Materials Today Communications
·
2021
·
IF 3.383
Jinzhao Guan,Kaiyu Xie,Aimin Liu,Zhongning Shi,Gong Chen,Miroslav Boca
In this study, Al–Si alloy, a precursor of the solar-grade silicon , was prepared via the aluminothermic reduction–molten salt electrolysis of SiO 2 in KF–AlF 3 molten salt by employing liquid aluminum as the working cathode. The reaction mechanism of the aluminothermic reduction of SiO 2 in KF–AlF 3 molten salt at 750 °C was determined by thermogravimetry–differential scanning calorimetry. The reaction rate equation for the aluminothermic reduction of SiO 2 in KF–AlF 3 molten salt was: d α dt = 7.156 × 10 24 e − 4.688 × 10 5 RT ( 1 − α ) 1.734 . In 49.4 wt% KF–47.6 wt% AlF 3 –3 wt% SiO 2 molten salt at 750 °C, the Si content in the Al–Si alloy obtained by the aluminothermic reduction–molten salt electrolysis of SiO 2 was 24.53 wt%. Compared with solely aluminothermic reduction of SiO 2 , the current efficiency in the process of the aluminothermic reduction–molten salt electrolysis of SiO 2 was evaluated. The results reveal that the Al–Si alloy is predominantly prepared in the aluminothermic reduction step, while supplemented by electrolysis. The calculated Faradic current efficiency of the proposed aluminothermic reduction–molten salt electrolysis process was 28.4%.
研究领域:
材料科学
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冶金工程
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DOI
高影响因子
Coatings
·
2025
·Vol. 15
·期 9
·1045
·
IF 2.8
Lingfeng Jiang,Yifei Chen,Haiyan Liu,Haoning Zhang,Li Zhao
Vanadium dioxide (VO2) has become one of the most promising smart temperature-controlled thin-film materials due to its reversible phase transition between a metallic and an insulating state at approximately 68 °C, accompanied by negligible volume change and excellent optical modulation properties. However, the practical application of VO2is still limited by its relatively high phase transition temperature and susceptibility to oxidation. To address these two major shortcomings, this study employed a one-step hydrothermal method to prepare a VO2nanopowder, followed by a chemical precipitation method to form a VO2@AlF3core–shell structure. The coated nanoparticles were then dispersed in a PVP ethanol solution, coated onto a glass substrate, and evaluated for performance. The experimental results indicate that when the molar ratio of VO2to AlF3reached 1:1, the phase transition temperature of VO2@AlF3was effectively reduced to 50.3 °C, significantly lower than the original temperature of 68 °C. Additionally, the material exhibited favorable optical properties, with a solar modulation ability (ΔTsol) of 17.2% and a luminous transmittance (Tlum) of 36.3%. After calcination in air at 300 °C for 3–6 h, the VO2core remained oxidation-resistant and maintained excellent phase-change thermal insulation properties.
研究领域:
材料科学
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纳米技术
·
智能涂层
·
功能材料
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隔热材料
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DOI
高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 151
·期 7
·2065-2074
·
IF 2.482
Yang Hong,Wu Sen,Chen Zhengfei,Li Lichun,Wang Haili,Liu Bing,Tang Haodong,Li Ying,Chen Aimin,Han Wenfeng
The AlF 3 catalysts with controlled morphology (cubic, hexahedron and octahedron) were synthesized via hydrothermal method using different solvents. The dehydrofluorination of 1,1,1,3,3-pentafluoropropane (HFC-245fa) was used as the model reaction to evaluate the catalytic performance of the AlF 3 catalysts with different morphology. Results showed that surface area, crystal structure, surface acidic properties together with the chemical composition of the AlF 3 catalyst were substantially influenced by the different morphology. XRD results showed that κ-AlF 3 crystalline structure was formed when using ethanol as solvent while β-AlF 3 crystalline structure was formed when using water as solvent. Among the three prepared AlF 3 samples, the AlF 3 -C catalyst with cubic shape demonstrated not only largest surface area but also most amount of medium-strength surface acid sites, resulting in enhanced reaction activity towards the dehydrofluorination reaction. The characteristic high Miller index crystal planes of (402) and (321) exposed on the cubic shaped AlF 3 -C catalyst is believed to be the main reason accounting for the high catalytic performance as there are equal amount of Al and F atoms exposed. Moreover, a reaction mechanism describing dedehydrofluorination of HFC-245fa on AlF 3 catalyst with equal amount of Al and F atoms exposed on certain crystal planes was proposed. Graphic Abstract
研究领域:
催化
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化学工程
·
环境科学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2019
·
IF 2.781
Wenfeng Han,Haili Wang,Bing Liu,Xiliang Li,Haodong Tang,Ying Li,Huazhang Liu
With Al(NO 3 ) 3 ·9H 2 O as the Al precursor and PVDF as the fluorine source, freestanding AlF 3 sub-microspheres were fabricated following calcination , without the involvement of corrosive HF solution. With the varying of Al(NO 3 ) 3 ·9H 2 O to PVDF weight ratio, θ -AlF 3 and β -AlF 3 , α -AlF 3 were obtained respectively. The formation mechanism, morphology, surface properties and catalytic activities for the dehydrofluorination of 1,1,1,2-tetrafluoroethane to trifluoroethylene were investigated. During the fabrication process, Al(NO 3 ) 3 interacts with O=C bond in DMF. Meanwhile, DMF further interacts with CH 2 species in PVDF. Following calcination , PVDF decomposes to CO 2 and HF fluorinating Al species to AlF 3 . The growth of AlF 3 crystal and particle are confined by PVDF. Consequently, θ -AlF 3 , β -AlF 3 and α -AlF 3 are achieved. At 450 °C, HFC-134a conversion of 23% and reaction rate of 1.9 mmol g −1 h −1 are approached over θ -AlF 3 catalyst. The reaction rate is almost 3 times higher than that of β -AlF 3 and is 40% higher than that of high surface area α -AlF 3 prepared by sol-gel method. No significant deactivation is observed in time on stream of 40 h. The stability is attributed to the interaction of AlF 3 with carbon frame work. The present study provides a scalable and facile synthesis route for AlF 3 spheres with controllable phase structures.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Pei Pei Yuan,Bin Hong Liu,He Peng Zhu,Wei Yuan Pan,Zhou Peng Li
In this work, the composites of LiBH 4 and AlF 3 were prepared and their hydrogen storage properties were investigated. The AlF 3 addition to LiBH 4 resulted in significant decreases in dehydrogenation temperature. All the x LiBH 4 + AlF 3 ( x = 1, 2, 3, 5) composites started to release hydrogen from about 100 °C. The dehydrogenation of the composites was accomplished through several steps, depending on the molar ratio of LiBH 4 to AlF 3 . A new phase Li 3 AlF 6 was formed during the first dehydrogenation step, which further reacted with LiBH 4 . AlB 2 was formed only at temperatures higher than 300 °C. Li 2 B 12 H 12 was detected as an intermediate. The dehydrogenation reactions have significantly reduced and thus favorable enthalpy changes. However, the reversibility of the composites needs to be improved.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 6
·1124
·
IF 4.967
Chen Shen,Shi Yan,Yapeng Ou,Qingjie Jiao
In this study, fluorinated polyurethane (FPU) was prepared from dialcohol-terminated perfluoropolyether as a soft segment; isophorone diisocyanate (IPDI) as a curing agent; 1,2,4-butanetriol (BT) as a crosslinker; and 1,4-butanediol (BDO) as a chain extender. Fourier transform infrared spectroscopy (FTIR) and1H NMR were used to characterize the structure of the FPU. The mechanical properties of the FPUs with different BDO and BT contents were also measured. The tensile strength and breaking elongation of the optimized FPU formula were 3.7 MPa and 412%, respectively. To find out the action mechanism of FPU on Al, FPU/Al was prepared by adding Al directly to FPU. The thermal decomposition of the FPU and FPU/Al was studied and compared by simultaneous differential scanning calorimetry-thermogravimetry-mass spectrometry (DSC-TG-MS). It was found that FPU can enhance the oxidation of Al by altering the oxide-shell properties. The combustion performance of the FPU propellant, compared with the corresponding hydroxyl-terminated polyether (HTPE)-based polyurethane (HPU) propellant, was recorded by a high-speed video camera. The FPU propellants were found to produce smaller agglomerates due to the generation of AlF3in the combustion process. These findings show that FPU may be a useful binder for tuning the agglomeration and reducing two-phase flow losses of aluminized propellants.
研究领域:
材料科学
·
推进剂研究
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DOI
高影响因子
SCRIPTA MATERIALIA
·
2014
·
IF 2.968
Dewen Wang,Lu Shen,Songlin Ran,Qing Huang
Transparent alumina was fabricated by spark plasma sintering with AlF 3 doping at a high heating rate of 100 °C min −1 and a moderate loading pressure of 73 MPa. The sintered AlF 3 -doped alumina was dark in color due to light absorption by F − substitution and by the resulting defects induced in the alumina lattice. An AlF 3 doping concentration of 0.1% was found best for producing transparent alumina. A possible mechanism was proposed to explain the doping effect under the present sintering condition .
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DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
·
2011
·Vol. 42
·期 5
·1065-1070
·
IF 0.974
Yan Hengwei,Yang Jianhong,Li Wangxing,Chen Shazi
KF-NaF-AlF 3 -based electrolyte is a promising low-temperature electrolyte for aluminum reduction. Alumina solubility in molten KF-NaF-AlF 3 -based electrolyte was determined as a function of the melt composition and temperature by measuring the weight loss of a rotating corundum disk and by using a LECO RO500 oxygen analyzer (LECO Corporation, St. Joseph, MI). The investigated temperature range is 1023 K to 1073 K (750 °C to 800 °C), and the total cryolite molar ratio (CRt = ([KF] + [NaF])/[AlF 3 ]) is 1.3 to 1.5; the content of NaF ranges from 0 mol pct to 50 mol pct. The effect of temperature, CaF 2 , and LiF on alumina solubility is discussed as well.
研究领域:
冶金学
·
材料科学
·
电化学
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2011
·
IF 2.089
Hengwei Yan,Jianhong Yang,Wangxing Li
The surface tension and density of molten KF–NaF–AlF3-based electrolytes were determined as a function of the melting composition and temperature by the Archimedean method and maximum bubble-pressure method, respectively. The investigated temperatures range from (1013 to 1103) K, and the total cryolite molar ratio (CRt = ([KF] + [NaF])/[AlF3]) is 1.3 to 1.41; the mole fraction of NaF ranges from 0.15 to 0.4. The effects of temperature and the content of CaF2 and Al2O3 on surface tension and density were also investigated. The results indicate that the density and the surface tension tend to increase with the NaF content and CRt. The density and the surface tension fit the linear relationship with temperature.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Coatings
·
2024
·Vol. 14
·期 8
·1021
·
IF 2.9
Tao Jiang,Junjie Xu,Chuntao Ge,Jie Pang,Jun Zhang,Geir Martin Haarberg,Saijun Xiao
Molten salt electrophoretic deposition is a novel method for preparing coatings of transition metal borides such as TiB2, which has emerged in recent years. To broaden the applications of transition metal boride coatings prepared by this method, this paper investigates the corrosion resistance of TiB2coatings, produced through molten salt electrophoretic deposition, to liquid zinc. By applying a cell voltage of 1.2 V (corresponding to an electric field of 0.6 V/cm) for 1 h in molten NaF-AlF3, the nanoscale TiB2particles migrated to the cathode and were deposited on the graphite substrate, forming a smooth and dense TiB2coating with a thickness of 43 μm. Subsequently, after subjecting the TiB2-coated graphite to corrosion resistance tested in molten zinc for 120 h of continuous immersion, no cracks were observed on the surface or within the coating. The produced TiB2coating demonstrated excellent corrosion resistance. These research results suggest that the fully dense TiB2coating on the graphite substrate, produced through molten salt electrophoretic deposition, exhibits excellent corrosion resistance to liquid zinc.
研究领域:
材料科学
·
腐蚀与防护
·
表面工程
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2020
·Vol. 103
·期 9
·5013-5027
·
IF 3.502
Yongbao Xiao,Yao Ji,Yichen Ye,Shujing Huang,Weichao Wang
Alkali-earth-metaphosphate-based fluoro-sulfo-phosphate M(PO 3 ) 2 –AlF 3 –MSO 4 (MPFS, M = Ca, Sr, Ba) glasses have been developed via simultaneously incorporating fluoride and sulfate into metaphosphate glass. Their glass-forming regions were efficiently determined under the guidance of thermodynamic calculation method. The physical and structural properties of BaPFS glass were investigated in detail. Furthermore, near-infrared spectroscopic properties of Er 3+ -doped BaPFS (Er–BaPFS) glass were studied. Physical parameters, such as Abbe's number ν d (55-75) and nonlinear refractive index n 2 (1.17-1.86 × 10 −13 esu), of BaPFS glass are strongly depended on P/F/S ratio. The structure of BaPFS glass gradually depolymerizes and tends to become multianionic when Ba(PO 3 ) 2 is substituted by AlF 3 and BaSO 4 . Anion-substitution strategy effectively modulates the property and structure of glass, providing a scheme to derive glass materials. In addition, enhanced emission at ~1.5 μm has been observed from Er–BaPFS glass along with large emission cross section (5.0-5.5 × 10 −21 cm 2 ) and long lifetime (6.7-7.3 ms), resulting in large figure of merit (3.46-3.84 × 10 −23 cm 2 ·s), which is a promising candidate for solid-state laser.
研究领域:
材料科学
·
光学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2026
·
IF 12.5
Qian Chen,Mingyu Xin,Hailiang Yang,Yuankui Huang,Yaoping Hu
The development of dynamic optical materials with time-dependent afterglow color (TDAC) is crucial for advanced anti-counterfeiting and information encryption but remains a formidable challenge. This work introduces a novel aluminum fluoride (AlF 3 ) matrix for the rigid confinement of carbon dots (CDs), yielding a CDs@AlF 3 composite that exhibits intense blue thermally activated delayed fluorescence (TADF) with a long lifetime of 994 ms and a high photoluminescence quantum yield of up to 23.4%. Remarkably, incorporation of lanthanide ions (Eu 3+ or Tb 3+ ) into the CDs@AlF 3 system fundamentally alters the emission mechanism, suppressing TADF and activating room-temperature phosphorescence from the CDs while simultaneously establishing a phosphorescence resonance energy transfer (PRET) pathway to the lanthanide acceptors. This creates dual afterglow centers with distinct decay kinetics. The resultant CDs@AlF 3 /Eu 3+ (or CDs@AlF 3 /Tb 3+ ) composites demonstrate fascinating TDAC phenomena, visually transitioning from red (or green) to blue over time after ceasing the excitation source. The PRET efficiency and emission color are precisely tunable by varying the lanthanide concentration. Furthermore, the composites exhibit exceptional stability against UV irradiation, harsh chemicals, and solvents. This matrix-based confinement and energy transfer strategy paves the way for designing smart optical materials with programmable temporal features for high-level security applications.
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高影响因子
危险品化学品经营许可证（带存储）