JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2019
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IF 2.298
Kui Wu,Ya Jun Li
The solubility and solution thermodynamics of azacyclotridecan-2-one in different solvents are indispensable for the purification and performance improvement of crystalline products in industry. In this paper, the solid–liquid equilibrium of azacyclotridecan-2-one in 15 pure solvents (methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, ethyl acetate, acetone, toluene, acetonitrile, dichloromethane, 1,2-dichlorobenzene, cyclohexanone, and tetrahydrofuran) from 273.15 to 323.15 K at atmospheric pressure was measured. The mole fraction solubility increased with the increase in temperature in all solvents studied. The modified Apelblat equation, Van’t Hoff equation, Buchowski–Ksiazczak λh equation, and nonrandom two-liquid (NRTL) activity coefficient model were used to correlate the experimental data. Consequently, some association parameters were obtained. As a result, the NRTL model provided the best fitting. The solubility data provide the basic data for the design and optimization of the azacyclotridecan-2-one crystallization process.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2019
·
IF 2.298
Yibo Fang,Zanjun Gao,Kangli Bao,Jiongliang Huang,Xiaosheng Ji,Xiaohong Han,Guangming Chen
The working pairs of HFCs + organic absorption solvents are commonly used in absorption systems. In this work, the vapor–liquid equilibrium (VLE) data of HFC-32 + DMETrEG at (293.15–343.15) K and HFC-32 + NMP at (323.15–343.15) K were measured in a dual cycle apparatus. The VLE data were correlated by Antione-type equation, NRTL, and PR + MHV1 + NRTL model, respectively. The predicted VLE data showed a good agreement with the experimental VLE data. NRTL model was recommended to predict the VLE data and characteristic of solution for HFC-32 + DMETrEG and HFC-32 + NMP, compared to PR + MHV1 + NRTL model. The comparison of VLE characteristics for five binary mixtures (HFC-32 + DMETrEG, HFC-32 + NMP, HFC-32 + DMF, HFC-32 + DMAC, and HFC-32 + DMEDEG) was carried out. The compared results showed that the system pressures of HFC-32 + DMETrEG and HFC-32 + NMP were lower than other three mixtures, and the negative deviations from Raoult’s law of HFC-32 + DMETrEG and HFC-32 + NMP were larger than the others, which indicated that the two mixtures were more suitable as the working fluids for absorption system.
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CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Qinglong Liu,Mingsheng Luo,Zhen Zhao,Qiuna Zhao
Sn-containing dendritic mesoporous silica nanoparticles (Sn-DMSNs) were successfully prepared by the in-situ co-assembly method. Sn-DMSNs preserve original structural characteristics with three-dimensional and center-radial pore structure. The nanoparticle sizes of Sn-DMSNs can be controlled systematically from 170 nm to 360 nm depending on the molar ratio of NaSal/CTAB. Sn species are incorporated into the matrix of silica and the highly dispersed SnO x species are achieved. Sn-DMSNs catalysts exhibit excellent catalytic performance and stability in the propane dehydrogenation. The highly dispersed SnO x species rather than polymeric SnO x or crystalline SnO 2 species contribute to the activation of propane and formation of propylene. The molar ratio of NaSal/CTAB also shows an important role in the structure of support and SnO x species. The excellent stability of Sn-DMSNs catalysts can be ascribed to the good ability to restrain coke formation and strong interaction between SnO x species and silica. The effect of potassium on Sn-DMSNs catalyst is also investigated.
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FLUID PHASE EQUILIBRIA
·
2019
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IF 2.514
Taotao Zhan,Ying Zhang,Junshuai Chen,Xiangyang Liu,Maogang He
n -Hexane is a significant component of industrial fluids. The speed of sound in supercritical n –hexane was measured by Brillouin light scattering (BLS) technique in the temperature range from (509.17–637.99) K along five isobars at p = (3.5, 4.5, 5.5, 6.5 and 7.5) MPa. The relative expanded measurement uncertainty in the speed of sound at the 95% confidence level is estimated to be 0.018. For the studied supercritical n –hexane, the change regularities of the speed of sound with increasing temperature and pressure are illustrated. Moreover, the well-known equation of state (EOS) proposed by Span and Wagner is assessed, and the absolute average deviation (AAD) between the experimental results and the calculated values is 0.89% for the whole examined p – T region.
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SCIENCE OF THE TOTAL ENVIRONMENT
·
2019
·
IF 5.589
Jing Wei,Chen Tu,Guodong Yuan,Yongqiang Zhou,Hailong Wang,Jian Lu
Multiple spectroscopic technologies and chemometric analyses were combined to explore the compositional characteristics and Cu binding performance of biochar-derived dissolved organic matter (DOM). The DOM samples were extracted from biochars produced from lignocellulose-rich rapeseed cake (RSC) by pyrolysis at 300, 500, and 700 °C (i.e., RSC300, RSC500, RSC700). Fourier transform infrared spectroscopy (FTIR) and carbon K-edge near-edge X-ray absorption fine structure spectroscopy (NEXAFS) analyses were combined to elucidate the molecular-level C species in the DOM. With the increasing pyrolysis temperature, DOM aromaticity increased, whereas the proportion of metal complexing sites (e.g., carboxyl and phenolic groups) decreased. Fluorescence excitation-emission matrix (EEM) spectroscopy with parallel factor analysis (PARAFAC) indicated that biochar DOM, irrespective of pyrolysis temperature, was mostly composed of three types of humic-like components (C1–C3), and a small amount of a protein-like component (C4). As charring temperature increased, DOM concentrations decreased substantially, but the humic-like C3 with abundant aromatic structures became predominant. Fluorescence quenching experiment and two-dimensional correlation spectroscopy (2D-COS) analysis suggested that the preferential Cu(II) binding fractions of the DOM were the humic-like substances. Moreover, the quenching curve fitting results for individual components indicated that despite the Cu(II) binding affinity was slightly enhanced as the pyrolysis temperature increased, the binding capacities of the four components decreased. In general, the DOM components from RSC biochar exhibited limited Cu(II) binding capacities (2.18–17.7 μmol L −1 ). Results from this study improved understanding of the mechanisms by which biochar DOM interacts with Cu, and provided tools for fast screening of biochars to reduce their environmental risks.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2019
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IF 2.29
Kangrui Sun,Hanyu Zheng,Yafei Guo,Lingzong Meng,Tianlong Deng
This paper reports the densities of CsB 5 O 8 (aq) in the range of salt concentrations from 0.02526 to 0.08148 mol·kg −1 , which were determined by an accurate Anton Paar Digital vibrating-tube densimeter at 5 K intervals from 283.15 to 363.15 K and 101 kPa. The apparent molar volume ( V ϕ ), the coefficient of thermal expansion ( α ), apparent molar expansibility of the solute ( ϕ E ) were calculated and variations of these properties against temperature and concentration were revealed minutely. According to Pitzer ion-interaction apparent molar volume model of aqueous electrolyte system, the Pitzer single salt parameters i.e. F MX ( β M X 0 v , β M X 1 v and C M X v , M = Cs + , X = [B 5 O 6 (OH) 4 ] - ), the temperature-dependence equation [ F MX ( i , p , T ) = a 1 + a 2 ln(T/298.15) + a 3 (T-298.15) + a 4 /(620-T) + a 5 (T-227), i = β M X 0 v , β M X 1 v and C M X v ] as well as their coefficients a i ( i = 1 to 5) in the binary system were obtained, which is not reported in the literature. The fitted results of single salt parameters β M X 0 v , β M X 1 v and C M X v were in good agreement with the experiment values, indicating that the single salt parameters and temperature relational coefficients for Cs[B 5 O 6 (OH) 4 ] obtained in this work are reliable.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 15
·14736-14744
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IF 2.195
Pu Zejun,Xia Jialing,Zheng Xiaoyi,Wang Qi,Liu Jingyue,Zhong Jiachun
In this work, the encapsulated barium titanate (BT) (C-PEN@BT) nanoparticles were successfully prepared via rotary coating technology combined with a post-treatment chemical bonding process, by using carboxyl-functionalized poly(arylene ether nitrile) (C-PEN) as modification agent. The TEM, FTIR and TGA results confirmed that the polymer layer (about 8 nm) has been uniformly surrounded on the surface of BT nanoparticles. Then, a facilitated physical dispersion technology was employed to prepare C-PEN@BT filled composite films using crystalline PEN as matrix and 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPH) as a novel cross-linking agent. The effects of both the surface modification of BT nanoparticles and matrix cross-linking on the mechanical, thermal and dielectric properties of PEN-based composites were investigated in detail. Compared with PEN-I film, the latter results showed that the strong interface interactions exerted between polymer matrix and CPEN layer on BT surface, especially the formation of cross-linking network across the PEN matrix, resulted in increased tensile strength and Young’ modulus by 29% and 32%, respectively. More importantly, the PEN/C-PEN@BT composite film shows stable dielectric properties in the temperature range of 20–204 °C, which is very close to the glass transition temperature.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
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IF 2.037
Chuanfeng Zhang,Guangqian Li,Lei Yue,Yongsheng Guo,Wenjun Fang
Densities and viscosities have been measured over the whole composition ranges for the binary mixtures of 2,2,4-trimethylpentane with methylcyclohexane, ethylcyclohexane, or n-butylcyclohexane at temperatures T = (293.15 to 343.15) K and atmospheric pressure. Meanwhile, the refractive indices and surface tensions were measured at T = (293.15 to 323.15) K and T = (293.15 to 308.15) K, respectively. The excess molar volumes, VmE, the viscosity deviations, Δη, and the surface tension deviations, Δγ, for these binary systems are calculated and fitted to the Redlich–Kister equation, and the regression coefficients and the standard deviations of the fittings are given. All of the VmE, Δη and Δγ values are negative over the whole composition range for these systems. The values of ΔnD for these binary mixtures are all small, even negligible. These results may be useful for the development of the hydrocarbon fuels.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2015
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IF 2.037
Rongrong Li,Jian Wan,Yingjie Zhang,Danxia Liang,Bin Zhang,Chenghong Li
The equilibrium solubility of sodium 1-naphthalenesulfonate in binary NaCl + water, Na2SO4 + water, and C2H5OH + water solvent mixtures was measured by a steady-state method at elevated temperatures from (278.15 to 323.15) K. The results of these data were correlated by a modified Apelblat equation. The dissolution enthalpy (ΔHd) and entropy (ΔSd) of sodium 1-naphthalenesulfonate in solutions of different mole fraction were obtained.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2015
·Vol. 26
·期 10
·7823-7828
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IF 1.569
Zhang Biao,Ye Feng,Liu Shichao,Liu Qiang,Gao Ye
A simple method, which include cold isostatic pressing and vacuum assisted infiltration, that can significantly improve the filler content, was employed to fabricate Bisphenol-A cyanate ester resin (BADCy)/Ni 0.5 Ti 0.5 NbO 4 composites with high-k and ultra-low-loss. Results show that briquetting pressure and sintering temperature for fabricating Ni 0.5 Ti 0.5 NbO 4 porous preforms have a great influence on the properties of BADCy/Ni 0.5 Ti 0.5 NbO 4 composites. The optimal process for the fabrication of BADCy/Ni 0.5 Ti 0.5 NbO 4 composites is fixing the briquetting pressure at 90 MPa and sintering temperature at 700 °C. The dielectric constant and loss of the composites are 22.79 and 4.17 × 10 −3 at 9041 MHz, respectively. Properties of this kind of composites can meet the requirements for high-k and ultra-low-loss PCB application.
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JOURNAL OF MOLECULAR LIQUIDS
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2017
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IF 3.648
Jing Zhang,Taotao Fu,Chunying Zhu,Youguang Ma
Densities and viscosities of glycine, L-alanine, L-valine, L-threonine and L-arginine in aqueous (0.1–0.5) mol·kg − 1 myo -inositol solutions were measured at T = (293.15, 303.15, 313.15 and 323.15) K and p = 0.101 MPa. The volumetric properties such as the apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), the limiting partial molar volumes of transfer (Δ tr V φ 0 ), the limiting apparent molar expansibility ( E 2 0 ), Hepler's constant and the isobaric thermal expansion coefficient ( α 2 ) were calculated through density. The viscometric properties such as the B -coefficient, the free energies of activation per mole of solvent (Δ μ 1 0 ≠ ) and solute (Δ μ 2 0 ≠ ) were obtained from the experimental viscosity data. The derived parameters hydration number and solvation number were also calculated through apparent molar volume and B -coefficient. From the volumetric and viscometric properties, the solute-solute and solute-solvent interactions in the studied systems were analyzed on the basis of co-sphere overlap model and transition state theory . Finally, the group contribution method was applied to calculate the contribution of (NH 3 + , COO − ), CH 2 , OH and CNHNHNH 2 of amino acids to V φ 0 , B -coefficient and Δ μ 2 0 ≠ .
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Journal of the American Chemical Society
·
2024
·
IF 14.4
Xiaoyu Song,Xinsheng Liu,Danwen Zhang,Jingyan Liao,Siqi Zhu,Wei Zheng
Two-dimensional organic–inorganic hybrid layered perovskites have emerged as a new generation of optoelectronic materials. However, the thermochromism in organic–inorganic hybrid layered perovskites has been rarely explored in depth. A further understanding of the mechanism is necessary and favorable for the application. Here, transparent centimeter-sized single crystals of the organic–inorganic hybrid layered perovskite (C6H5C2H4NH3)2PbBr4 (PEA2PbBr4) were synthesized using an improved evaporation method. As a typical organic–inorganic hybrid layered perovskite, the PEA2PbBr4 single crystal shows high-contrast and progressive thermochromism exhibiting a change from colorlessness and transparency to lemon yellow in a wide temperature range of 200–450 K. Based on the calculation through the Varshni equation, the temperature-induced bandgap change rate directly associated with the high-contrast thermochromism of PEA2PbBr4 reaching 0.8 meV/K. This value is higher than that of many three-dimensional perovskites and traditional IV–III semiconductors. Furthermore, the temperature-dependent 193 nm photoluminescence spectra suggest that this high temperature-induced bandgap change rate of PEA2PbBr4 is a result of the competitive interaction between lattice thermal expansion and electron–phonon coupling (Fröhlich coupling coefficient ΓLO = 2.215). Based on the characteristics introduced above, PEA2PbBr4 as an organic–inorganic hybrid layered perovskite has a better performance in achieving the balance between high-contrast and high room-temperature transmittance. Therefore, PEA2PbBr4 is a material with great potential in applications like temperature-indicating labels. This work provides valuable insights into the thermochromism of layered perovskites, offering a new material system and approach for developing thermochromic materials with higher sensitivity and efficiency.
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