JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Kangkang Yuan,Chen Shu,Kexin Meng,Wenjun Zhao,Guosheng Sun,Jien Zhu,Jin Chen,Yunlong Huang,Chengshun Li,Xiaotong Jin
Calcium zirconate (CaZrO 3 )-based fibrous membrane is a promising candidate in high-temperature areas for its high melting point, good phase stability up to 1900°C, low thermal conductivity, and low cost. To further enhance the high temperature flexibility of CaZrO 3 -based fibrous membrane without sacrificing stability, modification methods should be conducted. In the present work, a CaZrO 3 -BaZrO 3 dual-phasic structure was proposed to modify the high-temperature properties from the standpoint of phase competition. CaZrO 3 -BaZrO 3 fibrous membranes were prepared with the combination of the electrospinning method and pyrolysis process. The decomposition process, phase transformation, crystallize size, and microstructure evolution of CaZrO 3 -BaZrO 3 precursor fibrous membrane were characterized. The grain size, particle size, NIR reflectivity, high-temperature stability, fire retardancy, and high-temperature flexibility were also characterized and compared with other CaZrO 3 -based fibrous membranes. The higher thermal stability and flexibility of the CaZrO 3 -BaZrO 3 fibrous membrane at 1200°C would make it a good candidate for high-temperature insulating, high-temperature supporting, and high-temperature filtration.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Ze Zhu,Xiaoqian Zhang,Ying Peng,Zhenfeng Guo,Yongshuai Xie,Benxue Liu,Guanghui Zhang,Luyi Zhu,Xinqiang Wang,Yonggang Jiang,Jian Feng
Rare earth zirconates have incomparable chemical thermophysical properties , yet the difficulty of preparation methods limit their application as fibrous material. In present work, a spinnable La 2 Zr 2 O 7 precursor, named as carboxylate lanthanum-zirconium (COLZ), was developed using carboxylic acids as structural and functional ligands. When COLZ is in its liquid state, it can be readily processed into desired shapes, allowing preparation of high aspect ratio precursor fibers with dense and bonding-strong internal structures. The spinnability was explained by the transformation from solid to liquid state under external forces, in which dynamic bridging of carboxylate and hydroxyl between nano-sized colloidal particles play a key role. Due to weakly acidic ligands, organics in COLZ can be easily removed, making direct heat treatment at the target temperature possible, which is beneficial for massive production. The strategy of developing spinnable precursor could also be applied to prepare other rare earth zirconate fibers or new multi-oxide fibers.
研究领域:
材料科学
·
化学工程
·
纳米技术
·
热管理
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2015
·
IF 3.453
Shengxue Wang,Wei Li,Song Wang,Jinming Jiang,Zhaohui Chen
Hierarchical porous lanthanum zirconate (La 2 Zr 2 O 7 , LZO) monoliths have attracted numerous attentions as adsorption, catalysis, especially in high-temperature and high water-vapor-containing environments. Herein, La 2 Zr 2 O 7 monoliths with hierarchially distributed pores have been synthesized via a spontaneous route based on a non-alkoxide sol–gel process accompanied by phase separation. Nitrates of Zr(IV) and La(III) were used as precursors, propylene oxide and formamide were used as gelation inducers, and polyethylene glycol was used as phase separation inducer. The mechanisms of Zr(IV)/La(III) binary gelation process and competitive reaction between gelation and phase separation have been discussed. Zr(IV)/La(III) binary gels exist in the form of Zr(IV)-rich gel networks coupled with La(III)-rich discrete entities. The size of the pores can be controlled by adjusting the amount of gelation and separation inducers. The surface area of the as-prepared La 2 Zr 2 O 7 monoliths is 89 m 2 /g. La 2 Zr 2 O 7 monoliths are amorphous and heating in air at more than 600 °C leads to the formation of pyrochlore structure La 2 Zr 2 O 7 . With further increase in temperature, the crystalline degree of LZO monoliths increased. After heat treatment, the macroporous skeleton can be well retained. However, the macropores became slightly smaller and the solid skeleton became fragile. Sintering of the continuous skeleton occurred after heat treatment.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2017
·Vol. 24
·期 5
·1319-1326
·
IF 1.624
Guo Xingzhong,Ding Li,Ren Jing,Yang Hui
Monolithic lithium zirconate (Li 2 ZrO 3 ) with well-defined co-continuous macropores was successfully prepared via an epoxide-mediated sol–gel process accompanied by phase separation. Appropriate choice of poly(ethylene oxide) as a phase separation inducer and propyleneoxide as a gelation agent allows the production of continuous macroporous gel monolith. The dried gels are amorphous and tetragonal lithium zirconate ( t -Li 2 ZrO 3 ) precipitates firstly at 650 °C. The phase transformation from t -Li 2 ZrO 3 to monoclinic lithium zirconate ( m -Li 2 ZrO 3 ) initiates at 900 °C and completes when elevating the calcination temperature to 1000 °C. The macroporous structure is retained after heat-treatment, and the t -Li 2 ZrO 3 monolith with porosity of 43.3% and dense solid skeletons is obtained.
研究领域:
材料科学
·
化学工程
·
陶瓷
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2021
·Vol. 10
·期 6
·1389-1397
·
IF 6.707
Wang Yinghua,Ma Zhuang,Liu Ling,Liu Yanbo
During flight, many silicates (sand, dust, debris, fly ash, etc.) are ingested by an engine. They melt at high operating temperatures on the surface of thermal barrier coatings (TBCs) to form calcium-magnesium-aluminum-silicate (CMAS) amorphous settling. CMAS corrodes TBCs and causes many problems, such as composition segregation, degradation, cracking, and disbanding. As a new generation of TBC candidate materials, rare-earth zirconates (such as Sm 2 Zr 2 O 7 ) have good CMAS resistance properties. The reaction products of Sm 2 Zr 2 O 7 and CMAS and their subsequent changes were studied by the reaction of Sm 2 Zr 2 O 7 and excess CMAS at 1350 °C. After 1 h of reaction, Sm 2 Zr 2 O 7 powders were not completely corroded. The reaction products were Sm-apatite and c-ZrO 2 solid solution. After 4 h of reaction, all Sm 2 Zr 2 O 7 powders were completely corroded. After 24 h of reaction, Sm-apatite disappeared, and the c-ZrO 2 solid solution remained.
研究领域:
材料科学
·
航空工程
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 100
·期 10
·4491-4499
·
IF 2.841
Kangkang Yuan,Zhichao Yu,Chonghe Xu,Cong Feng,Xinzhu Gan,Xinqiang Wang,Luyi Zhu,Guanghui Zhang,Dong Xu
Acetic acid, lactic acid, and trifluoroacetic acid were used as complex agents for the preparation of dense barium zirconate fibers with electrospinning method. The formation of lactate when lactic acid was used as complex agent led to a mild decomposition process which was beneficial for the fabrication of dense barium zirconate fibers. High temperature stable intermediate phase of BaF 2 appeared when trifluoroacetic acid was used. The intermediate phase of BaF 2 was disadvantageous for pure and dense barium zirconate formation. While water vapor preheat treatment for BaF 2 contained fibers was an effective way for the fabrication of pure and dense barium zirconate fibers.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NUCLEAR MATERIALS
·
2018
·
IF 2.447
Xin Wang,Min Xue,Songbai Liu,Kuo Jiang
In this paper, (Gd 1− x Ce x ) 2 Zr 2 O 7+ x immobilized matrices with high cerium (Ce) amount-of-substance fractions (up to 90%) were prepared by sol-spray pyrolysis , and then sintered at 1600 °C in air. XRD results showed that all samples were in a mixture of pyrochlore and fluorite phase, even after sintering at 1600 °C. All the sintered bulks were dense, and the densities were independent of the additive content . The SEM results showed that all samples were chemically homogeneous. There was no segregation in the grain boundary. EDS quantification yielded a mean composition close to the stoichiometric chemical composition.
研究领域:
材料科学
·
核废料管理
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 24
·12735-12745
·
IF 11.9
Nana Xu,Xiaoshan Zhang,Haiyan Liu,Hui Xu,Shuang Wu,Bing Wang,Yingde Wang
Oxide ceramic fibers with softness and toughness are key materials in emerging fields like wearable devices and membrane technologies. However, the brittle failure of oxide ceramic fibers after thermal cycling leads to the loss of membrane architectures, which limits their long-term applications at high temperature. Here, we report a scalable approach of sol–gel electrospinning to synthesize a flexible and tough pyrochlore La1.85Al0.15Zr2O7 (L5AZO) nanofiber membrane (NFM) involving self-assembled 3D networks. The interactions between the nanoscale constituents lead to the assembled networks with high nodal connectivity and strong crosslinking between nanofibers, which may promote an enhancement of macroscopic mechanical properties by orders of magnitude. Ultrasonic dispersion and an amorphous secondary phase drive the formation of numerous L5AZO nuclei and soft grain boundaries, thus effectively refining grains and inhibiting crystallite growth. Indeed, the L5AZO NFM achieves both a high specific tensile modulus of ∼11.4 MPa cm3 g−1 and fracture toughness of ∼1032 J m−2, as well as high-temperature resistance above 1100 °C, which are advantageous for diverse structural applications. Furthermore, the simple processing technique of the NFM allows it to be fabricated into various functional devices, such as aerogels, thermal camouflage, and filtration membranes at high temperature. The mechanistic insights and manufacturability provided by this flexible and tough oxide NFM may create further opportunities for materials design and technological innovation.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE SCIENCES
·
2024
·
IF 3.4
Fei Ruan,Chonggui Lei,Xi Wu,Jinxiao Bao,Fen Zhou,Jianquan Gao,Guoqi Liu
To further investigate the electrochemical performance of Tm doped CaZrO 3 electrolyte, the CaZr 1 −x Tm x O 3 −α ( x = 0, 0.025, 0.05, 0.075 and 0.1) solid electrolyte specimens were prepared by high temperature solid state method. The phase structure and microstructure of the electrolyte samples were analyzed by Raman spectrum, XRD and SEM. The electrical conductivity of the specimen was measured at the temperature of 673∼1373K in hydrogen-rich and oxygen-rich atmosphere by the two-terminal AC impedance spectroscopy method. The H/D isotope effect of the specimen at different temperature was tested to confirm the dominant conducting carrier in predetermined temperature and atmosphere. It is found that proton is the dominant charge carrier both in oxygen-rich and hydrogen-rich atmosphere at the lower temperature below 1073 K. However, at higher temperature above 1073K, the predominant charge carrier seems to be oxygen ion vacancy in hydrogen-rich, whereas to be electron hole in oxygen-rich atmosphere, based on the analysis of the atmospheric dependence of the electrical conductivity. Moreover, partial conductivities of conducting species, the active doping amount of Tm and the standard Gibbs free energy changes for interstitial proton production by dissolution of water and hydrogen in Tm doped electrolyte were estimated based on crystal defect chemistry theory.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2021
·
IF 3.599
Lei Yu,Kuibao Zhang,Weiwei Li,Baozhu Luo
In this study, Sm-doped Gd 2 Zr 2 O 7 transparent ceramics were successfully prepared by high temperature vacuum sintering using combustion synthesized nanopowders . X-ray diffraction, solid ultraviolet absorption spectrophotometer and fluorescence spectrometer were employed to investigate the structural evolution and photoluminescence properties of as-prepared samples. The Sm-doped Gd 2 Zr 2 O 7 nanopowders are in defective fluorite structure, which transforms into pyrochlore structure after high temperature sintering . The 3% Sm-doped sample exhibits high in-line transmittance of 74.7% at the wavelength of 1000 nm. The fluorescence lifetimes of all samples excited at 404 nm and detected at 615 nm are in millisecond scale, and the concentration quenching occurs when the Sm doping concentration reaches to 10%.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2019
·
IF 5.04
Zifan Zhao
Fine grains and slow grain growth rate are beneficial to preventing the thermal stress-induced cracking and thermal conductivity increase of thermal barrier coatings . Inspired by the sluggish diffusion effect of high-entropy materials, a novel high-entropy (HE) rare-earth zirconate solid solution (La 0.2 Ce 0.2 Nd 0.2 Sm 0.2 Eu 0.2 ) 2 Zr 2 O 7 was designed and successfully synthesized in this work. The as-synthesized (La 0.2 Ce 0.2 Nd 0.2 Sm 0.2 Eu 0.2 ) 2 Zr 2 O 7 is phase-pure with homogeneous rare-earth element distribution. The thermal conductivity of as-synthesized (La 0.2 Ce 0.2 Nd 0.2 Sm 0.2 Eu 0.2 ) 2 Zr 2 O 7 at room temperature is as low as 0.76 W m-1 K-1. Moreover, after being heated at 1500 °C for 1–18 h, the average grain size of (La 0.2 Ce 0.2 Nd 0.2 Sm 0.2 Eu 0.2 ) 2 Zr 2 O 7 only increases from 1.69 μm to 3.92 μm, while the average grain size of La 2 Zr 2 O 7 increases from 1.96 μm to 8.89 μm. Low thermal conductivity and sluggish grain growth rate indicate that high-entropy (La 0.2 Ce 0.2 Nd 0.2 Sm 0.2 Eu 0.2 ) 2 Zr 2 O 7 is suitable for application as a thermal barrier coating material and it may possess good thermal stress-induced cracking resistance.
研究领域:
材料科学
·
热力学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Yueqi Shao,Jie Xu,Mingyue Wei,Hengchang Wang,Lang Lin,Fengying Fan,Xiaoying Feng,Ping Zhang,Feng Gao
Fibre-based porous ceramics are widely used as high-temperature insulation materials due to their good chemical stability and excellent thermal insulation performance. However, the potential roles and mechanical properties of high-entropy fibrous porous ceramics have rarely been explored. In this study, rare-earth zirconate (Dy 0.2 Y 0.2 Ho 0.2 Er 0.2 Yb 0.2 ) 2 Zr 2 O 7 (DYHEY) high-entropy nanofibrous porous ceramics (HENFPCs) were prepared using short-cut fibres by gel-casting combined with freeze-drying. The DYHEY HENFPCs exhibited very high porosity (93.86–97.50%), low thermal conductivity (0.0339–0.0741 W/(m·K)) and good compressive strength (53.17–129.65 kPa). The HENFPC sintered at 800 °C with 1 wt% agarose content exhibited the lowest room-temperature thermal conductivity of 0.0339 W/(m·K). Besides, when the front side temperature of HENFPCs reached above 1300 °C, the back side temperature was only about 200 °C. The temperature difference over 1100 °C revealed HENFEPCs get excellent thermal stability as ideal lightweight high-temperature thermal insulation materials.
研究领域:
材料科学
·
热能工程
✓ 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）