FUEL
·
2015
·
IF 3.52
Xiangyang Liu,Maogang He,Chao Su,Xuetao Qi,Nan Lv
In this work, the isobaric molar heat capacities of methyl caprate and methyl laurate were measured within the temperatures from 300 K to 380 K and at pressures from 0.1 MPa to 4.25 MPa. The measurements were carried out using a flow calorimeter. The results obtained show that the isobaric molar heat capacities of methyl caprate are lower than those of methyl laurate while the isobaric molar heat capacities of these two fatty acid methyl esters rise with the increasing temperature and fall with the increasing pressure. In addition, a correlation was proposed to predict the isobaric molar heat capacities of methyl caprate and methyl laurate. The absolute relative deviations between predicted and experimental isobaric molar heat capacities are less than 0.8%.
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Yuqi Su,Taotao Zhan,Xiangyang Liu,Maogang He,Ying Zhang
The mutual diffusion coefficients of (isooctane + n-heptane) and (n-decane + n-heptane) binary solutions were measured over the mass fraction from 0.05 to 0.95 at the pressure of 0.101 MPa, and at temperatures T = 288.15 K, 298.15 K, 308.15 K and 318.15 K, respectively. The expanded relative uncertainty of the digital holographic interferometry employed in this measurement was estimated to be 2.6% with the confidence level of 0.95 ( k = 2). The influences of temperature and composition on the mutual diffusion coefficients were discussed. Moreover, the semi-empirical correlations of mutual diffusion coefficients for (isooctane + n-heptane) and (n-decane + n-heptane) binary mixtures were given by fitting the experimental results as a function of temperature and mass fraction. The absolute average of relative deviations of the correlations are 0.72% for (isooctane + n-heptane) and 0.54% for (n-decane + n-heptane), respectively.
研究领域:
化学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2026
·
IF 2.5
Kaijian Li,Yuqi Su,Maogang He,Ying Zhang
Reliable diffusion data for alcohol–alkane mixtures are still limited, particularly for systems exhibiting strong non-ideal behavior. In this work, mutual diffusion coefficients for ethanol + n-hexane and n-butanol + n-hexane were measured over the entire composition range at 298.15–308.15 K using digital holographic interferometry. The relative standard uncertainty associated with the optical measurement subsystem was estimated to be 0.0118. After propagation of the identified instrumental uncertainty sources, including temperature control, phase-parameter determination, composition preparation, and material purity, the instrumental relative standard uncertainty of the diffusion coefficients was evaluated to be 0.0121, corresponding to an expanded uncertainty of approximately 2.42% (k = 2). Considering the additional variability among independent experimental realizations, the overall expanded relative uncertainty was estimated to be approximately 4.8% (k = 2). For both systems, the mutual diffusion coefficient shows a pronounced U-shaped dependence on composition, with a minimum at intermediate alcohol mass fractions. In the limit of ω 1 → 0, the mutual diffusion coefficient approaches the tracer diffusion coefficient of alcohol in n-hexane, corresponding to diffusion under infinite dilution conditions. The observed behavior reflects strong non-ideal interactions, primarily associated with hydrogen bonding and composition-dependent molecular interactions. Compared with ethanol, the n-butanol + n-hexane system exhibits stronger non-ideality, consistent with the longer alkyl chain of n-butanol. The experimental data were evaluated using the Darken, Vignes, and UNIDIF models. Among them, the UNIDIF model provided the best overall agreement, although deviations remain significant over the full composition range. For ethanol + n-hexane at 298.15 K, the present results show good agreement with available literature data in terms of the overall composition-dependent trend, supporting the reliability of the measurement methodology. The new diffusion data reported here extend the available database for alcohol–alkane systems and provide a consistent basis for improving transport modeling.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2020
·
IF 2.888
Taotao Zhan,Yuqi Su,Ying Zhang,Xiangyang Liu,Maogang He
The mutual diffusion coefficients of ethanol + n-heptane and diethyl carbonate (DEC) + n-heptane binary solutions were measured over the mass fraction from 0.05 to 0.95 at the pressure of 0.101 MPa, and at temperatures T = 288.15 K, 298.15 K, 308.15 K and 318.15 K. The expanded relative uncertainty ( k = 2) of the Mach-Zehnder digital holographic interferometry employed in the measurements was estimated to be less than 2.4% with the confidence level of 0.95. A semi-empirical correlation was used to fit the mutual diffusion coefficients as a function of concentration and temperature, which represents the experimental values with the absolute average relative deviations being 0.94% for ethanol + n-heptane and 0.90% for DEC + n-heptane. The temperature and concentration dependences of the mutual diffusion coefficients were investigated. The strongest non-ideal thermodynamic behaviors appear when the mass fraction of ethanol is within the limits of 0.45 to 0.65 or that of DEC is within the limits of 0.45 to 0.65. Besides, the mutual diffusion coefficients of ethanol + n-heptane and DEC + n-heptane binary solutions are found to be extremely sensitive to the solute concentration over the mass fraction of ethanol and DEC from 0.00 to 0.05, respectively.
研究领域:
物理化学
·
热力学
✓ 已验证
DOI
高影响因子
Journal of Chemistry
·
2021
·
IF 2.506
Xiaohui Song,Shuaiqi Sun,Lingzong Meng,Rongjian Ying,Yafei Guo,Tianlong Deng
The densities and pH values in the system NaBO2–Na2SO4–H2O at 298.15 K and 323.15 K were investigated. Combining the equilibrium constants for different boron species, the distributions of six boron species in the mixed solution were calculated with total boron concentration and pH values. The molar fractions of the six boron species are mainly affected by the total boron concentration and temperature, but rarely affected by the concentration of SO42–. The dominant boron species in the mixed solution at the two temperatures is B(OH)4‒. The mole fraction of B(OH)3, B5O6(OH)4‒, and B3O3(OH)4‒ can be neglected. The polyborate ions are easier to form as the temperature increases. The results of distribution for boron species in this study and those with the Pitzer model can both be used to describe the distribution of boron species in the mixed solution.
研究领域:
化学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 28
·14575-14582
·
IF 8.867
Zhicheng Shi,Jing Wang,Fan Mao,Chaoqiang Yang,Chao Zhang,Runhua Fan
High-k polymer composites are promising candidates for energy-storage capacitors and many other electronic devices. However, balancing the permittivity, loss and breakdown strength remains a challenge for us. Herein, theoretical calculations and experimental studies were simultaneously carried out to develop an original design of sandwich-structured composites consisting of alternating negative-k and positive-k layers toward high performance dielectric applications. It is experimentally proved that the trilayered composites are capable of balancing the two contrasting parameters of permittivity and loss. The introduction of negative-k layers into trilayered composites leads to a higher dielectric constant (ε′ ≈ 90@10 kHz) and low retained loss (tan δ ≈ 0.025@10 kHz) compared with those of the pristine PVDF (ε′ ≈ 10@10 kHz, tan δ ≈ 0.020@10 kHz). Moreover, the trilayered composites possess an obviously improved energy-storage capacity which is nearly 3 times higher than those of traditional trilayered composites without negative-k layers. Although the permittivity boost effect is still far below the theoretically predicted results and the mechanisms need to be further clarified, these results undoubtedly validated the feasibility of our design, and multilayer high-k composites with fascinating dielectric performances are expected to emerge in the near future via tailoring the properties of single layers and stacking sequences.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Yuqi Su,Songtao Cao,Taotao Zhan,Maogang He,Ying Zhang
The mutual diffusion coefficients of dimethyl carbonate + n -heptane and dimethyl carbonate + isooctane binary systems were measured at temperatures from 288.15 K to 318.15 K with the mass fraction of dimethyl carbonate from 0.05 to 0.95 under atmospheric pressure. All the mutual diffusion coefficients we reported are Fick diffusion coefficients, which were measured by the digital holographic interferometry. The expanded relative uncertainty for the measured mutual diffusion coefficients is estimated to 2.4% with the level of confidence of 0.95 (coverage factor k = 2). Moreover, a theoretical model (UNIDIF) of mutual diffusion coefficients for dimethyl carbonate + n -heptane and dimethyl carbonate + isooctane binary mixtures was given by fitting the experimental results, and the adjustable parameters and infinite dilution diffusion coefficients of these two solutions were given. The influences of temperature and composition on the mutual diffusion coefficients were discussed.
研究领域:
化学工程
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Qing Hao,Huan Zhou,Jing Yu Chang,Jie Li,Yun Zhao
Brine deposited in Chaerhan salt lake belongs to the chloride type and can be simplified into the hexnary system Li+, Na+, K+, Mg2+, Ca2+, Cl––H2O. The known solubility data indicate that significant salting-in effects exist in its subsystems of KCl–LiCl–H2O and KCl–CaCl2–H2O, which inevitably affect the properties and solubility behavior of actual brine. In this work, the solubility behavior study and phase diagram determination are extended to the quaternary system of Li+, K+, and Ca2+∥Cl––H2O. The phase equilibrium data at 298.15 and 273.15 K are reported, and five solid species, including two double salts KCl·CaCl2 and LiCl·CaCl2·5H2O, are found. The salting-in effect is still exhibited in the Li+, K+, and Ca2+∥Cl––H2O system and results in a very high total salt content at invariant points; e.g., they are 59.08 and 46.93% at 298.15 and 273.15 K, respectively.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Ruolin Han,Jiafei Ren,Zheng Zhou,Guang-Xin Chen,Qifang Li
Typically, the basic method to enhance the dielectric response of polymer-based composites is to fill giant dielectric ceramic fillers, such as BaTiO3 and CaCu3Ti4O12, into the polymer matrix. Here, by using low-k boron nitride (BN) with well-controlled microstructure and surface, we successfully prepared a high-k polymeric composite, where the improvement in the dielectric constant of the composite even exceeds that of composites containing BaTiO3 and CaCu3Ti4O12 particles at the same weight percent. First, a lamellar boron nitride nanosheet (BNNS) aerogel was prepared by bidirectional freezing and freeze drying, respectively, and then the aerogel was calcined at 1000 °C to obtain the lamellar BNNS skeleton with some hydroxyl groups. Finally, the epoxy resin (EP) was vacuum impregnated into the BNNS skeleton and cured inside to prepare the lamellar-structured BNNSs/EP (LBE) composites. Interestingly, the dielectric constants of LBE with a 10 wt % BNNS content reached 8.5 at 103 Hz, which was higher by 2.7 times than that of pure EP. The experimental data and the finite element simulations suggested that the increased dielectric constants of LBE resulted from the combination of two factors, namely, the lamellar microstructure and the hydroxyl groups. The stacking of the BNNS phase into a highly connected lamellar skeleton significantly increased the internal electric field and the polarization intensity, while the introduction of hydroxyl groups on the BNNS surface further improved the polarization of the composite, resulting in a significant increase in the dielectric constant of the LBE. This work provides a new strategy for improving the dielectric constant through the microstructure design of composites.
研究领域:
材料科学
·
复合材料
·
介电材料
·
聚合物科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Shuai Wang,Ruobing Yi,Yi Huang,Haoran Zuo,Yangtian Zhang,Yingying Huang,Liang Chen,Shanshan Liang
Multilayered graphene oxide (GO) membrane with sub-nanometer channels is an ideal candidate for desalination. However, excluding small ions using GO-based membranes in the pressured filtration processes remains a great challenge due to the tortuous transport paths of laminates and their water-swelling characteristic. In our previous work, we developed the cation-controlled theory to precisely regulate the interlayer spacing of GO membranes in aqueous solutions. In this work, we proposed an “ion-cage” strategy to enhance the stability (anti-swelling) of the K-controlled GO (icGO-K) membrane for achieving efficient desalination. The icGO-K membrane, coated with positively charged polyethyleneimine (PEI) on its upper and lower surfaces, immobilized intercalated cation K + between the laminates by electrostatic repulsion to maintain the stability of the confined interlayer spacing. The icGO-K membrane demonstrated superior rejection of 95.3 %, 83.2 %, 81.8 %, and 70.7 % for MgCl 2 , MgSO 4 , NaCl, and Na 2 SO 4 while maintaining competitive permeance of ∼ 3.5 L m -2 h −1 bar −1 in the desalination process. More importantly, the icGO-K membrane exhibited ultra-long desalination stability up to 720 h. The enhanced performance can be attributed to the synergistic effect of the confined interlayer spacing and surface electrostatic repulsion. Overall, this work provides attractive strategy to fabricate fine-tuning 2D laminate nanochannels for high efficiency of desalination application.
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 23
·1880
·
IF 4.4
Xiaonan Li,Tong Qin,Wenxu Zhang,Hong Wang,Yanhong Chen,Kangle Li,Qing Wang,Yibo Wang
When the power converter connects to the high-frequency transformer breaks through the bottleneck and reaches a frequency of 100 kHz or even higher, the high-frequency transformer’s inter-turn insulation faces more serious high-frequency discharge and high-temperature problems. In order to improve the service performance of oil-immersed high-frequency transformer insulation paper, composite K-BNNS particles are prepared by ultrasonic stripping, heat treatment, and thermomagnetic stirring. Then, K-BNNS particles are mixed with PMIA (polymeric m-phenylenediamine solution) slurry to produce composite aramid paper. And the effects of K-BNNS particles with different contents on the thermal conductivity, dielectric properties, partial discharge properties, and mechanical properties of aramid paper are explored. It can be found that, when the addition of composite particles (K-BNNS) is 10%, the comprehensive performance of composite aramid paper is the best. Compared with Nomex paper, the in-plane and through-plane thermal conductivity of composite insulating paper F-10 increased by 668.33% and 760.66%, respectively. Moreover, the high-frequency breakdown voltage increased by 48.73% and the tensile strength increased by 2.49%. The main reason is that the composite particles form a complete thermal conductive network in the aramid paper matrix and a large number of hydrogen bonds with the matrix, which enhances the internal interface bonding force of the material and changes the charge transport mechanism.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 14
·6785-6794
·
IF 11.301
Wenbin Wang,Zhu Shu,Jun Zhou,Dawei Meng,Zhengliang Zhao,Tiantian Li
Upgrading the melon-based bulk polymeric carbon nitride (PCN) into tri-s-triazine-based crystalline PCN has been proved effective and crucial to improve its intrinsic photocatalytic activity. Currently, facilitating the synthesis process of crystalline PCN and further optimizing its structure are challenging and have attracted increasing attentions. This work realized the facile one-step synthesis of K+-doped tri-s-triazine-based crystalline PCN with delicate box-shapes (KCCNB-x), by heating melamine with KCl using a vapor-deposition approach. KCCNB-30 demonstrated greatly boosted visible-light photocatalytic H2 evolution (HER) activity which is 33 times that of BCN. This benefits mainly from the facilitated photo-exciton transfer in the tri-s-triazine-based crystalline framework as well as the further enhanced light absorption in the box shape of KCCNB-30. Additionally, the versatility of this strategy was proved via successfully synthesizing Na+-doped tri-s-triazine-based crystalline PCN with box-shapes.
研究领域:
材料科学
·
能源化学
·
纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）