CHEMICAL ENGINEERING SCIENCE
·
2018
·
IF 3.306
Li-Zhi Zhang,Qian-Wen Su
Membranes of low thermal conductivity (thermal insulation) but high moisture permeability are highly desired in membrane-based humidification-dehumidification (MHDD) seawater desalination technology. The porous membranes with thermal insulation could decrease the heat losses in humidification, thus the system energy performance can be improved. To satisfy this purpose, in this study, a PVDF/SiO 2 (Si aerogel) composite bilayer membrane of low heat conductivity is prepared and analyzed. To solve the problem of cracking in forming SiO 2 layer, the casting solution (TEOS, H 2 O) is doped with a drying control chemical additive (DCCA) N, N -dimethylformamide (DMF) to decrease the surface tensions in the gel. Then performance analysis of the developed membranes are conducted and the membranes are characterized. The results found that the heat conductivity is decreased from 0.08199 W m −1 K −1 to 0.04487 W m −1 K −1 , with a penalty of effective moisture diffusivity sacrificed from 4.93 × 10 −6 m 2 /s to 2.42 × 10 −6 m 2 /s. They are superior to the available SiO 2 blend insulation membranes. Further, the membranes can be optimized by facile structural manipulations such as adjusting the SiO 2 layer thickness to realize the desired performance while balancing the paradox between the permeability and heat conductivity. This is the first time that heat conductivity of membranes can be manipulated for seawater desalination.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Wenyuan Ma,Yubo Luo,Zheng Ma,Chengjun Li,Yongxin Qian,Wang Li,Tianshun Xiong,Zheng Wang,Xin Li,Qinghui Jiang,Guanchun Wang,Junyou Yang
Herein, five new La 2 Zr 2 O 7 based high-entropy ceramic materials, such as (La 0.2 Ce 0.2 Gd 0.2 Y 0.2 Er 0.2 ) 2 Zr 2 O 7 , (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 , (La 0.2 Gd 0.2 Y 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 , (La 0.2 Ce 0.2 Y 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 , (La 0.2 Ce 0.2 Gd 0.2 Y 0.2 Sm 0.2 ) 2 Zr 2 O 7 ), were synthesized using a sol-gel and high-temperature sintering (1000 °C) method. The spark plasma sintered (SPS) (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 pellet shows a low thermal conductivity of 1.33 W m -1 K -1 at 773 K, and it also exhibits better CaO–MgO–Al 2 O 3 –SiO 2 corrosion resistance than that of Y 2 O 3 stabilized ZrO 2 . It shows that (La 0.2 Ce 0.2 Gd 0.2 Er 0.2 Sm 0.2 ) 2 Zr 2 O 7 has a promising application potential as a thermal barrier coating .
研究领域:
材料科学
·
能源工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2020
·
IF 4.825
Jingpeng Li,Shiqiang Hao,Shangqing Qu,Christopher Wolverton,Jing Zhao,Yonggang Wang
Transition-metal-based chalcogenides are a series of intriguing semiconductors with applications spanning various fields because of their rich structure and numerous functionalities. This paper reports the crystal structure and basic physical properties of a new quaternary chalcogenide In4Pb5.5Sb5S19. The crystal structure of In4Pb5.5Sb5S19 was determined by both powder and single-crystal X-ray diffraction techniques. In4Pb5.5Sb5S19 crystallizes in the monoclinic system with I2/m space group, and the structure parameters are a = 26.483 Å, b = 3.899 Å, c = 32.696 Å, and β = 111.86°. The polyhedral double chains of Sb3+ and Sb/Pb2+ as the main cations are parallel to each other and form a Jamesonite-like mineral structure through the short chain links of the distorted In, Pb, and Sb polyhedron. In4Pb5.5Sb5S19 exhibits a moderate experimental band gap of 1.42 eV, indicating its potential for application in solar cells and photocatalysis. In addition, In4Pb5.5Sb5S19 exhibits good ambient stability, and differential scanning calorimetry tests demonstrate that it is stable up to 892 K in a nitrogen atmosphere. Moreover, In4Pb5.5Sb5S19 exhibits extremely low thermal conductivity (0.438–0.478 W m–1 K–1 ranging from 300 to 700 K) compared with binary counterparts such as PbS and In2S3. Future chemical manipulation via elemental doping or defect engineering may make the title compound a potential thermoelectric or thermal insulating material.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Lijie Shi,Jun Ding,Xiangbin Chen,Xiang Qu,Zhiquan Chen,Man Jiang
Low-cost preparation of thermoelectric materials is crucial for reducing energy consumption. In this study, we prepared the nanopolycrystalline SnSe ceramic by combining the hydrothermal and cold sintering process (CSP) at a relatively low temperature of 170 °C from 300 MPa to 510 MPa. XRD analyses indicated that a pronounced preferential orientation of the cold sintered SnSe along the (h00) directions. SEM observations showed that a well-crystallized layered structure was formed. All SnSe samples exhibit remarkably low thermal conductivity of 0.3 Wm −1 K −1 at 773 K. This low thermal conductivity can be attributed to the use of ethanol as a transient liquid phase and the application of high pressure, which promotes the rearrangement of nanopolycrystals and introduces high densities of dislocations and stacking faults in SnSe. A maximum ZT value of 1.35 at 773 K was achieved for the 405 MPa sintered sample. This study provides a cost-effective and efficient strategy for the preparation of polycrystalline SnSe thermoelectric material.
研究领域:
材料科学
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Chufei Cheng,Ruixin Hao,Jiadong Hou,Fengnian Zhang,Fuhao Cheng,Ziqian Meng,Bei Ren,Yang Miao,Libiao Xin,Xiaomin Wang
In the thermal protection system of spacecraft, the bolts connecting the ceramic to the internal superalloy need to have low thermal conductivity and high strength . Two dense high entropy fluorite oxides (Zr 1/7 Hf 1/7 Ce 1/7 Y 2/7 La 2/7 )O 2-δ (ZHCYL) and (Zr 1/8 Hf 1/8 Ce 1/8 Y 1/4 La 1/4 Pr 1/8 )O 2-δ (ZHCYLP) were designed and synthesized by using the synergistic effect of plasma-assisted ball milling and spark plasma sintering(SPS). Through the synergistic effect of lattice distortion and oxygen vacancy guided by entropy regulation, ZHCYLP synthesized in this study has lower thermal conductivity(1.13 W·m −1 ·K −1 ), higher high temperature strength(192 MPa at 1000 °C) and high temperature phase stability up to 1600 °C than 8YSZ ceramics. The thermo-mechanical coupling finite element analysis results of high temperature bending test show that the variation trend of the maximum stress value of the sample is consistent with the experimental results. This shows that the mechanical and thermal properties of high entropy oxides can predict the variation trend of the maximum stress value in high temperature bending tests. It opens up a new way for designing and synthesizing high entropy oxide materials with low thermal conductivity and high strength which can be applied in the field of heat protection and load bearing.
研究领域:
材料科学
·
航天工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 9
·期 2
·1006-1013
·
IF 11.301
Zhou Li,Weihui Zhang,Bingchuan Gu,Chenxi Zhao,Bangjiao Ye,Chong Xiao,Yi Xie
Low thermal conductivity is commonly seen in amorphous or disordered systems, in which electrical conductivity is also very low, bringing considerable obstacles to the development of high-performance thermoelectric materials. Present study highlights the vacancy cluster-induced local disordered structure in Cu2ZnSnSe4 for the simultaneous achievement of low thermal conductivity and high electrical conductivity, thereby significantly enhancing its thermoelectric property. Comprehensive evidences from positron annihilation and HRTEM characterizations indicated that the vacancies in cation-deficient (VCu, VZn, and VSn) samples existed as vacancy clusters containing both cation vacancies and intrinsic Se vacancies, which induced the formation of localized disorderly oriented domains. These cation deficiencies contributed to the improved electrical conductivity and power factor of the corresponding Cu2(1−x)Zn1−ySn1−zSe4 samples via an increase in the hole carrier concentration. Moreover, the induced local disordering contributed to further reduced thermal conductivity via stronger phonon scattering. As a result, enhanced ZT performance was achieved in all cation deficient samples. Among them, Sn-deficient Cu2ZnSnSe4 obtained the highest ZT value of 0.44 at 750 K, which was two times larger than that of pristine sample (ZT = 0.14 at 750 K). The cation–anion vacancy cluster and local disordered structure elucidated in the present work open up a new avenue to tackle the entanglement of thermoelectric parameters by proper vacancy modulation.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Wei Gao,Zhenyu Wang,Yongzheng Zhang,Chunyin Shen,Yanli Wang,Liang Zhan
Phenolic aerogels have addressed considerate application in fabricating lightweight ablative materials owing to their excellent characteristics of large surface area, low bulk density, and low thermal conductivity . However, unsatisfactory thermal stability still limits their extensive applications. To enhance the thermal stability, we reported a facile co-precursor strategy to prepare boron-modified phenolic aerogels, through sol–gel polymerization of phenylboronic acid and phenolic resin. The thermal stability of hybrid aerogels is remarkably enhanced, achieving a char yield of up to 64.16 % at 850 ℃ due to the much higher bonding energy of B-O bonds. The phenyl-borates structure gradually transferred into B 2 O 3 , effectively fixing the oxygen content and reducing the carbon loss during the carbonization process. Moreover, the in-situ formed phenyl-borates structure contributes to forming a denser network, which affords the hybrid aerogels with diverse properties: low density (0.31–0.34 g/cm 3 ), a hierarchical micro- meso -macro porous structure with small particle size (28.42–48.58 nm), promoted compressive strength (20.65–28.46 MPa), and excellent insulation performance (0.0406–0.0564 W/(m•k)). These integrated superiorities enable the boron-modified phenolic aerogels to perform effectively in thermal insulation fields, especially for aerospace related industry.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Zijun Li,Shuo Wang,Mengqing Zhang,Jiayi Zheng,Tong Zhang
With the rapid development of laser technology, the safety of human and equipment is increasingly threatened by high-power laser. However, there are not any high-power laser protection materials without flame and smoke during irradiation. In this study, we investigated a series of RE 2 Ti 2 O 7 (RE = Y, La, Sm, Eu, Yb) ceramics with high reflectivity and low thermal conductivity and evaluated their laser ablation behaviors. The results showed that all RE 2 Ti 2 O 7 have high reflectivity comparable to that of metals, and their thermal conductivity is lower than 8YSZ. Laser ablation results showed all coatings were intact after irradiation under 500 W/cm 2 for 10 s. Even after irradiation under 1000 W/cm 2 for 10 s, no significant changes were observed in the Y 2 Ti 2 O 7 and La 2 Ti 2 O 7 coatings. Further exploration determined that the protection threshold of Y 2 Ti 2 O 7 was 84 s while that of La 2 Ti 2 O 7 was 163 s, indicating its superior laser protection capability. In conclusion, La 2 Ti 2 O 7 shows significant potential in high-power laser protection.
研究领域:
材料科学
·
激光技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2018
·
IF 3.794
Ming-Ye Yang,Jun-Wei Wang,Lin Li,Bin-Bin Dong,Xu Xin,Simeon Agathopoulos
This paper reports on the successful fabrication of γ-Y 2 Si 2 O 7 membranes with low thermal conductivity , which is an important membrane property for achieving high performance in membrane distillation process. Single-phase γ-Y 2 Si 2 O 7 powder was first synthesized by calcination of SiO 2 and Y 2 O 3 powders, with 3 wt% LiYO 2 as a sintering aid. The membrane was produced by tape-casting of a suspension of this powder. After sintering at 1300 °C for 4 h, a flat membrane was obtained, which had a thickness of 0.5 mm, 49% porosity, 0.9 μm pore diameter, and low thermal conductivity of 0.497 W/m⋅K at 32 °C, and 0.528 W/m⋅K at 100 °C. The obtained membrane presented hydrophobic features (water contact angle was 132°) after surface modification, which resulted in formation of a strongly adhered robust hydrophobic SiNCO nanoparticle layer on its surface. The resultant hydrophobic membrane was tested in water desalination experiments using a sweeping gas membrane distillation (SGMD) device. High water flux of 10.07 L⋅ m −2 ⋅ h −1 was achieved for a 20 wt% NaCl feeding solution and a temperature at the feed of 90 °C. Stable water flux and rejection rates were recorded in long-term experiments (>400 h).
研究领域:
材料科学
·
膜技术
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 8
·722
·
IF 4.4
Zhengtang Cai,Kaipeng Zheng,Chun Ma,Yu Fang,Yuyang Ma,Qinglin Deng,Han Li
Compared to SnTe and PbTe base materials, the GeTe matrix exhibits a relatively high Seebeck coefficient and power factor but has garnered significant attention due to its poor thermal transport performance and environmental characteristics. As a typical p-type IV–VI group thermoelectric material, W-doped GeTe material can bring additional enhancement to thermoelectric performance. In this study, the introduction of W, Ge1−xWxTe (x= 0, 0.002, 0.005, 0.007, 0.01, 0.03) resulted in the presence of high-valence state atoms, providing additional charge carriers, thereby elevating the material’s power factor to a maximum PFpeakof approximately 43 μW cm−1K−2, while slightly optimizing the Seebeck coefficient of the solid solution. Moreover, W doping can induce defects and promote slight rhombohedral distortion in the crystal structure of GeTe, further reducing the lattice thermal conductivityκlatto as low as approximately 0.14 W m−1K−1(x= 0.002 at 673 K), optimizing it to approximately 85% compared to the GeTe matrix. This led to the formation of a p-type multicomponent composite thermoelectric material with ultra-low thermal conductivity. Ultimately, W doping achieves the comprehensive enhancement of the thermoelectric performance of GeTe base materials, with the peak ZT value of sample Ge0.995W0.005Te reaching approximately 0.99 at 673 K, and the average ZT optimized to 0.76 in the high-temperature range of 573–723 K, representing an increase of approximately 17% compared to pristine GeTe within the same temperature range.
研究领域:
材料科学
·
能源材料
·
热电材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Yanfei Wang,Weiran Zhang,Jinping Du,Duan Li,Rongjun Liu
It is urgent to develop thermal barrier coating (TBC) topcoat materials with ultra-low thermal conductivities for next-generation gas turbine engines. A novel pyrochlore-based single-phased ceramic, tuned by codoping of lanthanum zirconate, (La 1-x Y x ) 2 (Zr 1-y Ce y ) 2 O 7 , has been synthesized from the solid state reaction method. The thermal conductivity of (La 1-x Y x ) 2 (Zr 1-y Ce y ) 2 O 7 not only exhibits a temperature-independent trend but also reaches as low as 0.93 W·m −1 ·K −1 , a value that is lowest of fully dense crystalline solids in open literature, attributing to the following two combined effects. The first is the strong scattering of phonons by small-sized Y 3+ cations occupying the oversized atomic cages formed by the distinctive pyrochlore structure. The second is the lattice softening effects arising from larger-sized Ce 4+ substituting Zr 4+ cations. The above two effects act in concert and thus form a glasslike and ultra-low thermal conductivity of (La 1-x Y x ) 2 (Zr 1-y Ce y ) 2 O 7 solid solutions, which is ideal for next-generation TBC topcoat applications.
研究领域:
材料科学
·
工程热物理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Jinxia Li,Jianjun Chen,Jiyu Tao,Hao Chen
The cotton fiber batt is one of the most commonly used thermal insulator in our lives at room temperature because of its flexible and porous structure . The SiC nanofibers have excellent mechanical, physical, and chemical properties such as high mechanical strength and modulus, low density, high-temperature resistance, which is a promising material for high temperature structural materials or thermal insulator. In this work, a flexible SiC nanofiber batt was fabricated from the cotton fiber batt by sol-gel carbothermal reduction reaction. The fluffy carbonized porous cotton batt was used as a template for the fabrication of sponge-liked SiC nanofiber batt composed of single crystalline β-SiC fibers. It exhibits good compressive flexibility, ultra-high porosity (a specific surface area was 30.90 m²/g), excellent high-temperature stability (ranging from −196 °C in liquid nitrogen to 1300 °C under the flame of butane blowtorch) and low thermal conductivity (0.02 W/(m·K) at room temperature). The SiC nanofiber batt, which has low density, excellent high-temperature resistance and oxidation resistance , is a promising material for high-temperature structural materials or thermal insulators under extreme conditions. The facile fabrication method of SiC nanofiber batt from common cotton batt provides a novel technique for economic industrial production of high temperature thermal insulation material .
研究领域:
材料科学
·
热能工程
✓ 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）