JOURNAL OF CHEMICAL THERMODYNAMICS
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2021
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IF 3.178
Rui-Zhi Cui,Yong-Ming Zhang,Ya-Ping Dong,Wu Li
In this paper, the solubility of unreported systems LiBr–NaBr–Li 2 SO 4 –Na 2 SO 4 –H 2 O, LiBr–KBr–Li 2 SO 4 –K 2 SO 4 –H 2 O and the subsystem LiBr–Li 2 SO 4 –H 2 O was measured by isothermal dissolution method at 298.15 K. Three phase diagrams are also given. It was found that the diagram of LiBr–Li 2 SO 4 –H 2 O system has only one invariant point of LiBr·2H 2 O + Li 2 SO 4 ·H 2 O. The phase diagram of LiBr–NaBr–Li 2 SO 4 –Na 2 SO 4 –H 2 O system includes eight crystallization regions LiBr·2H 2 O, Li 2 SO 4 ·H 2 O, NaBr·2H 2 O, NaBr, Na 2 SO 4 ·10H 2 O, Na 2 SO 4 , Li 2 SO 4 ·3Na 2 SO 4 ·12H 2 O, and Li 2 SO 4 ·Na 2 SO 4 . Five crystallization regions corresponded to two single salts KBr and K 2 SO 4 , two hydrate salts Li 2 SO 4 ·H 2 O and LiBr·2H 2 O, and one double salt Li 2 SO 4 ·K 2 SO 4 in LiBr–KBr–Li 2 SO 4 –K 2 SO 4 –H 2 O system. The relevant Pitzer parameter was obtained and the result predicted by Pitzer model was consistent with the experimental values.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
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IF 2.694
Yangyi Huang,Yuning Zhang,Haoran Liu,Weiping Luo
In this study, the solubilities of isophthalic acid (IPA) in N-methylformamide (NMFM), N-methylformanilide (NMFL), propanoic acid (PA), sulfolane, and dimethyl sulfoxide (DMSO) and m-toluic acid (m-TA) in acetone, cyclohexanone (CYC), 1-methyl-2-pyrrolidinone, NMFM, NMFL, N,N-dimethylformamide, PA, sulfolane, and DMSO were determined by the dynamic laser method at atmospheric pressure (101.2 kPa), and the solubility ratios between IPA and m-TA in different solvents were calculated. The temperature range of the experiment was between 290.15 and 348.15 K, in which the solubilities of IPA and m-TA in selected solvents were positively correlated with temperature. The maximum ratio between the mole fraction of solubilities of m-TA and IPA was in CYC and ranged from 68 to 84 for the temperature range under study. The experimental data were correlated by the Apelblat model, the Buchowski–Ksiazczak λh model, and the modified nonrandom two-liquid (NRTL) activity coefficient model.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Jian Yang,Jiangtao Wu,Shengshan Bi
As the main components of synthetic hydrocarbons obtained using gas to liquid conversion technologies, long-chain alkanes and alcohols play an important role in the Fischer–Tropsch process. So the reliable surface tension data of these fluids are significant for the understanding and eventual improvement of synthesis efficiency. In the present study, a new high temperature and high pressure pendant drop apparatus was developed and tested with n-heptane at temperatures from (303.15 to 473.15) K, and a good agreement between the experimental data and the literature data could be found. With the new apparatus, the experimental surface tension measurements of n-dodecane, n-hexadecane, 2,2,4,4,6,8,8-heptamethylnonane, n-octacosane, squalane, 1-dodecanol, 1,12-dodecandiol, 2-butyl-1-octanol, 1-hexadecanol and 2-hexyl-1-decanol were performed under saturation conditions over the temperature range from 303.15 K (348.15 K for n-octacosane and 1-hexadecanol, 373.15 K for 1,12-dodecandiol) to 573.15 K. The combined expanded uncertainties of temperature and surface tension with a level of confidence of 0.95 (k = 2) are estimated to be 20 mK and less than 1.5% over the entire temperature, respectively. Furthermore, the surface tension data were correlated with the modified van der Waals equation, and the average absolute deviations are within 0.65%. On the basis of the correlations, the comparisons of our experimental data with the available literature data were discussed, and the satisfactory agreement revealed that the experimental results of this work were reliable and reasonable.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2020
·Vol. 36
·期 6
·1234-1240
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IF 1.063
Cui Ruizhi,Li Wu,Dong Yaping,Li Jun
The stable phase equilibria of quaternary systems LiBr-NaBr-MgBr 2 -H 2 O and LiBr-KBr-MgBr 2 -H 2 O at 298.15 K were studied by both experimental measurement(isothermal solution saturation method) and theoretical prediction(Pitzer model). The solubilities of the saturated solution have been determined experimentally and two stable phase diagrams and relevant water diagrams of the two quaternary systems were obtained. Results show that quaternary system LiBr-NaBr-MgBr 2 -H 2 O is hydrate II type as NaBr and NaBr·2H 2 O coexistence. Its phase diagram consists of only one invariant point, four univariant curves, and five crystallization fields. The quaternary system LiBr-KBr-MgBr 2 -H 2 O is a complex type as the double salt KBr·MgBr 2 ·6H 2 O formed. In addition to this double salt, the three single salts LiBr·2H 2 O, KBr and MgBr 2 ·6H 2 O also crystallize. In this paper, the solubilities of phase equilibria in above quaternary systems were also calculated by the Pitzer’s electrolyte solution model. All the needed parameters can be obtained from the literature or be fitted by experimental data. On the Basis of the experimental and calculated results, the phase diagram of the quaternary system was plotted for comparison. It shows that the calculation results are consistent with the experimental ones.
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CATALYSIS LETTERS
·
2020
·Vol. 150
·期 8
·2437-2445
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IF 2.482
Yang Zhi,Luo Mingsheng,Liu Qinglong,Shi Buchang
A potassium- and copper-modified iron-based catalyst (K–Cu–Fe/SiO 2 ) was synthesized by the co-precipitated method. The general structural properties of the catalyst were characterized with various techniques, including SEM, XRD, H 2 -TPR, N 2 adsorption–desorption and Raman spectroscopy. The results reveal that the fresh catalyst is mainly composed of α-Fe 2 O 3 phase with rod-shaped morphology formed by nanoparticles. The effect of activation process on the Fischer–Tropsch synthesis catalytic performance was then investigated. It shows that activation process has an important influence on the reactive stability. The in situ XRD and in situ Raman spectroscopy were used to study the structural changes of the Fe-based catalyst during reduction and reaction processes. The Fe 2 C iron carbide as the main active phase was observed after reduction process. Graphic Abstract
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ZEITSCHRIFT FUR PHYSIKALISCHE CHEMIE-INTERNATIONAL JOURNAL OF RESEARCH IN PHYSICAL CHEMISTRY & CHEMICAL PHYSICS
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2020
·Vol. 235
·期 4
·451-466
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IF 2.03
Yuli Xue,Yan Zhang,Xiaoling Tan,Wenqing Li,Zhongshu Li,Shaonan Xu,Peng Zhang,Jian Wang,Peiping Zhang,Shiding Miao
It is of importance to reclaim single-salt of potash from Li + -type brines of low concentration. In this work the potassium salts KHCO 3 was efficiently separated from the lithium carbonate-type brines with the aid of CO 2 carbonation. The phase field was provided in which the precipitation of KHCO 3 occurs and single-salt of potassium can be obtained. The low concentration of [Li + ] was also successfully concentrated to a high level (8.1 g/L), and this concentration can be used as sources for Li + -salts production using pre-developed strategies, which looks forward wider applications of the lithium resources of natural brine. This state-of-art was traced via isotherm evaporation on the quaternary system of Li + –K + –CO 3 2− –H 2 O at 298.15 K in which the carbonation steps were performed by CO 2 . Metastable phase diagram was found to consist of three invariant points, seven univariant curves, and four crystallization fields corresponding to Li 2 CO 3 , KHCO 3 , potassium carbonate sesquihydrate (K 2 CO 3 ⋅ 3/2H 2 O), and a potassium carbonate and potassium bicarbonate double salt (K 2 CO 3 ⋅ 2 KHCO 3 ⋅ 1.5H 2 O). There was no crystallization field corresponding to LiHCO 3 . The pH-composition diagram and density-composition diagram were also plotted. This work was carried out in aim of extracting/separating single salts of alkali metals from carbonate-type brines of west China.
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Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 22
·7476-7484
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IF 7.059
Xudong Zhou,Xiaoyun Liu,Zhongkai Cui,Jinlou Gu,Shaoliang Lin,Qixin Zhuang
A new-type of hollow silica@ZIF-8 (HMS@ZIF-8) particle was successfully designed, fabricated and introduced into the fluorinated polybenzoxazole (6FPBO) matrix to prepare the HMS@ZIF-8/6FPBO composite film. Metal–organic frameworks (MOFs) were connected to the surface of hollow silica via covalent bonds, leading to the formation of a shell. Pre-6FPBO prepared from a precursor could be dissolved in organic solvents besides strong corrosive acids, which could protect the filler. HMS@ZIF-8/6FPBO composite films prepared through in situ polymerization and coating exhibited outstanding properties. At both high and room temperatures, the material exhibited excellent dielectric properties. The dielectric constant and dielectric loss decreased down to 2.12 and 0.04, respectively under 1 kHz with the filling of HMS@ZIF-8 particles. HMS@ZIF-8 particles as a filler, evenly dispersed in the matrix, could also improve the tensile modulus of 6FPBO. The tensile modulus of HMS@ZIF-8/6FPBO (6 wt%) increased up to 2.11 GPa, 54% higher than that of the pure 6FPBO matrix. Meanwhile, the composite films demonstrated excellent thermal stability, i.e. the 5% weight loss temperature was higher than 520 °C. This is the first report on MOFs being applied as low dielectric absorbing materials. We believe that the HMS@ZIF-8/6FPBO composite film designed and developed based on this strategy is suitable to be employed in large-scale integrated circuits owing to its excellent dielectric performance, mechanical properties and thermal stability.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
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IF 2.369
Shengzheng Guo,Yang He,Gang Wang,Weibing Dong,Xuxing Wan,Yanxiao Zhao,Shichao Du
The solubility of N-acetyl-l-leucine in 12 mono organic solvents (methanol, ethanol, n-propanol, 2-propanol, 1-butanol, isobutanol, 2-butanol, methyl acetate, ethyl acetate, propyl acetate, acetone, and acetonitrile) was determined by the gravimetric method over the temperatures ranging from 283.15 to 323.15 K at 0.1 MPa. The solubility of N-acetyl-l-leucine in each experimental solvent increases with increasing temperature. Moreover, the solubility is an order of magnitude higher in alcohol solvents than in other solvents, which is mainly attributed to the hydrogen bond formation. In addition, the experimental solubility data are correlated by three models, including the modified Apelblat equation, λh equation, and the nonrandom two-liquid (NRTL) model. All of the average relative deviation % values are less than 3.72%, which indicates that the three models have satisfactory correlations. Furthermore, the mixing thermodynamic properties of N-acetyl-l-leucine in 12 mono solvents including ΔmixG0, ΔmixH0, and ΔmixS0 are calculated based on the NRTL model, indicating that the mixing process was spontaneous.
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JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Da Li,Ruyi He,Kunpeng Yang,Jiao Sha,Yameng Wan,Yu Li,Xinding Yao,Tao Li,Baozeng Ren
The solubility of thiamethoxam in nine single solvents (acetic acid, methanol, acetonitrile, 2-methoxyethanol, 2-ethoxyethanol, propionic acid, DMSO, 1,4-dioxane, DMA) and binary mixed solvents (methanol + acetonitrile) was measured by dynamic laser method from 278.15 K to 323.15 K under pressure of 101.2 kPa. Modified Apelblat equation, λh equation, NRTL model, and Wilson model were used to fit the experimental data of pure solvents; for mixed solvents, Modified Apelblat equation, λh equation, Jouyban-acree model and Wilson model were used for solubility data correlation. The results showed that the fitting value is in good agreement with the experimental value, the solubility of thiamethoxam in selected solvents increased with the increase of temperature. It was found that the solubility of thiamethoxam in mixtures with different proportions of methanol and acetonitrile was higher than that of two single solvent, which might be related to the bipolarity/polarizability of the solvent. What’s more, the mixing enthalpy, entropy, and Gibbs free energy in pure and mixed solvents were obtained according to the Wilson model, the value of Δ mix G is negative in the dissolution, the value of Δ mix S is positive, indicating that the mixing process in selected solvents was entropy-driven. When thiamethoxam dissolved in methanol, acetic acid, propionic acid, the value of Δ mix H is positive, which showed that thiamethoxam was endothermic during dissolution, When thiamethoxam dissolved in acetonitrile, 2-methoxyethanol, 2-ethoxyethanol, DMSO, 1, 4-dioxane, DMA and mixed solvents the value of Δ mix H is negative, which showed that thiamethoxam was exothermic during dissolution. The solubility data, solubility model and thermodynamic parameters of thiamethoxam are of great significance to the application of thiamethoxam industrial production and crystallization.
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JOURNAL OF MOLECULAR LIQUIDS
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2020
·
IF 5.065
Xiaojie Liu,Chunying Zhu,Taotao Fu,Youguang Ma
The densities and viscosities of ternary solution of piperazine (PZ) + 2-Amino-2-methyl-1-propanol (AMP) + H 2 O were measured at P = 101 kPa and T = (303.15–343.15) K. The effects of temperature and concentration on the density and viscosity of ternary solution were investigated. The apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), viscosity B -coefficient, Helper's constant and the free energies of activation per mole of solvent ( Δμ 1 0≠ ) and solute ( Δμ 2 0≠ ) were calculated from the density and viscosity, respectively. The solute-solute and solvent-solute interactions were analyzed from the volumetric and viscometric properties. The results show that the PZ has a destructive effect on the structure of mixed solvent.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Wenyang Fan,Houchun Yan,Xin Huang,Zhaohui Liao,Qingsong Li,Zhanhua Ma
The liquid–liquid equilibrium (LLE) data of ternary systems n-hexane + 1-hexene + solvents (furfural and N,N-dimethylformamide) were determined experimentally at 298.2, 308.2, and 318.2 K under 101.3 kPa. The solvents’ extraction capacity was assessed by the solute distribution coefficient and selectivity. Othmer-Tobias and Hand equations were used to correlate the measured data to test the correlation of the experimental data, which the linear correlation is (R2) ≥ 0.99. Experimental LLE data was correlated utilizing the NRTL and UNIQUAC thermodynamic models with all of the RMSD and AARD values below 0.01 meaning that each ternary system satisfactory agreement at temperatures studied and the NRTL model gives a better agreement than the UNIQUAC model for ternary systems.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Jiale Wang,Guang Yao,Dong Hu,Sheng Huang,Junqi Liu,Quan Zhu
In order to investigate the interactive effect on the density of two-component mixtures, six mixtures of methylcyclohexane(1) + n-dodecane(2)/n-tetradecane(2)/n-hexadecane(2) and ethylcyclohexane(1) + n-dodecane(2)/n-tetradecane(2)/n-hexadecane(2) were measured by using the Anton Paar DMA 4200 M densimeter and a hand-operated pressure pump in the temperature and pressure ranges of T = 280 to 423.15 K and P = 0.1 to 9 MPa, respectively. Additionally, the combined standard uncertainty in the density of binary mixtures with n-hexadecane is uc(ρ) = 1.543 kg/m3, and for other mixtures, it is uc(ρ) = 1.541 kg/m3. The experimental data were successfully correlated with the empirically modified Toscani–Szwarc equation of state with a maximum regression deviation of less than 1.0630 kg/m3 for all the binary mixtures. On the basis of the experimental data and parameters of the regression model, isobaric thermal expansivity and isothermal compressibility were calculated and exhibited nonlinear behavior against the mole fraction, which is due to different molecular interactions between the two components.
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