CERAMICS INTERNATIONAL
·
2020
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IF 3.83
Jian Guo,Binbin Tong,Yixuan Chen,Jianguo Chen,Jinrong Cheng
0.75BiFeO 3 -0.25BaTiO 3 (0.75BF-0.25BT) ceramics have been widely studied because of their high Curie temperature , good thermal stability and lead-free trait. The evolution of domain motion during electric poling and thermal depoling processes is closely related to the piezoelectric properties and thermal stability of ferroelectric ceramics . Herein, the non-180° domain reversals of 0.75BF-0.25BT ceramics in these two processes were investigated by an in situ XRD technique. The non-180° domain switching fraction during the poling and depoling processes was calculated quantitatively based on the (111) and (11 1 ‾ ) diffraction peaks. During the poling process, the non-180° domain reversal percentage N 111 and piezoelectric properties increase abruptly when the poling field exceeds 35 kV/cm and then saturate at the electric field of 50 kV/cm (N 111 reaches the maximum value of 59%). The domains switched under the poling electric field of 50 kV/cm are stable below 500 °C. The depoling temperature is sensitive to the domain switching fraction under different poling electric fields, and the ceramics under a strong poling field possess excellent thermal stability and high depolarization temperatures. This work revealed the relationship between the electric properties, domain switching, poling electric field, and depoling temperature in the 0.75BF-0.25BT ceramics, which may pave the way to enhancing the room temperature piezoelectric properties and their thermal stability.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 11
·期 9
·1079
·
IF 4.146
Song Zhou,Xi Liu,Jian Xu,Hui Zhang,Xiaosong Liu,Pengcheng Li,Xiaodong Wen,Yong Yang,Yongwang Li
As an alternative to noble metal hydrogenation catalysts, pure molybdenum carbide displays unsatisfactory catalytic activity for arene hydrogenation. Precious metals such as palladium, platinum, and gold are widely used as additives to enhance the catalytic activities of molybdenum carbide, which severely limits its potential applications in industry. In this paper, iron-promoted molybdenum carbide was prepared and characterized by various techniques, including in situ XRD, synchrotron-based XPS and TEM. while the influence of Fe addition on catalytic performance for toluene hydrogenation was also studied. The experimental data disclose that a small amount of Fe doping strongly enhances catalytic stability in toluene hydrogenation, but the catalytic performance drops rapidly with higher loading amounts of Fe.Keywords:molybdenum carbide;Fe-promoter;toluene hydrogenation;synchrotron-based XPS;in situ XRD
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemistrySelect
·
2025
·Vol. 10
·期 14
·e202405719
·
IF 2
Zhengquan Zhang,Yuling Wang
Graphical AHNPs are prepared with complexing agent and deposition agent by aqueous solution deposition.The AHNPS's structures are confirmed through FTIR, XRD, and SEM.The reaction temperature have an effect on the size and phase of AHNPs and the degree of the aggregation.A formation mechanism of the AHNPs is represented. In this work, aluminate hydrate nanoparticles were successfully prepared with complexing agent (ethylenediamine) and deposition agent (hydrazinehydrate) by aqueous solution deposition.The aluminate hydrate nanoparticles were analyzed by FTIR, XRD, and SEM. The reaction temperature have an effect on the size and phase of aluminate hydrate nanoparticles, and the degree of the aggregation.When the temperature was at below 80°C, aluminate hydrate nanoparticles were mainly composed of Al(OH) 3 nanoparticles with nordstrandite phase;when the temperature was over 80°C, aluminate hydrate nanoparticles were mainly AlOOH nanoparticles with boehmite phase.The sizes of Al(OH) 3 nanoparticles were in the range of 50–200 nm with a good quality of dispersion, and the size of AlOOH nanoparticles were in the range of 300–800 nm with part of agglomeration and little dispersion.A formation mechanism of the AlOOH and Al(OH) 3 NPs was represented.
研究领域:
材料科学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2019
·
IF 0
Dandan Zhu,Lei Zhang,Yuhao Huang,Jiayu Li,Hui Fan,Hongyu Wang
In dual-ion batteries, the electrolyte solutions of LiPF6 dissolved into ethylmethyl carbonate (EMC) have demonstrated excellent compatibility with a graphite positive electrode. To further optimize the solutions, typical concentrations of LiPF6 are applied in Li/graphite cells. Traditional electrochemical tests, including galvanostatic charge–discharge and cyclic voltammetry, preliminarily verify that 2 M LiPF6-EMC is an appropriate choice for electrolyte solution. Furthermore, in situ XRD combined with EQCM clarified the crystal structural evolutions of the graphite electrode and the mass change during the PF6– anion storage in the graphite electrode. EMC transport is discovered in the opposite direction of the anion transport between the graphite electrode and the electrolyte solutions. NMR and IR analyses were explored to characterize the solvation states of anions in the solutions. In addition, the long-term cycling and rate capability of the graphite electrode are tested to address EMC’s role. A suitable concentration of EMC is vital for the satisfactory performance of the graphite positive electrode.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
Frontiers in Chemistry
·
2023
·
IF 5.5
Gao Bingliang,Liu Zhiwei,Deng Yifan
Al-Li alloy was prepared by electrodeposition on solid aluminum electrode in a urea-LiCl (77.5:22.5, mol%) molten salt system at 353–393 K. The results of cyclic voltammetry and chronopotentiometry show that underpotential deposition of Li occurs on the Al electrode and forms phases of Al(α) and AlLi(δ) which are confirmed by XRD measurements. Scanning electron microscopy observation of deposits indicates that Al-Li alloy with the thickness of 143 µm was obtained by potentiostatic electrolysis at −0.5 V vs. Li+/Li. The Li content in the alloy obtained at 373 K can reach 6.9 wt%. Galvanostatic electrolysis at 20 A demonstrated that Al-Li alloy coating on aluminum plate can be obtained from urea-LiCl electrolyte at 373 K in the atmosphere.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Defence Technology
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2020
·
IF 2.637
Yue-ting Wang,Xiao-ting Zhang,Jian-bing Xu,Yun Shen,Cheng-ai Wang,Fu-wei Li,Ze-hua Zhang,Jian Chen,Ying-hua Ye,Rui-qi Shen
In this study, Al–CuO nanocomposites were fabricated by sol-gel method. As a contrast, the thermite was prepared by physical mixing at the equivalence ratio of 0.5, 1, 2, respectively. The intermediates and samples as prepared were characterized by SEM and XRD. The exothermic properties of the two samples prepared at different equivalence ratios were tested and the reaction products were characterized by XRD. The SEM results show that the sample prepared by the sol-gel method demonstrates a micron-sized agglomerated sphere formed by a mutual wrapping of Al NPs and CuO NPs, and the particles are evenly distributed in the agglomerate. In addition, when the content of Al powder is seriously insufficient, the heat release of the sample prepared by physical mixing is 1.6 times that of by sol-gel method. With the increase of Al powder content, the exothermic properties of Al/CuO NPs prepared by sol-gel method began to increase significantly compared with physical mixing and the difference is 1.5 times when the equivalence ratio increases to 2. It can be concluded that the reason for this result may be attributed to the different mass transfer modes of components due to the different morphologies of samples.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
Polymers
·
2022
·Vol. 14
·期 19
·4127
·
IF 4.967
Xiaobao Li,Zhengjie Tang,Zhenbing Sun,John Simonsen,Zhinan Luo,Xiaoping Li,Jeffery J. Morrell
Carboxymethyl cellulose (CMC) is a cellulose derivative that can be obtained from wood, bamboo, rattan, straw, and other cellulosic materials. CMC can be used to produce biofilms for many purposes, but the properties of these resulting films make them unsuitable for some applications. The effects of three kinds of plant fiber addition on CMC film properties was investigated using CMC derived from eucalyptus bark cellulose. Tensile strength (TS) and elongation at break (EB) of CMC/sodium alginate/glycerol composite films were 26.2 MPa and 7.35%, respectively. Tensile strength of CMC composite films substantially increased, reaching an optimum at 0.50 g of fiber. The enhancement due to industrial hemp hurd fiber on CMC composite films was more obvious. Pretreatment with hydrogen peroxide (H2O2) and glacial acetic acid (CH3COOH) produced films with a TS of 35.9 MPa and an EB of 1.61%. TS values with pectinase pretreated fiber films was 41.3 MPa and EB was 1.76%. TS of films pretreated with pectinase and hemicellulase was 45.2 MPa and EB was 4.18%. Chemical and enzymatic treatment both improved fiber crystallinity, but film tensile strength was improved to a greater extent by enzymatic treatment. Surface roughness and pyrolysis residue of the film increased after fiber addition, but Fourier transform infrared spectroscopy (FTIR), opacity, and water vapor transmission coefficients were largely unchanged. Adding fiber improved tensile strength of CMC/sodium alginate/glycerol composite films and broadened the application range of CMC composite films without adversely affecting film performance.Keywords:eucalyptus bark;Yunnan pine wood;bamboo culms;industrial hemp hurd;FTIR;XRD;TG;mechanical properties
研究领域:
材料科学
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生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Chemistry
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2018
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IF 1.726
Dong Wang,Yujun Zhu
The bimetal catalyst Pt-Cu/SiO2 was prepared by the impregnation method. Its catalytic performance was investigated by the selective hydrogenation of cinnamaldehyde. Pt-Cu/SiO2 exhibited much higher selectivity (64.1%) to cinnamyl alcohol than Pt/SiO2 (3.7%), while they showed similar conversion of cinnamaldehyde. This enhancement was attributed to the increase in the amount of the Pt0 species on the Pt-Cu/SiO2 surface, which is derived from the interaction between Pt and Cu revealed by XRD and XPS.
研究领域:
化学工程
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催化
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 4
·668
·
IF 5.719
Qingyun Li,Lingyu Liu,Zihua Wang,Xuezhong Wang
A confined jet mixing reactor operated in continuous hydrothermal flow synthesis was investigated for the synthesis of CeO2-ZrO2(CZ) nanoparticles. The obtained ultrafine powders were characterized using scanning electron microscopy–energy dispersive spectrometry (SEM-EDS), inductively coupled plasma–atomic emission spectroscopy (ICP-AES), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) coupled with selected area electron diffraction (SAED), a BET (Brunauer-Emmett-Teller)-specific surface area test and pore analysis, oxygen storage capacity (OSC) test, and a H2temperature programmed reduction (H2-TPR) test. The XRD results show that all samples were composed of high-purity cubic CZ nanoparticles. High resolution transmission electron microscope (HR-TEM) analysis showed that CZ nanoparticles with uniform size and shape distributions were obtained in this investigation. The d-spacing values, determined based on the TEM-selected area electron diffraction (SAED) patterns, were in good agreements with the reference data. BET results showed that the prepared CZ samples had large specific surface areas. Pore volume and size distribution were obtained by pore analysis. Oxygen pulse adsorption technology was used to test the oxygen storage capacity of the sample. The redox capacity of the CZ material was determined by a H2temperature-programmed reduction test.Keywords:continuous hydrothermal flow synthesis;confined jet mixing reactor;CeO2-ZrO2nanoparticles;XRD;BET
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Jun-Feng Wang,Pan Liang
A pure barium borate of BaB 8 O 11 (OH) 4 ·3H 2 O has been synthesized and characterized by XRD, FT-IR, TGA, and chemical analysis. The molar enthalpies of solution of BaB 8 O 11 (OH) 4 ·3H 2 O in 1 mol dm −3 HCl(aq), and Ba(OH) 2 ·8H 2 O in the mixture solvent of {2.00 cm 3 of 1 mol·dm −3 HCl + H 3 BO 3 (aq)} were measured by microcalorimeter at T = 298.15 K, respectively. With the use of previously determined enthalpy of solution of H 3 BO 3 (s) in 1 mol·dm −3 HCl(aq), and the standard molar enthalpies of formation for Ba(OH) 2 ·8H 2 O(s), H 3 BO 3 (s), and H 2 O(l), the standard molar enthalpy of formation of −(7500.6 ± 6.5) kJ·mol −1 at T = 298.15 K was obtained based on an appropriate thermochemical cycle. Moreover, the molar enthalpy of formation of −6091.7 kJ mol −1 for [B 8 O 11 (OH) 4 ] 2− was estimated by a group contribution method, which was used to predict the Δ f H m o of a series of alkaline-earth metal borates for MB 8 O 11 (OH) 4 (M = Ca, Sr, Ba).
研究领域:
物理化学
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无机化学
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热化学
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Shuhui Liu,Hui Xie,Qingmin Cao,Yujie Ning,Yihan Song,Chengdong Zhang,Bin Liu
This research aims to improve the protective performance of coatings in harsh corrosive conditions by using functionalized self-healing microcapsules. CeO 2 /PUF MCs and PUF MCs were prepared via one-step emulsion polymerization . The microcapsules were implanted into epoxy coatings to investigate their self-healing performance. Multiple testing techniques, including SEM, FTIR, XRD , TGA , EIS , and NSS were used to characterize the morphology, crystal structure, chemical composition, thermal properties, and self-healing performance of the microcapsules and coatings. The experimental results indicated that the CeO 2 /PUF MCs had a spherical core-shell structure with a rough surface and an average diameter of 1583 nm. Meanwhile, the minimum corrosion products and the highest low-frequency impedance were found in CeO 2 /PUF MCs coating with artificial scratch, which demonstrated that the self-healing and anti-corrosion performance were significantly improved by the newly developed bi-functional microcapsules.
研究领域:
材料科学
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涂层技术
·
腐蚀科学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED MICROBIOLOGY
·
2025
·
IF 3.2
Zhang Chuhan,Qin Lijun
AimsTo determine the optimum conditions for extracting Eucommia ulmoides gum (EUG) from Eucommia ulmoides leaves during fermentation by Coprinellus disseminatus. At the same time, the EUG characteristics were characterized.Methods and resultsThe ability of C. disseminatus to secrete degrading enzymes, including enzyme activity and lignocellulose content, was observed by culturing C. disseminatus on a medium with different formulations. Based on the optimal formula, the fermentation conditions were determined by an orthogonal test and EUG was extracted. After that, the characteristic parameters of EUG were determined by FT-IR, 1H-NMR, SEM, POM, DSC, XRD and GPC. The results showed that the lignin and hemicellulose contents in Eucommia leaves decreased significantly with the increase of fermentation days, and C. disseminatus mediated fermentation had an obvious damage effect on the tissue of Eucommia leaves. At the same time, At the same time, xylan can be used as an initiator to induce the expression of degradation-related enzymes. The extraction yield of EUG from Eucommia ulmoides leaves after fermentation was 3.06%, which was significantly improved. The optimum fermentation conditions were 4% inoculum, 28°C fermentation temperature, and pH = 5. The results of infrared FT-IR and 1H-NMR showed that the extract had typical characteristics of EUG, and the surface and quenching part of the EUG were smooth, as observed by SEM. In addition, DSC and XRD analysis show that there are two crystal types, α and β, in the crystallization process of molten EUG. The main crystallization type of EUG extracted from fermented leaves was β type.ConclusionThe ability of C. disseminatus to produce degrading enzymes can effectively improve the extraction rate of EUG under optimal fermentation process. The method can maintain the integrity of gutta-percha better. EUG has the characteristics of good crystallinity, many β crystal types and high molecular weight.
研究领域:
生物技术
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生物化学
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材料科学
·
植物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）