JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
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IF 5.7
Sheng-Jin He,Ling-Feng Su,Chuang-Tian Zhan,Xiu-Bin Chen,Wei-Ming Guo,Shi-Kuan Sun,Li-Xiang Wu,Jia-Xiang Xue,Hua-Tay Lin
Low-temperature joining of SiC ceramics using raw CaO-Al 2 O 3 -MgO-SiO 2 mixed powders (CAMS-P) and CaO-Al 2 O 3 -MgO-SiO 2 glass (CAMS-G) as additives for the liquid-phase sintering of SiC nanopowders (NITE phase) in combination with surface oxidation was studied. Using CAMS-P as an additive for SiC joining required 1650 °C and produced a lower shear strength of 77.2 ± 3.5 MPa, compared to untreated SiC (108.2 ± 15.8 MPa). Using CAMS-G as an additive, the compactness of SiC joints obtained at 1550 °C was higher than that of NITE joints obtained at 1650 °C with CAMS-P as an additive. Nonetheless, the low joining temperature resulted in gaps and delaminations at the interface, and the joints strength was only 48.3 ± 5.6 MPa. Incorporating CAMS-G as an additive and surface oxidation achieved reliable NITE phase joining at 1550 °C, with no observed gaps or delaminations at the interface. The resulting joints strength was as high as 100.0 ± 0.8 MPa. The joining mechanism was discussed and compared, involving microstructural analysis .
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
SpringerPlus
·
2015
·Vol. 4
·期 1
·1-11
·
IF 0
Lou Shengfeng,Jia Lihua,Guo Xiangfeng,Wu Ping,Gao Lianbing,Wang Jianjun
Diethylene glycol monomethyl ether monolaurate (DGMEML) was synthesized via the reaction of diethylene glycol monomethyl ether (DGME) with methyl laurate (ML) by a new solid base catalyst of KF/CaO/AC, which was prepared by impregnation method using active carbon as carrier. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen physisorption-desorption and Hammett indicator methods; the effect of the mole ratio of KF to CaO, DGME to ML molar ratio, amount of catalyst, reaction time and temperature on the yield of DGMEML were studied; and the relationship between the structure of the catalyst and the yield of DGMEML was investigated. The formed KCaF3 and K2O were acting as the main active components in the catalytic transesterification; the highest yield of 96.3 % was obtained as KF-to-CaO molar ratio of 2.0, DGME to ML molar ratio of 4.0, catalyst amount of 5 wt%, and reaction time of 30 min at 75 °C; and the catalyst displayed good stability in the transesterification.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
PubMed
Nanoscale
·
2017
·Vol. 9
·期 41
·15990-15997
·
IF 7.367
Jiajia Zhang,Fang Cui,Linxu Xu,Xinzi Pan,Xiaoqiang Wang,Xiao Zhang,Tieyu Cui
Herein, a novel and facile high-yield strategy is reported to efficiently fabricate 1D self-supported Au/CaO nanocatalysts using dual metal co-ordination polymers as templates. Significantly, a uniform distribution of dual metal nanoparticles can be ensured due to the fact that both Ca2+ and Au3+ ions are initially introduced into the co-ordination polymer via chemical bonding with bifunctional organic linkers and then, the Au and CaO nanoparticles are formed simultaneously in one pot via calcination. Furthermore, the as-prepared Au/CaO nanoribbons exhibit excellent catalytic performance in the transesterification reaction, which can be attributed to the small size and high distribution of CaO nanoparticles as well as the special 1D structure with high surface area. Moreover, leaching and deactivation, which are the main problems of CaO-based catalysts, are remarkably reduced due to the presence of hydrophobic Au nanoparticles on the surface of the CaO nanoribbons. Consequently, the Au/CaO nanoribbons can be used as recyclable catalysts with high activity for biodiesel production.
研究领域:
材料科学
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催化化学
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2021
·
IF 8.001
Hui Li,Yongbo Wang,Xiaoling Ma,Min Guo,Yan Li,Guoning Li,Ping Cui,Shoujun Zhou,Mingzhi Yu
Ca 2+ ion leaching and poor pore structure are obstacles of CaO for biodiesel production . To this end, a typical Zr–based metal organic framework, UiO–66(Zr) is adopted to support calcium acetate to prepare CaO/ZrO 2 catalyst. For comparison, catalyst precursor is activated in nitrogen (UCN) and air (UCA) atmosphere, respectively. Preparation factors including calcium acetate addition and activation temperature are evaluated. Moreover, effects of transesterification parameters on oil conversion are investigated and the optimized parameters are further used to examine catalyst reusability . Meanwhile, catalysts are characterized with TG, XRD, XPS , FTIR, Hammett indicator titration, N 2 adsorption and desorption. Results reveal UCN calcined at 650 °C (UCN650) and UCA calcined at 700 °C (UCA700) separately exhibits the best catalytic performance. The maximum conversion of 96.99% is achieved by UCN650 with catalyst amount of 6 wt% and molar ratio of methanol to oil of 9 at 65 °C for 60 min. Even after being used 3 cycles, conversion of 92.76% is still achieved by UCN650. By contrast, UCA700 shows lower conversion of 92.94% at the first cycle with catalyst amount of 8 wt% and molar ratio of methanol to oil of 9 at 65 °C for 60 min.
研究领域:
催化化学
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材料科学
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Storage
·
2024
·
IF 8.9
Yi Fang,Yingjie Li,Youhao Zhang,Yuzhuo Wang,Zirui He,Kuihua Han,Jun Jie Wu
CaO/CaCO 3 energy storage is a promising technology to solve the intermittency of solar energy. Fluidized-bed reactors serve as crucial devices for calcination and carbonation in CaO/CaCO 3 energy storage system . This work presents the first observation of defluidization occurring in CaO/CaCO 3 energy storage process. The mechanism of defluidization was investigated through the exothermic experiment and computational fluid dynamics-discrete element method. Furthermore, the defluidization in the exothermic stage was mitigated by simultaneous nano-silica coating and SiO 2 fines addition. The result indicates that high CO 2 concentration (>80 %), small particle size (0.075–0.18 mm) and low initial bed temperature (700–800 °C) result in the defluidization. The defluidization leads to low exothermic performance of CaO particles and serious uneven temperature distribution in the exothermic stage during CaO/CaCO 3 energy storage process. The simulation result indicates that carbonation proceeding at zero-order kinetics leads to rapid CO 2 absorption in the emulsion phase . The absorption of CO 2 in the emulsion phase surpasses the replenishment of CO 2 from the bubbles, resulting in the contraction of the emulsion phase, which is the cause of defluidization in the exothermic stage. The combination of nano-silica coating for CaO and SiO 2 fines addition enhances the porosity in the emulsion phase, thereby facilitating the diffusion of CO 2 from the bubbles into the emulsion phase. Thus, the defluidization of CaO particles is eliminated by simultaneously coating with 5 wt% nano-silica and adding 3 wt% SiO 2 fines (50–75 μm). After this improvement in fluidization , the bed temperature difference is only 12 % of that in defluidization. Furthermore, the effective conversion of CaO particles increases by 10 % compared with that in defluidization. These findings are helpful for solving the defluidization of CaO particles in CaO/CaCO 3 energy process.
研究领域:
能源存储
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Pei Ren,Meiqi Han,Xingan Wang,Mu Zhang,Xudong Sun
Y 2 O 3 and CaO are ideal ceramic materials for precision casting of TiAl alloy, overcoming challenges associated with intricate component removal, such as turbine blades, leveraging the stability of Y 2 O 3 and the water solubility of CaO. To address these challenges, we employed Isobam104 in a novel gel casting method, serving as both a dispersant and a gelling agent. This method enabled us to create a stable Y 2 O 3 –CaCO 3 slurry with high solid content (up to 55 vol%) and low viscosity (101.51 mPa·s at a shear rate of 10 s −1 ). Following sintering at 1500 °C for 2 h, Y 2 O 3 –CaO composite ceramics were produced. Surprisingly, two distinct characteristics of CaO were noted. One showed a rod-shaped morphology with high chemical reactivity crucial for water solubility, while the other displayed a flat-like feature, forming a well-maintained interface due to its coherent or semi-coherent matching relationship with Y 2 O 3 , thereby providing excellent hydration resistance. Ultimately, we acquired composite ceramics showcasing a 30-day “shelf life" alongside exceptional water solubility. This establishes the theoretical groundwork for storing and employing soluble ceramic cores in the precision casting of TiAl alloy.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2025
·Vol. 36
·期 3
·1-12
·
IF 2.8
Huang Kai,Que Tao,Guo Xiang,Wang Rui,Ding Xiang,Zhou Hongqing
The advancement of high-density integration and packaging technologies necessitates the development of packaging materials that possess enhanced thermal conductivity and substantial mechanical strength. In this paper, we present a novel type of CaO–B 2 O 3 –SiO 2 /β-Si 3 N 4 composites synthesized through the solid-state reaction. The effects of β-Si 3 N 4 ceramic content on the sinterability, phase structure, microstructure, and properties of the composites were studied. As an excellent structural and functional material, the rod-like β-Si 3 N 4 ceramic not only enhanced the thermal conductivity (λ) and flexural strength of composite materials but also effectively reduced the thermal expansion coefficient (CTE) of the composite and maintained good high-frequency dielectric properties. The composite sample containing 15wt.% β-Si 3 N 4 demonstrated exceptional performance after sintering at 850 ℃ for 30 min, achieving a bulk density of 2.80 g/cm 3 , a relative permittivity of 6.52 with a dielectric loss of 1.94 × 10 –3 (15 GHz), a λ of 3.5 W/(m·K), a CTE value of 6.40 ppm/ ℃, and a flexural strength of 180.1 MPa. Additionally, the EDS line mapping indicates that there was no diffusion of silver at the interface, thereby affirming the favorable compatibility between the composite and the silver electrode. This characteristic positions the CBS/β-Si 3 N 4 composite as a potentially promising candidate for applications in electronic packaging.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Xiaodong Zhu,Fantao Kong,Xinsheng Ma
Li-added CaO-B 2 O 3 -SiO 2 (CBS) dielectric microwave substrates for low temperature co-fired ceramic (LTCC) applications were prepared using a solid-state reaction, and the effect of the LiF additive on the sintering behavior, dielectric performance and mechanical properties of the product was investigated. In this presently reported work, we found that the LiF additive could effectually reduce the sintering temperature of the CBS ceramics and also substantially improved the densification, dielectric and mechanical properties of it. The experimental results showed that an addition of 3 wt% LiF to the sample sintered at 790 °C resulted in a main crystalline phase of β-CaSiO3 which had excellent proprieties. These included an excellent degree of densification, ε r of 6.43, tan δ of 5.9 × 10 −4 and a volume resistivity of 8.20 × 10 11 Ω cm at 1 MHz, and flexural strength of 241 MPa.
研究领域:
材料科学
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电子工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Xuehua Shen,Ruirui Zhang,Ruiheng Zhang,Feng Xie,Han Hua,Pengju Wang,Feng Yan,Zewei Quan,Zuotai Zhang
CaO-based sorbents represent a highly viable solution for post-combustion CO 2 capture, with granulation commonly employed to mitigate elutriation in fluidized-bed reactors. Nonetheless, granulation markedly increases the density of these sorbents, thereby impairing their CO 2 uptakes and cyclic stability. In this study, a cost-effective strategy was developed by incorporating various pore-forming agents (agar, urea, straw, and biochar) into CaO-based particles (denoted as CaO+C+A, CaO+C+U, CaO+C+S, and CaO+C+B) to enhance their adsorption performance and durability. The findings revealed that the mechanical strength of uncalcined CaO-based particles remained unaltered by the incorporation of additives, whereas only the CaO+C+S particle maintained acceptable compressive strength (17.1 N) and a low attrition rate (6.6 %) after calcination. Compared with the CaO+C+A particle, the compressive strength of CaO+C+S particle was increased by 87.5 % and the attrition rate was decreased by 22.8 %. Meanwhile, the CaO+C+S particle exhibited the highest CO 2 adsorption performance, achieving 541 mg/g within 10 min, alongside outstanding cyclic stability, maintaining 217 mg/g after 20 cycles. This represents a 17.4 % increase in initial adsorption and a 25.3 % improvement in long-term stability compared to the control particle. These advancements are attributed to straw’s role in facilitating pore formation, refining CaO crystal size, and increasing the proportion of high-melting-phase (CaAl 4 Si 2 O 11 ). The first two factors markedly enhance the diffusion kinetics conditions and thus improving the CO 2 adsorption performance of CaO-based particles. Combined, these three factors enhance resistance to sintering by creating spatial physical barriers and increasing the melting point. This study offers a straightforward and cost-efficient modification approach to improve the CO 2 adsorption performance and durability of CaO-based particles.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Jiandong Hong,Yanfeng Zhao,Jiang Wu,Xialin Xie,Pengcheng Zhao,Shuai Li,Hong Yao,Guangqian Luo,Zhenhao Liu,Xin Yang
Calcium oxide (CaO), as a high temperature sorbent, has been widely applied in the field of heavy metal removal due to its low price and stable chemical properties, but CaO tends to sinter at high temperature, which affects the adsorption performance. In this work, Al 2 O 3 /CaO sorbent with resistance to sintering was synthesized via citric acid and calcine method, which was innovatively employed to the adsorption of As 2 O 3 combining experiment and theoretical analysis. The experimental results demonstrate that the adsorption capacity of untreated CaO reduces immensely with the temperature rising from 1073 to 1273 K, and arsenic adsorption capacity reduces from 303 to 50 mg/kg. Whereas, arsenic adsorption capacity of Al 2 O 3 /CaO almost maintains at high level and reaches to 534 mg/kg at 1173 K, which proves that the addition of Al 2 O 3 can improve the anti-sintering ability of CaO. Meanwhile, through density functional theory (DFT), the adsorption sites of Al 2 O 3 /CaO was further studied. Al site of Al 2 O 3 /CaO was found to be the main adsorption active site and electron transfer channel, which effectively facilitates the separation of lattice oxygen. Finally, the adsorption mechanism of As 2 O 3 on Al 2 O 3 /CaO was proposed.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
PROCESS SAFETY AND ENVIRONMENTAL PROTECTION
·
2025
·
IF 7.8
Guanxiang Wang,Chaoqun Li,Wenqing Xu,Xianchun Li,Yixi Wang,Tingyu Zhu
High proportion flue gas recirculation reduces oxygen content, affecting sintering production. To address combustion inhibition under low oxygen conditions, this study examines the impact of quasi-particle structure on combustion characteristics in hypoxic environments. The combustion characteristics of one-dimensional quasi-particles were quantitatively analyzed using non-isothermal and isothermal thermogravimetric experiments. The reactivity index and reaction rate constant of CaO-coated coke increased by 26.6% and 15%, respectively, compared to pure coke under 15% O₂ conditions. Subsequent studies have shown that CaO-coating increases the number of active sites and extends the diffusion path of combustion products, significantly enhancing the catalytic combustion effect. These findings were used to propose a CaO premixed low-oxygen sintering scheme. The effect of low-oxygen sintering of two-dimensional discrete fuels on production indexes was investigated by sintering pot experiments. Experimental results indicate that CaO premixing increases vertical sintering speed by 6.33%, enhancing productivity by 5.45%. Furthermore, the melting time of the surface layer is prolonged by 50%, leading to a 12.6% yield increase and a 1.9% improvement in drum strength. This study confirms that CaO premixing meets production requirements at 15% O 2 , thus providing data basis for improvements in the sinter flue gas recirculation rate.
研究领域:
冶金工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2019
·
IF 6.019
Rui Han,Jihui Gao,Siyu Wei,Yanlin Su,Chengzhi Su,Junfeng Li,Qingling Liu,Yukun Qin
The Calcium-Looping (CaL) process, based on the reversible carbonation/calcination of CaO, is a promising technology for thermochemical energy storage (TCES) in Concentrated Solar Power (CSP) plants. However, the major drawback of this technology is the rapid deactivation of CaO due to sintering. In this work, we have synthesized CaO-based, inert oxide-stabilized composites through a space-confined chemical vapor deposition process. Different synthesis parameters such as the inert material (Al 2 O 3 , SiO 2 or TiO 2 ) used as the stabilizer and the CaO concentration in the sorbent were investigated. Among the three different promoters used to increase the resistance of CaO toward sintering, Al 2 O 3 resulted in the most stable composites. The composite with only 5 mol.% Al showed an excellent CO 2 uptake capacity, 0.59 g CO 2 /g composite, over 50 cycles without any deactivation. Based on the calculation, this composite maintained an energy density of 1.50 GJ/t after 50 cycles, corresponding to 87% of the theoretical maximum. This high stability is attributed to the unique synthetic strategy in which the thermally stable oxide nanoparticles deposited on the surface of CaO crystalline grain and prevented its aggregation and overgrowth.
研究领域:
材料科学
·
能源工程
✓ 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）