CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Zaichun Sun,Bingchu Mei,Hao Zhou,Shaoyong Qin,Huijuan Zhang
High-quality (001) orientated bismuth oxobromide (BiOBr) thin films were deposited on polycrystalline Sn: In 2 O 3 -glass substrates at open-air atmospheric pressure with mist chemical vapor deposition (CVD). Generally, it is difficult to control the surface morphology and thickness for BiOBr because of the high anisotropic crystal structure and very volatile halide . In this study, the growing thickness of BiOBr thin films showed a linear correlation with deposition time. Small thickness resulted in limited absorption ability, while large thickness led to increase of electrical resistance. The surface morphology of (001) orientated BiOBr thin films can be improved obviously under the acidic environment via suppressing Bi 3+ hydrolysis. The (001) orientated BiOBr thin films that deposited by mixed solvent of DMF and 35% HNO 3 aqueous solution exhibited the highest photocurrent density with 0.33 mA cm −2 at 0.6 V vs Ag/AgCl. The intermediate thickness and continuous surface morphology effectively promote the transfer and separation of electron-hole pairs, leading to superior photoelectrochemical (PEC) performance.
研究领域:
材料科学
·
光电化学
✓ 已验证
DOI
高影响因子
ADVANCED POWDER TECHNOLOGY
·
2024
·
IF 4.2
Chen Jixi,Jia Jinqing,Zhu Mengyu
Water film thickness (WFT) has been discovered to significantly affect the performance of cement-based materials in previous studies. The purpose of this study is to apply the WFT theory to cement-based materials with early-strength agents. To this end, calcium chloride (CaCl 2 ) and triethanolamine (TEA) were used to prepare 32 groups of fresh pastes with varying water-cement ratios and different dosages of CaCl 2 /TEA. These pastes were tested for flow performance, setting time, and hardening performance. The comprehensive effects of WFT and early strength agents on the mobility and hardened properties of cement-based materials were discussed from the obtained results. Results show that WFT is still one of the main elements affecting the performance of cement-based materials in the presence of early strength agents. CaCl 2 increased the packing density of the paste, enhancing the excess water between particles and enlarging the WFT, which positively impacted the performance of the paste. In contrast, TEA decreased the WFT, increased the cohesion between particles, and declined the fluidity. Furthermore, as the water-cement (w/c) ratio raised, the WFT of the paste also increased. This caused cement particles to be enveloped in excess water, improving slip capacity and consequently increasing fluidity but reducing strength. Overall, WFT and admixture dosage can effectively predict the fluidity and mechanical properties of the paste.
研究领域:
土木工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2025
·
IF 9
Yidan Duan,He Li,Xiansong Shi,Xin Yu,Nengxiu Zhu,Joseph Imbrogno,Dan Zhao
Molecular separations involving organic liquid phases, such as organic solvent nanofiltration (OSN) and pervaporation (PV), demand robust membrane materials with excellent stability in aggressive organic solvents of a wide pH range. Porous crystalline framework materials, such as metal-organic frameworks (MOFs), have emerged as promising membrane materials for such separations due to their uniform and tunable pore sizes and high stability in organic solvents. However, the impact of membrane thickness on separation efficiency has rarely been reported. PCN-250 is a type of MOF exhibiting suitable pore size, excellent stability, and facile membrane-forming ability. Herein, we fabricated polycrystalline PCN-250 membranes of different membrane thicknesses and studied their impact on OSN and PV performance. The two membranes, PCN-250-s and PCN-250-t, were fabricated through secondary and tertiary growth, respectively. With robustness in organic solvents containing acid, PCN-250-s membrane exhibited good OSN performance, with rejections of 97.2–99.2 % to methyl blue (799 Da) in ethanol. Meanwhile, PCN-250-t membrane demonstrated 1600 h continuous PV working ability in dehydrating acidic water/ethanol (10/90 wt%) mixtures containing 5 wt% acetic acid, exhibiting a total flux of 4.42 kg m −2 h −1 and a water/ethanol (5/95 wt%) separation factor of 591. Our study unveils the influence of membrane thickness on organic liquid separation, suggesting that broadened applications of polycrystalline MOF membranes can be achieved simply by adjusting the crystal growth methods and relevant membrane fabrication procedures.
研究领域:
材料科学
·
分离技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Shouxiang Jiang,Linghui Peng,Ronghui Guo,Dagang Miao,Songmin Shang,Jiangtao Xu,Aishu Li
Iron III oxide (Fe 2 O 3 ) nanoparticles were coated on quartz fabric by electron beam evaporation (EBE) and then annealed in a muffle furnace under air atmosphere at 800 °C for 5 h. The Fe 2 O 3 coated fabric is characterized by energy dispersive X-ray spectroscopy, X-ray diffraction and scanning electron microscopy. The thickness and color performance of the Fe 2 O 3 film on the quartz fabric were measured with a surface profiler and color spectrophotometer, respectively. It is found that an increase of electron beam currents from 20 mA to 60 mA results in an increase of color depth of the coated fabric. The color of the Fe 2 O 3 coated quartz fabric is reddish yellow and changes to red after annealing. The thickness of the Fe 2 O 3 film also increases with the rise of electron beam current.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Nano Select
·
2021
·Vol. 2
·期 7
·1403-1416
·
IF 0
Bin Yang,Yang-nan Yu,Yang Pan,Shu-qing Wang,Xiang Xu,Ying-ying Wang,Jia-sheng Qian,Ru Xia,Peng Zhang,You Shi,You-lei Tu
In this research, series of PVDF microporous films with various polymer concentrations and thickness were prepared through thermally-induced phase separation in air condition with diphenyl carbonate as the diluent. Effects of polymer concentration and film thickness on the formation kinetics of microporous structure of PVDF thin films were in situ investigated via TII technique. The instantaneous heat conduction inside the films during film formation was also evaluated. Two types of parameter models were adopted in order to disclose the time and location dependence of TIPS film solidification kinetics, respectively. Hierarchical microstructures, crystallization behavior and thermal properties of the TIPS films were also characterized by SEM, DSC, and TGA, respectively. The current study could supply an insight into the fabrication of PVDF microporous films with target microstructure and desirable performance.
研究领域:
材料科学
·
高分子化学
·
膜科学技术
✓ 已验证
DOI
Nano Research
·
2020
·Vol. 13
·期 3
·684-690
·
IF 8.183
Wei Jing,Wang Xi,Sun Xiangyu,Yang Zhaofeng,Moreels Iwan,Xu Kun,Li Hongbo
Inorganic halide perovskites such as cesium lead iodide (CsPbI 3 ) have drawn tremendous attention, as their tunable band gaps are desirable for solar cells as well as light emitting diodes. However, due to their low Goldschmidt tolerance factor, the cubic phase of bulk CsPbX 3 —the variant with desirable band gap—is not stable in ambient, especially in humid air. Besides, the low solubility of CsX in precursor makes it difficult to control the film thickness and morphology of CsPbX 3 , which becomes another obstacle for the practical application of inorganic perovskite. Here, we report a polymer assisted deposition of high-quality CsPbI 2 Br film by spin-coating a polymer-blended CsPbI 2 Br precursor. The long-chained polymer increases the viscosity of the solution, which enables us to achieve a ca. 700-nm thick film with a low solution concentration of CsPbI 2 Br. Moreover, the polymer network helps to regulate the crystallization process and provides more crystallization sites for perovskite film, reducing grain size and thus improving the film coverage. Perovskite solar cells with the polymer network exhibit improved efficiency and reproducibility (0.72% standard deviation). Moreover, the device demonstrates excellent robustness against moisture and oxygen, and maintains 90% of its initial power conversion efficiency (PCEs) after aging 4 months in ambient conditions. The conception of polymer incorporation into inorganic perovskite films paves a way to further increase the performance, stability and reproducibility of inorganic perovskite devices.
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Xiaoshuai Yu,Mo Zhang,Lingjie Dai,Shah Noor,Yan Liu,Chuncheng Yang,Jianshe Lian,Guoyong Wang
Hydrogen production by water electrolysis is efficient and has high throughput. But the scarcity of current noble metal catalysts limits its scalability. In contrast, transition metals are rich in reserves. Replacing noble metal catalysts with them would significantly cut the cost of water electrolysis for hydrogen production. However, a single transition metal's catalytic performance is far from that of noble metals. Studies show multi-transition metallic elements often have better catalytic properties due to coupling effects, like those of iron, cobalt, nickel enhancing catalyst activity and selectivity. Also, iron, cobalt, and nickel phosphides easily get partially oxidized in air, forming an oxide layer with thickness order FeP > CoP > NiP. Adjusting the proportion of these elements can control the oxide film thickness, and a proper one can improve catalyst activity. This article explores the mechanism and coupling effect of iron, cobalt, and nickel phosphides as overall water splitting catalysts. The chosen Fe 0.2 Co 0.6 Ni 0.2 P with an optimal oxide film thickness shows good electrochemical performance for oxygen evolution reaction (280 mV in 1.0 M KOH at 100 mA cm⁻ 2 ), good hydrogen evolution reaction performance in both acidic and alkaline environments, and has the lowest overall hydrolytic potential in alkaline electrolyte with excellent 300-h stability.
研究领域:
材料科学
·
化学工程
·
可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Lin Li,Yunbo Dong,Xiao Jin,Zizhao Wang,Jinming Liu,Caili Dai
In water injection development of low-permeability reservoirs, the elevated flow resistance between the rock surface and the injected water results in enhanced injection pressure. Reducing the thickness of interfacial water film to expand flow radius is a new thought to achieve a decrease in injection pressure. In this work, a hydroxyl-containing cationic surfactant tetradecyl methyl dihydroxy-ethyl ammonium bromide (HTTAB) was designed and synthesized. The introduction of hydroxyl groups enhances the binding to the negatively-charged rock surface. HTTAB can modify the strong hydrophilic rock surface to a hydrophobic state, with the water contact angle increasing from 20.2° to 110.3°. HTTAB shows excellent drag-reducing effect, maintaining a drag reduction rate of over 30 % even after 30 PV of flushing. Particle Image Velocimetry (PIV) experiments show that after HTTAB adsorption, the interfacial slip velocity and centerline velocity can increase by 1.67 times and 33.66 % respectively, and the flow radius expands significantly. In addition, the thickness of the interfacial water film is obtained using Atomic Force Microscope (AFM). The results show that the thickness of the interfacial water film is reduced significantly from 79.42 nm to 8.85 nm. This study provides important guidance for the design of drag-reducing agents and the understanding of interfacial drag-reduction 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
Lubricants
·
2024
·Vol. 12
·期 3
·67
·
IF 3.1
Qiaoni Xu,Zhaogang Jing,Shijie Du,Feng Guo,Ruitao Mu
Glyceryl monostearate (GMS) was used as an organic friction modifier (OFM) and added to the base oil (PAO10, polyα-olefin) in this study. The film thickness and friction coefficient of the base oil added with GMS (PAO10G) under different slider inclinations and loads were investigated experimentally by using a slider-on-disc contact lubricant film measurement system, and the effect of the adsorption of GMS on the friction behavior of lubricant was studied. Contact angle hysteresis (CAH) was used to evaluate the wettability of the solid–liquid interface, and its correlation with the coefficient of friction was analyzed. The results show that CAH is in good agreement with the wettability of the solid–liquid interface. Compared with the base oil, the wettability of POA10G is weak, which can effectively reduce the coefficient of friction. However, different from the classical lubrication theory, the film thickness of PAO10G is higher than that of PAO10; this unusual phenomenon is preliminarily explained by the interface slippage in this paper.
研究领域:
机械工程
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Yunli Zhai,Baoquan Zhang,Xiufeng Liu,Ziqiang Tong
Spherical polyelectrolyte complexes (PECs) sized at 10–20 nm were synthesized to fabricate homogeneous polyelectrolyte complex membranes (HPECMs). The PEC dispersions at various concentrations were employed to manipulate the thickness of HPECMs. Zeta potentials were measured to quantify the charge density of PECs. Scanning electron microscopy was utilized to examine membrane morphology and thickness. The surface hydrophilicity of HPECMs was evaluated by using static water contact angles. Being subjected to isopropanol dehydration, the synthesized HPECMs with nano-sized spherical PECs exhibited excellent separation performance, good stability and durability. The HPECM with the thickness of 1.1 μm displayed a significantly high permeation flux (6.12 kg m –2 h −1 ) with an ideal water concentration in permeate (99.85 wt%). The use of nano-sized spherical PECs ensured the homogeneous nature of synthesized polyelectrolyte complex membranes, leading to the enhancement of pervaporation performances in isopropanol dehydration. The extension of this work would trigger a large-scale application of HPECMs for dehydration of organic solvents.
研究领域:
材料科学
·
分离技术
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Yuxuan Zhou,Yueting Wang,Zehua Zhang,Fuwei Li,Jian Cheng,Yinghua Ye,Jianbing Xu,Ruiqi Shen
The application and optimization of nano-composite energetic materials in the extreme and particular environment have become a subject of wide concern. Additionally, the design and selection of metastable intermixed composites (MICs) films in low pressure environment is the key problem to explore its future application. Here, 90 wt% high loading Al/CuO nanothermite films were prepared by a simple 3D direct writing approach. Four films with different thicknesses (66, 128, 152, 182 μm) were designed and their combustion properties were tested respectively. The low pressure combustion results show that the self-sustained burning rate of the film (thicker than 66 μm) can be adjusted and controlled in various air pressure environments (101–60 kPa). The self-sustained burning rate of film is affected by both thickness (66–182 μm) and air pressure (101–60 kPa). The lower the air pressure, the lower the burning rate. The greater the thickness, the higher the burning rate. The 66 μm film self-sustainedly burns at atmospheric pressure and extinguishes when the pressure was significantly reduced. The self-sustained combustion rates of the 128 and 152 μm film decreases with decreasing pressure until the pressure drops to 75 and 60 kPa respectively. The 182 μm film keeps self-sustained combustion in a manner of deflagration which is almost unaffected by air pressure, even when the pressure drops to 10 kPa. Simultaneously, it is found that the ignition temperature of the film is almost not affected by pressure. In addition, it is verified that the film has performances of excellent hydrophobic and combustion through air–water interface. These can cope with complex environmental humidity.
研究领域:
材料科学
·
燃烧学
·
航空航天工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULES
·
2025
·
IF 5.2
Ziyuan Zhou,Binghua Wang,Changyu Shen,Bin Zhang
Previous research studies on isotactic polypropylene (iPP) have shown that the ratio of growth rate β to α phase (Gβ/Gα) exceeds 1 when the crystallization temperature (Tc) is between the lower and upper critical temperature limits (Tc** ∼ 100 °C and Tc* ∼ 141 °C, respectively), due to the faster surface kinetics of β-iPP. However, in this work, we observed that when the film thickness (d) decreases from 24 to 9 nm, the temperature interval of Gβ/Gα > 1 narrows and even disappears, as Tc* gradually shifts to lower temperatures while Tc** remains constant. This is presumably because, as d decreases, the width (wd) of the depletion zone of β-iPP expands more significantly than that of α-iPP, resulting in slower diffusion toward the growth front of β-iPP. Consequently, Gβ decreases more than Gα as d diminishes, leading to a reduction in the value of Gβ/Gα, especially at higher Tc, where Gβ/Gα becomes less than 1. Moreover, we found that the diffusion activation energy (Eaβ) of β-iPP is consistently greater than that of α-iPP (Eaα) at a given d, and the gap between Eaα and Eaβ increases as d decreases. This further highlights that the slower diffusion process for β-iPP progressively becomes the main factor affecting the difference between Gα and Gβ as d diminishes.
研究领域:
材料科学
·
高分子物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）