JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Kang Du,Chang-Zhi Yin,Yan-Bo Guo,Xiao-Chuan Wang,Wen-Zhong Lu,Wen Lei
CaSn 1- x Ti x GeO 5 (0 ≤ x ≤ 1.0) ceramics were prepared using traditional solid-state reaction with sintering at 1275 °C – 1500 °C for 5 h. The Ti 4+ substitution for Sn 4+ inhibited the CaSnO 3 second phase of CaSnGeO 5 ceramic, and phase transition from triclinic with A 1 ¯ space group to monoclinic with A 2/ a space group and then to monoclinic with P 2 1 /a space group occurred in CaSn 1- x Ti x GeO 5 (0 ≤ x ≤ 1.0) ceramics. Evident changes in Sn/TiO 6 octahedron and Sn/TiO 6 octahedral chains were observed. A change in τ f from negative (‒62.9 ppm/°C) to positive (+18.7 ppm/°C) was achieved by controlling octahedral distortion. The large octahedral distortion contributed to near-zero τ ε for CaSn 1- x Ti x GeO 5 (0 ≤ x ≤ 0.8) ceramics. The broadening and shifting of ε r anomaly peaks for CaSn 1- x Ti x GeO 5 (0.8 ≤ x ≤ 1.0) ceramics greatly influenced τ ε , and the sudden increase in τ ε was attributed to the shift of ε r anomaly peaks to high temperature.
研究领域:
材料科学
·
固态物理
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Wei-Ming Guo,Zhi-Lin Zhang,Jing-Xi Li,Yang You,Shang-hua Wu,Hua-Tay Lin
Al 2 O 3 –B 4 C ceramics had poor densification, due to the formation of Al 18 B 4 O 33 phase by reaction between Al 2 O 3 and B 2 O 3 on the surface of B 4 C. In the present work, Y 2 O 3 or Ti additive together with ZrO 2 from milling media were introduced into Al 2 O 3 –B 4 C ceramics. Results showed that Y 2 O 3 reacted with B 2 O 3 to produce YBO 3 phase, and removed Al 18 B 4 O 33 phase, resulting in the improved densification and the coarse microstructure. However, Ti and ZrO 2 reacted with B 2 O 3 to produce hard TiB 2 and ZrB 2 phases, removed the most of Al 18 B 4 O 33 phase, refined microstructure by pinning effect of hard particles, and improved densification and mechanical properties .
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Jinyuan Hu,Boru Cai,Yaohui Wang,Zhengran Bian,Tianle Hou,Yanwei Sun
Amorphous metal–organic frameworks (MOFs) present significant potential for achieving high permeability and selectivity in separation applications. However, developing effective fabrication strategies for amorphous MOF membranes with well-defined channels remains a considerable challenge. In this study, amorphous titanium-based MOF membranes with concurrently optimized intercrystalline and intracrystalline selective transport channels were successfully prepared. The resulting membranes exhibited exceptional sieving performance for dyes with molecular weight cutoff of 600 Da. Additionally, defect-rich dual water channels within and between the amorphous MOF aggregates led to a remarkable water permeances up to 107.4 L m −2 h −1 bar −1 , significantly surpassing the benchmarks set by other nanofiltration membranes. This work offers valuable insights into the influence of amorphization on the design of a wide variety of MOF membranes, paving the way for advanced separation applications.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2022
·
IF 5.089
Ji Wang,Shuqing Zhang,Yiming Han,Lilei Zhang,Qingyin Wang,Gongying Wang,Xiaoming Zhang
PET (poly(ethylene terephthalate)) is one of the most important type of thermoplastic polyesters and widely used in various fields. Titanium-based catalysts are environmentally friendly and have higher catalytic activity than antimony-based catalysts when used in industry. However, titanium-based catalysts are prone to hydrolysis and result in discolored products. UiO-66 (Zr/Ti) with different Ti 4+ contents were successfully synthesized via one-step method. The material was characterized by XRD, SEM, FT-IR, XPS, BET and TG techniques. The results demonstrates that Ti 4+ was integrated into the UiO-66 framework. NH 3 - in situ DRIFTS, pyridine-IR, and NH 3 -TPD were used to explore the acidic properties of the samples, which proved that stable Lewis acidic sites are present in the samples even at 300 °C. The catalytic performance of UiO-66 (Zr/Ti) containing different Ti 4+ was explored under different conditions. At the same time, the scale-up experiment was carried out in a 5 L reactor, and the PET chips obtained had a lower b value. The catalytic reaction mechanism of UiO-66(Zr/Ti) was demonstrated by DFT calculations and the catalytic performance was close to Sb-based catalysts.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Ke Chen,Youhu Chen,Jianning Zhang,Yujie Song,Xiaobing Zhou,Mian Li,Xiaomeng Fan,Jie Zhou,Qing Huang
Medium- and high-entropy alloys or ceramics for tuning the physicochemical properties of materials by the combination of multiple principal elements have received much interest. Herein, a medium-entropy (Ti, Zr, Hf) 2 SC phase was synthesized attributing to the structural and chemical diversity of MAX phases. The crystal structure of (Ti, Zr, Hf) 2 SC was determined by the Rietveld refinement of XRD , SEM, and atom-resolved TEM along with EDS elemental analysis . Phase evolution of X-ray diffraction patterns and TG/DSC curves were employed to reveal the synthesis mechanism of (Ti, Zr, Hf) 2 SC from 2TiC–Zr–ZrC-2HfH 2 -3.2FeS reactant system. The Vicker's hardness and the electrical resistivity of (Ti, Zr, Hf) 2 SC were found higher than those of Ti 2 SC, but the thermal conductivity of (Ti, Zr, Hf) 2 SC was lower.
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2021
·Vol. 13
·期 15
·2433
·
IF 4.329
Lijian Sun,Limei Li,Xianhui An,Xueren Qian
From the perspective of sustainable development and practical applications, there has been a great need for the design of multifunctional transparent cellulose-based composite films. We herein propose a novel concept of improving the mechanical, fire-resistant and ultraviolet (UV)-blue light shielding properties of cellulose-based composite bioplastic films though in situ embedding nano-metal organic framework (MIL-125(Ti)-NH2) into regenerated cellulose gel. Regenerated cellulose hydrogel (CH) with a porous structure acts as a nanoreactor and stabilizer to facilitate the growth and anchorage of MIL-125(Ti)-NH2nanoparticles (MNPs). Subsequently, hot-pressing induces the formation of transparent MIL-125(Ti)-NH2@cellulose bioplastics (MNP@CBPs). As expected, the MNP@CBPs exhibit exceptional UV-blue light shielding capability, while retaining satisfactory optical transmittance. Meanwhile, with the incorporation of MNPs, the mechanical strength of MNP@CBPs is increased by 6.5~25.9%. In addition, MNPs enhance the flame retardant effect of the MNP@CBPs. The limited oxygen index (LOI) of the MNP@CBPs increased from 21.95 to 27.01%. The hot-pressing process improves the resistance of the MNP@CBPs to the penetration of water/non-aqueous liquids. This simple strategy would direct sustainable multifunctional MNP@CBPs toward diversified applications: food containers or packaging materials that can reduce or eliminate food spoilage, screen protectors for blocking harmful light, and promising candidates for protective plastic products, among others.Keywords:bioplastic;MIL-125(Ti)-NH2;fire-retardant;UV-blue light blocking;mechanical properties
研究领域:
材料科学
·
可持续发展
·
复合材料
✓ 已验证
DOI
PubMed
高影响因子
POWDER TECHNOLOGY
·
2013
·
IF 2.024
Dewen He,Cancheng Bai,Chongwen Jiang,Tao Zhou
Titanium containing MCM-41 is synthesized hydrothermally in the presence of structure-directing agent cetyltrimethylammonium bromide (CTAB). Bi- and tri-metal Fe and Zn are impregnated in these materials to improve the acid catalytic sites as well. XRD , BET nitrogen adsorption isotherm, TEM and SEM analysis confirm the presence of mesopores in the composite. The local environment of titanium incorporated into the mesoporous silicate material is investigated by FT-IR and UV–Vis spectroscopy. These results indicate the presence of active centers within the composite material Ti, Fe and Zn. The new composite materials are preliminarily tested in the hydrolysis of cellulose . All the titanium MCM-41 materials improve the conversion of cellulose, providing higher catalytic activity in hydrolysis. There is maximum sugar and 5-HMF concentration resulted from hydrolysis of cellulose with Fe/Ti-MCM-41 catalyst.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Yucheng Li,Jing Liu,Jing He,Luying Wang,Jiandu Lei
The effect of titanium as a promoter for the nickel-cobalt/silica-titania (NiCo/Si-Ti) catalyst in the hydrogenation of phenol was comparatively studied. In the phenol hydrogenation under mild reaction conditions (1 MPa H 2 pressure and 100 °C), the Ti-promoter induces the formation of the Co δ− −O V −Ti 3+ active sites and enhances the hydrogenation activity of the NiCo/Si catalyst to convert phenol to cyclohexanol. The catalytic hydrogenation with the optimal composition of the NiCo/Si-1.0Ti (Si:Ti ratio of 8.5:1) catalyst was completed within 1 h (conversion 98.2 % and selectivity >99 %), which was more efficiently than that with other Ti-doped catalysts and NiCo/Si as baseline, indicating a strong positive synergistic effect between the metal (Ni-Co) and support (Ti-Si) components of the catalyst in this reaction. Additionally, the kinetics, pathway and catalytic mechanism of the hydrogenation of phenol are also examined. Furthermore, the NiCo/Si-1.0Ti catalysts also showed a good performance at reducing the unstable oxygenated compounds in the bio-oil.
研究领域:
催化
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Ning Gao,Baolong Liu,Mengjie Fan,Yike Yao,Yunbo Wang,Xiaoqian Peng,Xupeng Zong,Fuyuan Xu,Yingwen Chen
This work addresses the atomic radius mismatch between Ti and Si and their limited substitution frequency by developing a sol–gel strategy to optimize active Ti site formation. A dual regulation approach, involving water and organic acids, controlled the hydrolysis rate and implemented a two-step process, forming Si-OH and Ti-OH bridging units. This enabled precise control over elemental assembly within the sol–gel system. Stabilization of the TiO x -SiO 2 mixed phase facilitated the formation of a highly active, amorphous TS aerogel catalyst, enriched with penta- and hexa -coordinated Ti. By optimizing preparation parameters, an efficient TS (1:4) aerogel catalyst was developed, achieving complete oxidative desulfurization (ODS) of 500 ppm DBT at 333 K in 10 min, with a maximum reaction rate constant (Kobs) of 0.447 min −1 and activation energy of 50.05 kJ/mol. The catalyst maintained ∼90 % desulfurization efficiency over six consecutive cycles using model oil containing sulfur compounds (BT, DBT, 4,6-DMDBT). Insights into peroxide transfer and catalyst degradation were obtained through multi-factor activity tests, active site evolution analysis, and DFT calculations. These findings improve Ti site optimization and provide a basis for refining sol–gel strategies to increase active Ti content.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2025
·
IF 14.3
Junjie Xu,Wei Sun,Xiang Xiong,Yi Zeng,Qingbo Wen
Conventional ultra-high-temperature ceramic-modified carbon/carbon composites (C/C-UHTCs) face limitations such as excessive erosion in the gas environment of solid rocket motors (SRMs). In contrast, metal-reinforced C/C-UHTCs exhibit enhanced mechanical properties, thermophysical characteristics, and resistance to high-temperature erosion. These advantages indicate significant potential for metal-reinforced C/C-UHTCs to augment the thrust capabilities of SRMs. This study demonstrated the preparation of (Hf, Zr, Ti)C-(Hf, Zr, Ti)B 2 -W-Cu cermet modified C/C composites using slurry infiltration and reactive melt infiltration at 1400°C. The microstructure, formation mechanisms, mechanical properties, and thermophysical properties of C/C-(Hf, Zr, Ti)C-(Hf, Zr, Ti)B 2 -W-Cu composite materials, as well as the ablation behavior of the composite materials under the SRM environment were compared. The results showed that the linear and mass ablation rates of the C/C-(Hf, Zr, Ti)C-(Hf, Zr, Ti)B 2 -W-Cu composite material decreased by 112.1% and 160.4% (0.074 mm s −1 , 0.086 g s −1 ), respectively, compared with those of the C/C-(Hf, Zr, Ti)C composite material. This could be attributed to the formation of a dense, high-strength W-skeleton composite (Hf, Zr, Ti)O 2 oxide layer during the ablation of the C/C-(Hf, Zr, Ti)C-(Hf, Zr, Ti)B 2 -W-Cu composite, which effectively resisted erosion from high-temperature, high-speed and high-particle-concentration two-phase gas flow. This work presents a novel approach to enhancing the ablation resistance of C/C-UHTCs and holds significant promise for the development of structural materials in SRM environments.
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Jinsu Yu,Hsinshen Ho,Jiangyi Chen
As a transmission part, the service life of the shaft parts directly affects the machining efficiency and economic benefit, and requires higher surface hardness and wear resistance. In this study, the Ti/B 4 C/dr40 composite powder was cladded on the shaft part surface via laser cladding to improve the microhardness and wear resistance. The microstructure evolution and phase structure were analyzed to reveal the strengthening mechanism of Ti and B 4 C on dr40 coating. The Ti/B 4 C/dr40 composite coating with low defects and good interface metallurgical bonding quality between coating and substrate was prepared on the 45# steel shaft part. The results show that the main phase in the Ti/B 4 C/dr40 composite coating is TiC, TiB 2 , Cr 2 C 3 , (Ti, Cr) C, (Ti, Cr, Fe, Ni) (C, B). With the addition content of Ti increasing, the grain densifies, the sieve-reticular structure and small strip phase at grain boundary and intergranular area change as massive phase. Moreover, the microhardness improves up to 2.05 times than that of dr40 coating. The in-situ synthesis of carbides and borides are evenly distributed in the coating, which improves the deformation resistance of the coating. In addition, the precipitation and solid solution strengthening caused by reinforcement phase also enhanced matrix strength for supporting reinforcement phases, improving the coating wear resistance.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Kui Liu,Liang Shi,Xueying Wang,Cheng Liu,Jie Li,Yulong Liao,Lichuan Jin,Dainan Zhang,Huaiwu Zhang
Herein, Li + -enriched Li (1+ x )2 ZnTi 3 O 8 ceramics are prepared via the solid-phase methods. As x increases, the unit cell volume gradually increases, while the grain size initially increases and then decreases gradually. The Li (1+0.06)2 ZnTi 3 O 8 ceramics exhibit the best dielectric properties : ε r = 25.92, Q × f = 109534 GHz (@7.37 GHz, which is a 48 % increase compared with the stoichiometric counterpart.), and τ f = −8.21 ppm/°C. The complex chemical bond theory and Raman spectroscopy reveal that Ti-O bonds have a significant effect on the dielectric properties . An optimal Li + enrichment leads to an overall reduction in the distortion of the Li/ZnO 4 tetrahedra, resulting in a reduction in τ f . First-principles calculations demonstrate that a suitable excess of Li + leads to an increase in the band-gap as well as an enhanced electron cloud density in the internal space of the Li1/ZnO 4 tetrahedra, thereby increasing the Q × f . In summary, Li + -enriched Li (1+0.06)2 ZnTi 3 O 8 ceramics are promising for a wide array of applications in microwave communications.
研究领域:
材料科学
·
固态物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）