FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Ruoning Zhang,Yanhui Zhang,Jingjing Yu,Yanxiang Gao,Like Mao
Understanding the thermal behavior of emulsions with complex structures was crucial for wider applications. However, the correlations between the structural units and emulsion properties at different temperatures are poorly understood. Herein, W/O emulsions stabilized by oleogels and nanoparticles were studied during thermal process, and dynamic interactions among the structural units occurred at micro-, meso-, and macroscales. Results revealed that the thermal behavior of W/O emulsions shifted from stable (25–50 °C) to sub-stable (50–60 °C), and unstable states (60–80 °C). Microstructural analysis confirmed that the particles desorbed from the interface and dissolved in the oil phase after heating, causing water droplet coalescence in the emulsions. This was attributed to the enhanced hydrophobic interactions between the particle dispersions and the oleogel, as the contact angle and interfacial tension were decreased during heating. At the mesoscale, the T 2 values of oleogels and nanoparticle dispersion were increased more than three times from 25 °C to 80 °C, leading to the higher mobility of protons in emulsions. At the macroscale, the viscoelastic modulus of emulsions at higher temperature were higher, together with less energy dissipated by friction and increased nonlinear response. Furthermore, the temperature-induced transformation of emulsion stability can be reversibly controlled at least three times. Insights into the complex behavior of emulsions across different temperature stages can inspire the design of emulsions for specific applications.
研究领域:
食品科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Superconductivity and Novel Magnetism
·
2013
·Vol. 27
·期 2
·411-420
·
IF 0.702
Guo Fengying,Wu Xiaomin,Ji Guijuan,Xu Jijing,Zou Lianchun,Gan Shucai
A novel composed W-type hexaferrite Ba 1− x
La
x
Co 2 Fe 16 O 27 was rapidly synthesized via a sol–gel self-combustion reaction. The effects of lanthanum ions on the oxidation state of iron ions and cobalt ions in hexaferrite were explored by X-ray photoelectron spectroscopy. The changes of the Fe 2p X-ray absorption spectra indicated that the nonequivalent substitution can lead to the transition Fe 3+ → Fe 2+ in Ba 1− x
La
x
Co 2 Fe 16 O 27 . However, the oxidation state of cobalt ions was maintained as Co 2+ . Moreover, the effects of La content on the phase composition, structural parameters, morphology, and static magnetic properties were also investigated in detail by using the X-ray diffractometer, scanning electron microscope, and vibrating sample magnetometer. The results indicated that the structural parameters decreased regularly with increasing the La content, and the magnetic properties were enhanced after substitution, which is beneficial for their application in various electrical devices employed for industrial and military applications.
研究领域:
材料科学
·
无机化学
·
磁性材料
·
固体物理
·
功能材料
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Guan-Yu Pan,Yu-Long Ma,Xiao-Xia Ma,Yong-Gang Sun,Jun-Min Lv,Jian-Li Zhang
Ni–W/MCM-41 as a non-noble metal catalyst for catalytic conversion of corn stalk pretreated with alkali into polyol was prepared by an impregnation method. The results showed that pretreatment corn stalk with alkali removed 41.79 wt% of hemicellulose and 60.21 wt% of lignin and thereby increased the content of cellulose from 41.13 wt% to 59.29 wt%. Data obtained from X-ray photoelectron spectra exhibited that there was an intense interaction between nickel and tungsten. Meanwhile, the Ni 17 W 3 alloy was evidenced by X-ray diffraction spectra. These were very beneficial to enhance the catalytic conversion of lignocellulose into polyol. The maximum yield of 71.37 wt% polyol was obtained by catalytic hydrogenation of lignocellulose to ethylene glycol and 1,2-propylene glycol utilizing 5%Ni–15%W/MCM-41 catalyst under H 2 pressure of 6 MPa and 250 °C for 2 h.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 4
·1-9
·
IF 1.92
Guo Fengying,Zi Wenwen,Ji Guijuan,Zou Lianchun,Gan Shucai
The W-type hexaferrite Ba 0.85 La 0.15 Co 2 Fe 16 O 27 composite with polyaniline was synthesized by a facile route of in-situ chemical oxidative polymerization. This novel organic–inorganic composite material (PANI/Ba 0.85 La 0.15 Co 2 Fe 16 O 27 ) can be used as a potential microwave absorber. And their microstructure, static magnetization, complex permittivity, permeability and microwave absorbing properties were subsequently investigated. Compared with pure W-type hexagonal ferrite, the composites have higher permittivity and reflection loss, which gradually increase with the increase of PANI content. The excellent microwave absorption in our experiment reached to −14.95 dB at 9.3 GHz with the layer thickness of 4 mm when the mass ratio was 0.7/0.5. More importantly, well reflection loss over a wide frequency range can be achieved by manipulating the content of PANI. The results indicated that the novel organic–inorganic materials composed of polyaniline and W-type hexagonal ferrite had an excellent microwave absorption property, and may be used as lightweight and highly effective microwave absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2024
·
IF 7.4
Yueqi Wu,Mingyong Jia,Zhifeng Huang,Qiang Shen,Fei Chen
The high-temperature corrosion behavior of a Si 3 N 4 /W composite under the molten MgCl 2 -NaCl-KCl salts has been investigated. It is suggested that the molten salts diffuse along the physical surface defects and enter the interior of adjacent Si 3 N 4 /W grains, leading to the 9.1% bending strength loss after 400 hours for corrosion. In air atmosphere, oxidation products WO 2 , WO 3 , and corrosion product MgWO 4 caused a 34.3% bending strength decrease after 400 hours for corrosion. This study elucidates the high-temperature molten chloride salt corrosion mechanisms of the Si 3 N 4 /W composite material under two different atmospheres. The composite demonstrates relatively excellent corrosion resistance in service environments.
研究领域:
材料科学
·
腐蚀工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2022
·
IF 4.804
Lei Huang,Yafei Pan,Jiuxing Zhang,Yong Du,Yuhui Zhang
W-30Si refractory targets were widely used as gate materials in the field of semiconductor integrated circuits. This work aimed to study the microstructure, densification mechanism, and mechanical properties of W-30Si targets prepared by spark plasma sintering (SPS). The results manifested that the punch displacement and relative density rose as temperatures increased, and the sintering route processed at 1200 °C included four parts. A fully dense target can be obtained at 1200 °C, while part of Si would volatilize at 1220 °C. No significant variation was observed in grain sizes from 1000 to 1200 °C, thus it was believed that the consolidation predominated over this temperature range. The effective stress exponent ( n ) was generally regarded as a parameter closely related to the densification mechanism. At the initial stage of 1000 to 1200 °C and the late stage of 1000 °C ( n < 1), the particle rearrangement had a major influence on the densification. At the late stage of 1050 to 1200 °C (1 < n < 2), the grain boundary diffusion was a significant factor for consolidation, and the activation energy ( n = 1.5) was estimated to be 931.40 kJ/mol. Besides, the microhardness rose with increasing temperatures. The present study laid the groundwork for future research on the fabrication of W-30Si targets by SPS.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2024
·
IF 4.3
Shiqi Chen,Liu Yang,Jun Shen
This study evaluated electron shielding capabilities of various materials using Geant4 Monte Carlo software. By analyzing materials with different atomic numbers, we designed and tested composite films and coatings for radiation protection. Under 1.2 MeV electron irradiation, these materials reduced the dose deposited in electronic components by over 70 %. The fabricated composite films (W–Al) reduced the actual total dose by 100 % with a 30.67 % mass increase, closely matching the simulation result of 75.36 %. The composite coatings (W–Al) reduced the dose by 89.2 % with a 33 % mass increase, matching the simulation result of 70 %. Cascade collision simulations revealed that higher PKA energies lead to longer times to reach the thermal peak, more peak defects, and more stable defect pairs. This is due to the displacement threshold energy of the atoms in aluminum and tungsten. These results demonstrate the effectiveness of our composite films and coatings in enhancing electron shielding performance and validate our design methods.
研究领域:
航空航天工程
·
材料科学
·
辐射物理学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Chunhua Li,Luqian Bao,Yubo Shi,Zhehang Tian,Yixin Ji,Mengyao Cui,Zhilei Zhao,Xianyou Wang
A hollow heterojunction of W-Zr-MOF-NH 2 @TpTt-COF (WZT) was fabricated by combining etched W-Zr-MOF-NH 2 with TpTt-COF. WZT, synthesized through acid etching and hydrothermal methods, showed better tetracycline degradation than pure W-Zr-MOF-NH 2 and pure TpTt-COF due to its larger specific surface area and more active sites. The surface of WZT contains abundant oxygen vacancies (OVs) that capture electrons, promoting the separation of photogenerated e - -h + pairs and increasing WZT’s photocatalytic activity. WZT (1:1, mass) showed 87% degradation of tetracycline under 300 W Xenon lamp irradiation. The results of cycling experiments demonstrated the high stability and reusability of WZT (1:1), making it feasible for production. The excellent photocatalytic degradation of tetracycline by WZT (1:1) originates from the formation of heterojunctions and the presence of surface OVs, which reduces the strong photogenerated e - -h + complexation efficiency. Possible photocatalytic degradation mechanisms are proposed while demonstrating the formation of Z-scheme heterojunction in WZT, which aligned with the experimental results of electron spin resonance (ESR). The tetracycline oxidative decomposition process involves the participation of •OH, 1 O 2 , • O 2 - , e - , and h + as proven by ESR and radical trapping experiments. This work proposes a research idea to prepare high-performance photocatalysts with MOF@COF type, featuring OVs-rich and Z-scheme heterojunctions.
研究领域:
材料科学
·
环境科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Hanzi Liu,Yi Zhang,Haiming Wang,Changfu You
Selective non-catalytic reduction of NOx (SNCR) with NH 3 is commonly used in industrial facilities like circulating fluidized bed (CFB) furnaces. However, the strongly temperature-dependent de-NOx feature confines its applications in a specific temperature range (900–1050 °C). Here, we report a new strategy on using Fe-Ni-W exchanged zeolite (0.5FNW-H) as a catalyst to extend the SNCR temperature window. In the CFB reactor, a significant NOx conversion improvement ranging from 14.1% to 80.9% was achieved at 700 to 850 °C by applying the developed catalyst. Catalyst dosage of 4500 h −1 (GHSV), a particle diameter of 0.1–0.3 mm, and NH 3 injection position at the dense-phase zone were found preferred for NOx reduction with the highest efficiency of ~85% at 700 °C. The physicochemical properties of the catalysts remained stable after the circulating reactions in the CFB reactor. The developed catalyst is particularly applicable for improving the SNCR performance when the thermal power plants are operated at low loads.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Changxiao Cao,Shaohua Gu,Zhaojie Song,Zehui Xie,Xuya Chang,Pingping Shen
Formation of water-in-oil (W/O) emulsion seriously limits heavy oil production, and the interfacial adsorption of heavy components of oil is the key to clarify the emulsification of crude oil and formation water. In this study, the viscosifying behavior of W/O emulsion was correlated with the interfacial adsorption of heavy components using two typical heavy oil samples, i.e., high-resins oil and high-asphaltenes oil. Results showed that the resins, instead of the asphaltenes , contributed to the pseudoplastic behavior of W/O emulsion. The interfacial adsorption of resins presented the lower interfacial tension (IFT), the higher interfacial viscosity and the stronger film stability. However, when more asphaltenes was adsorbed on the interface, the film of oil-water interface changed from viscous to brittle and breakable. According to the composition analysis, the interfacial activity of resins was much stronger than asphaltenes. Besides, the W/O emulsion formed using model oil with resins performed the better stability compared with that formed using model oil with asphaltenes. This study provided that the interfacial adsorption of resins enhanced the emulsifying ability of crude oil and the film stability of W/O emulsion, which heavily aggravated the viscosifying behavior.
研究领域:
石油工程
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Baosong Li,Dandan Li,Jun Zhang,Wei Chen,Weiwei Zhang
The incorporation of TiN and Y 2 O 3 nanoparticles together into Ni-W matrix have been investigated by pulse electrodeposition in present study. The microstructural, surface properties and corrosion resistance of Ni-W/TiN-Y 2 O 3 nanocrystalline coating have been studied. It illustrated that the electrodeposited coatings have dense and nodular structure without defects. Results confirmed that TiN and Y 2 O 3 particles were uniformly embedded in the composites. The embedded particles could improve the hardness and anti-corrosion properties of the obtained coating. The crystallite size calculated based on the preferred orientation (111) plane was of 14–17 nm, illustrating the formation of nanocrystalline structure. The mean R a value was about 84.6 nm. Electrochemical impedance tests revealed that the preferred combination of operating parameters for optimum corrosion resistance was 70%, 1000 Hz, 40 min and 4 A dm −2 . However, the best hardness and anti-wear properties were obtained at parameters of 50%, 500 Hz, 6 Adm −2 and 60 min. The extreme values of hardness and corrosion resistance were not realized simultaneously. The operating parameters should be kept in a certain balance to avoid the formation of inferior properties in any aspects of the coating; then the other performance advantages could be brought into full play. The preferred combination of operating parameters was optimized to be duty cycle of 70%, frequency of 1000 Hz, duration time of 40 min and average current density of 4 Adm −2 , which enabled the electrodeposited coating optimum corrosion resistance and high mechanical properties .
研究领域:
材料科学
·
电化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Magnetochemistry
·
2022
·Vol. 8
·期 10
·118
·
IF 3.336
Yujie Yang
W-type hexaferrites were discovered in the 1950s and are of interest for their potential applications. In this context, many researchers have conducted studies on the partial substitution of Fe sites in order to modify their electric and magnetic properties. In this study, W-type SrYb hexaferrites using Al3+as substitutes for Fe3+sites with the nominal composition Sr0.85Yb0.15Zn1.5Co0.5AlxFe16−xO27(0.00 ≤ x ≤ 1.25) were successfully synthesized via the two-step calcination method. The microstructures, spectral bands of characteristic functional groups, morphologies, and magnetic parameters of the prepared samples were characterized using XRD, FTIR, SEM, EDX, and VSM. The XRD results showed that, compared with the standard patterns for the W-type hexaferrite, the W-type SrYb hexaferrites with the Al content (x) of 0.00 ≤ x ≤ 1.25 were a single-W-type hexaferrite phase. SEM images showed the flakes and hexagonal grains of W-type hexaferrites with various Al content (x). The saturation magnetization (Ms) and magneton number (nB) decreased with Al content (x) from 0.00 to 1.25. The remanent magnetization (Mr) and coercivity (Hc) decreased with Al content (x) from 0.00 to 0.25. Additionally, when the Al content (x) ≥ 0.25,MrandHcincreased with the increase in the Al content (x). The magnetic anisotropy field (Ha) and first anisotropy constant (K1) increased with the Al content (x) increasing from 0.00 to 1.25. Al-substituted W-type SrYb hexaferrites with soft magnetic behavior, highMs, and lowerHcmay be used as microwave-absorbing materials.Keywords:two-step calcination method;W-type hexaferrites;magnetic properties;X-ray diffraction
研究领域:
材料科学
·
磁学
✓ 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）