ACS Applied Materials & Interfaces
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2024
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IF 8.3
Liying Hao,Jikui Sun,Qingyin Wang,Haijiao Xie,Xiangui Yang,Qiang Wei
As an atom-economical reaction, the direct generation of dimethyl carbonate (DMC) and ethylene glycol (EG) via the transesterification of CH3OH and ethylene carbonate (EC) has several promising applications, but the exploration of carriers with high specific surface areas and novel heterogeneous catalysts with more basic sites remains a long-standing research challenge. For this purpose, herein, a nitrogen-doped mesoporous carbon (NMC, 439 m2/g) based K–O2 Lewis base catalyst (K–O2/NMC) with well-dispersed strongly basic sites (2.23 mmol/g, 84.5%) was designed and synthesized. The compositions and structures of NMC and K–O2/NMC were comprehensively investigated via Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, CO2 temperature-programmed desorption, and contact angle measurements. The optimal structural configuration and electron cloud distribution of the K–O2/NMC catalyst were simulated using first-principles calculations. The electron transfer predominantly manifested as a flow from K–O to C–O/C–N, and the interatomic interactions between each atom were enhanced and exhibited a tendency for a more stable state after redistribution. Furthermore, the adsorption energies (Eads) of CH3OH at K–O–O and K–O–N sites were −1.4185 eV and −1.3377 eV, respectively, and the O atom in CH3OH exhibited a stronger adsorption tendency for the K atom at the K–O–O site. Under the optimal conditions, the EC conversion, DMC/EG selectivity, and turnover number/frequency were 80.9%, 98.6%/99.4%, and 40.5/60.8 h–1, respectively, with a reaction rate constant (k) of 0.1005 mol/(L·min). Results showed that the heterogeneous K–O2/NMC catalyst prepared herein greatly reduced the reaction cost while guaranteeing the catalytic effect, and the whole system required a lower reaction temperature (65 °C), a shorter reaction time (40 min), and a lower catalyst amount (2.0 wt % of EC). Therefore, K–O2/NMC can be used as a catalyst in different transesterification reactions.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2017
·Vol. 29
·期 2
·1269-1279
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IF 2.019
Hu Liang,Xia Yuting,Wang Qianqian,Yang Hui,Zhang Qi-long
In this work, a core–shell dendritic CuO@TiO 2 was constructed through a two-step chemical method. Structural analysis confirms the successful coating of TiO 2 on the CuO and the dendritic morphology was maintained after the coating process. The composites were prepared by using ferroelectric P(VDF-HFP) as matrix and synthesized particles as filler. The introduction of fillers influences the melting and crystallization process of the polymer matrix without altering the composition. The insulator layer suppresses the conductivity and dielectric loss by blocking the charge carriers while the composites exhibit improved dielectric constant in the frequency wide range of 10 2 –10 6 Hz and enhanced thermal conductivity. The composite with 20% CuO@TiO 2 exhibits a high dielectric constant of 51.7, low loss of 0.11 at 1 kHz and high thermal conductivity of 0.382 W/mK, showing huge potential for dielectric applications.
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JOURNAL OF CHEMICAL THERMODYNAMICS
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2012
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IF 2.422
Yingjie Xu,Bin Chen,Wu Qian,Haoran Li
Values of the density and viscosity of the pure ionic liquid n -butylammonium nitrate (N4NO 3 ) and its binary mixtures with methanol, ethanol, 1-propanol, and 1-butanol were measured at temperature ranging from T = (293.15 to 313.15) K. The thermal expansion coefficient, molecular volume, standard entropy, and lattice energy of N4NO 3 were deduced from the experimental density results. The temperature dependence of the viscosity of N4NO 3 was fitted to the fluidity equation. Excess molar volumes V E and viscosity deviations Δ η for the binary mixtures were calculated and fitted to the Redlich–Kister equation with satisfactory results. Both excess molar volumes and viscosity deviations show negative deviations for (N4NO 3 + alcohol) mixtures. The effect of the temperature and the size of the alcohol on the excess molar volumes and viscosity deviations are discussed and analysed. Other derived properties, such as the apparent molar volume, partial molar volume, excess partial molar volume, thermal expansion coefficient, and excess thermal expansion coefficient of the above-mentioned systems were also calculated.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2012
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IF 1.693
Xianjie Gong,Yongsheng Guo,Juan Xiao,Yuzhong Yang,Wenjun Fang
Densities, viscosities, and refractive indices are investigated for binary mixtures of 1,2,3,4-tetrahydronaphthalene with several n-alkanes, namely, octane, nonane, and decane, at different temperatures (293.15 K, 298.15 K, 303.15 K, and 313.15 K) and atmospheric pressure. The values of density (ρ) of the compounds were used to compute excess molar volume (VmE) of the solution. The refractive indices of these binary systems were also determined over the whole concentration range at 293.15 K and 303.15 K.
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FLUID PHASE EQUILIBRIA
·
2013
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IF 2.379
Yonghong Hu,Yumei Kai,Zheng Cao,Jiaojiao Li,Wenge Yang
The solubilities of dimethyl succinylsuccinate in tetrahydrofuran, acetic ether, acetone, acetonitrile, 1-propanol, ethanol and methanol pure solvents and tetrahydrofuran + methanol mixed solvents were measured within the temperature range 278.15 K to 333.15 K at atmospheric pressure. The solubility of dimethyl succinylsuccinate in those selected solvents increased with increasing temperature, and the dissolution in tetrahydrofuran is best. The semi-empirical Buchowski–Ksiazczak λh equation, the modified Apelblat equation and CNIBS/R-K equation were used to correlate with the solubility. In pure solvents the values of the sum of deviation (∑(% Dev )) for Apelblat and Buchowski–Ksiazczak λh equations are 1.1115 and 1.0383, respectively. In the tetrahydrofuran and methanol mixture, the sums of deviation (Σ(% Dev )) for Apelblat equation, Buchowski–Ksiazczak λh equation and CNIBS/R-K equation are 0.7587, 0.7059 and 1.4090, respectively. By comparing models, the solubilities predicted by Buchowski–Ksiazczak λh equation and Apelblat equation is reasonable in mixture solvent and pure solvent, respectively. The thermodynamic properties of the solution process, including the enthalpy, and entropy were calculated by the van’t Hoff analysis. The value of enthalpy and entropy were positive.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2014
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IF 2.045
Libin Chen,Ying Zhang,Sheng Wang,Xiong Zheng,Maogang He
The thermal diffusivities of 2-methoxy-2-methylpropane (MTBE, mass purity, > 0.990, GC) were measured by using the dynamic light scattering method at T = (303.15 to 493.15) K and p = (1.5 to 10) MPa, including saturated liquid, saturated vapor, and compressed liquid. The expanded relative uncertainty in thermal diffusivity was estimated to be less than 2.0 % over the entire investigated range. The polynomial representation for thermal diffusivity of MTBE was proposed by employing the experimental results. Comparing the calculated results with the experimental data, the average absolute deviations are 0.59 % for saturated liquid, 0.38 % for saturated vapor, and 0.43 % for compressed liquid.
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ACS Applied Polymer Materials
·
2024
·
IF 4.4
Guangjian Dai,Shengtao Zhang,Wenjie Yang,Chunxiang Wei,SanE Zhu,Zhongxing Geng,Eric W. M. Lee,Hongdian Lu,Bin Yu,Wei Yang
The exploration of biomass-derived thermosetting resins for implementation in flexible electronic packaging has emerged as a central focus. Herein, a daidzein-derived monomer (DDAB) was synthesized, which featured carbon–carbon double bonds. Biobased resins, namely, DDAB/3SH and DDAB/4SH, were meticulously fabricated via photocuring process, entailing the amalgamation of DDAB with trithiol (TPTMP) and tetrathiol (PETMP) monomers, respectively. DDAB/4SH showed impressive mechanical properties with a tensile strength of 28.1 MPa and elongation at break of 21.3%. Notably, owing to the augmented free volume inherent within the system, DDAB/3SH exhibited an exceptional elongation at a break of 111.7%, thereby surpassing the performance metrics of the majority of previously documented thiol-containing compounds. Moreover, both DDAB/3SH and DDAB/4SH demonstrated desirable dielectric properties. Specifically, within the frequency range of 15–16 GHz, DDAB/3SH achieved a minimum dielectric constant of 2.58. The exceptional dielectric performance, coupled with the tunable mechanical properties, proves the substantial application potential of DDAB/SH biomass-derived resins for flexible electronic packaging applications.
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Journal of Materials Chemistry C
·
2024
·Vol. 13
·期 1
·295-305
·
IF 5.7
Yanan Gao,Jingjing Wang,Jingxuan Yang,Yajie Wang,Wenjuan Tian,Bin Liu
Nitrogen-rich graphitic carbon nitride (g-C3N5) has garnered significant attention in photocatalytic hydrogen production due to its unique physicochemical properties. However, g-C3N5 faces persistent challenges stemming from rapid carrier recombination. In this study, we successfully synthesized a Pd/C3N5-K,I photocatalyst through sequential doping of non-metallic heteroatoms and metal nanoparticles. The Pd/C3N5-K,I photocatalyst demonstrates a remarkable enhancement in the photocatalytic H2 evolution rate (2.9 mmol g−1 h−1), approximately 14 times higher than that of pure g-C3N5 (0.2 mmol g−1 h−1). Characterization and calculation analyses reveal that iodine doping into the g-C3N5 skeleton leads to the formation of planar C–I bonds, facilitating C3N5 layer electron–hole pair separation. The subsequent insertion of Pd nanoparticles between the layers leads to electron accumulation on C3N5-K,I, while resulting in hole concentration on Pd nanoparticles, thereby facilitating thorough spatial separation of electron–hole pairs. The strategic co-doping of iodine and palladium nanoparticles effectively restrains carrier recombination of g-C3N5 by connecting intra- and inter-layer interactions. This study constitutes a novel conceptual framework for CN-based photocatalysts, offering a promising approach to improve their performance in hydrogen production applications.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2010
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IF 1.695
Xueqiao Xie,Yongsheng Yan,Juan Han,Yun Wang,Guowu Yin,Weisheng Guan
Liquid−liquid equilibrium data for the PPG400 (poly(propylene glycol)) + salt (potassium citrate, potassium tartarate, potassium oxalate) + water systems have been determined experimentally at T = (298.15, 308.15, and 318.15) K. The effects of temperature on the binodal curves and tie-lines were studied, and it was observed that an increase of the temperature generally led to an increase of the biphasic area. Furthermore, the binodal curves were fitted to a five-parameter equation relating the concentrations of PPG400 and salt. The effective excluded volume (EEV) values obtained from the binodal model were determined, and the salting-out ability of the anions follows the ordering citrate3− > tartarate2− ≈ oxalate2−. Finally, the Setschenow-type and Othmer−Tobias and Bancroft equations have been successfully used to correlate the tie-line compositions.
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INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Tingting Tang,Fangqing Ye,Huang Hua,Chaoyang Li,Jian Shen
With the rapid development of 5G communication technology, microwave dielectric ceramics with high dielectric constants are very conducive to the miniaturization of passive devices. Here, Ba3Ti4–x(Ni1/3Nb2/3)xNb4O21 (BTN ∼ NN, 0.03 ≤ x ≤ 0.15) ceramics with hexagonal phases are synthesized via the solid-phase route. The composite (Ni1/3Nb2/3)4+ ion substitution strategy can substantially improve the microwave dielectric properties of the Ba3Ti4Nb4O21 (BTN) ceramic. The εr and Q × f values depend on the ionicity (Nb–O bonds) and lattice energies (Nb(1)–O3 and Nb(1)–O2(1) bonds). The microwave dielectric properties of the BTN ∼ NN (x = 0.09) ceramic sintered at 1250 °C are εr = 60.3, Q × f = 22073 GHz, and τf = 78.1 ppm/°C. A miniaturized all-ceramic radome (@400 mm × 400 mm × 8 mm) for 5G beam-splitting function is designed and demonstrated using this ceramic. Compared to other radomes designed for other work utilizing low εr, the size of this radome has been reduced by 3/7. The reflection coefficients of the beam splitting function are all 0.73, and the phase shifts are all 360°. This work contributes to the development of miniaturized passive devices from a materials point of view.
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Biomass Conversion and Biorefinery
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2024
·
IF 3.5
Wang Huan,Luo Yijia,Wang Shan,Chen Youning,Zhao Wei
Magnetized pitaya peel bio-based carbon aerogel (MCA) was prepared by hydrothermal and freeze-drying methods; then, magnetized bio-based carbon aerogel (MCKEA) was obtained by the surface functionalization of MCA with 3-amino-1, 2-propylene glycol and KH-550. MCA and MCKEA were characterized by SEM, FT-IR, and XRD. The adsorption properties of MCA and MCKEA for dyes were investigated. It showed that the adsorption capacity of MCKEA for dyes was greater than that of MCA, especially for acid chromium blue K. The adsorption of acid chromium blue K by MCKEA conforms to the pseudo-second-order kinetic model and Langmuir adsorption model. The reusability experimental results showed that MCKEA can be reused for nine times. So MCKEA is a kind of adsorbent with high efficiency, high reusability, and low cost, which has broad application prospect. Graphical Abstract
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Manman Lu,Haoyuan Wang,Jianwei Fan,Zhilong Zeng,Yijia Li,Min Zhou,Xiong Liu
This study compared the physicochemical and structural properties, and in vitro digestibility of Amorphophallus konjac K. Koch starch (AKS) and Amorphophallus dunnii starch (ADS), by using potato starch (PS) as a control. ADS exhibited larger granule sizes, which led to higher transparency, swelling power (SP), and water solubility than AKS. Both AKS and ADS exhibited A-type crystalline patterns; however, ADS demonstrated higher relative crystallinity, gelatinization transition temperatures, and enthalpies of gelatinization, which may be due to higher 1047/1022 and more double helix contents. Regarding rheological and pasting properties, ADS exhibited greater viscosity than that of AKS, likely due to larger particle size and higher SP. In vitro digestion analysis revealed that >50 % of each starch type consisted of rapidly digestible starch. Notably, ADS contained the highest amount of resistant starch among the three types. The estimated glycemic index (eGI) values of AKS and ADS were 65.54 ± 0.54 and 63.28 ± 0.36, respectively, indicating that both starch types belong to the medium GI food category, though AKS was significantly higher than ADS. These findings suggest that konjac starch serves as a beneficial dietary carbohydrate alternative. AKS may be suited for fast-digesting food formulas for individuals with digestive impairment, whereas ADS could be advantageous for those managing diabetes.
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