COMPOSITE INTERFACES
·
2020
·
IF 2.32
Abbas Daham,Abdeldjalil Zegaoui,Hamid Abdelhafid Ghouti,Mehdi Derradji,Wan-an Cai,Jun Wang,Wen-bin Liu,Jun-yi Wang,Zaoui Moussa
In this work, short carbon fibers were first surface-grafted with various amounts of epoxy terminated hyperbranched polymers, and then utilized as reinforcing phases in various thermosetting polymeric blends composed of dicyanate ester of bisphenol-A (DCBA) and bisphenol-A based benzoxazine (BA-a) resins. The Fourier Transform Infrared Spectroscopy (FTIR) test validated the surface modification of the short fibers and confirmed the reaction between the coated fibers and the DCBA/BA-a resin blend. The composites’ mechanical properties were evaluated and the obtained results revealed that at the maximum fiber loadings, the bending strength and modulus as well as the impact strength were identified to be 217.8 MPa, 7.1 GPa, and 18.4 kJ/m2, respectively. The scanning electron microscope (SEM) analysis established that the enhancements were basically attributed to the good dispersion and adhesion of the coated carbon fibers within the resin matrix.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Qiu-Yue Zhang,Jiao-Jiao Han,Yao Huang,Yan Chen,Xi Yan,Wan-Zhong Lang
Three powders of Ba 0.95 Zr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY095), BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY), Ba 1.05 Zr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY105) with different Ba contents were synthesized using solid state reaction method. The effects of Ba non-stoichiometry on structure defect , sinterability and hydrogen permeability were investigated in details. The results of XRD and SEM revealed that the excess of BaO (BZCY105) was beneficial to the formation of single phase and membrane sinterability, while the deficiency of BaO (BZCY095) was counterproductive because of the vaporization of BaO at high temperature. Moreover, according to XPS , EPR, FT-IR, Raman and UV–Vis analysis, BZCY105 contained more oxygen vacancies than BZCY095 and BZCY. Additionally, the hydrogen permeation flux through BZCY105 membrane was the highest one because excess BaO favors protonic and grain boundary conductivities. Finally, the mechanism of Ba non-stoichiometry in Ba 1-x Zr 0.1 Ce 0.7 Y 0.2 O 3-δ was proposed. For BZCY105, the excess BaO might be substituted into Ce site to form more oxygen vacancies. As for BZCY095, the dopant of Y might tend to be substituted into Ba site, decreasing the concentration of oxygen vacancy.
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
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2015
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IF 2.947
Xiaowei Chi,Zhaoyin Wen,Jingchao Zhang,Yu Liu
A novel hybrid route, combining simple co-precipitation and conventional solid state reaction, is proposed for the first time to synthesize BaCe 0.4 Zr 0.4 Y 0.2 O 3− δ powders at a temperature as low as 1150 °C. This temperature is much lower than that used for conventional solid state reaction method and even comparable to that used in sol–gel route. The reasons for the low calcination temperature are analyzed in detail from the macroscopic to microscopic viewpoints. Moreover, with the powders made by the novel method, dense ceramic could be easily obtained. Further, impedance data illustrated that its electrical conductivity in wet H 2 at 750 °C is up to 1.39 × 10 −2 S/cm, which is the highest among all the samples prepared by the three different methods and much higher than the reported results related to BCZY proton conductors . Also, the new method is particularly suitable for other multi-component oxides .
研究领域:
材料科学
·
无机化学
✓ 已验证
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2018
·
IF 5.018
Qiangqiang Xiao,Wenhui Yuan,Li Li,Tao Xu
Latent thermal energy storage using phase change material (PCM) is an effective way to store and transport energy. In this work, expanded graphite was modified using octylphenol polyoxyethylene ether to generate modified expanded graphite (MEG), and then a novel shape-stabilized Ba(OH) 2 ·8H 2 O/MEG composite PCM was synthesized by incorporating Ba(OH) 2 ·8H 2 O into MEG matrix. Mass fractions of Ba(OH) 2 ·8H 2 O in composite PCM were calculated from 74% to 93%. The effects of MEG on properties of PCM were investigated using scanning electron microscopy, X-ray diffraction, differential scanning calorimetry and thermal constant analyzer. The results indicated that MEG had the desired compatibility with Ba(OH) 2 ·8H 2 O. The phase separation of Ba(OH) 2 ·8H 2 O was effectively inhibited by the MEG matrix and the supercooling temperature decreased from 13 °C for Ba(OH) 2 ·8H 2 O to 2.4 °C for composite PCM with a MEG matrix density of 200 g/L. At the same matrix density, the thermal conductivity of composite PCM reached 3.58 W/(m K), 1.84 times higher than that of Ba(OH) 2 ·8H 2 O. The latent heat was approximately equal to the product of the latent heat of Ba(OH) 2 ·8H 2 O and its mass fraction. Moreover, the enthalpy loss of the composite PCM was negligible after 400 cycles, showing good thermal reliability.
研究领域:
材料科学
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能源存储
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yan Zhao,Pengjun Zhao,Qing Zhao,Donglin He,Wenwen Kong,Bing Wu,Aimin Chang
Herein, Mg–Al–Si–Ba–O-based glass ceramics were studied as potential candidates to protect Mn–Co–Ni–O-based negative temperature coefficient (NTC) thermistors at high temperatures such as 900 °C. The ceramics were prepared in three glass formulations (1#: 15MgO–15Al 2 O 3 -44.7SiO 2 –25BaO, 2#: 17MgO–17Al 2 O 3 –41SiO 2 –25BaO and 3#: 17MgO–17Al 2 O 3 –41SiO 2 –20BaO–5Y 2 O 3 (in mol%)) and their glass-transition temperatures ( T g ) were determined using the differential scanning calorimetry (DSC) method. Scanning electronic microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the parent glasses and glass-ceramic coatings. The sealing effects of the glass ceramics were examined by conducting an insulation test. The glass-ceramic sealing structures were subjected to 1000 thermal shock cycles at temperatures varying from room temperature to 900 °C. Notably, the sealing structure of glass-ceramic coating 1# was compact at a T g of 760.9 °C. The glass-ceramic coatings effectively maintained the NTC properties of the sensitive ceramics in all three formulations. Interestingly, the glass-ceramic coating 3# containing Y 2 O 3 demonstrated an increase in electrical resistance. Both the NTC thermistors coated with 1# and 2# glass formulations successfully passed 1000 thermal shock cycles without visible failures, and their resistance change ratios were well below the requisite 20%.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2018
·Vol. 148
·期 11
·3402-3412
·
IF 2.911
Bao Qiang,Qi Hui,Zhang Chunlei,Ning Chunli,Zhang Yi,Jiang Ye,Wu Yifan,Gui Wenying,Wang Zhenlu
Abstract In this work, titanium-doped mesoporous Al 2 O 3 (γ-Ti–Al 2 O 3 ) was prepared by an evaporation-induced self-assembly method and used as a carrier of Ba/γ-Ti–Al 2 O 3 catalyst to catalyze the aldol condensation of methyl acetate with formaldehyde to methyl acrylate in a fixed-bed reactor. The catalysts were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, N 2 adsorption–desorption, pyridine absorption performed via Fourier transform infrared spectroscope (Py-IR), and NH 3 and CO 2 temperature-programmed desorption (NH 3 and CO 2 -TPD). Experimental results indicated that the doping of the titanium species into the frame work of mesoporous Al 2 O 3 (γ-Ti–Al 2 O 3 ) had a significant influence on the catalytic activity via modifying the acid–base surface properties of the catalyst. Furthermore, the Ba/γ-Ti–Al 2 O 3 catalyst demonstrated excellent catalytic performance, with a methyl acetate conversion rate of 50% and methyl acrylate selectivity up to 90.2%. Compared with the Ba/Al 2 O 3 catalyst, the Ba/γ-Ti–Al 2 O 3 catalyst had better catalytic activity, stability and potential for practical application, which was likely due to an increased number of Lewis acid sites, especially the medium acid sites. Graphical Abstract Barium supported mesoporous γ-Ti–Al 2 O 3 catalyst was found to be an effective catalyst for vapor phase aldol condensation of methyl acetate with formaldehyde.
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
ACS Applied Nano Materials
·
2023
·
IF 5.9
De-hua Wang,He-bin Li,Hong-wei He,Yang Deng,Ye Lu,Le Zhang,Ke-qing Ruan,Xiao-xiong Wang
Piezoelectric catalysis has become an emerging research field in recent years, which has received extensive attention. Nanoparticles and nanowires have been developed as piezoelectric catalytic materials. However, in practical research, the use of nanoparticles is not easy for the recovery of samples and will cause secondary pollution, and the current piezoelectric catalysis requires the help of high-frequency ultrasound, which increases the consumption of extra energy and cannot be applied on a large scale. In this study, a self-supporting macroscopic flexible inorganic (Ba,Ca)TiO3:Pr nanofiber membrane was successfully prepared by electrospinning. Natural energy (water flushing) was used to drive the flexible inorganic (Ba,Ca)TiO3:Pr nanofiber membrane for piezoelectric catalytic degradation of organic dyes. The results show that the flexible inorganic (Ba,Ca)TiO3:Pr nanofiber membrane driven by water washing has an obvious piezoelectric catalytic degradation effect on dyes. When the water flow rate was 450 L/h and the concentration of CR solution was 10 mg/L, the catalytic efficiency can reach 91.69%. This study provides a green and feasible method for the preparation of flexible inorganic piezoelectric catalytic materials and the catalytic degradation of organic dyes.
研究领域:
材料科学
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环境科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 1
·1-14
·
IF 2.8
Zhang Yajuan,Lu Yang,Shan Yiting,Wang Jie,Feng Jingmin,Zhou Hongqing
Herein, (1 − x )CaO–Al 2 O 3 –B 2 O 3 –SiO 2 (CABS)/ x Ba(Mg 1/3 Nb 2/3 )O 3 (BMN; x = 0.4, 0.45, 0.5, 0.55, and 0.6) composites were prepared, and the impact of the BMN and low-softening-point glass content in CABS/BMN composites on the sintering, dielectric, thermal, and mechanical properties of the prepared composites was investigated. The main crystal phases of the CABS/BMN composites are BMN and Ba 2 NaNb 5 O 15 (BNN). The crystallization temperature of the composite was reduced by an appropriate amount of BMN. BMN ceramics (40–60 wt%) was added to the CABS glass, and the composites were sintered at 800 °C, 825 °C, 850 °C, 875 °C, and 900 °C. To elucidate the influence mechanism of different glass contents and sintering temperatures on the properties of the composites, different qualitative and quantitative instruments were used to study the composite properties. The CABS/BMN composite containing 50 wt% CABS glass sintered at 875 °C exhibits the following ideal properties: volumetric density of 3.57 g/cm 3 , dielectric constant of 17.97, dielectric loss of 6 × 10 −4 , \(Q \times f\) value of 10,947 at 9.5 GHz, bending strength of 157.7 MPa, and coefficient of thermal expansion of 5.9 ppm/K. Microstructure analysis reveals that the microstructure of the composite is dense, the pores are few, the surface morphology is uniform and flat, and the composite does not react with silver electrodes, making it suitable for applications utilizing medium dielectric constant low-temperature co-fired ceramic materials at low sintering temperatures.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Kai Lv,Xu Liang,Qinglin Yao,Liangmiao Zhang,Zongtao Zhang,Yanfeng Gao
This work reports a series of yellow-green near-infrared (NIR) reflective pigments, Ba(Mg 6-x-y Zn y Ti 6-x Cr 2x )O 19 (x = 0–1.0, y = 0–2.5), with strong NIR reflectivity for solar thermal energy regulation. Comprehensive analyses were carried out to characterize the obtained pigments including X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, UV–Vis–NIR spectrophotometry, and CIE L*a*b* color measurement. Absorption spectra of Ba(Mg 6-x Ti 6-x Cr 2x )O 19 showed that the yellow-green absorption is attributed to the octahedrally coordinated Cr 3+ with d-d electron transitions of 4 A 2 (F)→ 4 T 1 (F) and 4 A 2 (F)→ 4 T 2 (F). However, their broad absorption peak centered at 1200 nm severely deteriorated the insulating properties of the pigments. Through substituting Mg with Zn, the obtained pigment Ba(Mg 2.5 Zn 2.5 Ti 5 Cr 2 )O 19 showed an excellent NIR solar reflectance (R* = 67 %) with color performances (L* = 61.98, a* = −18.72, b* = 22.23). EnergyPlus simulation results show that for a warm city (Haikou), the Ba(Mg 2.5 Zn 2.5 Ti 5 Cr 2 )O 19 coating for the external surface of a model house (TSR = 35 %, R* = 55 %) can reduce annual cooling energy consumption by 8 % of the house.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2021
·
IF 4.641
Jiayu Li,Jiqing Lv,Feng Shi,Ze-Ming Qi,Runhao Han,Jing Wang
Double perovskite structured Ba(Mg 1/2 Mo 1/2 )O 3 (BMM) ceramics were prepared by traditional solid sintering methods at different sintering temperatures (T s =1250–1325 °C). X-ray diffraction (XRD) data proved a 1:1 ordered face-centered cubic lattice (Fm-3 m), and the ceramic sintered at 1300 °C obtained maximum relative density. The lattice vibration characteristics were identified by Raman spectroscopy and far-infrared reflection spectroscopy. Based on the far-infrared data, a four-parameter semi-quantum model (FPSQ) was applied to calculate the intrinsic properties of BMM ceramics, and the obtained results approximated the measured values. The Raman shift of the BMM F 2g (B) mode (attributed to the centrosymmetric vibration of Ba atom) was shown to be negatively correlated with the corrected permittivity and Ba-O bond length. With increasing sintering temperature (T s ), the relative density is positively correlated with the quality factor ( Q × f) , and the change of Ba-O bond length leads to distortion of the oxygen octahedron, which is positively correlated with the dielectric constant. The sintered BMM ceramics obtained their best dielectric properties at 1300 °C ( ε r = 4.987, Q × f = 23,069 GHz, f = 11.16 GHz).
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
·
2018
·
IF 3.046
Ting Wang,Qing Ma,S.-H. Song
Pure and Ba-Zr co-doped multiferroic BiFeO 3 nanopowders are synthesized via sol-gel method. X-ray diffraction demonstrates the transformation of crystal structure (from R3c to R3c + P4mm) and the absence of impurity phase. Scanning electron microscopy and transmission electron microscopy indicate that the co-doping leads to a decrease in particle size and the Bi 0.85 Ba 0.15 Fe 0.95 Zr 0.05 sample has a particle size of 30–60 nm. Surprisingly, the room-temperature magnetization hysteresis loops change to be soft ferromagnetic with co-doping. The maximum and remnant magnetizations of the as-prepared nanopowders first increase and then decrease with increasing dopant concentration with the Bi 0.85 Ba 0.15 Fe 0.95 Zr 0.05 sample having the best magnetic properties. The enhanced magnetization is due to the crystal lattice distortion caused by the ionic-radius difference between the substituent and host elements and the suppression of the antiferromagnetic spiral spin structure induced by the size effect of the nanopowders.
研究领域:
材料科学
·
纳米科技
·
多铁性材料
·
固态化学
·
磁学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Jiacheng Xiao,Yuqing Liu,Jiarui Wang,Zexin Mo,Chenyu Liu,Zhan Lin,Dong Luo
Lithium-rich manganese-based cathode materials, represented as xLi 2 MnO 3 ·(1-x)LiMO 2 (M = Ni, Co, or Mn), exhibit high specific capacity and low cost, making them promising candidates for next-generation high-energy-density lithium-ion battery cathodes. However, the low covalency of the Li–O–Li configuration renders these cathode materials highly susceptible to irreversible oxygen release and structural evolution, leading to severe voltage and capacity degradation, which hinders their practical application. To address this issue, this study employs a Ba/Ti co-doping strategy to modulate the oxygen electron and reinforce the structure of lithium-rich manganese-based cathode materials. Post-cycling results indicate that Ti/Ba co-doping effectively suppresses electrolyte corrosion and surface/interface reactions, improves the reversibility of O-redox during cycling, and enhances the structural stability of both the bulk and surface of the materials. As a result, the Ba/Ti co-doped sample exhibits an excellent capacity retention of 95.2 % after 300 cycles.
研究领域:
材料科学
·
电化学
✓ 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）