CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Xiongzhang Liu,Hui Luo,Jiaji Yang,Xian Wang,Zewen Qu,Heng Luo,Rongzhou Gong
TiB 2 –MgO microwave absorbing materials with TiB 2 as the absorber, MgO as the matrix are prepared by spark plasma sintering (SPS). The influences of commercial TiB 2 content and sintering temperature on dielectric and microwave absorption (MA) properties are studied. Besides, to optimize the MA performance, TiB 2 –MgO composite containing TiB 2 synthesized by the carbonthermal process is prepared. Meanwhile, its high-temperature dielectric and MA properties are investigated. Indeed, both the commercial TiB 2 content and sintering temperature play key roles in dielectric and MA properties, as they reaching 8 wt% and 1400 °C, the composite presents the optimal MA performance. For composite with synthetic TiB 2 as the absorber, the temperature has a positive effect on dielectric and MA properties. The enhanced high-temperature MA properties with minimum reflection loss ( RL min ) of −52.11 dB at 1.6 mm under 500 °C and effective absorption bandwidth (EAB, RL < −5 dB) of 4.2 GHz at 1.4–1.6 mm under 800 °C are obtained, which is mainly attributed to the temperature-dependent interfacial polarization compared to the temperature-insensitive conductivity. The excellent mechanical properties (flexural strength = 212.48 MPa), thin absorbing layer (d < 2 mm), enhanced thermal stability and high-temperature MA properties indicate that the TiB 2 –MgO composites can be considered as new candidates for high-temperature structure microwave absorbing materials.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 106
·期 2
·1159-1169
·
IF 4.186
Binfeng Zhao,Xianqiang Chen,Naichao Chen,Xinwei Xu,Yani Lu,Jin Cheng,Hong Wang
With the development of 5G/6G communication, the requirements of portable devices for miniaturization and multifunction make low-temperature co-fired ceramic (LTCC) more and more important. In the area of high-frequency high-density passive integration, microwave dielectric ceramics with a low dielectric loss and high thermal conductivity are urgently needed to ensure the effective signals transmission and system reliability. However, most microwave dielectric ceramics with a low dielectric loss were not applicable for the LTCC technology due to the high sintering temperature. In this work, a series of MgO-based ceramics [(100 − x ) wt.% MgO– x wt.% (0.2SrF 2 –0.8LiF) ( x = 5,7,10)] were prepared by solid-state reaction method. The addition of sintering aid 0.2SrF 2 –0.8LiF (S 2 L 8 ) decreased the sintering temperature below 880°C without degrading the microwave dielectric properties of ceramics. Microwave dielectric properties of ceramics, including quality factor Q × f , relative permittivity ε r , and temperature coefficient of resonant frequency τ f , were investigated to find the optimum composition and sintering temperature. In general, MgO–7 wt.% S 2 L 8 ceramic sintered at 860°C exhibits outstanding properties of Q × f = 180 233 GHz, ε r = 9.11, τ f = −40.33 ppm/°C, and a high thermal conductivity of 24.02 W/(m K). This series of ceramics are suitable to be co-fired with Ag electrodes. With all those great properties, this series of MgO-based ceramics are expected to be the candidates for LTCC applications in 5G/6G technology.
研究领域:
材料科学
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通信技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2021
·
IF 6.024
Liji Zhang,Yuhang Zheng,Yafei Guo,Shengbin Bai,Meishan Song,Pu Huang,Xinzheng Wei,Jian Sun,Changhai Li,Jiaqing Zhang,Chuanwen Zhao
Thermochemical energy storage (TCES) by means of reversible chemical reactions represents a promising strategy for harnessing renewable energy and recovering industrial waste heat. In this work, alkali metal nitrate promoted MgO composites were synthesized, and the MgO–CO2 working pair was suggested as an alternative candidate for harvesting intermediate-temperature industrial waste heat. However, it remains unclear how operating parameters would affect the heat storage density, and the long-term cycling stability of the alkali metal nitrate promoted MgO composites under harsh conditions close to practical application scenarios needs to be clarified. The objectives of this work are to expound the effects of operating parameters on TCES performance and to evaluate the long-term cycling stability of the alkali metal nitrate promoted MgO composites. With increasing NaNO3 content, the heat storage density of NaNO3–MgO increases dramatically first and then exhibits no significant change. With rising carbonation temperature, the heat storage density of the 10NaNO3–MgO composite increases first and then declines marginally, while it increases with the increasing CO2 partial pressure. Doping alkali metal nitrate eutectic mixtures adversely affects the heat storage density. 10NaNO3–MgO exhibits a high heat storage density of 2291 kJ/kg at 340 °C in 100% CO2. The 10NaNO3–MgO and 10(K–Na)NO3–MgO composites suffer a significant decline in heat storage density within 10 consecutive cycles, while 10(Li–Na)NO3–MgO retains good stability with a slight decrease of heat storage density from 1073 to 770 kJ/kg in 50% CO2. The desired 10(Li–Na)NO3–MgO is suggested as a promising material for TCES application.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2025
·
IF 4.3
Jinbo Song,Ting Qu,Jinpeng Zhang,Yanxin Jia,Jieying Jing,Wen-Ying Li
CaCO 3 -MgO sorbents were prepared through mechanochemical methods to overcome the poor stability of MgO sorbents caused by sintering and agglomeration. The alkali metal salt-promoted MgCa5 (AMS-MgCa5) sorbent, with 5 wt% CaCO 3 doping, demonstrated the highest cycling stability, with an initial CO 2 capture capacity of 13.9 mmol/g, which stabilized at 9 mmol/g after 10 cycles, and the CO 2 capture ratio reached 77 %. The superior cycling stability of the sorbents was attributed to the existence of CaMg(CO 3 ) 2 , which enhanced the capture rate during the CO 2 chemisorption process. Additionally, the doped CaCO 3 served as an inert support, enhancing CO 2 diffusion and mass transfer, ensuring the uniform coverage of alkali metal salt on the MgO surface, and inhibiting the growth of MgO particles.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2025
·
IF 3.8
Shuo Yan,Yuhong Chen,Ziqiang Yin,Binwei Huang,Quanxing Ren,Tihao Cao,Xuxin Ping,Ruibin Liu,Zhengren Huang,Qing Huang,Yinsheng Li
SiC ceramics were fabricated by spark plasma sintering of β-SiC powder with various rare-earth (RE = La, Gd, Yb, Sc) oxides and magnesia additives. The phase compositions, microstructures, lattice oxygen contents, and thermal conductivities were systematically investigated. A decrease in the cationic radius of rare-earth element resulted in an increased cationic field strength. This enhanced attraction to oxygen anion led to higher viscosity and improved high-temperature stability of the intergranular RE-Mg-Si-O liquid phase. After sintering at 1850°C, influenced by liquid-phase viscosity, the degree of β→α phase transformation in SiC and the grain size decreased with decreasing cationic radius of rare-earth element. After sintering at 2050°C, the liquid-phase viscosity significantly decreased, but volatilization became pronounced. The extent of β→α phase transformation and the grain size were affected by both liquid-phase viscosity and volatility. Larger grain size and higher affinity of rare-earth cations for oxygen anions contributed to reduce lattice oxygen content. The thermal conductivities of the SiC ceramics ranged from 192 to 229 W/mK. Notably, the SiC ceramic with Yb 2 O 3 -MgO additives exhibited the largest grain size, the lowest lattice oxygen content, and the elimination of β/α heterophase boundaries, thereby achieving the highest thermal conductivity of 229 W/mK.
研究领域:
材料科学
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热传导工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Shuai Yan,Sen Wang,Gaobin Liu,Qi Yuan,Kuoming Song,He Zhao,Xin Li,Rongzheng Shen
Herein, MgO–12 % TiO 2 (w) ceramics with different contents of Bi 2 O 3 –CuO sintering aid were prepared using a solid-state method. The effects of the sintering aid content on the sintering temperature and the dielectric and mechanical properties of the ceramics were studied. The material was characterized using scanning electron microscopy and X-ray diffraction and Precision LCR tester and universal testing machine and Archimedes drainage method. When the Bi 2 O 3 –CuO content was less than 9 wt%, the ceramic sample has higher dielectric properties. When the Bi 2 O 3 –CuO content was greater than 9 wt%, the dielectric properties will deteriorate. This is because Bi 2 O 3 participates in the chemical reaction between MgO and TiO 2 , forming a high dielectric loss Bi 4 Ti 3 O 7 phase. At high temperatures, Cu 2+ can easily change valence to Cu + , promoting oxygen vacancies and increasing dielectric loss in ceramic samples. The introduction of Bi 2 O 3 –CuO produces new MgTiO 3 , Mg 2 TiO 4 , and Bi 4 Ti 3 O 12 phases in the sample structure, resulting in a structure in which the MgO grains in the sample are surrounded by the new phases that appear around them. This structure fills the pores, increases density, enhances mechanical properties. The dielectric properties of the ceramics were the when the sintering temperature was 1050 °C, and the Bi 2 O 3 –CuO content was 3 wt%. The dielectric constant and dielectric loss were 11.19 and 1.17 × 10 −4 , respectively. The bending strength of the ceramic sample increased from 138.72 MPa to 179.64 MPa when the Bi 2 O 3 –CuO content was increased from 3 wt% to 15 wt%. The Bi 2 O 3 –CuO sintering aid enables MgO to be better applied in ceramic substrates.
研究领域:
材料科学
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电子材料
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Hai Liang,Ying Jiang,Shuxin Wang,Zhishuang Xue,Chunfeng Wang,Wanting Wang,Xiuyuan Zuo,Yan Dai,Xuehua Ruan
The recycling of phosphate from wastewater using regenerable and highly efficient MgO-modified biochar for Mg-P fertilizer application is of great interest. However, the practical application of MgO-modified biochar for the removal and recycling of phosphate is hindered by its short-recycled service-life. Herein, a facile yet scalable method is proposed to fabricate porous MgO nanofiber-functionalized biochar (PMgNF-BC) with enhanced phosphate adsorption and regeneration performances from wastewater using waste biomass and magnesite. The as-prepared PMgNF-BC exhibited the maximum phosphate adsorption capacities of 594.53, 661.57, and 725.43 mg/g at 298.15 K, 308.15 K and 318.15 K, respectively. More importantly, PMgNF-BC demonstrated excellent regeneration performance with the removal efficiency of 84.2 % after eight regeneration cycles. Furthermore, the regenerated PMgNF-BC exhibited the well-preserved fiber shape of MgO on BC, enabling splendid regeneration performance. This work validates PMgNF-BC as a sustainable adsorbent for recycling phosphorus from wastewater, addressing the urgent need for synthesizing biochar with high regeneration performance.
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
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Yan Wang,Jin Wang,Junxia Wang,Long Kang,Tongming Zhang,Xusheng Li,Yijie Tang
In this work, the helium irradiation effects were systematically investigated on MgO-Nd 2 Zr 2 O 7 (hereafter M-NZO) composite ceramics used for inert matrix fuel, in which the ion fluences range from 5 × 10 16 to 3 × 10 17 ions/cm 2 at room temperature. It was demonstrated that M-NZO composite ceramic shows superior radiation tolerance after He implantation. Specifically, MgO had almost no phase transition and extensive amorphization . And Nd 2 Zr 2 O 7 phase possessed slightly pyrochlore-fluorite-amorphization structural transformation, while part of Nd 2 Zr 2 O 7 maintained the ordered pyrochlore structure and co-existed with the irradiation-induced disordered fluorite structure. Importantly, GIXRD results indicated that MgO phase presents higher resistance to radiated damage than Nd 2 Zr 2 O 7 phase. Besides, SEM images illustrated that MgO particles have substantially less fragmentation than Nd 2 Zr 2 O 7 particles due to the higher thermal conductivity of MgO. It reconfirmed that MgO phase resists irradiation damage better than Nd 2 Zr 2 O 7 phase in post-irradiated M-NZO composite ceramics.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2020
·Vol. 20
·期 2
·810-818
·
IF 1.134
Zhao Junfeng,Yan Kou,Wen Xuemin,Xu Huashan
Porous MgO nanostructures were synthesized in large-scale by a simple solution combustion method using citric acid and glucose as the fuel. The resulting porous nanostructure powders were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron
microscopy (TEM), and N2 adsorption–desorption isotherms. The SEM and TEM images demonstrated that the type of fuel used during the combustion synthesis strongly affects the morphology and structure. The use of glucose aggregated the structure with majority particle sizes
in the range 3560 nm and a surface area of 40.55 m2g-1, while the use of citric acid results in a large network structure with smaller particle sizes (30–50 nm) and a larger surface area of 53.88 m2g-1. The two samples synthesized from glucose
and citric acid exhibited excellent adsorption performance for Congo red with the maximum capacity reaching 1500.98 mg g-1 and 1638.08 mg g-1, respectively. These results indicate that the porous MgO synthesized by the solution combustion is a potential candidate for
the removal of pollutant dye in water.
研究领域:
材料科学
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环境科学
·
纳米技术
✓ 已验证
DOI
PubMed
高影响因子
FUEL
·
2023
·
IF 7.4
Lixia Li,Zhechao Huang,Fenghao Shu,Ying Gao,Jinxing Long
Novel techniques for upgrading heavy lignin bio-oil, the phenolic oligomer from lignin depolymerization, are of great significance for achieving better utilization efficiency of carbon element in lignin. In this study, we proposed an efficient approach for producing high-quality oxygen-containing fuel from the renewable lignin bio-oil via the C-O bond cleavage and the subsequent hydrogenation over the Cu and Ni supported on alkaline MgO . Noticeably, the optimized Cu 6 Ni 20 /MgO resulted in inspiring yields of ethylbenzene (88.6%) and cyclohexanol (98.3%) from lignin dimers, and a colorless fuel with a high-heating value of 31.4 MJ kg −1 from the realistic lignin bio-oil. The results of catalyst characterization also unveiled that introducing Cu species reduced the formation of NiMgO x solid solution, which increased the content of Ni 0 and consequently promoted the performance of upgrading lignin bio-oil. Furthermore, the recondensation of phenolic oligomers could be effectively restrained by the alkaline MgO. In addition, a plausible mechanism was proposed. Therefore, this work opens a promising avenue to designing efficient strategies for utilizing the heavy components from lignin depolymerization.
研究领域:
化学工程
·
可再生能源
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Meiting Yang,Qin Wang,Yao Tong,Lanlan Zhai,Weidong Xiang,Xiaojuan Liang
All-inorganic perovskite CsPbX 3 (X = Cl, Br, I) nanocrystals (NCs) are becoming a critical material for the narrow-band fluorescent material in the field of backlit displays. Herein, CsPbBr 3 (CPB) NCs glasses with finely adjustable wavelength were successfully prepared in the narrow range of 522–533 nm by controlling the content of MgO in borosilicate glass matrix. It is surprising that the addition of MgO enhances the optical properties of CPB NCs, as well as improves their stability. Furthermore, in order to verify its application in backlight display, the light conversion film with a color gamut of up to 129% of NTSC 1953 was successfully prepared, displaying more details of object color on the liquid crystal display (LCD) screen compared with commercial one. These results undoubtedly provide a broad road for wide color gamut backlight display with respect to perovskite nanomaterials.
研究领域:
材料科学
·
光学工程
·
显示技术
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2016
·
IF 2.101
Dong Feng,Xudong Luo,Guodong Zhang,Zhipeng Xie
In order to determine the relationship between the property of MgOAl 2 O 3 SiO 2 composite ceramics and molar ratios of MgO/Al 2 O 3 , especially the sintering behavior and thermal shock resistance, the MgOAl 2 O 3 SiO 2 composite ceramics were fabricated with micro-size MgO , Al 2 O 3 powder and nano-size SiO 2 as main raw materials. The sample was characterized by phase analysis, densification and thermal shock times. Moreover, field emission scanning electron microscope was also conducted to study microstructure of the samples before and after thermal shock. Effect of different molar ratios of MgO/Al 2 O 3 on the sintering behavior and thermal shock resistance of composite ceramics were investigated. The results showed that the sample possess better sintering behavior and thermal shock resistance with the molar ratio of MgO/Al 2 O 3 equal to 2/1. Grains of periclase and spinel were directly bonded together, resulting in a dense and compact microstructure, and the bulk density of obtained sample reached 3.4 g/cm 3 . The microstructure of sample after thermal shock revealed that the crack propagation path was deflected and bifurcated, the main-crack propagation was restricted and more fracture energy was consumed, the thermal shock resistance of composite ceramics was greatly improved.
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
危险品化学品经营许可证（带存储）