TRIBOLOGY LETTERS
·
2019
·Vol. 67
·期 1
·1-17
·
IF 2.235
Zhao Yuanliang,Qi Xiaowen,Zhang Wenli,Fan Bingli,Yang Qingxiang
The effects of copper nanoparticles (Cu) located in different regions of polytetrafluoroethylene/polyimide (PTFE/PI) blends on the morphology, thermal, mechanical, and tribological properties of PTFE composites were studied. Region one is PI phases (the corresponding composites is denoted as PPC), region two is PTFE phases and the interface between PTFE and PI (the corresponding composites is denoted as PPC-m). Results indicate that the incorporation of Cu nanoparticles into PI phases improves the dispersibility and homogeneity of PI phases. As a consequence, the crystallinity of PTFE composites is reduced, but compressive strength and modulus of PTFE composites are enhanced by 50.3% and 14.4% respectively. In addition, self-lubricity and wear resistance of PTFE composites are improved by 10.4% and 50.5%. Scanning electron microscopy (SEM) demonstrates that PI phases with Cu nanoparticles hinder the direct contact between PTFE matrix and counterparts. However, Cu nanoparticles located in PTFE matrix and the interface between PTFE and PI deteriorates the dispersibility and homogeneity of PI phases, which lead to the poor mechanical and tribological performance of PTFE composites.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 17
·52018
·
IF 3.125
Xianggui Zhang,Xianglong Li,Antuo Wang,Bin Yang,Teng Hou,Yishen Lu,Jing Zhou
The separation of stable oil/water emulsions is an urgent global issue. In this work, a porous and superhydrophobic polytetrafluoroethylene (PTFE) fibrous membrane was obtained by first centrifugal spinning PTFE/potato starch fibers and then heat treating the fibers to remove the starch. Results showed that spherical protrusions and irregular striped protrusions appeared on the surface of the prepared PTFE fibers, which significantly increased the roughness and hydrophobicity of the fibrous membrane. In addition, number density and shapes of these protrusions could be tuned by changing the extent of the heat treatment and the potato amylose content during the fiber preparation. The water contact angle on the structured PTFE membranes was as high as 160°, and the water sliding angle was as low as 3.4°. The results of oil/water separation experiments showed that the oil removal rate reached 99.5% based a permeability of 3670 L/m 2 /h, which suggested that the obtained PTFE fibrous membrane has great potential for use in oil/water emulsions separation.
研究领域:
材料科学
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环境工程
·
膜分离技术
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表面科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Shigen Bai,Yong Tang,Gong Chen,Yaopeng Wu,Yifu Liang,Shu Yang,Huilong Liu,Yingxi Xie
Supercapacitors (SCs) have garnered increasing attention as an alternative energy storage device but the relatively low potential window and energy density impede their application prospect. Herein, we propose a novel three-dimensional (3D) packaging method for the first time, utilizing high flexible phosphor-copper sheets (PCSs) sprayed with polytetrafluoroethylene (PTFE) and covered with polyimide (PI) films on their both sides as the serial medium followed by CO 2 laser irradiation to fabricate all-solid-state flexible high voltage supercapacitors (HVSCs). This method achieves double voltage output in the limited PI membrane compared with common 2D encapsulation. As a result, as-obtained HVSCs deliver not only an enhanced mechanical tensile strength up to 18.23 MPa but also the outstanding electrochemical performances, including ultrahigh working voltage window (10 V), high energy density (37.68 μWh/cm 2 ) and power density (3.38 mW/cm 2 ). Owing to the excellent flexibility, the HVSCs can be arbitrarily bent or twisted without obvious attenuation on capacitive property. After 10000 cycles, the capacitance retention of HVSCs still maintains to be 90.2%. This novel 3D packaging strategy may pave the way for developing high-performing SCs with wide operating voltage and high energy density for flexible displays, wearable equipment and integrated electrical devices.
研究领域:
材料科学
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纳米技术
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能源存储
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柔性电子
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电化学
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高分子材料
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先进制造
✓ 已验证
DOI
高影响因子
Journal of Tissue Engineering and Regenerative Medicine
·
2022
·Vol. 16
·期 12
·1163-1172
·
IF 4.323
Yulu Liu,Ya Liu,Zhiyuan Bai,Dongfang Wang,Yiyang Xu,Qian Li
With the prevalence of cardiovascular diseases, developing cardiovascular supplements is becoming increasingly urgent. The ability of cells to rapidly adhere and proliferate to achieve endothelialization is extremely important for vascular grafts. In this work, we electrospun polytetrafluoroethylene (PTFE) nanofibrous membranes and used induced crystallization to manufacture poly(ε-caprolactone) (PCL) shish-kebab microstructures on PTFE nanofibers to overcome the inertness of PTFE, and promote cell adhesion and proliferation. PCL lamella periodically grew on the surface of PTFE nanofibers yielding a hierarchical structure, which improved the biocompatibility and mechanical properties of the PTFE nanofibrous membrane. The deposition of PCL lamella improved the hydrophilicity of electrospun PTFE nanofibers membrane, leading to good cell proliferation and adhesion. Also, due to the surface inertness of the substrate material PTFE, this PTFE/PCL composite film has good anti-platelet adhesion properties. Furthermore, cell proliferation could be regulated by controlling the integrity of the PCL crystal network. The vascular patch showed similar mechanical properties to natural blood vessels, providing a new strategy for vascular tissue engineering.
研究领域:
生物医学工程
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组织工程
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材料科学
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心血管病学
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再生医学
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生物材料
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纳米技术
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2016
·Vol. 27
·期 11
·1501-1507
·
IF 1.823
Zhubo Liu,Bing Zhou,A.V. Rogachev,M.A. Yarmolenko
Polytetrafluoroethylene (PTFE) composite coatings doped copper acetate and polyurethane (PU) were prepared on rubber substrate by low-energy electron beam dispersion technique. The effects of dopant and glow discharge treatment on the surface morphology, structure and tribological properties of the coatings were investigated. The results showed that Cu–PTFE composite coatings form uniform surface and dense column structure with spherical aggregations under glow discharge treatment. PU coating shows the large size of protuberance structure but PU–PTFE coating presents spherical structure. Both of the coatings become relative dense and smooth after discharge treatment, and Cu–PU–PTFE composite coatings possess a smoother surface and lower polar component of surface energy. Cu doping weakens the crystallinity and ordering degree of composite coatings, but glow discharge increases the ordering degree and branched structure of C―H groups. Friction experiment indicated that Cu fails to improve the wear resistance of PTFE coatings but glow discharge treatment can do it. Cu–PU–PTFE coatings after discharge treatment have the higher wear resistance and lower coefficient of friction. Copyright © 2016 John Wiley & Sons, Ltd.
研究领域:
材料科学
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表面工程
·
高分子材料
·
摩擦学
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等离子体物理
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涂层技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2013
·
IF 4.093
Qiang Xu,Yang Yang,Jie Yang,Xiaozu Wang,Zhaohui Wang,Yong Wang
Conformal and smooth TiO 2 thin layers were coated on the surface of porous PTFE membranes subjected to a plasma activation process by atomic layer deposition (ALD). In contrast, TiO 2 was deposited on the PTFE surface as globular particulates without plasma activation due to the inert chemical nature of PTFE surface. X-ray photoelectron spectrometry confirmed the formation of functional groups on the plasma-activated PTFE surface which served as active sites for the homogeneous adsorption and reaction of ALD precursors. Scanning and transmission electron microscopy revealed the uniformity of the deposited layer and the precise control of its thickness by changing ALD cycle numbers. The water contact angle measurement showed that the hydrophobic surface gradually turned to be near superhydrophilic with the increment of ALD numbers. Also, the membrane mean pore size was progressively reduced by simply altering the ALD numbers. At proper deposition conditions , the modified membranes gained an increase of pure water flux of more than 150% and simultaneously a doubled retention compared to the original unmodified membrane. This research provides an efficient approach devoid of any harsh treatments to modifying PTFE membranes for achieving specific functions, which also can be applied to other organic materials especially with chemical inert surface.
研究领域:
材料科学
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膜科学与技术
·
表面工程
·
高分子化学
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环境工程
·
纳米科技
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yu Liu,Meng Huang,Fangyu Xiong,Jiexin Zhu,Qinyou An
Zinc-ion batteries (ZIBs) using zinc metal as anode materials suffer from Zn dendrite formation and hydrogen evolution during the stripping/plating process, which will lead to performance degradation and hinder practical application. Herein, the 1,4,5,8-naphthalene diimide (NI) is proposed as a promising dendrite-free organic anode material for ZIBs . Moreover, the effect of different binders on electrochemical performance of NI electrode is investigated. Compared NI electrode with polyvinylidene fluoride (PVDF) binder, the NI electrode with the polytetrafluoroethylene (PTFE) binder shows highly enhanced rate capability (122.2 mA h g – 1 at 5 A g – 1 ) and cycling performance (123.3 mA h g – 1 at 3 A g – 1 after 2200 cycles). The improvement cycling stability of NI is attributed to PTFE binder, which effectively maintains electrode structure and inhibits dissolution of organic molecules during the cycling process. In addition, the ion kinetics analyses reveal that the superior rate capability is provided by the capacitive charge storage. And the carbonyl group of NI is active center of electrochemistry, which is revealed by in-situ attenuated total reflection–Fourier transform infrared (ATR-FTIR) and ex-situ Raman. Besides, the aqueous Zn-ion full cell based on metal-free NI anode and Prussian blue analogues (PBAs) cathode exhibits excellent rate capability (113.9 mA h g – 1 at 10.0 A g – 1 ), high operation voltage of ~ 1.2 V (at 1.0 A g – 1 ) and energy density of 50.2 Wh kg total – 1 . This work may provide a new design inspiration to develop organic dendrite-free zinc anodes for high-performance aqueous ZIBs batteries.
研究领域:
电化学
·
能源材料
·
电池技术
·
功能材料
·
应用化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）