CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
An-Nan Chen,Jia-Min Wu,Huan Xiao,Jing-Yan Chen,Xiao-Yan Zhang,Fen Chen,Yi-Xin Ma,Chen-Hui Li,Qing-Song Wei,Yu-Sheng Shi
A novel rapid, uniform and non-contamination in-situ solidification method for alumina suspension by DCC-HVCI method using MgO sintering additive as coagulating agent was reported. MgO was used to release Mg 2+ in suspensions via reaction with acetic acid generated from glycerol diacetate (GDA) at elevated temperature as well as to improve density and suppress grain growth of alumina ceramics during sintering. Influence of adding 0.7 wt% MgO with 2.0 vol% GDA in alumina suspension on coagulation process and properties of green bodies and sintered samples were investigated. It was indicated that the controlled coagulation of the suspension could be achieved after treating at 70 °C for 10 min. Homogeneous composition distribution of Mg element in EDS result indicated the uniform solidification of suspensions. Compressive strength of wet-coagulated bodies is 2.09±0.25 MPa. Dense alumina ceramics with relative density of 99.2% and flexural strength of 354±16 MPa sintered at 1650 °C for 4 h present homogeneous microstructure. The result indicated that the novel DCC-HVCI method via a sintering additive reaction with no contamination, short coagulation time and uniform in-situ solidification is a promising colloidal forming method for preparing high-performance ceramic components with complex shape.
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
·
2024
·
IF 5.1
Guo Tian,Linzhao Ma,Qianbiao Du,Longxiang Jiang,Hongzhi Xiao,Hao Li
A novel type of Li 3 NbO 4 –Li 2 TiO 3 - x MgO (LLM x , x = 1–5) ceramics were prepared using the solid-state reaction method. When the sintering temperature is between 1180 °C and 1300 °C, the solid solution ceramics with cubic rock salt structure are obtained. As the MgO content increases, the ε r value decreases, the τ f value is basically constant, and Q×f exhibits ideal dielectric properties at x = 4 ( ε r = 15.26, Q×f = 119,456 GHz ( f = 9.97 GHz), τ f = −35.9 ppm/°C). The Raman spectrum analysis was used to examine and understand the vibration mode and intrinsic mechanism of dielectric properties in ceramics. Additionally, a dielectric resonant antenna based on LLM 4 ceramic is fabricated with a resonant frequency of 7.23 GHz (|S 11 | = −45.6 dB), a higher gain and broadband width of 501 MHz.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2018
·Vol. 102
·期 5
·2415-2425
·
IF 2.956
Jingyuan Chu,Yue Zhao,Guangyu Jiang,Wei Wu,Zhiwei Zhang,Zhiyong Hong,Zhijian Jin
Tuning substrate properties is an effective methodology to modulate the texture development of MgO films deposited by ion beam-assisted deposition (IBAD) process for epitaxial oxide films. Herein, a solution deposition planarization (SDP) technique is employed to deposit Gd-Zr-O layer for engineering surface properties of the flexible metal substrate. The correlation between the Gd-Zr-O thin film microstructure and the IBAD-MgO texture is investigated. The coordinated study on atomic force microscopy (AFM) and reflection high-energy electron diffraction (RHEED) reveal that the grain coarsening during high-temperature sintering negatively influences the texture formation of IBAD-MgO. Moreover, the chemical environment of the atoms on the surface of Gd-Zr-O seed layer also plays a critical role, which is normally overlooked. The X-ray photoelectron spectroscopy (XPS) analysis indicates that the carbon residue and intermediate phase result in the poor texture of the IBAD-MgO. This phenomenon is related to the partial decomposition and synthesis reactions due to the lower sintering temperature or reduced surface to volume ratio. We demonstrate the high-quality texture of IBAD-MgO layer, deposited on mono-coated thick Gd-Zr-O film, by using optimal heat-treatment conditions. The cross-sectional TEM images present the dense Gd-Zr-O film with Gd 2 Zr 2 O 7 nanograins. The multifunctionalities, such as planarization, a barrier layer, and seed layer, of Gd-Zr-O layers are realized in full-stacked CeO 2 /LaMnO 3 /IBAD-MgO/SDP-Gd-Zr-O/C276 samples. This work demonstrates a route for simplifying the architecture of 2G-HTS using Gd-Zr-O layer and explores the effect of the surface properties on texture formation in IBAD-MgO layer.
研究领域:
材料科学
·
物理学
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产品关联
DOI
高影响因子
APPLIED ENERGY
·
2020
·
IF 8.848
J. Yan,Z.H. Pan,C.Y. Zhao
Thermochemical heat storage uses a reversible chemical reaction to store thermal energy. This thermal energy storage method has high energy density and allows long-term thermal energy storage. MgO/Mg(OH) 2 is a promising reversible reaction for thermochemical heat storage systems. The performance of this reversible reaction inside a reactor plays a key role in its practical applications. The direct type heat transfer reactor is a novel design compared with an indirect powder bed reactor. It allows the gaseous heat transfer fluid to flow through the powder in order to break the heat transfer limitation from the heat exchanger between the MgO/Mg(OH) 2 powder and the heat transfer fluid. In this study, we evaluated the performance of a direct type MgO/Mg(OH) 2 reactor under various operating conditions. Parametric analyses indicated that the heat output is limited by the reaction rate rather than the heat transfer efficiency. Results also showed the best bed thickness in order to achieve the highest temperature output. Material characterization indicated that the MgO/Mg(OH) 2 particles did not agglomerate with each other after 15 heat charging and discharging cycles.
研究领域:
能源科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2020
·
IF 4.982
Muhammad Masood Khan,Lijun Jin,Muhammad Mahmood Khan,Yang Li,Hammad Saulat,Yun Zhang,Muhammad Sarfraz,Jialong Zhu,Haoquan Hu
The composite catalysts AC-Ni/MgO-Al 2 O 3 were prepared by the co-precipitation method with activated carbon (AC) and [Ni,Mg,Al]-hydrotalcite as the precursors, and characterized by XRD , TG-DTG, N 2 adsorption, H 2 -TPR and SEM, respectively. The resultant catalysts were examined for CO 2 reforming of methane. The results showed that the introduction of AC into Ni/MgO-Al 2 O 3 catalyst improved the textural properties, especially the surface area and pore volume of mesopores , and decreased the size of metal Ni. Compared with Ni/MgO-Al 2 O 3 , the composite AC-Ni/MgO-Al 2 O 3 exhibited higher catalytic activity , stability and H 2 /CO ratio. But the AC content obviously influenced the catalytic performances. High AC loading resulted in the decline of catalytic activity owing to lower surface area and fewer active Ni content in the catalyst. 10AC-Ni/MgO-Al 2 O 3 with 10% AC displayed the best catalytic activity and stability compared with Ni/MgO-Al 2 O 3 . About 86.2% conversion of CH 4 , 91.3% conversion of CO 2 and above 0.95 ratio of H 2 /CO were achieved over 10AC-Ni/MgO-Al 2 O 3 sample for the reaction time of 5430 min. This work provides a route to improve catalytic performances of Ni-based catalysts in CO 2 reforming of methane.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
ELECTROANALYSIS
·
2016
·Vol. 28
·期 12
·2939-2946
·
IF 2.471
Hangjia Shen,Danfeng Qin,Yuzhen Li,Shouzhu Li,Chi Yang,Qunhui Yuan,Thomas Wagberg,Guangzhi Hu
Mesoporous materials have exceptional properties for application owing to their ability to absorb and interact with guest species. A novel MgO/OMC composite with mesoporous structure was successfully synthesized via in situ magnesiothermic reduction. The structure was confirmed by N 2 sorption isotherms, X-ray diffraction pattern (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). By using nafion and bismuth films as co-modifiers, the MgO/OMC composite material shows high sensitivity of 0.113 μA ⋅ L μg −1 and lower background current for electrochemical determination of lead ion (Pb 2+ ) by using anodic stripping voltammetry. The high specific surface area and good mass transfer on the proposed mesoporous material, as well as the outstanding adsorption abilities of MgO to metal ions and the excellent conductivity of the carbon skeleton contribute to the enhanced electrochemical response of Pb 2+ . As the stripping response of Bi/MgO/OMC-Nafion/PGE is highly linear (R 2 =0.998) over a Pb 2+ concentration range of 2 to 300 μg/L, it was successfully used to analyse Pb 2+ in real tap-water samples with good recoveries.
研究领域:
材料科学
·
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 8
·7582-7589
·
IF 2.195
Xu Yuan,Zhang Kaituo,Fu Lei,Tong Ting,Cao Le,Zhang Qifeng,Chen Ligui
MgO addition Ba(Zr 0.15 Ti 0.85 )O 3 (BZT) ceramics was prepared using conventional solid state reaction method and effect the MgO content in BZT ceramics on their sintering temperature, microscopic appearance, dielectric properties and ferroelectric properties was investigated. The result is that the addition of MgO can greatly reduce the sintering temperature of BZT ceramics. The average grain size can be gradually reduced as the concentration of MgO increases. The lattice constant is reduced by Mg 2+ entering the crystal structure instead of Ti 4+ or Zr 4+ . BZT ceramics exhibit excellent dielectric properties when a small amount of MgO was added. The maximum dielectric constant moves to the low temperature region when MgO content was increases. The hysteresis loop becomes thinner and the coercive field was significantly reduced.
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Ying-juan Hao,Bing Liu,Li-gang Tian,Fa-tang Li,Jie Ren,Shao-jia Liu,Ying Liu,Jun Zhao,Xiao-jing Wang
Seeking a simple and moderate route to generate reactive oxygen species (ROS) for antibiosis is of great interest and challenge. This work demonstrates that molecule transition and electron rearrangement processes can directly occur only through chemisorption interaction between the adsorbed O2 and high-energy {111} facet-exposed MgO with abundant surface oxygen vacancies (SOVs), hence producing singlet oxygen and superoxide anion radicals without light irradiation. These ROS were confirmed by electron paramagnetic resonance, in situ Raman, and scavenger experiments. Furthermore, heat plays a crucial role for the electron transfer process to accelerate the formation of ·O2–, which is verified by temperature kinetic experiments of nitro blue tetrazolium reduction in the dark. Therefore, the presence of oxygen vacancy can be considered as an intensification of the activation process. The designed MgO is acquired in one step via constructing a reduction atmosphere during the combustion reaction process, which has an ability similar to that of noble metal Pd to activate molecular oxygen and can be used as an effective bacteriocide in the dark.
研究领域:
材料科学
·
生物学
·
医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Xue Bai,Tao Fan,Gang Chen,Jie Wang,Cong Ji,Chao Chen,Zixuan Zhang,Wei Cai,Rongli Gao,Chunlin Fu
NaMg 0.12 Nb 0.88 O 3 - x BiYbO 3 (abbreviated as NMN- x BY) ( x = 0, 0.005, 0.01, 0.015, 0.02, 0.04 and 0.08) ceramics were fabricated by using a traditional solid-state reaction method. The crystal structure, morphology, relaxation behavior and energy storage properties of NMN- x BY) ceramics were systematically investigated. X-ray diffraction patterns (XRD) demonstrates that all samples present a single pseudo-cubic phase. It is also found that the grain sizes vary irregular with the BY content, and it can be reduced by the appropriate addition of BY content as indicated by scanning electron morphology. From the measured dielectric properties , it can be seen that all samples are transformed from normal ferroelectric (FEs) to relaxor ferroelectric (RFEs). The maximum relaxor diffuseness coefficient γ (∼1.78) is obtained for 0.98NMN-0.02BY ceramic. As x increases, the polarization-electric ( P - E ) hysteresis loops gradually become slimmer. The largest discharged energy density (∼0.998 J/cm 3 ) and the maximum energy efficiency (∼70%) are obtained at 170 kV/cm for x = 0.04. Meanwhile, the discharge energy densities present relatively excellent temperature stability for x = 0.02 in the temperature range from 20 to 140 °C. This work demonstrates a wide potential application in enhancing the storage properties of lead-free ferroelectric materials by co-doping MgO and bismuth-based perovskites .
研究领域:
材料科学
·
电介质物理
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Liqing Zhang,Bo Li,Yonggang Wei,Haoyuan Xu
Environmental problems caused by Cr(VI) need to be solved urgently. As a green and safe adsorbent, magnesium oxide has the characteristics of strong adsorption capacity and safety, non-toxic and harmless. In this study, high-performance Cr(VI) adsorption material (F-MgO) was prepared by combination hydrothermal modification of recycling MgO and doping of solid waste fly ash with the MgO that was a by-product of high magnesium laterite nickel ore. The adsorption properties of F MgO composites for Cr(VI) were evaluated, and the maximum adsorption capacity of Cr(VI) by F MgO reaches 172.6 mg/g at pH = 2.0. The F-MgO also showed high stability and excellent cycle adsorption performance. The adsorption mechanism was extensively studied by adsorption kinetics and DFT theoretical calculation, and electrostatic adsorption and chemical interaction between Cr(VI) and F MgO active sites were demonstrated. The prepared F MgO composites from waste resources with a simple synthetic method have great potential in the treatment of chrome-containing wastewater to achieve the purpose of treating waste with waste.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
OPTICS EXPRESS
·
2025
·Vol. 33
·期 9
·19594-19604
·
IF 3.3
Xincheng Cai,Junjing Duan,Zhangyi Huang,Zhangyi Huang,Zhangyi Huang,Lexing Liang,Boyao Ma,Zhenyu Zhang,Mao Deng,Mao Deng,Jianqi Qi,Jianqi Qi,Jianqi Qi,Tiecheng Lu
Y2O3–MgO composites are optical materials with promising applications for mid-infrared windows in extreme environments. Considering the refractive index differences between different phases and the Hall–Petch effect, intensifying phase homogeneity and reducing grain size enhances the optical and mechanical properties of composites. The grain sizes of composites are also influenced by phase homogeneity. However, research on the relationship and mechanism of phase homogeneity with the optical and mechanical properties of Y2O3–MgO composites is not quantitative and lacks gradient data support. In this study, the phase homogeneity was quantified and utilized as a gradient parameter to fabricate Y2O3–MgO composites by regulating the solvothermal temperature during powder synthesis. As the phase homogeneity increases, scattering is reduced and the grain size decreases, resulting in improved properties (transmittance at ∼6 μm rises from ∼5.5% to ∼81.5%). The gradientization and quantitative analysis of phase homogeneity in Y2O3–MgO composites can serve as a reference on optical composites, aiding in the optimization of properties.
研究领域:
材料科学
·
光学
·
机械工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 7
·期 1
·168-180
·
IF 5.287
Xiaoxiong Huang,Yong Men,Jinguo Wang,Wei An,Yuanqiang Wang
A series of magnesia–silica binary composite catalysts with different molar ratios were prepared using various preparation methods and evaluated for the one-step production of 1,3-butadiene (BD) from bio-ethanol. The MgO–SiO2 catalyst prepared by wet-kneading is distinguished from the samples prepared by other methods by its superior activity. An exceptionally high productivity of butadiene with the high ethanol conversion of 95% and BD selectivity of 77% was obtained over wet-kneaded hierarchical flower-like MgO nanostructures with the catalytic material made up of SiO2 spheres (with a MgO : SiO2 molar ratio of 65 : 35 at 450 °C and an WHSV of 4.1 h−1), which translates into an unprecedented BD yield of 0.025 mol gcat−1 h−1. The as-prepared catalysts were characterized by XRD, FESEM, BET, FT-IR, UV/vis, CO2-TPD and NH3-TPD. The Mg precursor used and the preparation method are found to influence the extent of MgO and SiO2 interactions during preparation, as estimated by various techniques, which, in turn, was found to correlate with the catalytic performance. A subtle balance of surface acidity/basicity was found to be necessary to achieve a high butadiene yield which can be obtained by variation of MgO : SiO2 ratios in wet-kneaded samples. In view of the difference in catalytic activity and the physicochemical properties of the MgO–SiO2 composite catalysts, the Si–O–Mg chemical bond formed by the strong MgO and SiO2 interaction is suggested to be essential for the balanced surface acid/base sites in relation to the strong interaction between MgO and SiO2 and the consequent high catalytic performance.
研究领域:
催化化学
·
材料科学
·
能源化学
✓ 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）