2 kPa). The experimental SLE data for the two binary systems were reported, and both systems showed simple eutectic behavior. The SLE data were further correlated by Wilson and NRTL (nonrandom two-liquid) models, and the optimally fitted parameters of the two systems were presented. Computational studies on geometric optimization and energy calculation were performed using density functional theory, and the lower energy configuration of 2-tert-butyl-5-methylphenol quarterhydrate could explain the spontaneous incorporation of water in the anhydrous form. These novel data provide valuable information in designing and optimizing the melt crystallization process of tert-butylmethylphenol isomers.