VACUUM
·
2022
·
IF 4.11
Chaofei Bai,Shengnan Li,Desheng Yang,Jie Li,Guoping Li,Yunjun Luo
Nanothermite has attracted much attention because of the larger interface contact area between oxidizer and fuel. Usually, one of the important ways to improve the reaction and combustion performance is to make fuel contact with oxidizer more closely, so the preparation of large specific surface area oxidizer is a very effective method. Therefore, tremella NiO were prepared in ethylene glycol using nickel acetate as precursor by means of mediated self-assembly and calcination process, with a specific surface area of 310.69m 2 /g. which was an oxidant to prepare Al@NiO nanothermite by ultrasonic mixing. The thermal properties , combustion performance of Al@NiO were analyzed by differential scanning calorimetry and high-speed camera, and compared with Al/NiO nanothermite prepared by using commercially purchased Al and NiO as raw materials. Compared with Al/NiO, the heat release of Al@NiO increased by 268J/g, the activation energy decreased by 88 kJ/mol, and the combustion flame was brighter, the combustion time was shorter, and the energy release was faster. It was also found that stoichiometric ratio has significant effects on the energy output of nanothermite, and the fuel-rich formula has more prominent energy characteristics. The alcohol-thermal synthesis method adopted in this paper is also expected to be applied to other nanothermite systems.
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DOI
高影响因子
NANO
·
2021
·
IF 1.556
Xin Wang,Guo-Dong Han,Juan Wang
Due to the high theoretical capacity of sulfur (1675 mAh g − 1 ) , low cost and environmental friendliness, lithium-sulfur batteries have shown broad prospects in future energy conversion and storage systems. However, the shuttle effect and insulating properties of sulfur restrict its practical application. Herein, we report a facile approach to fabricate Al-TDC@S-PPy composite material as lithium-sulfur battery electrode. In this strategy, a topological porous Al-TDC ( TDC = 2 ,5-thiophenedicarboxylate) with 8-connected clusters is reported, which can provide strong adsorption for dissolved intermediate polysulfides and alleviate volume expansion. Meanwhile, Polypyrrole, (PPy) as a conductive and flexible additive to expedite electron transport, improves electrical conductivity. Consequently, the Al-TDC@S-PPy composite cathode exhibits a higher initial specific capacity (1310.4 mAh g − 1 at 0.2 C). The final reversible capacity is 411.0 mAh g − 1 after 200 cycles at 1 C. We can extend this strategy to other metal-organic frameworks (MOFs) and manufacture MOF/conductive polymer composite electrodes for high-performance lithium-sulfur batteries.
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DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2021
·
IF 2.993
Guanghui Han,Rui Sui,Yongsheng Yu,Li Wang,Menggang Li,Ji Li,Hu Liu,Weiwei Yang
Ion substitution is considered to be one of the efficient approaches to improve the magnetic properties of the barium hexaferrites. In this work, we fabricated BaFe 12− x Al x O 19 ( x = 0, 1, 2, 4, 6) via a simple auto-combustion method and investigated their structures, morphologies and magnetic properties. The coercivity is greatly affected by annealing temperature and Al 3+ content. In addition, the Al 3+ substitution sites in BaFe 12− x Al x O 19 were further investigated by the Mössbauer spectroscopy and the superparamagnetic components were found in the BaFe 8 Al 4 O 19 and BaFe 6 Al 6 O 19 . The highest coercivity of 13.7 kOe was achieved in the BaFe 8 Al 4 O 19 , which increases by 168.6% compared with that of BaFe 12 O 19 . This work opens up a new and meaningful insight for the understanding of microstructure and coercivity mechanism towards the Al 3+ substituted barium hexaferrites.
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2020
·
IF 3.871
Lei Xiao,Lujia Zhao,Xiang Ke,Tengyue Zhang,Gazi Hao,Yubing Hu,Guangpu Zhang,Hu Guo,Wei Jiang
Nanothermites have a promising study in micro propellant due to its faster reaction rate, higher energy-release efficiency, and significantly enhanced combustion performance. However, most thermites prepared by physical mixing are easy to separate during the propellant preparation process, significantly impeding the embodiment of the advantages of thermite. In this study, Al/CuO/PVDF microspheres incorporating high explosive RDX have been successfully assembled by electrospray technology. The thermal and combustion performance of the composite microspheres have significantly improved. They have shorter delay time, burning time, and higher pressure, pressurization rate than the physical mixtures, which are attributed to their uniform structure and the interaction of the components. And based on combustion tests, the combustion performance of microspheres is mainly affected by the content of RDX. These results indicate that the electrospray technology and adding RDX into microspheres are effective methods to prepare nanothermites with enhanced reactivity.
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高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2016
·Vol. 99
·期 4
·1151-1154
·
IF 2.787
Jun Qu,Xuewei Li,Zhiwu Lei,Zhao Li,Min Chen,Qiwu Zhang
Tetraborate pillared Li–Al layered double hydroxide was synthesized for the first time by a mechano-hydrothermal process in which gibbsite (Al(OH) 3 ) sample was first activated by a ball milling, followed by hydrothermal treatment with Li 2 B 4 O 7 in water at 95°C. Activation of gibbsite Al(OH) 3 induced by mechanochemical process was essential for the formation of thin disk-like Li–Al LDH intercalated with borate anion. When in excess the activated Al(OH) 3 was transformed into bayerite phase during the hydrothermal process.
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高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-10
·
IF 5.228
Zheng Guoqiang,Zhang Wenchao,Shen Ruiqi,Ye Jiahai,Qin Zhichun,Chao Yimin
Mn 2 O 3 has been selected to realize nanothermite membrane for the first time in the literature. Mn 2 O 3 /Al nanothermite has been synthesized by magnetron sputtering a layer of Al film onto three-dimensionally ordered macroporous (3DOM) Mn 2 O 3 skeleton. The energy release is significantly enhanced owing to the unusual 3DOM structure, which ensures Al and Mn 2 O 3 to integrate compactly in nanoscale and greatly increase effective contact area. The morphology and DSC curve of the nanothermite membrane have been investigated at various aluminizing times. At the optimized aluminizing time of 30 min, energy release reaches a maximum of 2.09 kJ∙g −1 , where the Al layer thickness plays a decisive role in the total energy release. This method possesses advantages of high compatibility with MEMS and can be applied to other nanothermite systems easily, which will make great contribution to little-known nanothermite research.
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DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Xiaogang Guo,Xueming Li,Zhibo Wei,Xiaolin Li,Lidan Niu
Superhydrophobic tri-dimensional Ni/Al coatings (3DNACs) with great application value have been successfully fabricated via a simple two-step method combined with hydrogen bubble dynamic template and electrophoretic deposition technique after 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane treatment. The surface morphologies and chemical compositions were analyzed by FE-SEM, EDS, XRD, AFM and FT-IR in detail. The water contact angle of superhydrophobic 3DNACs surface was as high as 156 ± 2° (>150) much larger than that of unmodified samples. Moreover, the obtained samples exhibited great thermal properties and combustion performance. Thus, the superhydrophobic 3DNACs with prominent exothermic capability turn out to be a promising novel energy in field of mirco/nano energy materials for longer-term storage or transportation, especially in high humid environment.
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高影响因子
APPLIED CLAY SCIENCE
·
2015
·
IF 2.467
Jun Qu,Xiaoman He,Bentao Wang,Lihua Zhong,Lei Wan,Xuewei Li,Shaoxian Song,Qiwu Zhang
In this study, we introduced a solvent-free mechanochemical route to synthesize Li–Al layered double hydroxide through a two-step grinding of LiOH and Al(OH) 3 , in which the mixture powder with Li/Al molar ratio at 1/2 was first dry ground for 2 h and then wet ground for another 1 h with water addition without any heating operation. The as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), thermogravimetry (TG), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The products possessed highly crystalline of Li–Al LDH phase with no evident impure phases, presenting an easy and effective preparation of Li–Al LDH by using solvent-free mechanochemical approach.
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DOI
高影响因子
ENERGY & FUELS
·
2025
·
IF 5.3
Xiaoteng Cui,Mingsheng Luo,Zhi Yang,Roshni Rahman,Ziyuan Li,Wenshuai Yang,Lingman Xia
As a greenhouse gas, carbon dioxide is also a rich carbon resource that can be effectively utilized to tackle the global warming crisis. This paper presents an in-depth investigation of the impact of the Cu content on the structure of Cu–Zn–Al layered double hydroxides (LDHs) from a novel perspective. The CO2 hydrogenation performance of the derived catalyst, the LDO, is also evaluated in the methanol synthesis reaction. All catalysts were evaluated at 3.0 MPa, a carbon dioxide to hydrogen ratio of 3, and a space velocity of 3600 mL·g–1·h–1. The results from this work indicate that the catalyst with a Cu:Zn ratio of 11:4 exhibited the highest methanol selectivity of 63.9% at 230 °C. At 250 °C, the catalysts also yielded the highest methanol selectivity of 50% only, along with a CO2 conversion as high as 17.8%. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) data suggest that the CO2-to-methanol reaction follows the formate (HCOO*) mechanism for this catalyst. Results from this work offer a novel approach to designing Cu-LDH-based catalysts, which offers valuable insights for the efficient chemical utilization of CO2.
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高影响因子
POWDER TECHNOLOGY
·
2012
·
IF 2.08
Chongwen Jiang,Aixian Su,Xuemei Li,Tao Zhou,Dewen He
A series of MCM-41 mesoporous molecular sieves with different Si/Al molar ratio has been synthesized by hydrothermal crystalline method using cetyltrimethylammonium bromide as structural template, sodium silicate as silica source and sodium aluminate as aluminum source in alkaline solution. The results show that all the samples have hexagonal mesoporous structure. The secondary restructured materials exhibit well defined structure and the long distance order of the mesopores . The mesoporous structure for Si/Al = 25 MCM-41 with high specific area can be maintained after hydrothermal stability test in boiling water more than 12 h, showing that the secondary restructure can enhance the hydrothermal stability of MCM-41 with the pore diameter size of larger than 3.3 nm and BET surface area of more than 800 m 2 ·g − 1 . Furthermore, MCM-41 with Si/Al = 25 has the optimal hydrothermal stability due to the introduction of Al atom.
研究领域:
材料科学
·
无机化学
·
纳米材料
·
多孔材料
·
催化化学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2024
·
IF 4.3
Yonghui Yang,Hengwei Yan,Pengchen Yang,Zhanwei Liu,Guang Yang
The segregation of aluminum-silicon alloys directly impacts the mechanical and chemical properties of the alloys, Therefore, homogenization of alloys is of great significance for alloys. This study initially investigated the electrochemical behavior of aluminum (III) and silicon (IV) during the preparation of aluminum-silicon (Al-Si) alloys in NaF-AlF 3 -Al 2 O 3 -SiO 2 molten salts through cyclic voltammetry and steady-state polarization. The results revealed that Al 2 O 3 underwent one-step reduction to Al, whereas SiO 2 underwent a two-step reduction process to Si. In addition, electrolysis experiments were carried out in a NaF-AlF 3 -Al 2 O 3 -SiO 2 -5wt%CaF 2 -1wt%MgF 2 -2wt%LiF molten salt system with molecular ratio of 2.4. These experiments involved variations in current density, electrolysis time, Al 2 O 3 and SiO 2 additions. It is worth noting that under the conditions of current density of 0.7 A/cm 2 , electrolysis time of 2 h, and silica addition of 2 %, the reduction rate of silicon reached a maximum value of 72.57 %, at which time the silicon in the aluminum-silicon alloys showed a dendritic structure, which was uniformly distributed throughout the entire alloy, and the segregation of the alloy was effectively avoided.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 35
·期 1
·1-13
·
IF 2.8
Sun Qin,Yang Wanchun,Hu Zhongyu,Jia Gaozhi,Wang Yangyang
Copper pastes are widely used in metallization of ceramic surfaces but are limited by poor oxidation resistance, high resistivity, and low bonding strength. In this work, the 30Bi 2 O 3 –55B 2 O 3 –15ZnO glass powder was prepared by the melt-quenching method. A copper paste containing the glass powder and formic acid-treated copper microparticles was used for metallization of α -Al 2 O 3 ceramic surface. The copper thick films were obtained by low-temperature sintering after screen printing. The effects of the glass powder contents on resistivities and shear strengths of the copper films on α -Al 2 O 3 ceramic substrate were analyzed. The microstructures of the copper thick films and the interfacial bonding mechanism on the α -Al 2 O 3 ceramic surface were investigated in detail. The copper thick film with 10-wt% 30Bi 2 O 3 –55B 2 O 3 –15ZnO glass and sintered at 650 °C for 20 min exhibited a low resistivity (3.38 ± 0.94 µΩ cm) and a high shear strength (35.24 ± 1.2 MPa). ZnAl 2 O 4 and Bi 2 B 4 O 9 were detected on the edges of the copper film near the interface, which enhanced interfacial binding between the copper thick films and the α -Al 2 O 3 ceramic substrate. These results demonstrated that the low-temperature sintering copper paste containing 30Bi 2 O 3 –55B 2 O 3 –15ZnO glass was effective for α -Al 2 O 3 ceramic surface metallization.
研究领域:
材料科学
·
陶瓷
·
冶金学
·
电子封装
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高影响因子
危险品化学品经营许可证（带存储）