JOURNAL OF MEMBRANE SCIENCE
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2021
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IF 8.742
Peng Wei,Yang Sui,Xi Li,Qingkun Liu,Bensheng Zhu,Chuanbo Cong,Xiaoyu Meng,Qiong Zhou
The proton exchange membrane (PEM) is the core unit in fuel cells, in which the balance among proton conductivity, dimensional stability and durability is a long-term pursuit. Nanofiber composite membrane as the most facile and practical strategy, however, commonly suffers from the obviously reduced proton conductivity although the dimensional stability and durability can be improved distinctly. Herein this work, we proposed a sandwich-structure nanofiber composite PEM, in which the inexpensive proton-transport matrix of sulfonated poly (ether ether ketone) (SPEEK) is sandwiched between polyimide (PI) nanofibers mats via simple steps. Thanks to the support for the matrix and resistance to the tough working condition provided by the PI nanofiber mats, significantly improved stability and durability in contrast to the referenced PEM of SPEEK. More importantly, with respect to the proton conductivity, a numerically equivalent initial proton conductivity and significantly improved proton conductivity stability, in comparing to the SPEEK membrane, has been achieved; where the conductivity only decreased by 21% in our sandwich-structure PEM after 6 weeks, much less than that of commercial Nafion 117 of 30% and pure SPEEK of 55%. Such results can be attributed to the hydrogen bond interaction between PI nanofibers and SPEEK matrix and thus the formation of the sulfonic acid-rich layer in our developed PI/SPEEK/PI membrane, confirmed by in situ Fourier Transform Infrared Spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscope (TEM). This combination of high proton conductivity, long-term stability, low cost, simple preparation suggests the sandwich-like PEM will provide a promising commercial application for future PEMs.
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
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2016
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IF 2.357
Penggang Li,Fengzhu Lv,Leipeng Liu,Ling Ding,Yihe Zhang
Iron oxides/PI fiber membranes, especially magnetic PI membranes, are important flexible porous materials available application in the field of wave absorption, magnetic recording, membrane separation and catalysts. Therefore, α-Fe 2 O 3 loaded PI composite fibers were prepared by electrospinning of poly(amic acid) PAA solution followed by loading Fe 3+ on the PAA membrane by ion-exchange and then imidization. Then the α-Fe 2 O 3 on PI membrane were reduced by H 2 to give magnetic PI membranes. The content of α-Fe 2 O 3 and Fe 3 O 4 on PI can be controlled by adjustment the ion-exchange time. The saturation magnetization of the composite membranes can reach up to 4 emu/g and the final composite membranes have magnetic response ability.
研究领域:
材料科学
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纳米技术
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高分子科学
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磁性材料
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功能复合材料
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
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2022
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IF 6.14
Zhimin Hao,Juntao Wu
A complex air pollution environment requires filters to be multifunctional. Nanofibrous materials with surface-loaded metal–organic frameworks (MOF-fibers) are reasonable structures for multifunctional air filtration. These materials can not only utilize the network structure of fibers to intercept particulate matter (PM) but also retain the porous structure of the MOFs to adsorb toxic gas. Epitaxial growth methods are commonly utilized to prepare MOF-fibers but are uneconomical and time-consuming. Herein, a facile self-assembly strategy is developed to prepare zeolitic imidazolate framework-polyimide (ZIF-PI) nanofibers with an interconnected network structure and high porosity for air filtration applications. Due to their unique structure, the ZIF-PI nanofibrous membrane exhibited high PM2.5 filtration efficiency and enhanced SO2 adsorption capacity. Moreover, by exploring the morphology evolution of the ZIF-PI nanofibrous membrane, a possible “synergistic effect of hydrophobic and electrostatic force” self-assembly mechanism was demonstrated.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Lingchao Xu,Xin An,Junfeng She,Hongping Li,Linhua Zhu,Wenshuai Zhu,Huaming Li,Wei Jiang
Heterogeneous catalysts are usually constructed by immobilizing active species on appropriate supports. However, the dispersibility is difficult to precisely control. In this work, three representative Mo-based MOFs (Mo-MOFs) were constructed by assembling various organic linkers and MoO 3 , where the Mo atoms are homogeneously dispersed due to the coordination. The results illustrated that the obtained Mo-MOF-PI synthesized with 2-propyl imidazole as the ligands exhibited an extremely fast reaction rate, achieving 99.4% sulfur removal of DBT within only 12 min. Compared to other similar catalysts, Mo-MOF-PI showed much higher catalytic activity with a turnover frequency value of 19.2 h −1 . Moreover, it can be reused at least 20 times without a dramatic reduction in catalytic performance. Thus, the as-prepared Mo-MOF catalysts show great potential in large-scale industrial applications.
研究领域:
化学工程
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催化材料
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
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2016
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IF 4.803
Yang Zhang,Dan Wang,Xintong Zhang,Ying Chen,Lina Kong,Peng Chen,Yinglin Wang,Changhua Wang,Lingling Wang,Yichun Liu
Improving charge transportation and interfacial charge transfer in semiconductor photoelectrodes are two critical issues for achieving high-efficiency photoelectrochemical (PEC) water splitting. Herein, a combined hydrogenation treatment and cobalt-phosphate (Co-Pi) deposition is reported to dramatically enhance the PEC performance of nanoporous BiVO 4 photoanode. Linear sweep voltammograms show that after the combined treatment, photocurrent density of nanoporous BiVO 4 photoanode is increased for ca. 3 times at 1.23 V versus reversible hydrogen electrode (RHE), and the onset potential is negatively shifted from 0.53 V to 0.23 V versus RHE. Combined photoluminescence, Mott-Schottky, open circuit potential, as well as electrochemical impedance spectroscopy analyses reveal the synergistic effect of hydrogenation treatment and Co-Pi deposition on enhancing the PEC performance of nanoporous BiVO 4 photoanode, facilitating both charge transportation and interfacial charge transfer without aggravating charge recombination.
研究领域:
材料科学
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能源科学
✓ 已验证
DOI
高影响因子
Nano Energy
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2017
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IF 12.343
Xiaolin Lv,Kaiqi Nie,Huiwen Lan,Xin Li,Youyong Li,Xuhui Sun,Jun Zhong,Shuit-Tong Lee
Hematite is a promising photocatalyst for solar water splitting while its performance has been severely limited by various factors. Recently surface Fe 2 TiO 5 layer was widely reported to enhance the performance of hematite with a favorable band position to facilitate hole transport. Here we further show that the Fe 2 TiO 5 -incorporation in bulk hematite can also improve the performance with faster charge separation. Moreover, it can be well coupled with surface P-modification to simultaneously improve charge separation and hole transfer with a synergetic effect. The Ti and P co-modified hematite shows a significantly enhanced photocurrent of 2.37 mA/cm 2 at 1.23 V vs. RHE when compared to the pristine value of 0.85 mA/cm 2 . After coupling with Co-Pi catalysts, the hematite sample can even achieve a stable, high photocurrent of 2.90 mA/cm 2 at 1.23 V vs. RHE. The design of Ti and P co-modified hematite hollow nanostructures can be used as a promising candidate for solar water splitting applications. The discrete Fe 2 TiO 5 -incorporation also provides a good insight on the mechanism to understand other Ti-based treatments of hematite.
研究领域:
材料科学
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光催化
✓ 已验证
DOI
高影响因子
Small
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2024
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IF 13
Haodong Gu,Li Tian,Qiuqi Zhang,Xiao You,Mengmeng Wang,Shaoming Dong,Jinshan Yang
Electromagnetic protection in extreme environments requires materials with excellent thermal insulation capability and mechanical property to withstand severe temperature fluctuations and complex external stresses. Achieving strong electromagnetic wave absorption (EMA) while sustaining these exceptional properties remains a significant challenge. Herein, a facile approach is demonstrated to fabricate a biomimetic leaf-vein MXene/CNTs/PI (MCP) aerogel with parallel venations through bidirectional freeze-casting method. Due to its multi-arch lamellar structure and parallel venations within the aerogel layers, the ultralight MCP aerogel (16.9 mg·cm −3 ) achieves a minimum reflection loss (RL min ) of −75.8 dB and a maximum effective absorption bandwidth (EAB max ) of 7.14 GHz with an absorber content of only 2.4 wt%, which also exhibits superelasticity and structural stability over a wide temperature range from −196 to 400 °C. Moreover, this unique structure facilitates rapid heat dissipation within the layers, while significantly impeding heat transfer between adjacent layers, achieving an ultralow thermal conductivity of 15.3 mW·m −1 ·K −1 for thermal superinsulation. The combination of excellent EMA performance, robust structural stability, and thermal superinsulation provides a potential design scheme under extreme conditions, especially in aerospace applications.
研究领域:
材料科学
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航空航天工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
An Wang,Jiayou Liao,Xu Wu,Xianjie Meng,Jiwei Ma,Siyuan Peng,Yinghua Shen,Chengyun Gao
This study employs the same diamine monomer to synthesize polyimide (PI) and Tröger’s Base-based polymers of intrinsic microporosity (TB), which exhibit infinite miscibility due to like-dissolves-like phenomenon. The TB and PI exhibit significantly different thermal decomposition temperatures, enabling the partial carbonization of TB at a lower temperature while retaining the favorable mechanical properties of PI. Consequentially, This work propose a novel method to prepare blend membranes with a partial amorphous carbon structure. These membranes have excellent gas separation performance, similar to that of carbon membranes, while also retaining the machinability of traditional polymer membranes. The molecular structure of the material is characterized using 1H NMR and FTIR spectra, while the microscopic morphology is observed through scanning electron microscopy. Molecular dynamics simulations confirm the compatibility of both polymers and explain the improved properties. Gas transportation measurement confirms that PI@TB blend membranes demonstrate significant improvement in gas separation performance compared to original membranes. Specifically, enhancements in the gas separation performance of CO 2 /CH 4 , H 2 /CH 4 , and O 2 /N 2 systems have been observed, with the CO 2 /CH 4 pair demonstrating the most remarkable improvements, surpassing the 2019 Robeson upper limit. This design strategy can be applied to produce blend membranes containing amorphous carbon that exhibit great potential for high-performance separation processes in the future.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Kaixuan Sun,Yifei Tang,Yan Huang,Yuchao Zhao,Xingming Jie,Yabin Zhang,Qinglin Huang
Polyimide (PI) has garnered increasing attention in the field of membrane technology owing to its excellent comprehensive performance. In this work, PI nanofibrous membranes with a controllable pore structure were fabricated by the thermal imidization of electrospun polyamide acid (PAA) nanofibrous membranes. Polytetrafluoroethylene (PTFE) and poly(tetrafluoroethylene-hexafluoropropylene) (FEP) particles were introduced into the PAA nanofibrous membrane with the aim of enhancing the membrane's hydrophobicity and regulating its pore structure by electrospraying the PTFE/FEP mixed aqueous dispersion. During the thermal imidization process, melt casting of FEP particles occurred, leading to the adhesion of PI nanofibrous membranes and subsequent regulation of the membrane's pore structure. Meanwhile, due to the imidization temperature being lower than PTFE’s melting temperature, the unmelted PTFE particles would further enhance the membrane’s hydrophobicity. We have successfully provided a novel method for fabricating PI nanofibrous membranes with controllable pore structures and excellent hydrophobicity to expand their applications in membrane separation . Owing to the hydrophobicity and lipophilicity, the obtained PI nanofibrous membranes were applied to oil-water (kerosene/water) separation to characterize the separation performance. The results showed that, following the regulation of the pore structure, the PI nanofibrous membranes exhibited a high oil flux (203.83 L/m 2 ·h) and separation efficiency (＞99.00%) without external pressure.
研究领域:
材料科学
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膜技术
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of the Taiwan Institute of Chemical Engineers
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2024
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IF 5.5
Jinxue Cheng,Zhipeng Feng,Zhihang Wang,Xiaoliang Yu,Zhi Fan,Peibin Zhang,Jing Cui,Minjie Guo
Background With the increased demand for energy storage devices, transparency, flexibility, and miniaturization are gradually becoming the future development direction of energy storage devices, among which supercapacitors have unexceptionable application potential. However, due to the limitation of substrate material, the flexibility, transparency, thermal properties, and mechanical properties of supercapacitors cannot be perfectly unified. Methods Herein, we fabricated a series of transparent Polyimide (PI) films by combining para-amide-linked diamine (AB-TFMB) with different ratios of Pyromellitic dianhydride (PMDA) and 4,4′-(Hexafluoroisopropylidene)diphthalic anhydride (6FDA). A series of characterizations were conducted regarding the thermal stability, mechanical properties, dielectricity, optical properties, transmittance, moisture absorption, and solubility of the PI films. The transparent PI film was used as a flexible substrate and assembled into a transparent supercapacitor. Significant findings The results showed that the comprehensive performance of PI films could be effectively regulated by changing the monomer types and contents. Also, the assembled transparent supercapacitor exhibited good capacitance characteristics, and the capacitance retention rate after bending at different angles and repeating bending 10,000 times can reach 100 % and 99.45 %, respectively. These promising results demonstrate that turning PI monomers is a favorable method for preparing transparent supercapacitors, which is conducive to the development of transparent flexible supercapacitors in the future.
研究领域:
材料科学
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能源存储技术
✓ 已验证
产品关联
DOI
高影响因子
IONICS
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2024
·
IF 2.4
Yan Lingxiao,Feng Xiaojuan,Wang Hongyan,Chen Yu,Wang Lulu,Xue Song
High-performance polymeric separators are indispensable materials for advanced rechargeable lithium-ion batteries (LIBs). In general, separators must simultaneously possess the following qualifications: flame retardancy, mechanical strength, wettability, and ion conductivity. In this study, polyethylenimide (PEI), which is rich in amino groups, was grafted onto the surface of polyimide fibre membranes by impregnation, resulting in the preparation of PI-PEI composite separator. The grafting of PEI on PI nanofibres resulted in the bonding of fibres, which enhanced the stability of the pore structure and mechanical properties of the nanofibres. Furthermore, the number of polar groups on the surface of the PEI grafted by the PI separator increased, which enhanced the electrolyte affinity of the PEI-PI separator. The influence of PEI concentration on the properties of the separator, electrochemical properties, and cell performances was also discussed, and the optimal PEI concentration (4%PEI) was identified. The PI-4%PEI composite separator exhibited superior wettability, mechanical strength, flame retardancy, and minimal interface impedance. In particular, PI-4%PEI separators display superior capability (127.9 mAh·g −1 @5C) in comparison to PP separators (115.4 mAh·g −1 @5C). Furthermore, the cell employing the PI-4%PEI separator displays high cycling stability and discharge specific capacity over 100 cycles at 1C. Concurrently, the modified polyimide separator exhibits remarkable stability, ensuring that the lithium-ion battery can operate safely even under high temperature working conditions.
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
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IF 11.698
Qiang Guo,Hui Li,Qian Zhang,Yanlin Zhang
In recent years, the frequent eutrophication of water bodies around the world has led to the accumulation of microcystins (MC-LR) in water bodies, causing great harm to humans and aquatic organisms. In this study, a Z-scheme Ag 3 PO 4 /NG/PI composite photocatalyst was fabricated by using silver orthophosphate, nitrogen-doped graphene and polyimide for photocatalytic degradation of MC-LR under visible light irradiation. The structure, morphology and optical properties of Ag 3 PO 4 /NG/PI were characterized by XRD, SEM, TEM, XPS, FT-IR, BET, and UV–vis DRS. The degradation ratio of MC-LR by Ag 3 PO 4 /NG/PI photocatalysts was higher (up to 94.4%) than that of pure Ag 3 PO 4 for MC-LR degradation within 10 h under visible light irradiation, and the kinetic constant over Ag 3 PO 4 /NG/PI was ∼7 times of pure Ag 3 PO 4 . Based on the results of Liquid Chromatography–Mass Spectrometry (LC–MS), the possible degradation pathways of MC-LR were proposed. Photoelectrochemistry measurement (the photocurrent response, electrochemical impedance spectroscopy and Mott-Schottky plots), radical trapping experiment, electron spin resonance test, PL spectroscopy and analysis of band gap have revealed that the photocatalysis of Ag 3 PO 4 /NG/PI follows the Z-scheme mechanism, which can not only promote the separation and migration of photogenerated carriers to reduce re-combination, but also maintain a strong redox capacity. Meanwhile, the stability of Ag 3 PO 4 /NG/PI photocatalyst is greatly improved because the photogenerated electrons (e − ) of Ag 3 PO 4 are migrated to NG to suppress the photo-corrosion of Ag 3 PO 4 .
研究领域:
环境科学
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材料科学
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化学
✓ 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）