JOURNAL OF ALLOYS AND COMPOUNDS
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2026
·
IF 6.7
Bei-Chen Gao,Yu Tian,Run-Ping Liu,Yi-Xin Wang,Yang You,Wei-Ming Guo,Hua-Tay Lin
A two-step method including low-temperature pretreatment and high-temperature homogenization was developed to prepare high-purity (Ti 0.2 V 0.2 Ta 0.2 Nb 0.2 Hf 0.2 )(C 0.75 N 0.25 ) powder. In the first step, the reaction mixture was heated to 1450 ℃ to form intermediate carbonitride phases through carbothermal reduction-nitridation, and the second step at 1700 ℃ produced a single-phase high-entropy carbonitride. The powder prepared by single-step treatment at 1750 ℃ contained 2.28 wt% nitrogen and 0.18 wt% oxygen. In contrast, the two-step powder exhibited higher nitrogen content (2.45 wt%) and lower oxygen content (0.09 wt%), and the formation of a complete single-phase solid solution enabled accurate calculation of its composition (Ti 0.2 V 0.2 Ta 0.2 Nb 0.2 Hf 0.2 )(C 0.78 N 0.21 O 0.01 ). The ceramic prepared from the two-step powder achieved 99.8% relative density, with an average grain size of 4.58 ± 0.32 μm, a Vickers hardness of 22.73 ± 0.51 GPa, and a fracture toughness of 3.16 ± 0.30 MPa·m 1/2 , whereas the single-step ceramic reached only 86.5% relative density.
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JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2025
·Vol. 45
·期 15
·117640
·
IF 6.2
Li Xu,Wei Liao,Xiaosong Zhou,Yongqiang Tan
The influences of Cr 3 C 2 addition on phase formation, microstructures and mechanical properties of (Zr,Ti,Nb,Ta,Hf)C prepared from binary carbides mixtures by spark plasma sintering were studied. The introduction of 4/3 mol.% Cr 3 C 2 significantly lowered the minimum temperature for uniform high-entropy phase (Zr,Ti,Nb,Ta,Hf)C from 2200 °C for to 1900 °C. The lower solubility limit of Cr in (Zr,Ti,Nb,Ta,Hf,Cr)C results in excessive Cr 3 C 2 -based carbides, which tends to segregate along grain boundaries at higher sintering temperatures while locate at triple junctions at lower sintering temperatures . High mechanical strength of 599 MPa were obtained when 4/3 mol.% Cr 2 C 3 was added and sintered at 1900 °C. The fine grain size and Cr 3 C 2 -based carbides are responsible for the high mechanical properties. More Cr 2 C 3 addition results in lower mechanical properties due to excessive Cr 3 C 2 -based carbides.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Yinglan Li,Qipeng Wei,Jianshuo Su,Huaizhen Zhang,Zhiping Fan,Zhuang Ding,Min Wen,Min Liu,Yanna Zhao
In this study, the interaction among multifunctional excipients, including polysaccharides, cellulose derivatives, and surfactants, was particularly investigated, together with its impact on the physicochemical properties of astaxanthin amorphous solid dispersions (ASTX ASDs). It was indicated that Span 20 could rapidly form hemimicelles or aggregates in the presence of hypromellose acetate succinate HF (HPMCAS-HF, HF) or Soluplus®, while octenyl succinic anhydride modified starch (OSA-starch) efficiently assisted in the coalescence inhibition of drug-excipients aggregates, which was jointly beneficial to the recrystallization inhibition of amorphous ASTX. ASTX ASDs were further prepared with OSA-starch, HPMCAS-HF/Soluplus®, and Span 20 as the wall materials. DSC, SEM, and XRD confirmed that crystalline ASTX had transformed to amorphous state in the ASDs, while FT-IR spectra provided evidence suggesting the existence of hydrogen bonds and hydrophobic interaction between ASTX and the excipients. The dissolution of ASTX ASDs in different media revealed significant promotion, while the pharmacokinetic results further demonstrated the oral bioavailability of ASTX ASDs enhanced remarkably, exhibiting 2.75-fold (SD 1 ) and 1.87-fold (SD 2 ) increase, respectively, compared to ASTX bulk powder. In summary, the cellulose derivatives-surfactant interaction had great impact on the physicochemical properties of ASTX ASDs, and their combinations exhibited great potential for delivering the hydrophobic bioactive compounds efficiently.
研究领域:
药学
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材料科学
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药理学
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PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Jingcheng Du,Li Chen,Xinjuan Zeng,Shuai Yu,Wei Zhou,Luxi Tan,Lichun Dong,Cailong Zhou,Jiang Cheng
UiO-66 metal–organic frameworks (MOFs) are unstable in some harsh aqueous environments, which limit their practical applications. We demonstrate a postsynthetic modification methodology to transform hydrophilic Zr(Hf)-UiO-66 into superhydrophobic Zr(Hf)-UiO-66-SH-y (SH = thiol, y = fluoroalkyl) by introducing long fluoroalkyl chains into organic linkers through a thiol–ene click reaction. Water contact angles of the four modified UiO-66 MOFs are all larger than 150°. The grafted low-surface-energy fluorine-containing groups become an effective protective shield for the MOFs, making them exhibit remarkable stability in extreme conditions such as alkaline (pH = 12), saturated HCl, and high concentration of NaCl solution (20 wt %). The Zr-UiO-66 MOFs grafted with 1H,1H,2H-perfluoro-1-hexene have high CO2 adsorption contents of 1.54 and 2.88 mmol·g–1 at 298 and 273 K, respectively. Moreover, the superhydrophobic MOFs also showed potential application in oil/water separation.
研究领域:
材料科学
·
化学工程
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DOI
PubMed
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Yulan Yu,Guanghui Feng,Yujun Jia,Hejun Li
In this work, AlN whisker-reinforced (Zr, Hf)O 2 coating was prepared on SiC coated carbon/carbon composites by sol-gel and plasma spraying methods. Its cyclic ablation resistance was evaluated using an oxyacetylene torch with a heat flux of 2.38 MW/m 2 . After ablation, the coating showed apparently decreased crack sizes and quantity as compared with the one without AlN whisker addition, pointing out its better crack tolerance. Moreover, the coating had a thinner oxidized region based on the linear ablation rate (−0.042 µm/s), greatly lower than that of pure oxide coating (−0.922 µm/s). After detailed observation and characterization, probable protection mechanism was proposed.
研究领域:
材料科学
·
航空航天工程
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Yi Cao,Piao Ruan,YuFeng Xue,Yue Cao,Huang He,Wenfeng Qiu
Nowadays, materials that possess high activity and natural oxygen vacancy have garnered significant attention as potential electrode materials for supercapacitors . In this study, we successfully prepared the Hf 6 Ta 2 O 17 (HTO) nanofibres (NFs) with an orthorhombic superlattice structure using the electrospinning technique and sintering process. The characterization results indicate that the HTO NFs synthesized at 750 °C show good micro nanostructures and outstanding electrochemical properties . To enhance its energy storage performance, additional oxygen vacancies (OVs) were introduced through a carbothermal treatment under an Ar atmosphere. Although longer reduction reaction times can produce more OVs, the integration of grain boundaries and the growth of grain size caused by large annealing times may limit its electrochemical performance. Therefore, the HTO NFs treated for 1 h (HTO/C-1) exhibited the maximum C s of 925 F·g −1 at 1 A·g −1 with a larger voltage window of 2.1 V. Furthermore, a symmetric supercapacitor fabricated by two reduced HTO NFs electrodes and 1 M Na 2 SO 4 solution, recorded as r-HTO NFs//r-HTO NFs. The device demonstrated excellent energy density of 73.3 Wh·kg −1 (at power density of 1050 W·kg −1 ) and a long cycling life (81.8% retained after 5000 cycles). These results suggest that the optimized reduction process can provide appropriate oxygen vacancies in HTO NFs, thereby effectively enhancing its performance.
研究领域:
材料科学
·
能源存储
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高影响因子
JOURNAL OF FOOD COMPOSITION AND ANALYSIS
·
2025
·
IF 4.6
Qianqian Liu,Qi Chen,Wenhao Zhang,Ru Liu,Dingxuan Li,Qingcui Chu
In this work, the porous nanomaterial zeolite imidazolate framework-67 (ZIF-67) and tributyl phosphate (TBP) were introduced to co-modify the hollow-fiber liquid-phase microextraction (HF-LPME) for the first time. The extract of five typical flavor enhancers (vanillin, o-vanillin, ethyl vanillin, vanillinol and vanilla acetone) could be directly injected for electrophoretic separation and amperometric detection. The obtained optimum extraction conditions were as followed: supported liquid membrane, tributyl phosphate containing 0.050 mg mL -1 of ZIF-67; donor phase, 10 mL (pH 4.00 adjusted by HCl); acceptor phase, 10 μL (0.20 M NaOH); stirring rate, 500 rpm; extraction temperature, 25 °C; and extraction time, 45 min. Based on the synergistic enrichment effect of ZIF-67 and TBP, this HF-LPME could provide the enrichment factors of 207(V-OH)-890 times (EVA) for the flavor enhancers. This method has been successfully used for the analyses of milk, milk powder and milk tea samples. The limits of detection were 0.15-3.0 μg L -1 (S/N=3), and the recovery data were in the range of 80.1-115.5%. This developed method is easy to operate and has low consumption of solvents and samples, providing a green alternative method for the detection of typical flavor enhancers in dairy products. Besides, the greenness and eco-friendliness of the proposed method was assessed using the green analytical procedure index and analytical eco-scale tools.
研究领域:
分析化学
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食品科学
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纳米技术
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分离科学
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电化学
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高影响因子
Materials Today Communications
·
2026
·
IF 4.5
Wei Gan,Can Jiang,Yao Wang,Min Ling,Shengfu Zhang
It is challenging to develop well-designed photocatalysts with high activity. In this work, TiO 2 nanotubes (TiO 2 -NTs，TNT) with well-morphology and high {001} facets exposure ratio were directly synthesized by H 3 PO 4 /HF-assisted two-step anodic oxidation. The results show that the addition of 3 wt% H 3 PO 4 and 0.5 wt% HF into the electrolyte facilitates the preparation of TiO 2 -NTs with an average crack density of 0 % and {001} facets exposure ratios up to 80.00 %. Moreover, the PO 4 3- and HPO 4 2- in the anode effectively hinder the generation of electron current and release of oxygen bubbles on the surface of Ti substrate, which reduces the surface cracks of TiO 2 -NTs. The F - in the electrolyte is adsorbed on the {001} facets of the TiO 2 -NTs, which decreases the energy of the O-Ti-O, thus achieving the purpose of high {001} facets exposure ratio. Ultimately, the excellent optical properties, in conjunction with the synergistic effect of {001} facets-selective orientation and O V , significantly enhanced the photocatalytic activity of TiO 2 -NTs, resulting in the removal of 90.32 % Rhodamine B in 120 min under visible light illumination. This work could shed light on the new approach to the rational design of high-efficiency TiO 2 -NTs-based photocatalysts.
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高影响因子
MATERIALS CHARACTERIZATION
·
2026
·
IF 6.2
Jun Zhao,Xiang Ji,Peipei Wang,Leihua Xu,Peizhong Feng,Guozheng Lv,Changlin He,Xuanru Ren
A Hf-based borosilicate glass modification strategy is proposed to enhance the oxidation resistance of ZrB 2 -MoSi 2 ceramics. • Moderate HfO 2 addition forms in-situ dense Zr-Hf-Si-O multiphase glass layer, suppressing oxygen inward diffusion. • ZMGH30 sample shows 23.73% lower oxidation weight gain, 70.38% lower average oxidation rate, and 61.17% hardness retention. To address the issues of loose oxide scale and insufficient protective performance in ZrB 2 -MoSi 2 composite ceramics under ultra-high temperature oxidizing environments, caused by the volatilization of B 2 O 3 and the self-depletion of MoSi 2 , A novel Hf-based borosilicate glass modification strategy is proposed by this work. The effects of varying HfO 2 contents on the oxidation resistance and mechanical properties of the ceramics after oxidation at 1700 °C for 100 min were systematically investigated. The results indicate that, with an appropriate amount of HfO 2 modification, a continuous Zr-Hf-Si-O multiphase glass layer forms in situ during oxidation, significantly suppressing the inward diffusion of oxygen. Compared with the unmodified sample, the ZMGH30 sample exhibits a 23.73% reduction in oxidation weight gain, a 70.38% decrease in average oxidation rate, and an increase in hardness retention to 61.17%. Excessive HfO 2 leads to excessively high viscosity of the glass layer, Hf element agglomeration, and dendritic precipitation, thereby weakening the self-healing ability and deteriorating the oxidation resistance. A new approach for developing ultra-high temperature ceramics that combine excellent oxidation resistance and mechanical reliability is provided by this work.
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高影响因子
ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Hengyu Hao,Yuya Abe,Haixin Guo,Xiao Zhang,Richard Lee Smith Jr
Bifunctional Lewis (L) acid (Ni- or Hf-) site–Brønsted (B) acid catalysts designed to promote transfer hydrogenation reactions were prepared via hydrothermal and solvothermal methods using safe mixed solvents and sustainable precursors. By using N,N-dimethylformamide as a basis for the desired basicity, mixed solvents could be identified that allowed catalysts to be prepared with tunable ratios of Lewis to Brønsted acid sites (L/B). The as-prepared catalysts promoted transfer hydrogenation of furfural and ethanolysis to form ethyl levulinate (EL) using ethanol as a solvent and hydrogen donor source. Among the catalysts, sulfonated Hf-catalysts prepared with a cyclopentanone/formic acid mixed solvent (Hf-CPN/FA) with an L/B ratio of 6.4 gave 95% furfural conversion with 51.9% yield of EL, while the sulfonated Hf catalyst prepared with a cyclopentanone/γ-valerolactone mixed solvent (Hf-CPN/GVL) with a total Lewis and Brønsted acid site amount of 85.1 μmol/g gave 100% furfuryl alcohol (FAL) conversion with 72.5% yield of EL. Brønsted acid sites promoted reversible acetalization of furfural with ethanol into 2-furaldehyde diethyl acetal, while Lewis acid sites promoted furfural transfer hydrogenation into FAL and EL and further conversion into γ-valerolactone. The methods developed in this work eliminate dipolar aprotic solvents and harsh acids used in catalyst synthesis and allow sustainable production of EL from biomass-related chemicals.
研究领域:
化学工程
·
催化
·
绿色化学
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有机化学
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生物质转化
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高影响因子
Solids
·
2025
·Vol. 6
·期 4
·66
·
IF 2.4
Chenxing Liao,Feng Zhou,Wei Xie,Liaolin Zhang
Mn4+-doped fluoride red phosphors are widely used in white LED lighting and display applications due to their excellent luminescent properties. However, their synthesis relies heavily on highly toxic aqueous hydrofluoric acid, which not only causes severe environmental and soil/water pollution but also makes it difficult to control the microstructure of the products due to the rapid reaction rate. In this study, low-melting-point NH4HF2was used as the molten salt, with KMnO4and MnF2as manganese sources, to synthesize the red phosphor K3AlF6: Mn4+via the molten salt method. After the reaction, impurities such as NH4HF2were removed by washing with a dilute H2O2solution. The microstructure, photoluminescence properties, thermal quenching behavior, and application in warm white light-emitting diodes (W-LEDs) of the K3AlF6: Mn4+phosphors were investigated. The results indicate that the phosphors prepared by this method consist of a single pure phase. By adjusting the molten salt content, the morphology of the product can be transformed from nanoparticle-like to nanorod-like structures. All products exhibit the characteristic red emission of Mn4+under blue and violet light excitation, with the optimally doped sample achieving an internal quantum efficiency (IQE) of 69% under blue light excitation. The combination of the obtained K3AlF6: Mn4+with the yellow phosphor YAG enabled the fabrication of W-LEDs. These W-LEDs achieved a color rendering index (Ra) of 86.8, a luminous efficacy (LE) of 77 lm/W, and a correlated color temperature (CCT) of 3690 K, along with excellent color stability under operating conditions.
研究领域:
材料科学
·
光电子学
·
固态化学
·
发光材料
·
LED技术
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高影响因子
RARE METALS
·
2024
·Vol. 43
·期 6
·2682-2694
·
IF 9.6
Hu Jie,Lao Hong-Xin,Xu Xiu-Wu,Wang Wei-Kang,Wang Le-Le,Liu Qin-Qin
Though there are numerous intrinsic merits of metal-organic frameworks (MOFs), low charge separation efficiency has imposed heavy restrictions on their photocatalytic application. Herein, in situ porphyrin ligand substitution, as a strategy for improving the charge separation efficiency and increasing the amounts of active sites, has been designed and realized in a Hf-biphenyl dicarboxylic acid (BPDC) MOF. Specifically, a size and geometry matched meso-tetra (4-carboxyphenyl) porphyrin (TCPP) ligand was selected and doped into Hf-BPDC MOF by forming coordinating bonds with Hf centers, forming dual-ligand Hf-BPDC-TCPP MOF. The resultant Hf-BPDC-TCPP MOF showed significantly improved activity and chemical stability in the photocatalytic H 2 generation (261 μmol·g −1 ·h −1 ) and tetracycline (TC) degradation reactions (95.8%), which was 48 and 1.47 folds higher than that of the Hf-BPDC MOF. Photophysical and electrochemical studies revealed that the introduction of porphyrin ligand could generate a stronger internal electric field for boosting the charge separation and transfer, increase the specific surface area for providing more active sites, and narrow the band gap to enhance the visible light absorption. This in situ ligand substitution method provides a promising approach to build a tunable platform for constructing high-performance MOF photocatalysts. Graphical Abstract
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