JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Ying Zhang,Junshuai Chen,Taotao Zhan,Xiangyang Liu,Maogang He
Ethyl myristate is one of the main components of biodiesels and its thermophysical properties are critical to be supplemented and perfected. In this work, the speed of sound and thermal diffusivity of ethyl myristate were measured by the light scattering method. The investigated temperature and pressure is ranged from 303.15 K to 560.15 K and up to 10 MPa. The relative expanded uncertainties of the speed of sound and thermal diffusivity were estimated to be less than 1.3% and 2.6% (k = 2), respectively. The correlations for the speed of sound and thermal diffusivity as function of temperature and pressure were presented based on the experimental data. The absolute average deviations (AADs) between the experimental data and the calculated results are 0.04% for the speed of sound at atmospheric pressure, 0.07% for the speed of sound at p > 0.1 MPa and 0.28% for the thermal diffusivity , respectively.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Zhen Wan,Cheng Li,Ronghui Liu,Wei Zhou,Wenjing Fan,Chuanxue Huang,Yang Liu
Two-dimensional (2D) Ti3C2Tx MXene materials show great potential in electrochemical and flexible sensors due to their high electrical conductivity, good chemical stability, and special delaminated structure. However, their thermal properties were rarely studied, which remarkably affect the stability and safety of various devices. Here, we fabricated a suspended MXene drum resonator photothermally driven by a sinusoidally modulated laser, measured the thermal time constant by demodulating the thermomechanical motion, and then calculated the thermal conductivity and thermal diffusivity of the MXene film. Experiments show the thermal conductivity of the film increases from 3.10 to 3.58 W/m·K while the thermal diffusivity from 1.06 × 10–6 to 1.22 × 10–6 m2/s when temperature increases from 300 to 360 K. We also confirm the film thermal conductivity is mainly contributed by phonon transport rather than electron transport. Furthermore, the relationship between the mechanical and thermal properties of the MXene films was disclosed. The thermal conductivity decreases when film strain increases, caused by enhanced phonon scattering and softening of high-frequency phonons. The measurements provide a noninvasive method to analyze the thermal characteristics of suspended MXene films, which can be further extended to the thermal properties of other 2D materials.
研究领域:
材料科学
·
热物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FLUID PHASE EQUILIBRIA
·
2019
·
IF 2.514
Ying Zhang,Taotao Zhan,Junshuai Chen,Xiangyang Liu,Maogang He
The use of ethyl decanoate combined with conventional diesel or biodiesel could be economically attractive. Thermophysical properties of ethyl decanoate at high temperatures can be an essential guidance for the structural design and optimization of the fuel injection system in diesel engine. The measurements of the speed of sound and the thermal diffusivity of ethyl decanoate (EeC10: 0) were carried out by the light scattering method, which are along five isobaric lines from (0.1–10) MPa at the temperatures (300.71–562.07) K and (295.34–565.49) K, respectively. The expanded relative uncertainties ( k = 2) of the measurement systems are estimated to be 1.2% for speed of sound and 2.4% for thermal diffusivity. The thermal conductivities of ethyl decanoate at pressures up to 10 MPa and in the temperature range (303–363) K are derived, which agree well with literature values finding an AAD of 0.81%. The pρT dependences of the thermal conductivity are analyzed based on the vibrational theory. The results obtained show that the higher density of biofuels leads to smaller distances between oscillating molecules, of which the collision probability and intermolecular energy transport are enhanced. The consistent behaviors of biofuels that higher density leads to higher conductivity, and the dependence of the thermal conductivity on density becomes smaller with temperature increase are verified.
研究领域:
热物理学
·
燃料工程
·
动力工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF THERMOPHYSICS
·
2014
·Vol. 35
·期 8
·1450-1464
·
IF 0.623
Wang Sheng,Zhang Ying,He Mao-Gang,Zheng Xiong,Chen Li-Bin
Transport and thermodynamic properties of pentane are necessary for the design and verification of reactors in pentane isomerization and degradation processes. However, there are few experimental data of these properties, especially in the high-temperature region. In this work, the thermal diffusivity and the sound speed of pentane have measured by dynamic light scattering and Brillouin light scattering, respectively. Pentane has been investigated under saturated conditions over a wide temperature range, from about 300 K up to the liquid–vapor critical point. It is estimated that: the standard uncertainty of temperature is \(u(T) = 0.01\) K for the hydrodynamic region and \(u(T) = 0.026\) K for the critical region; the relative expanded uncertainty in the thermal diffusivity is \(U_\mathrm{r}(a) = 0.03\) and the relative expanded uncertainty in the speed of sound is \(U_\mathrm{r}(c_\mathrm{s}) = 0.005\) with a coverage factor of \(k = 2\) . The thermal diffusivity and the sound-speed experimental data are also represented as functions of temperature. Finally, the results are discussed in detail in comparison with literature results and various prediction methods.
研究领域:
化学工程
·
物理化学
✓ 已验证
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2025
·
IF 2.7
Xin Wu,Chao Yan,Ying Hu,Junlei Tang,Xiuli Zhao,Mao Chen
Vitrimers are covalently crosslinked networks with dynamic bond exchange, where their dynamic behavior is typically regulated by adjusting network structures or incorporating fillers. This study introduces graphite flakes (GFs) into sulfur-containing. Vitrimers to investigate their effects on mechanical properties, stress relaxation, and thermal conductivity. The results demonstrate that adding 10 wt.% GFs increases tensile strength by 4.37% compared to pure epoxy vitrimer, while higher filler content reduces toughness and decelerates stress relaxation. At 160 °C, the characteristic relaxation time rises from 15.35 s (pure vitrimer) to 108.85 s (40 wt% GFs composite). The Arrhenius prefactor ( τ₀ ) decreases with GFs loading, whereas the activation energy ( E a ) remains nearly unaffected. Additionally, 40 wt.% GFs enhance thermal diffusivity by 110.17% due to oriented phonon transport channels. Chemical recycling via DTT solution achieves complete matrix degradation and filler recovery without damaging GFs. This study provided valuable insights for optimizing vitrimer composites, particularly in enhancing thermal conductivity and modulating dynamic properties.
研究领域:
材料科学
·
复合材料
·
可持续材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2025
·
IF 2.1
Xinyu Liu,Yuhang Chen,Zhao Lei,Long Cheng,Maogang He,Ying Zhang
Isooctane is an ideal gasoline component with a high octane number and low volatility. However, there is a lack of research on the thermal properties of isooctane, especially near the critical point. This work uses dynamic light scattering to measure the thermal diffusivity of isooctane in the temperature range of (298.15–583.15) K, along 8 isobaric lines p = (0.1, 2.0, 2.5, 2.7, 3.0, 3.5, 5.0, 7.5) MPa, and analyzes the trend of thermal diffusivity with temperature and pressure. The average relative combined expanded uncertainty of the thermal diffusivity is 0.0214. Meanwhile, the experimental data were compared with the calculated values from thermal conductivity, and the absolute average values of the relative deviation and maximum deviation were 2.88 and 8.22%, respectively.
研究领域:
物理化学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2019
·
IF 3.621
Weilong Chen,Kun Wu,Zhencai Qu,Mangeng Lu
It has been known that phonon mean free path along polymer chains is much larger than in transverse directions because weak interaction between polymer chains leads to chain distortion and entanglement. In order to improve intensity of intermolecular interaction, a series of co-polyesters (CPE) containing different content of offset π-π stacking structure in side chains were synthesized by means of polycondensation and transesterification in this work. WAXD patterns unfolded diffraction peak at 2θ of 27.6°, standing for structure of offset π-π stacking. On enlarging intensity of offset π-π stacking interaction, specific heat capacity of CPE increased from 1.140 Jg −1 K −1 to 1.410 Jg −1 K −1 and thermal diffusivity rose from 0.194mm 2 s −1 to 0.245mm 2 s −1 . As a result, CPE sample exhibited excellent thermal conductivity (TC) of 0.381 Wm −1 K −1 , which is around twice that of traditional thermoplastics. Hence offset π-π stacking interaction could strengthen capacity of heat absorption and thermal conduction at the same time, which might be a good candidate for enhancing thermal conductivity of intrinsic polymers. Furthermore, strong π-π interaction in side chains could maintain modulus when temperature is over glass temperature. And the Young modulus grew from 0.14 GPa to 0.44 GPa with the augment of offset π-π stacking structure.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2021
·
IF 2.775
Junshuai Chen,Hongwei Xing,Taotao Zhan,Libin Chen,Maogang He,Ying Zhang
Ethanol is a common industrial substance and widely applied in technological and scientific applications, of which the thermophysical properties especially near the critical point are scarce. In this work, the thermal diffusivity of ethanol was determined by the dynamic light scattering method in the temperature ranging from (293 to 564) K and along six isobaric lines including 0.1, 2.5, 5, 6.2, 7.5 and 10 MPa. The relative uncertainty of the thermal diffusivity experimental system is estimated to be less than 2.6% for coverage factor of k = 2 with the level of confidence 0.95. The variation of thermal diffusivity with the temperature and pressure was analyzed. In addition, the comparison between the experimental data and the calculated values from thermal conductivity was made, and the absolute average of relative deviation (AARD) between them is 0.96%.
研究领域:
化学工程
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Yuqi Su,Pengcheng Sun,Junshuai Chen,Maogang He,Ying Zhang
The transport properties including thermal diffusivity and Fick diffusion coefficient are of great significance to the optimization of heat and mass transfer processes in the combustion of gasoline. In this work, the thermal diffusivities and Fick diffusion coefficients of ethanol + isooctane binary mixtures were measured by dynamic light scattering method at mole fraction of ethanol x 1 = 0.1, 0.3, 0.5, 0.7 and 0.9, and over the temperature range from 323.15 K to 523.15 K along the isobaric lines including 2.5 MPa, 5 MPa, 7.5 MPa and 10 MPa. The variation of thermal diffusivity and Fick diffusion coefficient with the temperature, pressure and composition was analyzed to guide the optimization of combustion process. Four classic estimation models were used for the calculation of the thermal diffusivities of the binary mixtures of ethanol + isooctane. The Scheffé model has the best calculation performance with the average absolute relative deviations (AARD) of 2.09 %. The UNIDIF model was used to estimate the Fick diffusion coefficients of ethanol + isooctane with the AARD of 4.75 %.
研究领域:
化学工程
·
燃烧科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Weilong Chen,Kun Wu,Bingfei Nan,Mangeng Lu
Thermal conductivity (TC) of polymers can be enhanced by incorporating rigid conjugated structures, which will result in sacrifice of other characteristics such as flexibility. To deal with such problem, a series of polyesters (PEmC) with long methylene units in main chains were synthesized by polycondensation and transesterification . A sharp increment of 219.7% in TC was observed and the maximum TC reached to 0.227 Wm −1 K −1 , which is twice that of traditional thermoplastic . It is intriguing that thermal diffusivity for above samples changed few while specific heat capacity of PEmC increased from 0.620 J g −1 K −1 to 1.470 J g −1 K −1 on elongating the length of flexible methylene segments in main chains. Thus TC in this system was mainly enhanced by enhancing specific heat capacity. Due to flexible segments in main chains, Young modulus of PEmC (around 0.2 GPa) is one order of magnitude lower than that of conventional thermoplastic. Moreover, PEmC exhibited good performance both in maintaining flexibility below glass-transition temperature and preserving modulus above glass-transition temperature, which might be remarkable in potential application for flexible electronics.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
FLUID PHASE EQUILIBRIA
·
2016
·
IF 1.846
Ying Zhang,Xiong Zheng,Maogang He,Yutian Chen
The thermal diffusivity and the speed of sound in dibutyl ether (DBE) were measured using light scattering method, including saturated liquid/vapor and supercritical region. The expanded relative uncertainty ( k = 2) of the thermal diffusivity and the speed of sound was estimated to be less than 2% and 0.5% over the whole investigated range of states. Polynomial representations for the thermal diffusivity and the speed of sound were fitted to the data in saturated liquid/vapor. For the thermal diffusivity, the AAD is 0.50% for the saturated liquid and 0.67% for the saturated vapor . For the speed of sound, the AAD is 0.41% for the saturated liquid and 0.35% for the saturated vapor. The tendency of the thermal diffusivity and the speed of sound to temperature and pressure in supercritical region are also analyzed.
研究领域:
物理化学
·
热力学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Sehreish Abrar,Zhuang Ma,Ling Liu,Faisal Nazeer,Abdul Malik
In this work, novel equiatomic high entropy (Dy 1/4 Ho 1/4 Tm 1/4 Yb 1/4 ) 2 Si 2 O 7 or (4RE 1/4 ) 2 Si 2 O 7 ceramic pyrosilicate was fabricated through a single solid solution method to use as environmental barrier coating. The SEM analysis of high entropy powders shows the homogenous mixing and XRD proves the formation of single β-phase after milling and sintering. The coefficient of thermal expansion was reported as (2.3–4.8 × 10 −6 K −1 ) from 400 K −1 to 1723 K −1 . The ultra-low thermal diffusivity (0.4 mm 2 s −1 ) and thermal conductivity (0.8 W/m°C) were reported at 1500 °C for this novel HE ceramic disilicate. The as fabricated (4RE 1/4 ) 2 Si 2 O 7 pyrosilicate shows an excellent CMAS resistant for even up to 48 h and negligible amount of Ca is able to penetrate in the substrate. Rare earth disilicate species with intermediate radii such as Tm 3+ helps in maintaining phase stability along with passive element Yb 3+ of smaller radii which also protect the interface from severe CMAS attack. However, the rare earth species with larger radii such as Dy 3+ and Ho 3+ actively take part in apatite formation leading to reduced corrosion activity of CMAS melt by changing its composition. This result confirms the application of (4RE 1/4 ) 2 Si 2 O 7 as a potential candidate to be used as protecting coating material in harsh combustion environments.
研究领域:
材料科学
·
高温材料
✓ 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）