INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
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IF 3.141
Weiqiang Song,Lantao Yang,Xi Ma,Gaoqiang Liang
CaO and MgO were used to neutralize aluminum dihydric tripolyphosphate (ADTP) by co-grinding, and the effects of CaO and MgO on anticorrosive performance of ADTP on mild steel were studied. The efficiency of the resulting multicomponent pigments as corrosion inhibitors for mild steel boards in 3.5% w/w NaCl solution was determined by electrochemical measurements. The results showed that the anticorrosive performance depended on the component of the pigments and the feeding order of ADTP, CaO, and MgO in grinding. ADTP/MgO/CaO displayed more high performance than others, which was attributed to the relatively integrated passivating film constructed on the surface of the test board. And the anticorrosion of waterborne epoxy coatings was effective and persistent.
研究领域:
材料科学
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腐蚀与防护
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DOI
高影响因子
RENEWABLE ENERGY
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2023
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IF 8.7
Azhar Abbas Khosa,Xinyue Han,C.Y. Zhao
CaCO 3 /CaO thermochemical energy storage (TCES) system has been widely studied on laboratory scale for its potential in concentrated solar power (CSP) plants. However, there is still need for the large-scale experiments based on which a detailed analysis can be obtained to improve this system for real-time applications. In this study, we developed a packed bed reactor capable of operating at high temperature and pressure providing the carbonation and decarbonation reactions of CaCO 3 /CaO reaction pair. The heat storage process is studied with the aspect of different decarbonation temperatures and different sample sizes (amount of sample in grams) placed in the reactor. Furthermore, we compared the heat storage performance of pure and composite samples. The heat release process is performed by varying the concentration of CO 2 and the sample size of the loaded material. The results showed that the heat storage rate and efficiency improve by increasing the temperature of the decarbonation, implying that this reaction must be carried out above 925 °C for better performance. The heat is released smoothly and at a good rate when the concentration of CO 2 is high in the reactor. Also, carbonation reaction (heat release process) depicts that CaCO 3 /CaO TCES system has a great potential to be used as a heat pump and is capable of upgrading the temperature of the released heat from lower to higher value.
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DOI
高影响因子
ENERGY
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2022
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IF 8.857
Hao Sun,Mingzhe Ma,Mengmeng Fan,Kang Sun,Wei Xu,Kui Wang,Baojun Li,Jianchun Jiang
Heterogeneous catalysts with excellent activity and stability are challenges for biodiesel production . Herein, two typical biomass derived mesoporous activated carbon (by chemical activation ( CAC ) and physical activation (PAC)) supported nano-CaO catalysts were prepared by regulated methods. By simple impregnation of calcium nitrate, the catalytic biodiesel yield over CaO/CAC was distinctly increased from 9.16% to 98.4% with the extreme elimination of phosphate groups in the carbon matrix. The catalytic activity of CaO/PAC was enhanced from 70.1% to 96.0% with a deposition-precipitation method for nano-CaO introduction. The abundant surface oxygenated groups of CAC could dispersively anchor the calcium species, leading to dispersion of stable nano-CaO (∼11.7 nm) in the mesopores, high basic sites concentration and excellent catalytic activity and stability. The developed mesopores with large diameter promote disperse growth of calcium oxide, diffusion rate and tolerance of bulky reaction molecules, and accessibility to the active sites, resulting in the improvement of catalytic performance. Both the phosphate groups elimination and deposition-precipitation technique effectively improved the surface area, mesopore volume, basic sites density and biodiesel yield of supported nano-CaO catalysts. The optimal CAC enhanced the catalytic activity 16-fold compared to pristine CaO, and CaO/CAC catalyst presented excellent reusability for transesterification without post-treatment.
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
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2022
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IF 4.171
Yingying Chen,Enrou Mei,Xiaojuan Liang,Qing Chen,Weidong Xiang
All-inorganic perovskite nanocrystals (PNCs) hold tremendous prospect in optoelectronics , while the instability has always troubled us to the wide application of perovskite materials. Here, the dual-phase CsPb 2 Br 5 /CsPbBr 3 PNCs were precipitated in the phosphosilicate glass matrix by a melt-quenching method for the first time. Impressively, the introduction of alkaline earth metal oxide CaO was utilized to adjust glass structure, and successfully realizing the conversion between the two phases. To our surprise, the CsPb 2 Br 5 /CsPbBr 3 @glass (PNG) owned the optical characteristics such as narrowband emission, high photoluminescence quantum yield (PLQY ∼ 52%) and tunable PL emission (505–526 nm). In addition, the obtained CsPb 2 Br 5 /CsPbBr 3 @glass exhibited excellent thermal, water and light stabilities. More excitingly, a conceptual experiment was carried out through commercial TFT-LCD devices, and the color gamut of the prepared PNG@PET yellow-emitting composite film covered 130% of National Television System Committee (NTSC) and 97% of Rec.2020, and maintained excellent display performance even after 72 h of continuous operation. This work undoubtedly not only provided a new avenue to control the precipitate composite perovskites in glass, but also demonstrated composite perovskites materials have great potentials for future practical backlit display applications.
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2022
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IF 5.532
Jiawei Wei,Bingqiang Han,Yaowu Wei,Nan Li,Yilong Wang,Junlong Duan,Jiali Fu
In this paper, the influence of the CaO, MnO and Cr 2 O 3 on the decomposition mechanism, sintering process and properties of zircon ceramics were studied. The X-ray diffraction (XRD), microstructure, pore characteristics and densification behaviour were used to evaluate the decomposition mechanism and the properties of the zircon ceramics. The results indicated that the addition of CaO could accelerate the decomposition rate of zircon by the formation of the solid solution, which caused the appearance of the large pores to weaken the properties. Cr 2 O 3 could limit the sintering process, decomposition reaction and grain growth of zircon to degrade the performance of the zircon ceramics. The addition of MnO promoted the grains growth and had no effect on the decomposition of zircon by the formation of solid solution. Thus, the zircon ceramics with MnO rendered an optimal bulk density and an apparent porosity of 3.53 g/cm 3 and 22.5%, a high compressive strength of 212.6 MPa sintered at 1550 °C.
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2022
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IF 16.744
Yongqing Xu,Bowen Lu,Cong Luo,Fan Wu,Xiaoshan Li,Liqi Zhang
Calcium looping (CaL) is a promising thermochemical energy storage (TCES) technology to convert solar energy to power in CO 2 Brayton cycle. However, the energy storage density (ESD) of the CaO-based heat carries decays drastically over the CaL cycles, and the energy storage performance of the CaO-based materials in a close-loop CaL-TCES system is still unclear. In this work, a novel Na 2 CO 3 modified method was proposed to enhance the ESD of the CaO-based materials over the close-loop CaL-TCES process, and the enhancing mechanism was investigated by the simultaneous thermal analyzer, X-ray diffraction, electron microscopy, N 2 physisorption, X-ray photoelectron spectroscopy. The “10Na 2 CO 3 /CaO” showed more promising ESD over the cycles, even though it suffered sintering. After 60 cycles, the “10Na 2 CO 3 /CaO” still held an ESD of 594 kJ/kg, which was 2.27 times that of “Neat CaO” when cycled at “850 °C–900 °C” mode. Increase the carbonation temperature from 650 °C to 850 °C, the cyclic energy storage densities of the “10Na 2 CO 3 /CaO” ascended rapidly, which was opposite to the “Neat CaO”. The optimum operating condition for the “10Na 2 CO 3 /CaO” is “850 °C–900 °C” when operated in the close-loop CaL-TCES system. The Na + species that enriched on the surface of the CaO grains were in amorphous or melting state, and they would react with CaO to form Na-Ca solid solution over the cycles. The “10Na 2 CO 3 /CaO” has a tendency of sintering over the cycles, but Na 2 CO 3 improves reaction kinetics. One suggested mechanism is that the Na + species may break through the mass transfer barriers to absorb CO 2 during the carbonation process. Therefore, although the Na 2 CO 3 doped CaO materials had poorer surface topography, they held much higher ESD over the repeated cycles.
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DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
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2023
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IF 7.4
Yanchen Oinam,Suhawn Ju,Myoungsu Shin,Sukhoon Pyo
This study aimed to investigate the influence of natural cellulose fibers (NCFs) on improving the hydration characteristics of cementless ultra-high performance concrete (UHPC) using CaO-activated ground granulated blast furnace slag (GGBFS). The NCFs were added in a saturated condition as an internal-curing agent so as to supply additional water to the UHPC matrix and subsequently increase the reactivity of unhydrated phases. To evaluate the hydration characteristics, saturated NCFs were added at 0 to 1.5 wt% of the GGBFS plus CaO. TGA and FTIR analyses showed that, as the amount of NCFs increased, the formation of hydration products was improved as evidenced by an increase in heat of hydration, indicating that more reactions of unhydrated phases occurred. Similarly, morphologies of the samples revealed the formation of hydration products on and near the surfaces of the NCFs due to the additional water exerted during the process of internal curing. Moreover, the compressive and tensile strengths were not compromised by the incorporation of weak and flexible NCFs, but rather a slight improvement was observed with a certain content of NCFs.
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DOI
高影响因子
Colloid and Interface Science Communications
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2023
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IF 4.5
Lihuan Wang,Feng Gan,Jinpeng Mo,Jing Zhao,Xi Yu,Hui Yu
Rare earth-doped bioactive ceramics are promising biomaterials due to their unique optical properties, biocompatibility, antioxidants, and antibacterial activity. In this study, a series of SiO 2 -CaO-Er 2 O 3 nanofiber mats were fabricated by sol-gel electrospinning. The morphology, flexibility, physicochemical and biological properties of the nanofibers were investigated. The flexibility of the nanofiber mats containing 5 and 10 wt% of Er 2 O 3 was better than that of samples without or with >10 wt% Er 2 O 3 . The chemical property assay indicated that addition of Er can lead to changes in the degree of crystallinity and the degree of silica network polymerization, which further affect the flexibility. Photoluminescent spectra showed that the Er-doped nanofibers exist green and near infrared emissions. The in vitro bio experiments demonstrated that Er-doped nanofibers present excellent biocompatibility, and the mineralization experiment demonstrated that Er-doped nanofibers present favorable mineralization activity. Therefore, these SiO 2 -CaO-Er 2 O 3 flexible nanofibers may be promising candidates for biomedical applications.
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
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IF 6.3
Fei Gao,Bo Liao,Wenmiao Li,Rui Yu
Molten salt electrorefining offers a promising approach for green and efficient recycling of waste cemented carbides. However, the conventional halide-based electrolytes suffer from volatile tungsten halide losses and only recover metallic tungsten, necessitating energy-intensive carburization to recover tungsten carbide (WC). Herein, we propose a novel electrolytic refining and recovery method based on an oxygen-containing CaCl 2 -CaO molten salt electrolyte. The introduction of CaO suppresses the formation of volatile tungsten halides, enabling simultaneous dissolution of carbon (C) and tungsten (W) in the WC-Co anode to non-volatile CaCO 3 and CaWO 4 , respectively. Retention of Co in the anode slime is achieved through controlling anodic potential, realizing component separation. The dissolved CaCO 3 and CaWO 4 are reduced at the cathode, resulting in the generation of WC powder. This work accomplishes the direct recycling of WC from spent cemented carbides without intermediate stages. The composite products of WC and carbon are deposited on the cathodes, of which morphologies are comprised of granular aggregates and flakes. The presence of carbon suppresses the formation of W 2 C and W. However, the residual carbon does not affect hard alloy reprocessing since the W/C ratio can be adjusted via controlled W addition during subsequent alloying. This paper proposes a novel short-process green recycling technology for strategic tungsten resources.
研究领域:
材料科学
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冶金学
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电化学
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回收技术
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可持续加工
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2024
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IF 5.8
Liqi Zhang,Xu Zhang,Bowen Huang,Yusheng Yang,Zengwu Zhao
Titanium is an excellent structural and functional material . At present, the production of titanium has long process cycle, high energy consumption, serious pollution and other characteristics, so the development of low-cost titanium production methods has extremely far-reaching significance. In this work, the electrochemical reduction process of Ti(IV) and Ti(II) in the CaF 2 -CaO melt were investigated by cyclic voltammetry and square wave voltammetry measurements at 1740 K, respectively. In the CaF 2 -CaO-5 wt% TiO 2 melt, Ti(IV) ions were reduced to Ti by one step. One measure was taken to lower the valence state of Ti ions : Ti(IV) ions in the melt was changed to Ti(II) by adding Ti 0 . Ti(IV) ions were reduced in two steps: in the CaF 2 -CaO-5 wt% TiO 2 -Ti 0 melt, Ti(IV) → Ti(II) and Ti(II) → Ti, respectively, and in the CaF 2 -CaO-5 wt% TiO, the Ti(II) ions were reduced in a single step: Ti(II) → Ti. It was found that both migration and mass transfer affected the reduction processes. In contrast to the Ti(IV) reduction to Ti process, the Ti(II) reduction to Ti process showed a higher diffusion rate. Electrolytes and electrodes were analyzed after titanium electrodeposition by XRD . It was found that there were no metal titanium was detected in the electrolyte placed close to the cathode after electrodeposition . It believed that the formed metallic Ti reacted with dissolved O 2- in the melt to form TiO. The reduction process of Ti(IV) on the iron electrode was investigated, the metal Ti was reduced by alloying process, the oxidation of Ti was hindered, there was a dense structure layer of CaTiO 3 outside the reduced metal Ti that prevented the ions transfer and affected the Ti(IV) ions migration process, which might be the main factor that the Ti(IV) reduction process was controlled by migration. The lower valence state of Ti in the melt promoted the formation of Ca 2 TiO 4 , which increased the ion migration rate and decreased the mass transfer rate. It was suggested that titanium or titanium alloys may be prepared by reducing the valence of Ti(IV) in minerals and altering the melt composition. It is feasible to prepare titanium and titanium alloys by MOE short process using ore as raw material.
研究领域:
冶金学
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材料科学
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产品关联
DOI
高影响因子
METALLURGICAL AND MATERIALS TRANSACTIONS B-PROCESS METALLURGY AND MATERIALS PROCESSING SCIENCE
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2024
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IF 2.4
Zhang Xu,Zhang Liqi,Huang Bowen,Yang Yusheng,Zhao Zengwu
Materials like metallic iron and its alloys are essential to daily living and industrial production. The benefits of using electrolysis technology to prepare iron and its alloys are great efficiency, controllability, and environmental protection. This study focuses on the feasibility of the electrochemical method for the direct preparation of metallic iron and Si–Fe alloys in iron ores with high fluoride content. The electrochemical behavior of Fe(II) and Fe(III) in molten SiO 2 –CaO–CaF 2 slag on tungsten electrodes was investigated by using cyclic voltammetry and square wave voltammetry methods. It was determined that the reduction of Fe(II) ions follows a one-step two-electron transfer process: Fe(II) + 2e − → Fe(0). The reduction of Fe(III) involves a two-step electron transfer process: Fe(III) + e − → Fe(II) and Fe(II) + 2e − → Fe(0), respectively. The Fe(II)/Fe(0) process is an irreversible reaction controlled by diffusion. The diffusion coefficient of Fe(II) is D Fe(II) = 1.5 × 10 −6 cm 2 s −1 . The cathodic deposits of iron were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS). The findings indicate that the production of Fe 2 Si alloy through electrolysis is more favorable when Fe(II) is present in the slag, while the production of metallic iron is more favorable when Fe(III) is present in the slag. This work provides a basis for the electrochemical direct preparation of Fe–Si alloy and metallic iron in high fluorine iron ore.
研究领域:
冶金学
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材料科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
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2024
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IF 5.1
Jiefu Lang,Ke Ren,Yiguang Wang
As a thermal barrier coating (TBC) material, 8 wt% yttria-stabilized zirconia (8YSZ) exhibits poor resistance against calcium–magnesium–aluminosilicate (CMAS) corrosion. This is caused by the penetration of molten CMAS glass and the depletion of Y 3+ , which limits the lifetime of 8YSZ. In this study, a multi-rare-earth-oxide-doped zirconia (15 wt% (Lu 0.2 Yb 0.2 Dy 0.2 Gd 0.2 Y 0.2 )–ZrO 2 , denoted as 15LYDGY–SZ) ceramic was prepared to examine its interaction with CMAS. The sluggish diffusion effect and the competition between various dopant elements toward reaction with CMAS effectively slow down the atomic diffusion and limit the transformation of tetragonal phase into monoclinic phase in 15LYDGY–SZ ceramic. Compared with the currently used 8YSZ ceramic, the corrosion resistance of 15LYDGY–SZ to CMAS and its retention rate of fracture toughness after CMAS corrosion are improved. The results show that the multi-rare-earth-oxide-doped zirconia ceramic prepared in this study is a promising candidate material for the development of future TBCs.
研究领域:
材料科学
·
航空工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）