JOURNAL OF POROUS MATERIALS
·
2016
·Vol. 23
·期 4
·867-875
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IF 1.385
Guo Xingzhong,Song Jie,Ren Jing,Yang Fanger,Kanamori Kazuyoshi,Nakanishi Kazuki
Yttria-stabilized zirconia monoliths with well-defined macropores and high porosity have been successfully fabricated via sol–gel process accompanied by phase separation. Propylene oxide acts as an acid consumer to mediate sol–gel process, and poly (ethylene oxide) is used to induce phase separation. Ethylene glycol is applied as chelating agent, and formamide serves as drying control chemical additive to inhibit cracking during drying stage. Proper proportion of the starting compositions allows the generation of well-defined macroporous YSZ monoliths with co-continuous skeletons and porosity as high as more than 60 %. The dried gels are amorphous and crystalline of ZrO 2 precipitates after heat treatment between 400 and 1200 °C without formation of monoclinic ZrO 2 , which indicating a wide application prospects.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 22
·5426
·
IF 3.1
Zengqing Sun,Xiaoyu Li,Jinxin Xing,Min Gan,Zhiyun Ji,Yong Lyu
In this study, 12 mol% ceria-stabilized tetragonal zirconia polycrystal ceramics with xNd2O3(where x equals 0, 0.1, 0.2, 0.3, 0.4, 0.5, and 0.7) were synthesized via the solid-state method, and the effects of Nd2O3doping amounts on the mechanical properties and microstructure were studied. The results show that with an increase in the Nd2O3doping amount, the grain size of the ceramics was reduced from 2.93 μm to 0.69 μm. The hardness and strength of the ceramics increased significantly, while the fracture toughness decreased. The reduction in fracture toughness was attributed to the reduction in tetragonal grain size, which suppressed the tetragonal–monoclinic phase transformation caused by stress. Additionally, as the content of Nd2O3increased, the formation of cubic zirconia accelerated, but no second phase was observed. Most importantly, when the doping amount of Nd2O3reached 0.3 mol%, the comprehensive mechanical characteristics of the ceramics were optimal. This provides a research basis for the preparation of nanoscale 12 mol% ceria-stabilized tetragonal zirconia polycrystal ceramics.
研究领域:
材料科学
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陶瓷工程
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DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2019
·
IF 4.029
Hang Qin,Wenming Guo,Xin Huang,Pengzhao Gao,Hanning Xiao
8 mol% yttria-stabilized ZrO 2 (8YSZ) nanofiltration (NF) membranes were prepared from size-controlled spherical ZrO 2 nanoparticles with an average diameter of ˜10 nm and a particle roundness value greater than 0.90, and the nanoparticles were efficiently fabricated by a reverse micelles (RMs)-mediated sol-gel process. It was found that yttria doping not only suppressed the tetragonal to monoclinic (t-m) phase transition, ensuring the membranes integrity, but also decreased the tetragonal grain size, increased the specific surface area, narrowed the pore size distribution and thus optimized the NF performance. The as-prepared 8YSZ NF membranes with a thickness of ˜260 nm exhibited high NF performances, while the pure water permeability and molecular weight cut-off (MWCO) were 3.9-4.2 L m −2 h -1 bar -1 and 800 ± 50 Da respectively. In the treatment of pesticide wastewater, the removal rate of carbofuran by 8YSZ NF membranes was more than 82%, while the maximum removal rate could reach 89%. Furthermore, the contaminated membranes could be restored as ever after alkali wash and low-temperature calcination , implementing multiple reuses.
研究领域:
材料科学
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环境工程
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Hongju Qiu,Yanqiong Zhang,Weiwei Huang,Jinhui Peng,Jin Chen,Lei Gao,Mamdouh Omran,Nan Li,Guo Chen
Tetragonal zirconia nanopowders (3Y-TZP NPs) stabilized by 3 mol % Y2O3 were synthesized by a novel sol–gel–flux method. The effects of calcination temperature, Y2O3 content, and molten salt system (NaCl + KCl binary system and NaCl unary system) on the phase composition and morphology of nanopowders (NPs) were investigated. Meanwhile, the sintering properties of the prepared 3Y-TZP NPs were studied. The 3Y-TZP NPs and sintered ceramics were characterized by thermogravimetry-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, and X-ray fluorescence (XRF) spectroscopy. The results show that the optimum calcination temperature for obtaining dispersed ZrO2 NPs is reduced from 800 to 660 °C when the NaCl unary system is substituted by the NaCl + KCl binary system. 3Y-TZP NPs with a single tetragonal phase are obtained in the NaCl + KCl binary system when Y2O3 content in the raw material is 5 mol %. The average particle size of the obtained ZrO2 NPs is reduced from 47.25 nm in the unary system to 26.18 nm in the binary system because of the lower calcining temperature. Furthermore, the 3Y-TZP NPs obtained in the binary system have narrower particle size distribution and better sintering performance than ZrO2 NPs obtained in the unary system. After sintering for 4 h at 1200 °C, the former generated 3Y-TZP ceramics with higher density and finer grain size. This work produced narrow-distributed well-dispersed 3Y-TZP NPs with quasi-spherical morphology, which are good candidates for the applications, including oxygen sensors and thermal barrier coatings.
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
CLINICAL ORAL IMPLANTS RESEARCH
·
2014
·Vol. 26
·期 3
·332-341
·
IF 3.123
Nicolas Villard,Chaminda Seneviratne,James Kit Hon Tsoi,Markku Heinonen,Jukka Matinlinna
Objectives The aim of the present study was to evaluate the effect of novel silane system coatings on zirconia and titanium implant surfaces and the attachment of the fungal pathogen Candida albicans . Materials and methods Titanium and zirconia specimens were silica-coated and silanized either with a commercial silane primer (RelyX Ceramic Primer™, 3M ESPE) or a novel silane system primer. The novel silane system primer was a blend of 1.0 vol% 3-acryloxypropyltrimethoxysilane and 0.3 vol% bis-1,2-(triethoxysilyl)ethane diluted in acidified ethanol-water solvent. The surface roughness (R a ), the surface free energy and the chemical composition of substrate surfaces after treatments were evaluated. C. albcans biofilms were developed on silica-coated + silanized surfaces during 48 h of incubation time. Colony forming units (CFU) and real-time PCR (RT-PCR) quantified the cells on the material surfaces. Statistical analyses were carried out by 1-way ANOVA, Tukey post hoc and Games Howell post hoc test at 5% significance level (p) . Results On zirconia and titanium surfaces, the R a and the chemical composition of the specimens were equal ( P < 0.05). The surface free energy was decreased on titanium specimens and increased on zirconia specimen after silanization. CFU of C. albicans was significantly lower on zirconia coated with RelyX Ceramic Primer™, ( P < 0.001) and on titanium coated with both silanes ( P = 0.002). RT-PCR revealed no differences between the mean quantities of C. albicans ( P ≥ 0.067). Conclusion Silica-coating and silanization had modified the titanium and zirconia surfaces significantly. Both the control and experimental silane primers might inhibit the biofilm formation of C. albicans .
研究领域:
口腔医学
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微生物学
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材料科学
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DOI
PubMed
高影响因子
Journal of Central South University
·
2023
·Vol. 30
·期 5
·1512-1522
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IF 4.4
Dong Zhao-wang,Duan Liang-hong,Liu Han-ning,Guo Xue-yi,Xia Yang
High-purity zirconium metal has been of rising significance to the nuclear and energy industry. However, zirconium exhibits a strong chemical affinity to oxygen, which causes high-purity zirconium metal to be difficult to produce cost-effectively. Powder metallurgy for preparing zirconium metal can achieve near net forming of zirconium metal. Zirconium powder can be prepared by deoxidation of zirconium hydride powder. In this study, an efficient process was proposed to prepare high-purity ZrH 2 using magnesium powder as reducing agent in hydrogen atmosphere. A specific investigation was conducted on the effect of hydrogen on the magnesiothermic reduction and deoxidation of ZrO 2 . As indicated from the results, the oxygen content of the reduced powder in Ar was over three times that in H 2 atmosphere at 750 °C for 240 min. Moreover, a passive oxide layer, with a thickness of ~2.76 nm in H 2 and of ~8.51 nm in argon, was formed on the edge of the reduced powder. In accordance with thermodynamic calculation, hydrogen was found to be capable of destabilizing Zr-O solution. An ultra-high pure zirconium hydride powder containing <350×10 −6 oxygen and particle size of <100 µm was prepared as assisted by hydrogen.
研究领域:
材料科学
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核能工程
·
粉末冶金
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Xuan Tang,Ming Wang,Bingjing Tang,Yunkun Zhao,Wangcheng Zhan,Yanglong Guo,Li Wang,Sheng Dai,Yun Guo
Realizing the potential benefits of nanoscale metal catalysts requires highly dispersed active sites and control of their local environment. Herein, we develop a catalyst synthesis route for manipulating the local environment of highly dispersed metal-active sites via the targeted deposition of Pd near highly dispersed ZrOx on ZSM-5 zeolite using electrostatic interactions. The formed heteroatom Pd-ZrOx in zeolite catalysts is characterized by scanning transmission electron microscopy (STEM), in situ infrared spectroscopy, temperature-programmed desorption (TPD) of O2, and temperature-programmed surface reaction (TPSR) of CH4. The combination of diverse characterization results demonstrates the heteroatom Pd-ZrOx species rendering a higher dispersion and lower oxygen coordination of Pd species, appropriately tuning the strength of Pd–O bonds, and providing abundant active oxygen species to accelerate the dissociation of CH4. Therefore, the catalytic performance of Pd species is effectively enhanced with the lowest temperature of 90% CH4 conversion decreasing from 390 °C (without ZrOx) to 340 °C. Our work provides a strategy of engineering to anchor highly dispersed noble metal species and regulate the local environment to tune catalytic properties.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION
·
2017
·Vol. 38
·期 1
·30-36
·
IF 0.938
Sun W. Z.,Cheng J. G.,Huang Z. K.,Jiang Y.,Wu L. E.,Liu L. M.
The present work determined the phase relations in Si-Al-M-O-C (M = Zr, Mg) systems, involving SiC-Al 2 O 3 -ZrO 2 , SiC-Al 2 O 3 -MgO, SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO systems by XRD phase analyses of the solid-state reacted samples from powder mixtures of SiC, Al 2 O 3 , ZrO 2 , MgO and SiO 2 . Within these systems, SiC was respectively compatible with other neighboring phases, forming a set of four-phase compatibility tetrahedrons. The subsolidus phase diagrams of the SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO quaternary systems were presented.
研究领域:
材料科学
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陶瓷学
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DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 8
·2293-2301
·
IF 3.186
Liu Xueping,Shi Shengbin,Yang Su,Gu Liuyu,Gao Lijing,Zhang Jin,Xiao Guomin
Using etherification to convert glycerol into biofuel additives is an effective way to solve the current problem of excess glycerol. In this study, a series of environmentally friendly (x)HPW/ZrO 2 catalysts were synthesized for the etherification of glycerol and tert-butyl alcohol (TBA). The internal microstructure and acidity analysis of the synthesized samples were derived from BET, XRD, Raman spectroscopy, FTIR, SEM, NH 3 -TPD and Py-FTIR. The results revealed that the synthesized catalysts retained the complete Keggin structure of phosphotungstic acid (HPW) which supported on it. The (15)HPW/ZrO 2 catalyst with suitable structure and acidity had an excellent catalytic effect on the etherification reaction. Driven by the (15)HPW/ZrO 2 catalyst, the optimal reaction conditions were determined from parameters of reaction temperature, time, molar rate of glycerol and TBA, and catalyst dosage. 93.2% glycerol conversion and 42.5% selectivity of multi-substituted tert-butyl glycerol ethers (DTBG + TTBG) were obtained under optimal conditions. In addition, even after a total of four consecutive reactions, (15)HPW/ZrO 2 catalyst still demonstrated relatively good catalytic activity. Graphic Abstract
研究领域:
催化化学
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可再生能源
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环境科学
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Le Fu,Fuqing Jiang,Bo Li,Yongxin Cheng,Guofu Xu,Jiwu Huang,Håkan Engqvist,Wei Xia
The addition of dopant(s) is an effective strategy to regulate the microstructure and properties of ZrO 2 -based ceramics. In this study, we investigated the effects of ternary element alloying, namely tantalum (Ta), niobium (Nb), and hafnium (Hf) elements, on the microstructure and transformability of ZrO 2 nanocrystallites in a ZrO 2 -SiO 2 nanocrystalline glass-ceramic (NCGC) during sintering and thermal treatments. The ternary dopants enhanced the transformability of tetragonal ZrO 2 (t-ZrO 2 ) nanocrystallites during sintering, i.e., the dopants acted as t-ZrO 2 destabilizer. The Ta, Nb and Hf elements dissolved in ZrO 2 nanocrystallites, forming ZrO 2 solid solution. Meanwhile, lamella nanotwins were formed within many ZrO 2 nanocrystallites. No obvious segregation of dopants was detected at ZrO 2 grain boundaries. t-ZrO 2 and monoclinic (m) ZrO 2 nanocrystallites were metastable in thermal treatments process, with “t” to “m” and the reverse “m” to “t” polymorphic transformation occurred simultaneously. Meanwhile, t-ZrO 2 and m-ZrO 2 nanocrystallites had a great tendency to grow larger during thermal treatments.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
Materials Today Nano
·
2022
·
IF 13.364
X.L. Zhang,X. Zhang,L.C. Zhang,Z.G. Huang,F. Fang,J.J. Hu,Y.X. Yang,M.X. Gao,H.G. Pan,Y.F. Liu
Transition metal catalysts are particularly effective in improving the reaction kinetics of light metal hydrides for reversible hydrogen storage . Herein, tetragonal ZrO 2 hierarchical nanoparticles (nano-ZrO 2 ) composed of primary particles of ∼4 nm in diameter are successfully synthesized by a facile one-pot solvothermal process. The unique hierarchical structure features homogeneous distributions of in situ formed multivalent Zr-based species, which allow superior catalytic activity for hydrogen storage in MgH 2 . The MgH 2 +10 wt% nano-ZrO 2 starts releasing H 2 at 163 °C after one activation, which is 107 °C lower than additive-free MgH 2 , and 50 °C lower than that of bulk ZrO 2 -doped MgH 2 . At 230 °C, 5.9 wt% of H is rapidly liberated within 20 min from the nano-ZrO 2 -containing MgH 2 . More importantly, the material shows superior hydrogenation kinetics compared with all reported catalyst-modified MgH 2 . The nano-ZrO 2 -containing Mg took up 4.0 wt% of H in only 12 s at 100 °C under 50 bar H 2 , 400 times faster than the bulk-ZrO 2 -modified sample. Even at 50 °C, approximately 1.8 wt% H was absorbed within 1 min. Our findings provide useful insights into the design and development of high-performance catalysts toward solid-state hydrogen storage materials.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
International Journal of Extreme Manufacturing
·
2024
·Vol. 6
·期 5
·055002
·
IF 16.1
Lurun Xu,Jingchao Tao,Zhuguo Li,Guo He,Dongshi Zhang
Exsolution, as an effective approach to constructing particle-decorated interfaces, is still challenging to yield interfacial films rather than isolated particles. Inspired by in vivo near-infrared laser photothermal therapy, using 3 mol% Y2O3 stabilized tetragonal zirconia polycrystals (3Y-TZP) as host oxide matrix and iron-oxide (Fe3O4/γ-Fe2O3/α-Fe2O3) materials as photothermal modulator and exsolution resource, femtosecond laser ultrafast exsolution approach is presented enabling to conquer this challenge. The key is to trigger photothermal annealing behavior via femtosecond laser ablation to initialize phase transition from monoclinic zirconia (m-ZrO2) to tetragonal zirconia (t-ZrO2) and induce t-ZrO2 columnar crystal growth. Fe-ions rapidly segregate along grain boundaries and diffuse towards the outmost surface, and become 'frozen', highlighting the potential to use photothermal materials and ultrafast heating/quenching behaviors of femtosecond laser ablation for interfacial exsolution. Triggering interfacial iron-oxide coloring exsolution is composition and concentration dependent. Photothermal materials themselves and corresponding photothermal transition capacity play a crucial role, initializing at 2 wt%, 3 wt%, and 5 wt% for Fe3O4/γ-Fe2O3/α-Fe2O3 doped 3Y-TZP samples. Due to different photothermal effects, exsolution states of ablated 5 wt% Fe3O4/γ-Fe2O3/α-Fe2O3-doped 3Y-TZP samples are totally different, with whole coverage, exhaustion (ablated away) and partial exsolution (rich in the grain boundaries in subsurface), respectively. Femtosecond laser ultrafast photothermal exsolution is uniquely featured by up to now the deepest microscale (10 μm from 5 wt%-Fe3O4-3Y-TZP sample) Fe-elemental deficient layer for exsolution and the whole coverage of exsolved materials rather than the formation of isolated exsolved particles by other methods. It is believed that this novel exsolution method may pave a good way to modulate interfacial properties for extensive applications in the fields of biology, optics/photonics, energy, catalysis, environment, etc.
研究领域:
材料科学
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光学
·
生物医学工程
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DOI
高影响因子
危险品化学品经营许可证（带存储）