JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2024
·
IF 5.8
Xian Dang,Zhulin Huang,Jieyan Yuan,Ke Li,Mengen Hu,Zhuoming Xie,Haoran Song,Bensong Chen,Xinyang Li,Ming Li,Xiaoye Hu,Yue Li
High-purity, nano-sized (Ti 0.2 Zr 0.2 Nb 0.2 Mo 0.2 Hf 0.2 )B 2 (TZNMH) diboride powders were successfully synthesized via a combined flocculation precipitation and boro/carbothermal reduction method. Then, the solid solution formation, thermal radiation performance and mechanical properties of TZNMH were investigated. It is found that high entropy effect endows TZNMH ceramic with outstanding near-blackbody radiation performance in the UV-Vis-NIR region, with a thermal emissivity ≥ 95%. This is because high entropy induces robust intraband transition. A dense and single-phase TZNMH ceramic was obtained by spark plasma sintering with high hardness (HV 0.1 =31.6 GPa) which remained above 30 GPa even after 60 h exposure at 1800 °C in Ar environment. This high hardness of TZNMH ceramic is believed to arise from the strong hybridization between metals and boron, as revealed by density functional theory calculations. This study demonstrates that high-entropy boride ceramics can be used as ideal high-temperature structural component with high thermal emissivity.
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Xinyu Ping,Xiaoyu Pan,Bin Meng,Qingqing Yang,Wenlong Zhang
The dielectric performance of BaTiO 3 -based ceramic capacitors must be improved for further miniaturization and integration of energy storage devices. This study combines two optimization strategies, the grain refinement and high-entropy effect, to design BaTiO 3 -based high-entropy nanocrystalline ceramics: Ba(Ti 0.2 Zr 0.2 Nb 0.2 Y 0.2 Sn 0.2 )O 3 (HEO1) and Ba(Ti 0.2 Zr 0.2 Nb 0.2 Yb 0.2 Hf 0.2 )O 3 (HEO2). These ceramics were synthesized using fast hot-pressing sintering (FHPS), yielding HEO1-FHPS and HEO2-FHPS samples, both of which exhibit a pure perovskite structure, similar to that of samples fabricated via conventional solid-state sintering (CS), namely HEO1-CS and HEO2-CS. The relative densities of the HEO1-FHPS (96.18 %) and HEO2-FHPS (98.34 %) samples are higher than those of HEO1-CS (95.47 %) and HEO2-CS (95.40 %). In addition, the grain sizes of HEO1-FHPS (0.092 μm) and HEO2-FHPS (0.084 μm) are notably smaller than those of HEO1-CS (2.48 μm) and HEO2-CS (2.91 μm). The high relative density and small grain size of HEO1 and HEO2 improve their maximum permittivity, increase the Curie temperature and enhance dielectric stability. Furthermore, compared with HEO1-CS and HEO2-CS, HEO1-FHPS and HEO2-FHPS exhibit higher critical electric field strengths (359 and 389 kV/cm), greater recoverable energy densities (0.40 and 0.88 J/cm 3 ) and improved energy storage efficiencies (69.6 % and 70.4 %). These findings provide a promising approach for developing BaTiO 3 -based ceramics with enhanced dielectric performance.
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
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2020
·
IF 4.652
H.W. Deng,Z.M. Xie,M.M. Wang,Y. Chen,R. Liu,J.F. Yang,T. Zhang,X.P. Wang,Q.F. Fang,C.S. Liu,Y. Xiong
A promising strategy involving the synergetic effects of the high-entropy engineering and interface architectures has been proposed to realize the thermal stability of nanocrystalline alloys. A bulk dual-phase nanocrystalline (DPNC-) AlCoCuNi medium-entropy alloy was prepared by mechanical alloying (MA) and spark plasma sintering (SPS) process. These DPNC structures include Cu-rich and AlCoNi-rich nanocrystallines (NCs) with an average grain size of 46 nm. This DPNC-AlCoCuNi material could maintain the nanostructures as well as a high hardness of about 580 HV even after annealing at 900 °C for 50 h. The extremely high thermal stability has been attributed to the extensive thermal-stabled low-energy phase boundaries, low-angle grain boundaries, the high-entropy and sluggish diffusion effects.
研究领域:
材料科学
·
冶金工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 106
·期 7
·4343-4357
·
IF 3.9
Liping Lai,Mengdi Gan,Jun Wang,Lin Chen,Xiubing Liang,Jing Feng,XiaoYu Chong
Tailoring the structure and properties of materials using the high-entropy (HE) effect is of significant interest in the fields of environmental and thermal barrier coatings (TBCs). In this work, a new class of dense HE rare-earth niobates was successfully prepared by a solid-phase reaction method, including (Sm 1/5 Dy 1/5 Ho 1/5 Er 1/5 Yb 1/5 )NbO 4 (5HERN), (Sm 1/6 Dy 1/6 Ho 1/6 Er 1/6 Yb 1/6 Lu 1/6 )NbO 4 (6HERN), (Sm 1/7 Dy 1/7 Ho 1/7 Er 1/7 Yb 1/7 Lu 1/7 Gd 1/7 )NbO 4 (7HERN), and (Sm 1/8 Dy 1/8 Ho 1/8 Er 1/8 Yb 1/8 Lu 1/8 Gd 1/8 Tm 1/8 )NbO 4 (8HERN), along with eight single rare-earth niobates (RENbO 4 , RE = Sm, Dy, Ho, Er, Yb, Lu, Gd, and Tm). X-ray diffraction analysis showed that 5–8HERN are single-phase solid solutions with a monoclinic structure (space group C 12/ c 1). The thermal expansion coefficients of 7HERN and 8HERN exceed 11 × 10 −6 K −1 at 1200°C and are much higher than those of the RENbO 4 compositions (10.13–10.74 × 10 −6 K −1 ) and other some HE rare-earth oxides (10.27–10.87 × 10 −6 K −1 ). Importantly, 5–8HERN have lower oxygen-ion conductivity and higher activation energy than yttrium-stabilized zirconia (YSZ) and the RENbO 4 compositions. The oxygen-ion conductivity of 5HERN (7.52 × 10 −7 S cm −1 , 900°C) was 10 5 times lower than that of YSZ (0.01 S cm −1 , 750°C). The hardness of 5–8HERN is ∼7.81–8.46 GPa and these compositions have low intrinsic lattice thermal conductivity at high temperature (1.28–1.69 W m −1 K −1 at 900°C). The mechanism by which the HE effect improved the material properties was elucidated. Young's modulus, hardness, thermal expansion coefficient, and intrinsic lattice thermal conductivity are linearly related to the mass, size, and distortion degree of samples. In contrast, the oxygen-ion conductivity depends on both the degrees of disorder and distortion and the oxygen-ion vacancy concentration. Based on their overall performance, especially their high thermal expansion coefficients and excellent oxygen-barrier performance, HE rare-earth niobates show potential for further development as TBC materials.
研究领域:
材料科学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Yin'an Zhu,Weiji Dai,Xu Zhong,Tao Lu,Ye Pan
The electrochemical anodic behavior of transition metal compounds plays an undeniably non-negligible role across many electrooxidation reactions. In this work, a chronopotentiometric technique was employed to activate the multicomponent non-noble metal oxyfluorides in-situ for oxygen evolution reaction (OER). It is interesting to unravel that the increasing applied current density helps to reconstruct the catalyst into nanoporous core–shell structure and introduce metal oxyhydroxide on the surface, which guarantees more channels for efficient ion/mass transportation and thus contributes to exposing more active sites for catalytic reaction. The activated five-membered oxyfluoride shows the best catalytic activity with overpotential of 348 ± 2 mV to achieve the current density of 10 mA/cm 2 and a Tafel slope of 110.3 ± 0.1 mV/dec, in contrast with the pristine one (532 ± 2 mV & 240.2 ± 0.1 mV/dec). It still maintains high stability after long time OER measurement, making it a promising succedaneum for noble metal catalysts. The high-entropy effect, amorphous state and high active sites density jointly contribute to its enhanced OER performance. This work provides new ideas for realizing the potential of inactive elements via entropy engineering and using electrochemical self-reconstruction to modify semiconductors for advanced water oxidation.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Smart Materials and Structures
·
2021
·Vol. 30
·期 10
·105009
·
IF 3.585
Yifu Huang,Wentao Tang,Zekun Deng,Wenhong Ruan
This work presents a novel strategy of performing a reversible microcrystalline-spherulite morphology transition based on photo-triggered immiscible phase aggregation in semi-crystalline block polymer. We propose that by assembling or disintegrating immiscible photo-active aggregates during melt crystallization under illuminations, end-to-end distance R of the photo-inactive semi-crystalline polymer chains can be adjusted to generate high-entropy state, R< R0 or low-entropy state, R > R0. Thus, the corresponding entropic effect influences chain nucleation and can be used to control crystallization morphologies. Besides, photo-tunable mechanical and electrical properties can be also simultaneously endowed. Promising potential applications of this study for optical patterning, memory materials and solid-state electrochemistry can be anticipated.
研究领域:
材料科学
·
高分子化学
·
光学材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2014
·
IF 6.687
Xiao Y. Luo,Fang Ding,Wen J. Lin,Yu Q. Qi,Hao R. Li,Cong M. Wang
A strategy for improving the capture of CO2 was developed through the entropic effect by tuning the geometric construction of anion-functionalized ionic liquids. Several kinds of anion-functionalized ionic liquids with the amino group at the para or ortho position were designed and applied for the capture of CO2, which indicates that the former exhibited both higher capacity and lower enthalpy, resulting in the efficient and energy-saving CO2 capture. Viscosity measurements, spectroscopic investigations, and quantum chemical calculations showed that such a unique behavior originated from the entropic effect, which was induced by the intermolecular hydrogen bonding in these ionic liquids. The entropic control for gas separation developed by this work provides an efficient strategy to both increased capacity and reduced enthalpy.
研究领域:
化学工程
·
环境科学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2019
·
IF 4.978
Zhenjiang He,Yuxi Yang,Peng Bai,Xianghai Guo
Selective adsorption and separation of three xylene isomers of seven stable metal-organic frameworks (MOFs) were investigated, where MIL-53(Cr) manifested the highest adsorption capacity and apparent preference for o -xylene. Further detailed studies with MIL-53(Cr) showed that pseudo-second-order model fit best with adsorption kinetics of xylene isomers, and the isotherms were perfectly fitted by Langmuir isotherm model. The adsorption was proved to be a quick process, and both the changes of entropy and enthalpy contributed to the o -xylene selectivity, but which mainly resulted from the entropy effect. The adsorption capacity of preferable isomer o -xylene, on account of better packing efficiency, was record-breaking 8.19 mmol/g, and selectivity of OX/PX, OX/MX and MX/PX were 13.75, 8.01 and 1.72, respectively. Both the adsorption capacity and OX selectivity on MIL-53(Cr) in liquid phase adsorption and breakthrough experiments were super high, which discriminated it from zeolites and other materials reported so far. Combined with extremely short equilibrium time and high stability, MIL-53(Cr) can be a promising adsorbent for separation of xylenes in industrial process.
研究领域:
化学工程
·
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2022
·
IF 8.008
Guohua Qi,Chen Xu,Jiafeng Wang,Yu Tian,Bo Wang,Ying Zhang,Kongshuo Ma,Xingkang Diao,Yongdong Jin
Cell differentiation plays a vital role in mediating organ formation and tissue repair and regeneration. Although rapid and effective methods to stimulate cell differentiation for clinical purposes are highly desired, it remains a great challenge in the medical fields. Herein, a highly effective and conceptual optical method was developed based on a plasmonic chip platform (made of 2D AuNPs nanomembranes). through effective light-augmented plasmonic regulation of cellular bioenergetics (CBE) and an entropy effect at bionano interfaces, to promote rapid cell differentiation. Compared with traditional methods, the developed optoplasmonic method greatly shortens cell differentiation time from usually more than 10 days to only about 3 days. Upon the optoplasmonic treatment of cells, the conformational and vibration entropy changes of cell membranes were clearly revealed through theoretical simulation and fingerprint spectra of cell membranes. Meanwhile, during the treatment process, bioenergetics levels of cells were elevated with increasing mitochondrial membrane potential (Δψm), which accelerates cell differentiation and proliferation. The developed optoplasmonic method is highly efficient and easy to implement, provides a new perspective and avenue for cell differentiation and proliferation, and has potential application prospects in accelerating tissue repair and regeneration.
研究领域:
生物医学工程
·
细胞生物学
·
组织工程
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）