INTERNATIONAL JOURNAL OF THERMAL SCIENCES
·
2014
·
IF 2.563
Yuan-Xiang Fu,Zhuo-Xian He,Dong-Chuan Mo,Shu-Shen Lu
Graphene-epoxy thermal conductive adhesive was obtained using few-layer graphene sheets as additives which were fabricated by a re-expansion and exfoliation method. The experimental results show that graphene sheets can effectively enhance the thermal conductivity of epoxy matrix , with 4.01 W m −1 K −1 for the maximum filling loading of weight 10.10%, which is enhanced by more than 22 times of the pure epoxy resin , about 2.2 times higher than that of the same resin with the maximum weight 16.81% filled with graphite nanoflakes, and approximately 2.4 times higher than that of the same resin with the maximum weight 44.3% filled with the natural graphite powder .
研究领域:
材料科学
·
热传导工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Xiaofang Liu,Hengyang Wang,Bin Zhang,Sikang Zheng,Yao Chen,Hong Zhang,Xianhua Chen,Guoyu Wang,Xiaoyuan Zhou,Guang Han
SnSe, possessing strong lattice anharmonicity and structural anisotropy, has attracted massive attention in thermoelectric conversion. Herein, we demonstrate that simultaneously optimized electrical and thermal transport properties are achieved in SnS 2 -alloyed SnSe polycrystalline materials , which were fabricated via sintering the mixture of solution-synthesized SnSe microplates and SnS 2 nanoplates. Resulting from the increased carrier concentration, p-type (SnSe) 1– x (SnS 2 ) x ( x = 0.5%, 1%) samples obtain much-improved power factor between 300 K and 373 K, e.g. 0.72 mW m –1 K –2 at 300 K for (SnSe) 0.99 (SnS 2 ) 0.01 , which is enhanced by 53% compared to that of SnSe. Additionally, the existing point defects and planar defects effectively strengthen phonon scattering, thus reducing the lattice thermal conductivity , for example, 0.47 W m –1 K –1 at 773 K for the x = 0.02 sample. Eventually, a maximum zT of 0.80 at 823 K and an average zT of 0.52 over 300 – 823 K are obtained in the (SnSe) 0.99 (SnS 2 ) 0.01 sample, which are increased by 33% and 45% compared to those of SnSe, respectively. This study demonstrates a secondary phase alloying strategy to synergistically optimize the electrical and thermal properties of polycrystalline SnSe.
研究领域:
材料科学
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2022
·
IF 6.371
Xing Yang,Jun Guo,Zi-Yuan Wang,Wen-Hao Gu,Quan Shan,Jing Feng,Zhen-Hua Ge
Bi 2 S 3 -based materials with low thermal conductivity and high Seebeck coefficient has been regarded as promising thermoelectric materials for years. To optimize the thermoelectric properties of Bi 2 S 3 materials, (Se, Cl)-co-doped nanostructured Bi 2 S 3 bulks were prepared by hydrothermal method combined with spark plasma sintering . The doping contents of Se and Cl in Bi 2 S 3 depend on the reaction time of the hydrothermal process. A high power factor of 450 μWm −1 K −2 was achieved for Bi 2 S 3 sample with the reaction time of 24 h owing to the substitution of S by Se and Cl. Meanwhile, a low thermal conductivity of 0.35 Wm −1 K −1 is obtained for the Bi 2 S 3 sample with the reaction time of 18 h, owing to the strong phonon scattering caused by the high density of grain boundaries, pores and point defect . Therefore, benefiting from the improved electrical transport properties and reduced thermal conductivity, a peak ZT value of ~ 0.57 was obtained at 673 K for the Bi 2 S 3 sample with the reaction time of 24 h.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Energy
·
2022
·
IF 9.257
Hong Zhang,Yao Chen,Xiaofang Liu,Hengyang Wang,Chengzhi Niu,Sikang Zheng,Bin Zhang,Xu Lu,Guoyu Wang,Guang Han,Xiaoyuan Zhou
SnSe-based materials, comprising nontoxic, eco-friendly and abundant elements, have intrinsically low lattice thermal conductivity , which are promising candidates for thermoelectric conversion. However, unmodified, polycrystalline SnSe reveals poor electrical transport properties due to the lower carrier mobility . Herein, two-dimensional Ti 3 C 2 T x MXene has been incorporated into SnSe matrix by solution synthesis and fast consolidation, which efficiently increases the carrier mobility and concentration; accordingly, the electrical conductivity is improved in the temperature range of 323–523 K. Meanwhile, SnSe/Ti 3 C 2 T x composites achieve diminished lattice thermal conductivity, delivering a low value of 0.41 W m −1 K −1 at 773 K. Ultimately, a peak zT of 0.93 at 773 K is attained in SnSe/Ti 3 C 2 T x composite with addition of 0.3 wt% Ti 3 C 2 T x , representing a 66% increase compared to that of SnSe. This work sheds light on the thermoelectric performance improvement of polycrystalline SnSe by controllably incorporating two-dimensional MXene.
研究领域:
材料科学
·
能源转换技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Zhuang Fu,Jia-Ling Jiang,Song-Tao Dong,Miao-Cheng Yu,Lijun Zhao,Lei Wang,Shu-Hua Yao
In this study, the facile synthesis method of Bi 2 − x Zr x O 2 Se ( x = 0, 0.02, 0.04, and 0.06) ceramics using a combining the high-energy ball milling and cold pressing was reported. The effects of zirconium (Zr) doping on the microstructure and thermoelectric properties of Bi 2 O 2 Se were systematically investigated. The results indicate that the powder samples were synthesized as a single phase with no impurities. With increasing Zr content, conductivity increased from 13.49 S to 34.91 S cm −1 at 773 K. The thermal conductivity of Bi 1.98 Zr 0.02 O 2 Se was also reduced to 0.51 W m −1 K −1 . The maximum power factor (PF) value of the Bi 1.96 Zr 0.04 O 2 Se sample was 186 μW m −1 K −2 at 773 K. A peak ZT of around 0.27 was achieved for the Bi 1.96 Zr 0.04 O 2 Se sample, which is approximately 2.4 times greater than that of un-doped one (∼0.11). The results indicate that Zr-doping significantly improves the thermoelectric properties of the Bi 2 O 2 Se system.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2022
·Vol. 20
·期 3
·1855-1864
·
IF 2.328
Shi Fu,Zengchao Yang,Honghua Li,Liang Wang,Yong Li,Jiangtao Li
Si 3 N 4 ceramics were prepared by gas pressure sintering at 1900°C for 12 h under a nitrogen pressure of 1 MPa using Gd 2 O 3 and MgSiN 2 as sintering additives. The effects of the Gd 2 O 3 /MgSiN 2 ratio on the densification, microstructure, mechanical properties, and thermal conductivity of Si 3 N 4 ceramics were systematically investigated. It was found that a low Gd 2 O 3 /MgSiN 2 ratio facilitated the thermal diffusivity of Si 3 N 4 ceramics while a high Gd 2 O 3 /MgSiN 2 ratio benefited the densification and mechanical properties. When the Gd 2 O 3 /MgSiN 2 ratio was 1:1, Si 3 N 4 ceramics obtained an obvious exaggerated bimodal microstructure and the optimal properties. The thermal conductivity, flexural strength, and fracture toughness were 124 W·m −1 ·k −1 , 648 MPa, and 9.12 MPa·m 1/2 , respectively. Comparing with the results in the literature, it was shown that Gd 2 O 3 -MgSiN 2 was an effective additives system for obtaining Si 3 N 4 ceramics with high thermal conductivity and superior mechanical properties.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2023
·Vol. 224
·期 19
·2300078
·
IF 2.5
Yifei Wu,Kun Wu,Fei Xiao,Wenjie Diao,Daguang He,Hui Yang,Jun Shi
High thermal conductivity polymeric dielectrics with advanced dielectric properties are urgently demanded in various applications. In this study, a series of thermoplastic polyesters containing different content of fluorine and mesogenic unit in main chains are synthesized utilizing polycondensation. The preferred orientation of liquid crystal can effectively inhibit phonon scattering, and the introduction of fluorine can reduce the polarizability of the polymer and increase the free volume. By introducing the biphenyl mesogenic unit and fluorine into the main chain, its thermal conductivity has been increased to 0.425 Wm −1 k −1 from 0.183 Wm −1 k −1 (the polymer without liquid crystal element), which is 132% higher than that of the liquid crystal polymer without fluorine. In addition, the dielectric constant of polyester decreased to 2.97, and the dielectric loss drops to 8.74 × 10 −4 . The influence mechanism of two ways on its thermal and dielectric properties is explored. Good thermal conductivity and excellent dielectric properties make potential in the thermal management system and 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
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Yun Liu,Ruixiang Liu,Yuanhang Zheng,Jixue Zhao,Tianyi Sui,Xiaolei Li,Bin Lin
To investigate the mechanism of the influence of the sintering additive ratio on the microstructure evolution of silicon nitride (Si 3 N 4 ) ceramics, Si 3 N 4 ceramics were prepared by gas pressure sintering using different ratios of Y 2 O 3 /MgSiN 2 as additives. Varying the ratio of Y 2 O 3 /MgSiN 2 changed the composition of the liquid phase, thereby affecting the densification process and phase transformation rate of Si 3 N 4 ceramics, and ultimately changing their microstructure. The reduction in the Y 2 O 3 /MgSiN 2 ratio raised the N/O and Si/O ratios in the system, which increased the liquid phase viscosity. The Si 3 N 4 grain distribution varied from "normal to bimodal". In the case of increasing the proportion of MgSiN 2 and prolonging the sintering time, more of the glass phase evaporated, which reduced the content of the low thermal conductivity phase and increased the continuity of Si 3 N 4 /Si 3 N 4 . Therefore, Si 3 N 4 ceramics with 1 wt% Y 2 O 3 and 5 wt% MgSiN 2 exhibited excellent properties after sintering at 1900 °C for 12 h, with thermal conductivity, bending strength , and fracture toughness of 106.7 Wm −1 K −1 , 776 MPa, and 11.66 MPa m 1/2 , respectively.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2022
·
IF 10.508
Ruiwen Ji,Meng Lei,Cécile Genevois,Wenda Zhang,Xing Ming,Lunhua He,Mathieu Allix,Congling Yin,Xiaojun Kuang,Xianran Xing
Layered materials coupling a two-dimensional strong-bonding layered network with much weaker van der Waals (vdW) interaction between the layers are sought after for the development of nanoelectronics and energy conversion devices. It is important to elucidate the layer stacking rules in these vdW materials and control the thickness of the strong-bonding layers for tuning the nanosheet height during exfoliation and therefore tailor physical properties. Here, we show that the single Bi2O2Se ionic layer in the three-anion vdW semiconductor Bi4O4SeCl2 showing extremely low thermal conductivity can be expanded to higher-order layers forming a homologous series Bi2+2nO2+2nSenX2 (X = Cl, Br) with variable ionic layer thicknesses. Bi4O4SeX2 (n = 1) and Bi6O6Se2X2 (n = 2) were isolated as single-phase materials, while materials with larger layer thicknesses such as Bi8O8Se3Cl2 (n = 3) contain different defect-intergrowth structures at the crystallite scale. The anionic disorder of Se and X within the Bi2O2Se and Bi2O2X2 slabs is a critical factor in the stabilization of Bi2+2nO2+2nSenX2. The ∼50% Se substitution by X anions in the Bi2O2Se slab as related to the weak interlayer interaction can serve as a stabilization criterion of Bi2+2nO2+2nSenX2. All of these materials show similar optical indirect band gaps of ∼1.05 eV, originating from the electronic states in the Bi2O2Se slabs. Pellets prepared from these vdW materials possessed low bulk resistivities (100 Ω·cm) and exceptionally low and tunable thermal conductivities (0.66 W/mK and lower) parallel to the pressing axis of the pellets (heavier the halogen is, lower is the thermal conductivity). The results presented here provide important multiple anion chemistry for tailoring the ionic-bonding network into different thicknesses in the vdW layered structures and therefore their physical properties.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE-POLAND
·
2020
·Vol. 38
·期 3
·502-507
·
IF 0.911
Meihua Hu,Ning Bi,Mingming Liu,Guangjin Gao,Shangsheng Li,Taichao Su
The improved TiB2 ceramics were obtained in sintering process at the pressure of 5.5 GPa and temperature of 1550 °C in presence of metallic Co powder. The effect of Co content (ranging from 0 wt.% to 10.0 wt.%) on the phase composition, density, microstructure, Vickers hardness and thermal conductivity of TiB2 ceramics was analyzed. A small amount of new phase Co2B has been created in the reaction of TiB2 and Co. The relative density of sintered TiB2 ceramics reached 98.1 %. When the mass fraction of Co increased, the porosity increased, while the hardness first increased and then decreased. The maximal Vickers hardness values were equal to 33.3 GPa or 28.2 GPa when the used load was of 4.9 N or 9.8 N, respectively. The highest reached value of thermal conductivity was 88.9 W˙m−1 ˙ K−1. The dense TiB2 ceramics with improved hardness and thermal conductivity were ascribed to the high pressure sintering method and Co sintering aid. High pressure sintering method provides a new way for the preparation of ceramics materials.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Wendong Liu,Zhihui Lei,Rui Yang,Wenkui Xing,Peng Tao,Wen Shang,Benwei Fu,Chengyi Song,Tao Deng
This paper studies the impact of hot pressing on the electrical and thermal performance of thick (thickness >5 μm) conducting polymer poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) films after acid treatment. Thick conducting polymer films usually exhibit low electrical and thermal conductivities similar to bulk polymer because charge and heat carriers are easily scattered by the irregular arrangement of crystalline domains inside the polymer. In this work, the in-plane electrical conductivity of thick hot-pressed PEDOT:PSS film exceeded 1500 S/cm, and 50% enhancement was obtained in comparison with its non-hot-pressed counterparts. Its in-plane thermal conductivity reached as high as 1.11 W/mK (improved by almost 100% compared to acid-treated PEDOT:PSS films), which is comparable to that of some commercial thermal pads. Such electrical and thermal enhancement via the hot-pressing process is attributed to the optimized morphology and microstructures, which provide short paths for thermal and electrical transportation. We have also demonstrated that the hot-pressed PEDOT:PSS films could be potentially utilized as a flexible conductor and heat spreader for application in flexible electronics and thermal management, respectively. This study not only offers a new insight into the process–property relationship for conducting polymers but also further enables the use of PEDOT:PSS films with simultaneously improved electrical and thermal performance in practical applications, such as thermal management for organic electrodes in batteries, flexible electronics, soft robotics, and bioelectronics.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Advanced Electronic Materials
·
2018
·Vol. 5
·期 1
·1800548
·
IF 5.466
Changzeng Yan,Tianhang Yu,Chao Ji,Dae Joon Kang,Ning Wang,Rong Sun,Ching-Ping Wong
Ever-increasing packaging and power densities of modern electronic devices in the present “More-than-Moore” technology era demand higher performance thermal interface materials (TIMs). However, conventional composite TIMs require higher loading to achieve better thermal conductive property, resulting in a mechanical problem. The poor wetting property of matrix loading materials further increases the interfacial thermal resistance (ITR). In this work, a one-step hydrothermal method is employed to grow 2D molybdenum disulfide (MoS 2 ) nanosheets on a tellurium (Te) nanowire skeleton and silver (Ag) nanoparticles are further decorated on MoS 2 nanosheets via the photoreduction method. The in-plane thermal conductivity of the final nanocomposite reaches as high as 10.4 W m −1 K −1 , which is 4,160% higher than that of a pure epoxy resin and one order of magnitude higher than that of conventional polymeric nanocomposites. The 3D interconnected heat transferring network of Te/MoS 2 /Ag greatly enhances the thermal stability of the composite in practical applications. The rational materials design concept may contribute to the development of new types of high-performance thermal management materials.
研究领域:
材料科学
·
热管理技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）