THERMOCHIMICA ACTA
·
2016
·
IF 1.938
X.K. Gao,X. Wen,H. Zhou,Q. Zhu,J.L. Wang,X.Y. Li
In this work, a novel and simple method was put forward to measure the isobaric specific heat capacity for the kerosene RP-3 with a flow-calorimeter at the conditions of high temperature and high pressure. Based on the energy conservation principle, the formula for heat capacity was derived and its measurement was realized by the convective mixing method between the hot and cold fuel. Taking the precision of the instrument and the error transfer into account, the relative expanded uncertainty of this method was acquired of about ± 6.38% (coverage factor k = 2). Meanwhile, the accuracy and reliability were verified by the standard material of water and n -decane. In the temperature range from (296.2–719.0) K and under pressure range from (2.4–4.0) MPa, the measurement for the kerosene RP-3 was carried out and the experimental observations were compared and agreed well with the published data. At last, an empirical correlation relationship of heat capacity due to the temperature and pressure was presented by using Garg’s model with the measured experimental data.
研究领域:
物理化学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2019
·
IF 2.298
Taotao Zhan,Ying Zhang,Qi Zhou,Junshuai Chen,Xiaopo Wang,Xiangyang Liu,Maogang He
Ethyl nonanoate is a promising component of biodiesel with a satisfactory cetane number and reactivity. The speeds of sound in ethyl nonanoate were measured by the Brillouin light scattering (BLS) method within the temperatures from 295.24 to 593.15 K and at pressures up to 10 MPa. The relative expanded uncertainty (k = 2) of our BLS experimental system is estimated to be less than 0.7%. The densities of ethyl nonanoate were measured using a vibrating tube densimeter at atmospheric pressure in the temperature range of 293.15–353.15 K, and the absolute average relative deviation between the experimental densities and the literature data is 0.12%. For temperatures between 303.15 and 353.15 K and at pressures up to 10 MPa, these measurements were used to calculate densities, isobaric heat capacities, and indirect derivative properties including the isobaric thermal expansion, the isothermal compressibility, the isentropic compressibility, and the internal pressure. The comparison between the calculated isobaric heat capacities and the literature values shows a satisfactory agreement with an absolute average relative deviation of 0.18% and a maximum deviation of 0.38%. At the end, the dependences of internal pressure of ethyl nonanoate on temperature and pressure were found to be in accordance with those of ethyl caprylate and ethyl caprate.
研究领域:
物理化学
·
燃料科学
✓ 已验证
产品关联
DOI
高影响因子
THERMOCHIMICA ACTA
·
2024
·
IF 3.1
Xue Lan,Yu Li,Xianmin Zhang,Wei Xu,Hao Chen,Jiandang Liu,Hongjun Zhang,Xiaozheng Lan
To study the phase behavior and role of defects in the ion conduction of a well-investigated plastic crystal electrolyte, we measured the low-temperature heat capacities of quinuclidinium hexafluorophosphate ([HQ]PF 6 ) plastic crystal and the defects of pure [HQ]PF 6 and its mixtures containing lithium ions and chloride ions. The heat capacities of the pure material show two solid‒solid phase transitions at room temperature and a low temperature. Positron annihilation lifetime spectroscopy (PALS) revealed the phase dependence of the defect size for both the pure material and the mixtures. The defects in these two mixtures expand largely to approximately 2 (with Li + ) and 2.5 (with Cl − ) times larger than those in the pure material. The relationships between the ionic conductivity and vacancy volume of the pure material and the mixtures obey the Cohen−Turnbull free volume model, which is also phase dependent. This work help elucidate defect-assisted ion transfer in organic ionic plastic crystals.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED THERMAL ENGINEERING
·
2016
·
IF 3.043
Aihong Du,Huiwen Yuan,Wei Liao,Haobo Zhou,Chunhua Lu,Zhongzi Xu
Cost-effective thermal energy storage materials are vital to the application of solar thermal power plants . One focus of this paper is improving thermal and mechanical properties of the thermal energy storage materials; the second focus lies in reducing the investment cost. On the basis of aluminate cementitious composites with 1 wt% nano-SiO 2 , 1 wt% nano-Cu and 15 wt% Cu powders, we introduced different wt% (0, 5, 10, and 15) of Fe powders to gradually replace 15 wt% Cu powders. The samples were heated at 105, 350, and 900 °C, respectively. As a result, when the content of Fe powders substitution was 10 wt%, volume heat capacity, thermal conductivity and compressive strength of the composites after heat-treatment at 900 °C were up to 2.38 MJ m −3 K −1 , 1.45 W m −1 K −1 , and 73.8 MPa respectively, which were 26.6%, 26.1%, and 24.0% higher than those of the composites with 15 wt% Cu powders. At the same time, the investment of the composites with 10 wt% Fe powders substitution was reduced almost 62.0%, compared with that of the composites with 15 wt% Cu powders. In addition, XRD and MIP were employed to characteristic the mineral phases and the pore structures of the aluminate cementitious composites, respectively.
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2022
·
IF 3.269
Lingyan Gui,Dongdong Li,Jiangtao Wu,Xianyang Meng
The apparent molar heat capacities of LiBO 2 (aq), NaBO 2 (aq), KBO 2 (aq), Na 2 B 4 O 7 (aq) and K 2 B 4 O 7 (aq) solutions at molalities from 0.01 to 2.6 mol·kg −1 , and at temperatures T = (298.12, 313.13 and 328.14) K have been determined using a Picker flow calorimeter built in this work. Further, the standard heat capacities of these solutes were derived from the experimental data by extrapolation to infinite dilution using the Pitzer ion-interaction model. The group contribution method is used to calculate the standard molar heat capacities of tetraborate ion in three equilibria for different assumptions, among which the prediction on the assumption that the standard molar heat capacity of reaction for the association reaction is zero is the most reasonable, and the results are in good agreement with the experimental data.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Zhuoyang Li,Yang Zhang,Guishang Pei,Mengjiao Jiao,Xuewei Lv
MnV 2 O 6 and Mn 2 V 2 O 7 are essential compounds in the manganese salt roasting process for extracting vanadium and serve as excellent battery materials. Determining their thermodynamic properties is of significant theoretical and practical importance. In this study, MnV 2 O 6 and Mn 2 V 2 O 7 were synthesized through solid-state synthesis under a nitrogen atmosphere, and their crystal structures were analyzed using X-ray powder diffraction. The heat capacity of MnV 2 O 6 and Mn 2 V 2 O 7 were measured using relaxation calorimetry over the temperature range of 2–300 K. The entropy at 298.15 K, including magnetic contributions, was calculated as 178.99 ± 5.35 J K -1 ·mol -1 for MnV 2 O 6 and Mn 2 V 2 O 7 for 258.93 ± 6.47 J K -1 ·mol -1 . The standard molar enthalpies of formation were determined using high-temperature solution calorimetry in a molten lead borate solvent, yielding -1997.09 ± 23.97 for MnV 2 O 6 and -2427.71 ± 29.12 kJ mol -1 for Mn 2 V 2 O 7 from their element references. Based on these reliable experimental data, other thermodynamic properties, including enthalpy changes, entropy, and Gibbs free energy, were calculated. Finally, thermodynamic simulations were conducted to analyze phase evolution during the manganese salt roasting process and to evaluate the water solubility of MnV 2 O 6 and Mn 2 V 2 O 7 .
研究领域:
材料科学
·
热力学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2021
·
IF 2.694
Linmao Tang,Yuan Guo,Zuoxiang Zeng,Weilan Xue
The density and liquid heat capacity of propyl cinnamate were measured in the temperature range from 290.15 to 503.15 K by a pycnometer and automatic adiabatic calorimeter and correlated with temperature by the linear equation and quadratic polynomial, respectively. Vapor pressure data of propyl cinnamate were determined by the ebulliometric method at 419.15–559.15 K, and they are in accordance with the Antoine equation. The vaporization enthalpy ΔvapH (Tb) of propyl cinnamate at normal boiling point was attained based on the Clausius–Clapeyron equation. The standard enthalpy of vaporization ΔvapH (298.15 K) was calculated by the Othmer method and verified by the Watson relation.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2023
·Vol. 158
·期 12
·
IF 4.4
Song Kun,Jin Xin,Lv Xiaodong,Xin Yuntao,Lv Xuewei
Lithium-ion batteries (LIBs) are widely used in electronic applications because of their high voltage, high specific energy, long lifespan, and other characteristics. Electrode materials have garnered interest as an indispensable component of LIBs. Na 7 [H 2 PV 14 O 42 ] is used as an electrode material because of its excellent properties. In this study, Na 7 [H 2 PV 14 O 42 ] was synthesized by the water bath method using NaVO 3 as the raw material, experimentally characterized, and its thermodynamic data were measured using the Neumann–Kopp rule from 298.15 to 843 K, a Physical Property Measurement System from 15 to 309 K, and the MHTC 96 line from 473 to 773 K. The data were fitted to the Debye–Einstein heat capacity equation at low temperatures and a polynomial function at higher temperatures. The heat capacity equation of Na 7 [H 2 PV 14 O 42 ] was obtained from the fitted curves. The corresponding enthalpy ( ▵ 298.15 T H m ), entropy ( ▵ 298.15 T S m ), and Gibbs energy ( ▵ 298.15 T G m ) (from 298.15 to 800 K) were calculated according to the heat capacity equation. The obtained heat capacity of Na 7 [H 2 PV 14 O 42 ], as a function of temperature, was modeled as Cp = 1502.30 + 0.27T − 2.44E7T −2 J mol −1 K −1 (473–773 K). This study can compensate for the thermodynamic deficiency of Na 7 [H 2 PV 14 O 42 ].
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2017
·
IF 2.726
Rui Jia,Keyan Sun,Rongchun Li,Youyou Zhang,Wenxia Wang,Heng Yin,Dawei Fang,Quan Shi,Zhicheng Tan
In recent years, sugar alcohols have attracted much attention due to their remarkable phase change properties for thermal energy storage applications. The thermodynamic properties especially the heat capacities would play a crucial role in theoretically and technically investigating the energy storage performance for sugar alcohols. However, as far as we known, the heat capacities of sugar alcohols have never been studied in a wide temperature region. In this study, we have measured the heat capacities of six sugar alcohols of D-mannitol, Myo-Inositol, xylitol, D-arabinitol, L-arabinitol and erythritol in the temperature range from T = (1.9 to 550) K for the first time using a combination of Physical Property Measurement System and differential scanning calorimeter. Based on the heat capacity curve fitting, the standard molar heat capacity, entropy and enthalpy at 298.15 K and 0.1 MPa, and melting temperature and transition enthalpy in the solid–liquid phase transition region were consequently obtained for these sugar alcohols. Moreover, the heat capacity and phase transition properties obtained in this work were also compared with previous results reported in literature.
研究领域:
热力学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2024
·
IF 2
Jumei Xu,Yu Qi,Zuoxiang Zeng,Weilan Xue
The density and the heat capacity of (E,E)-methyl sorbate (MS) were measured from 286.35 to 433.25 K using a pycnometer and an adiabatic calorimeter, respectively. The saturated vapor pressure of MS was determined by the ebulliometric method from 344.95 to 455.15 K and correlated by the Antoine equation with an average relative deviation of 1.68%. The enthalpy of vaporization of MS at the normal boiling point was figured out to be 44.29 kJ mol–1 according to the Clausius–Clapeyron equation. Based on the Othmer method, the standard enthalpy of vaporization of MS was obtained using three substances as a reference, and the calculated results were further verified by the Watson relation and the Clarke–Glew equation.
研究领域:
物理化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 18
·4611
·
IF 3.1
Chuang Zhu,Minhao Xu,Baiyuan Tian,Manting Gu,Li Gong
The aim of this study is to further enhance the thermal storage and heat transfer performances of a low-melting-point quinary salt. The eutectic salt was prepared using LiNO3, NaNO3, KNO3, NaNO2, and KNO2as raw materials, followed by the doping of nano-SiO2and nano-MgO into the base salt using a microwave-assisted method. The thermal properties of the samples were analyzed using a Synchronous Thermal Analyzer and a Laser Flash Apparatus. The co-doping of two types of nanoparticles was found to significantly enhance the specific heat capacity of the base salt. The maximum specific heat reached 2.36 J/(g·K), showing a 50.4% increase compared to the base salt. The thermal conductivity of molten salts can be affected by nanoparticles. An observed sample demonstrated a thermal diffusivity of 0.286 mm2/s, indicating a 19.2% improvement over the base salt, which may be attributed to enhanced phonon thermal efficiency. In addition, this study revealed that while interfacial thermal resistance can enhance specific heat capacity, it can also lead to a decrease in the thermal conductivity efficiency of materials. This work can offer insights and references for the enhancement of molten salt properties.
研究领域:
材料科学
·
热能工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2022
·
IF 6.633
Changhui Liu,Wenjie Sun,Yixuan Huo,Jiateng Zhao,Zafar Said
Working fluids act as a core role in low-grade thermal energy transportation. Deep eutectic solvent (DES), as a novel environmental solvent, has good stability and environmentally friendly, suitable for a variety of heat exchange environment. It has been emerging in working fluids thanks to superior chemical stability, low vapor pressure and promising rheological properties. While, relatively poor thermal conduction efficiency hinders its practical use. Adding nanoparticles to the DES, which is also coined to be nanofluid, provides a facile way to enhance the thermal conductivity as well as other related thermophysical properties. In this article, glycerol/choline chloride (ChCl) DES based nanofluids were prepared by dispersion of nano-TiO 2 , Fe 2 O 3 , CuO, SiC and carbon. Viscosity and thermal conductivity (TC) were studied comprehensively as functions of testing temperature and mass fraction. The highest thermal conductivity was found to be increased by up to 4.23%. More importantly, specific heat capacity, the other key factor in energy transportation for working fluids were studied with respect to that of nano-additive and temperature, indicates that it could be effectively increased by 26.23% compared to that of pristine base solvent. Mechanistic study by means of a set of experimental ways reveals that hydrogen bond association between DES and nanoparticle is responsible for this specific heat capacity increment.
研究领域:
材料科学
·
热力学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）