CHEMICAL PHYSICS LETTERS
·
2018
·
IF 1.686
Huaiwei Zhang,Jianbo Qi,Zhenguo Ji
Synergic effects of rare earth-magnesium based hydrides (LaH 3 -MgH 2 ) on thermal dehydrogenation of potassium borohydride (KBH 4 ) are discussed in the paper. Comparing to above 675 K for the LaH 3 -MgH 2 or KBH 4 , the dehydrogenation temperature can be decreased to 346 K for the composites (LaH 3 -MgH 2 -KBH 4 ). The apparent activation energy of desorption process for the mixture is also greatly reduced. On the other hand, the products in the temperature programmed desorption process are also illustrated.
研究领域:
材料化学
·
无机化学
·
能源材料
·
储氢材料
·
固态化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Cong Peng,Yongtao Li,Qingan Zhang
Magnesium hydride is a promising hydrogen storage material and how to improve its sorption kinetics is one of challenges in practical applications. In this paper, a new approach is proposed to catalyze MgH 2 with highly dispersed Ni nanoparticles by in-situ hydrogenolysis of nickelocene (NiCp 2 ) in ball milling process. After ball milling under 4 MPa hydrogen atmosphere for 15 h, the MgH 2 –16.1 wt% NiCp 2 sample exhibits a homogeneous morphology where the in-situ formed Ni nanoparticles with size of ~8 nm are highly dispersed in MgH 2 matrix. During initial dehydrogenation , Ni would react with MgH 2 to form Mg 2 Ni which inherits the configuration of its high dispersion. In the subsequent hydrogen absorption and desorption cycles, the much fine and highly dispersed Ni-based catalytic phase contributes to the superior hydrogen desorption kinetics of MgH 2 with a high-capacity retention rate of ~96% after 50 cycles. This work demonstrates that the in-situ formation of highly dispersed catalytic species is beneficial for improving hydrogen storage properties of MgH 2 .
研究领域:
材料科学
·
无机化学
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能源化学
·
纳米催化
·
氢储能
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
·
2019
·Vol. 31
·期 10
·04019237
·
IF 1.984
Yongshan Tan,Hongfa Yu,Wanli Bi,Nan Wang,Na Zhang
A new type of material, magnesium oxysulfate cement (MOSC), has attracted widespread attention as an environmentally friendly and low-energy inorganic green cementitious material due to its outstanding performance. In this study, electrochemical impedance spectroscopy (EIS) and in situ X-ray diffraction (XRD) were used to characterize the hydration behavior and process of MOSC. EIS was also used to investigate the effect of fly ash (FA) on the hydration behavior of MOSC. Mercury intrusion porosimetry (MIP), backscattered scanning electron microscopy (BSE), and scanning electron microscopy (SEM) were used to study the evolution of the pore structure and micromorphology of MOSC incorporated with FA. The results show that the resistance values (?1) in the equivalent circuit for MOSC increase with increasing curing time. The incorporation of FA can affect the resistance values for each element in the equivalent circuit. In the early stages of hydration (1 day and 2 days), high-volume FA can reduce the degree of hydration of MOSC paste. At the later stages of hydration, the resistance values (?1) increase with increasing FA content. The MIP, BSE, and SEM results also show that the porosity of MOSC decreases with increasing FA content; the incorporation of FA can significantly improve the morphology of MOSC, resulting in a denser microstructure. This study shows that the electrochemical impedance spectroscopy is a powerful technique to investigate the hydration behavior and process of MOSC, and the results also indicate that FA is a good mineral admixture used as a partial substitute for MOSC cementitious materials.
研究领域:
材料科学
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硅酸盐工程
·
建筑材料
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无机非金属材料
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绿色建材
✓ 已验证
DOI
高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
·
2018
·Vol. 71
·期 6
·416-421
·
IF 1.059
Ouyang Dong,Zhihong Zhang,Zhenhai Fu,Xiang Li
A new phase-change material (PCM) CaCl2·6H2O + MgCl2·6H2O + NH4Cl was investigated in this paper. MgCl2·6H2O and NH4Cl were mixed with CaCl2·6H2O to obtain CaCl2·6H2O as a eutectic hydrate salt. The results show that the eutectic composition of the PCM is as follows: 90 wt- % CaCl2·6H2O, 6.25 wt- % MgCl2·6H2O and 3.75 wt- % NH4Cl; the undercooling degree is less than 1.5°C when the nucleating agent is 2 wt- % SrCl2·6H2O or 1.5 wt- % Ba(OH)2·8H2O. The phase-change temperature and latent heat are respectively 25.3°C and 144.3 J g−1 when the composition is 90 wt- % CaCl2·6H2O, 6.25 wt- % MgCl2·6H2O, 3.75 wt- %, NH4Cl, with 2 wt- % SrCl2·6H2O as nucleating agent, and 2 wt- % carboxymethyl cellulose as thickener. In addition, when the composition is changed to 90 wt- % CaCl2·6H2O, 6.25 wt- % MgCl2·6H2O, 3.75 wt- % NH4Cl, 1.5 wt- % Ba(OH)2·8H2O and 2 wt- % carboxymethyl cellulose, the phase change temperature and latent heat are 25.2°C and 139.3 J g−1, respectively.
研究领域:
材料科学
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热能存储
·
化学工程
✓ 已验证
DOI
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2013
·Vol. 33
·期 8
·5044-5050
·
IF 2.404
Y.H. Xia,B.P. Zhang,C.X. Lu,L. Geng
In this paper, corrosion resistance of the Mg–4.0Zn–0.2Ca alloy was modified by micro-arc oxidation (MAO) process. The microstructure and phase constituents of MAO layer were characterized by SEM, XRD and X-ray photoelectron spectroscopy (XPS). The corrosion resistance of MAO treated Mg–4.0Zn–0.2Ca alloy in the simulated body fluid were characterized by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The microstructure results indicated that a kind of ceramic film was composed by MgO and MgF 2 was formed on the surface of Mg–4.0Zn–0.2Ca alloy after MAO treatment. The electrochemical test reveals that the corrosion resistance of MAO treated samples increase 1 order of magnitude. The mechanical intensity test showed that the MAO treated samples has suitable mechanical properties.
研究领域:
生物医学工程
·
材料科学
·
生物材料
·
表面工程
·
腐蚀科学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS LETTERS
·
2024
·Vol. 124
·期 9
·
IF 3.5
Zhou Pengfei,Zhang Pengcheng
The Li 2 Mg 3 Ti 1 − x Al 4 x /3 O 6 (0 ≤ x ≤ 0.1) ceramics are synthesized using the solid phase method, showing excellent microwave dielectric properties with ε r = 14.05, Q × f = 144 500 GHz, and τ f = −43 ppm/°C at x = 0.04. Rietveld refinements, based on the XRD data, reveal that the Li 2 Mg 3 Ti 1 − x Al 4 x /3 O 6 ceramics crystallize in the rock salt structure with Fm-3m space group. The relationship between the crystal structure and intrinsic microwave dielectric properties is studied in detail. The variation in the dielectric constant is related to ionic polarization and relative density. The quality factor (Q × f) demonstrates a strong correlation with lattice energy, relative density, and concentration of Ti 3+ . The variation of τ f is influenced by the bond thermal expansion coefficient and bond valence. The dielectric resonant antenna, manufactured from Li 2 Mg 3 Ti 0.96 Al 0.0533 O 6 -0.09TiO 2 ceramic with near-zero τ f , shows a bandwidth of 230 MHz at 7.40 GHz and a high radiant efficiency, which indicates that high-quality factor Li 2 Mg 3 Ti 0.96 Al 0.0533 O 6 ceramic has significant potential in relevant fields such as 5G and smart driving.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
POLYMER COMPOSITES
·
2017
·Vol. 39
·期 10
·3676-3685
·
IF 2.324
Juan Gong,Weihong Guo,Kai Wang,Jiaoyang Xiong
In order to enhance the adhesion and compatibility of magnesium hydroxide sulfate hydrate (MHSH) whiskers with polyvinyl chloride (PVC), and prepare high performance MHSH/PVC composites, chitosan (CS) is coated on the surface of MHSH whiskers by a facile method. The effect of the CS-coated MHSH (CS-MHSH) whisker and its toughness and reinforcement for PVC are studied. A thin layer coated on the surface of MHSH whiskers after modification is investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The efficacy of surface modification is confirmed by fourier transform infrared spectroscopy (FTIR), X-ray power diffraction analyses (XRD) and energy disperse spectroscopy (EDS). The optimum modification concentration of CS is 0.025%. The notched impact strength and flexural modulus of PVC composite with 15 phr CS-MHSH whiskers are increased by 85.5% and 58.5% compared with those of pure PVC, and by 48.3% and 4.1% compared with those of the PVC composite with 15 phr unmodified MHSH whiskers. A better thermal stability of CS-MHSH/PVC composite is showed by thermogravimetric analysis (TGA). Dynamic mechanical analysis (DMA) result indicates that CS-MHSH whiskers have a better dispersion and a stronger interfacial adhesion with PVC matrix. POLYM. COMPOS., 39:3676–3685, 2018. © 2017 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
SURFACE ENGINEERING
·
2024
·
IF 2.4
Jie Qin,Wenhui Yao,Liang Wu,Fusheng Pan
To enhance anti-corrosion property of AZ31 magnesium alloys, slippery liquid-infused porous surfaces (SLIPSs) were prepared on benzoate-intercalated Mg-Al layered double hydroxides (LDHs). The typical morphology of SLIPSs was determined using a scanning electron microscope, and the successful loading of benzoate ions was confirmed by an X-ray diffractometer (XRD). Especially, this work focused on revealing how hydrothermal time affected the resistance to corrosion of SLIPSs. The electrochemical results indicated that when the hydrothermal duration was 24 h, the developed SLIPS exhibited remarkably improved corrosion resistance accompanied by the lowest corrosion current density of 2.5 × 10−3 μA cm−2. Furthermore, the results of immersion test demonstrated the superiority of SLIPSs in anti-corrosion durability. Based on the obtained results, the prepared SLIPSs can be promising candidates for the improvement in anti-corrosion performance of magnesium alloys.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
DOI
高影响因子
Advances in Materials Science and Engineering
·
2018
·Vol. 2018
·期 1
·1253635
·
IF 1.372
Shiyue Pan,Meijuan Li,Fei Chen,Zhixiong Huang,Qiang Shen,Lianmeng Zhang
New types of piezoelectric damping materials, including carbon nanotubes (CNTs)/lead magnesium niobate (PMN)/epoxy (EP) resin, are developed. The tan δ area (TA) analysis method is selected to evaluate the damping properties which obviously clarifies the effect of maximum loss factor (tan δ ) and effective temperature range on damping properties. Furthermore, the dominant factor of damping enhancement is quantitatively analyzed via the value of TA. Compared with PMN, the interfacial friction of CNTs acts as the dominant factor for the content less than 0.6 wt.%. The maximum damping percentage of CNTs reaches 29.14%. CNTs form loop circuits gradually with the content of CNTs increasing, and electrical energy generated via piezoelectric effect of PMN is efficiently dissipated through the conductive network. Thus, PMN becomes the dominant factor as the content of CNTs exceeds 0.8 wt.%, and the damping percentage reaches 47.43% at the content of CNTs of 1.0 wt.%.
研究领域:
材料科学
·
高分子复合材料
·
功能材料
·
智能材料
·
力学性能
·
电学性能
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Chuang Jie,Hao Liu,Zhoufu Wang,Xitang Wang,Yan Ma
To improve the energy-saving capacity of magnesia refractory castables for working lining of high-temperature kilns, this study presents the researches on microstructure and properties of lightweight magnesia refractory castables with porous matrix fabricated by direct foaming method. The results show that formation of closed-pores in the matrix significantly enhanced high-temperature thermal insulation performance of castables with minor changes of slag corrosion resistance . The thermal conductivity of the lightweight magnesia castables at 1000 °C was below 1.2 W/m·K, which is 47.8% lower than that of the referenced magnesia castable. The increasing content of SDS (foaming agent, over 0.02 wt%) led to increments of size and number of large-sized pores, resulting in the significantly decreased density and mechanical performances. The slag resistance mechanism reveals that, in addition to intergranular penetration, the accumulation of slag and penetration between adjacent pores were the major ways of slag mass transfer in lightweight magnesia castables. In conclusion, controlling the size (below 53.2 μm), number and distribution of closed-pores in the matrix is effective to realize the coupling of high thermal insulation, mechanical properties and slag resistance for lightweight magnesia castables used in the metallurgical field.
研究领域:
材料科学
·
耐火材料
·
无机非金属材料
·
高温工程材料
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2023
·Vol. 27
·期 12
·3339-3346
·
IF 2.5
He Yanzhi,Xia Tianchen,Zhang Chang,Zhao Xiangyu
Magnesium has been regarded as an intriguing anode material for chloride ion batteries (CIB) because of its abundant resources, multi-electron reaction feature, and high volumetric capacity. However, the passivation of magnesium in the electrolyte and formation of insulating MgCl 2 discharge product lead to poor reaction activity of magnesium anode in CIBs. Herein, the Mg 2 Sn alloy prepared by mechanical alloying of magnesium and tin powders is first developed as the anode material with enhanced interfacial activity in the CIB using a metal chloride cathode. The cathode exhibits a significant increase in the discharge capacity from 82 to 175 mAh g −1 when an Mg/carbon anode was replaced by the Mg 2 Sn alloy anode. The discharge capacity can be further increased to more than 200 mAh g −1 when the graphene nanoplatelet is incorporated in the Mg 2 Sn alloy by mechanical milling, thus demonstrating the highly active alloy anode for chloride ion storage. This strategy also benefits the improvement in the cycling performance of the magnesium anode.
研究领域:
材料科学
·
电化学
·
能源存储
·
无机非金属材料
·
纳米材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Jinglian Zhu,Xu Zhang,Haiguang Gao,Yuting Shao,Yana Liu,Yunfeng Zhu,Jiguang Zhang,Liquan Li
Rechargeable magnesium batteries (rMBs) are promising techniques suitable for large-scale energy storage systems with low-cost and high safety. However, their development is severely hindered by strong coulombic effect between bivalent Mg 2+ and cathode materials . In this work, two dimensional hierarchical nano-micro hybrids are synthesized by in-situ generating VS 4 nanosheets on carbon-coated Ti 3 C 2 MXene matrix (denoted as VS 4 @Ti 3 C 2 /C). A high-performance rMB system is built by using the hierarchical nano-micro hybrids cathode, magnesium foil anode, and 0.25 M methylpyrrolidinium chloride in 0.25 M 2PhMgCl-AlCl 3 /tetrahydrofuran as the electrolyte. The existence of V–C bond proves that VS 4 is anchored on the surface of Ti 3 C 2 via a strong chemical bond, rather than simply by adsorption. The unique hierarchical nano-micro structure improves the accessibility of the electrolyte and reduces the charge transfer resistance, leading to a high discharge capacity of 492 mA h g −1 at 50 mA g −1 , an outstanding rate performance of 129 mA h g −1 at 1000 mA g −1 , and excellent cycling performance (over 900 cycles at 500 mA g −1 ). Moreover, reversible intercalation of MgCl + into VS 4 @Ti 3 C 2 /C is revealed by investigating the evolution of the hybrids during different electrochemical states. This study will shed light on designing high-performance MXene-based cathode materials for multivalent batteries.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
多价离子电池
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）