APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Qingkai Zheng,Muhammad Chhattal,Changning Bai,Zhiwen Zheng,Dan Qiao,Zhenbin Gong,Junyan Zhang
Polytetrafluoroethylene (PTFE) is in the limelight due to its self-lubricating properties and outstanding corrosion resistance. Nevertheless, it suffers from severe adhesive and abrasive wear, resulting in barriers to the achievement of robust superlubricity and reliability of moving parts. Herein, two green protic ionic liquids (ILs) are synthesized using alkyl amine and carboxylic acids with long molecular chains, which are applied in PTFE/steel tribo-pair, showing a robust superlubricity under high contact pressure. Compared with conventional lubricating oils (PAO8, PAO10 and PEG400), as-prepared ILs show the lowest coefficients of friction less than 0.008, and the lowest wear volume of PTFE with the adhesive and abrasive wear of PTFE significantly inhibited. The excellent lubricating performance attributes to the thick and dense Stern layer as well as the formation of tribo-chemical film. This work, for the first time, achieves superlubricity on soft material substrates and guides the lubricants design for PTFE tribological applications.
研究领域:
材料科学
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摩擦学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Wangping Qin,Ruike Zhang,Yan Fu,Jie Chang
PTDF is prepared by a convenient ionic reaction of phytic acid, terephthalic dihydrazide and iron salts in water. It is a new type of high efficiency flame retardant. PTDF has high phosphorus and nitrogen content and good thermal stability, which can effectively improve the flame retardancy of PLA. PTFE is an anti-drip agent and is often used to improve the flame retardancy of PLA together with flame retardants. The addition of 4 wt% PTDF and 0.1 wt% PTFE made PLA reach V-0 flame retardant grade from non-flame retardant, and the oxygen index increased from 19.5 % to 24.5 %. With the increase of PTDF content, the performance of PLA improved significantly. The peak heat release rate (PHRR) and THR of PLA/6PTDF composites decrease by 27.4 % and 16.2 %, respectively, and the flame retardant index FRI increase by 232 %, showing excellent flame retardant efficiency. 6 wt% PTDF can increase the crystallinity of PLA by 25.9 %, tensile strength, maximum force required for impact fracture and notch impact strength by 12 %, 37 % and 129 %, respectively, and effectively improve the mechanical properties and toughness of the composite. The bio-based flame-retardant PLA/PTDF composites reported in this paper can be applied to office equipment.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBON
·
2021
·
IF 9.594
Yawen Yang,Gaochuang Yang,Kaiming Hou,Honggang Wang,Na Wang,Shengrong Yang,Jinqing Wang
In this work, a novel lubricating additive was designed and synthesized via self-assembling of wrapped PTFE nanoparticles by exfoliated MXene nanosheets . Then the p MXene@polytetrafluoroethylene ( p MXene@PTFE) hybrid was introduced into epoxy coating and painted to substrate. The composite with PTFE would effectively alleviate the oxidation of MXene sheets. The research results show that the epoxy-based composite coating has excellent friction-reduction and wear-resistance properties in dry air, humid air (RH = 80%), and vacuum (3 × 10 −5 Mbar) environments, achieving multi-environmental stability binary composite coating. The performance improvement of composite coating mainly depends on the following points: (a) the lubricating synergistic effect of MXene sheets and PTFE hybrid additive with core-shell structure; (b) the good dispersibility and adhesion of composite additive in the epoxy matrix ; (c) the formation of protective film on the upper counterpart. The obtained friction results demonstrate that self-assembled p MXene@PTFE epoxy coatings greatly enhance the lubricating and anti-wear properties in multiple environments, establishing a promising platform for the design and application of novel high-performance additive with environmental insensitivity.
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
Surfaces and Interfaces
·
2025
·
IF 6.3
Wenjuan Cui,Zhengang Chen,Ruinan Xiong,Leyan Tang,Ling Zhu,Chenyang Cai,Xiaosong Zhou
Corrosion resistance is a critical challenge for magnesium alloys, particularly AZ31B, in aerospace, military, and biomedical applications. This study investigates the anti-corrosion performance of superhydrophobic SiO₂ NPs-modified PTFE/PUA hybrid coatings on AZ31B, fabricated using rod and spray painting techniques. The coatings exhibited excellent superhydrophobic properties, with contact angles exceeding 155° and a contact angle hysteresis (CAH) below 5° Electrochemical evaluations of superhydrophobic SiO₂ NPs-modified PTFE coatings demonstrated a reduction in i corr by four orders of magnitude compared to that of raw AZ31B Mg alloys, achieving a corrosion inhibition efficiency (η p ) of ∼ 99.9 % in a 3.5 wt % NaCl solution. The E corr shifted positively by 0.968 V and 1.022 V, respectively. Additionally, the R ct of the SiO₂ NPs-PTFE hybrid coatings increased by four orders of magnitude compared to blank PTFE-0-R coatings, indicating robust and enhanced corrosion resistance. The study also found minimal differences in corrosion protection based on fabrication technique, while SiO₂ NPs-PUA coatings showed limited effectiveness in corrosion resistance. These findings highlight the potential of superhydrophobic PTFE hybrid coatings in addressing corrosion challenges for magnesium alloys.
研究领域:
材料科学
·
腐蚀与防护
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Huiji Xiao,Yongjie Hao,Jingli Wu,Xianzhe Meng,Fei Feng,Fengqi Xu,Siyi Luo,Bo Jiang
Recently, there are still some controversial mechanisms of the 3D electrocatalytic oxidation system, which would probably confound its industrial application. From the conventional viewpoint, the Ti 4 O 7 material may be the desired particle electrodes in the 3D system since its high oxygen evolution potential favors the production of • OH via H 2 O splitting reaction at the anode side of Ti 4 O 7 particle electrodes. In fact, the incorporation of Ti 4 O 7 particles showed phenol degradation of 88% and COD removal of 51% within 120 min, under the optimum conditions at energy consumption of 0.668 kWh g −1 COD, the performance of which was much lower than those in many previous literatures. In contrast, the prepared carbon black-polytetrafluoroethylene composite (CB-PTFE) particles with abundant oxygen-containing functional groups could yield considerable amounts of H 2 O 2 (200 mg L −1 ) in the 3D reactor and achieved a complete degradation of phenol and COD removal of 80% in the presence of Fe 2+ , accompanying a low energy consumption of only 0.080 kWh g −1 COD. It was estimated that only 20% of Ti 4 O 7 particles near the anode attained the potential over 2.73 V/SCE at 30 mA cm −2 based on the potential test and simulation, responsible for the low yield of • OH via the H 2 O splitting on Ti 4 O 7 (1.74 × 10 −14 M), and the main role of Ti 4 O 7 particle electrodes in phenol degradation was through direct oxidation. For the CB-PTFE-based 3D system, current density of 10 mA cm −2 was sufficient for all the CB-PTFE particles to attain cathodic potential of −0.67 V/SCE, conducive to the high yield of H 2 O 2 and • OH (9.11 × 10 −14 M) in the presence of Fe 2+ , and the • OH-mediated indirect oxidation was mainly responsible for the phenol degradation. Generally, this study can provide a deep insight into the 3D electrocatalytic oxidation technology and help to develop the high-efficiency and cost-efficient 3D technologies for industrial application.
研究领域:
环境科学
·
电化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
·
2019
·Vol. 29
·期 5
·1738-1745
·
IF 1.637
Li Minjia,Chen Feng,Liu Chengbao,Qian Junchao,Wu Zhengying,Chen Zhigang
Polytetrafluoroethylene (PTFE)/polyvinyl alcohol (PVA)/ZnO composite fiber membranes were prepared by electrospinning, and PTFE/ZnO composite films were obtained after removing PVA. Considering that the spinning solution has good spinning performance, the PTFE/ZnO composite film has good flexibility and durability. The zinc oxide powder is evenly fixed on the surface of PTFE fibers, so that the film’s flexibility will not be affected during high-temperature calcination. The scanning electron micrograph shows that the morphology of the film is similar to the surface of the lotus leaf. The properties of PTFE/ZnO composite films were investigated by hydrophobic angle test and oil–water separation experiments. Results show that the PTFE/ZnO composite film has good hydrophobicity and oil–water separation performance. With the decrease in ZnO, the contact angle of the PTFE/ZnO composite film increased, and the oil–water separation performance improved. When the amount of ZnO added was 0.025 g, the contact angle was 160.9°, and the oil–water separation performance was the best.
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
TRIBOLOGY LETTERS
·
2018
·Vol. 66
·期 2
·1-11
·
IF 2.182
Lv Yan,Wang Wei,Xie Guoxin,Luo Jianbin
Black phosphorus (BP), a newly emerging two-dimensional material, has recently received considerable attention. Our recent work suggested that BP nanosheets exhibit extraordinary mechanical and lubrication properties. In the present work, the tribological properties of polyetheretherketone (PEEK)/polytetrafluoroethylene (PTFE) and carbon fiber (CF)/PTFE composites with BP nanosheets have been investigated. The morphologies and surface element distribution of the worn tracks of the tribopair surfaces were examined by different analytical techniques. The results show that the coefficients of friction (COFs) of both the PEEK/PTFE and CF/PTFE composites decreased dramatically after the addition of BP nanosheets, and the minimum COF of the composite was 0.04, which was a quarter of that of the PTFE composite without BP nanosheets. After BP nanosheets were added into the composites, the wear rate of the PTFE/PEEK composite decreased dramatically, while that of the CF/PTFE composite increased significantly with the increase in the filler concentration. The analysis of the lubrication mechanism of the PTFE composite with BP nanosheets suggested that BP nanosheets could be constantly supplied into the contact area and gradually formed a BP film composed of phosphorus oxide and phosphoric acid on the counterpart surface instead of the formation of PTFE transfer film. The formed BP transfer film promoted the friction reduction and the disappearance of the adhesive wear.
研究领域:
材料科学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2017
·
IF 3.151
Haiming Song,Hongwei Yu,Lijing Zhu,Lixin Xue,Dichao Wu,Hao Chen
A facile one-step process was developed to generate hydrophilic coating on polytetrafluoroethylene (PTFE) hollow fiber membranes based on co-deposition of polymerized dopamine (PDA) and poly (ethyleneimine) (PEI) from aqueous solutions. For comparison, step-by-step coating of PDA and PEI was also applied to modify PTFE membranes. ATR-FTIR, XPS , SEM, AFM and water contact angle measurements were applied to analyze the surface chemistry and morphology evolution of the modified PTFE membranes at varied grafting yields. PDA and PEI were successfully deposited on PTFE membranes while the hydrophilicity and wettability of the modified membrane were greatly improved. The modified PTFE membranes showed high water permeate fluxes, good long-term stability and durability in strong acidic aqueous solution. Although PTFE hollow fiber membranes samples modified by a step-by-step dip-coating process with PDA and PEI tent to lose their hydrophilicity in strong alkaline solutions, the co-deposited PTFE membranes with PDA and PEI were found to have good durability in aqueous solution at pH 13. This work provides a one-step method to improve the hydrophilicity and chemical stability of the PTFE hollow fiber membranes for water treatment applications.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2023
·
IF 3
Daixiong Zhang,Lin Zhuo,Qing Xiang
Polytetrafluoroethylene (PTFE) is known as the ‘king of plastics’ because of its excellent resistance for both acid and alkali medium, so the coatings composed of PTFE have an attractive application prospect in the field of corrosion protection. In this work, with a solvent of ethanol containing 0.05 g·L −1 PEI + 0.1 mM nitric acid as the dispersion system, the PTFE coatings were successfully prepared onto the Mg-3Al-1Zn (AZ31) alloy sheets by electrophoretic deposition (EPD) strategy. The morphology of the electrophoretic PTFE coating was further reshaped through a sintering post-treatment at 380 °C in argon atmosphere. In 3.5 wt% NaCl solution, the corrosion current density was remarkably reduced (3.92 × 10 −6 A·cm −2 for the bare AZ31 vs 1.54 × 10 −9 A·cm −2 for the sintered PTFE coating AZ31), and the charge transfer resistance was significant increased (299.92 Ω·cm 2 for the bare AZ31 vs 2.79 × 10 6 Ω·cm 2 for the sintered PTFE coating AZ31), which means the electrophoretic-sintered PTFE coating can significantly improve the corrosion resistance of AZ31 alloys. Moreover, it is also suggested that the electrophoretic-sintered PTFE coating may be a general anti-corrosion strategy for a series of metal materials.
研究领域:
材料科学
·
腐蚀与防护
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Ran Chen,Junfeng Liu,Xingzheng Wang,Linlin Kong,Leyun Feng,Jingkai Han,Hao Bai,Fubing Bao
Porous membranes are widely used for filtration, especially those with homogenous pore size and strong mechanical strength. Here, we develop a programmable electrospinning system and fabricate porous membranes consisted of orthogonally aligned nanofibers. The porous fibrous membranes possess more homogeneous pore size and stronger mechanical strength when compared to traditional porous membrane with disordered nanofibers. By physically modifying the membrane surface with PTFE nanoparticles, we obtain a filter membrane, which has both large oil contact angle in water and large water contact angle in oil. Synergism between hierarchical structure and surface property realizes a high separation efficiency of both oil-in-water and water-in-oil emulsions. The technique to control the structure of fibrous membrane, combined with the method to modify the surface of nanofibers, provides a great opportunity to design advanced fibrous membrane for various applications.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2022
·
IF 4.889
Jiu-Si Wang,Rong-Rong Cai,Shun-Jie Wu,Li-Zhi Zhang
Electret filter media has been considered as the most effective and economical filtration material due to its additional electrostatic filtration effect. However, the regeneration and recycling of electret filter media is a great challenge, as its stored charge would dissipate during filtration process, resulting in a significant efficiency reduction after cleaning. To address this problem, based on liquid–solid contact electrification (C-E) theory and self-cleaning property of hydrophobic surface, we successfully designed and fabricated a reusable PTFE electret filter membrane. After water droplets charging/cleaning, the surface charge of the membrane can be recovered to 100–110%, and the pressure drop can be restored to > 93%, exhibiting an excellent regeneration performance. Then the effect of particle wettability on cleaning performance was investigated. The hydrophilic PM 2.5 on hydrophobic surface was found to be easier to clean by droplets rolling than the hydrophobic PM 2.5 due to its stronger adhesion to the droplets. Furthermore, based on the theory of ion transfer at the solid–liquid interface, the charge evolution of the hydrophobic PTFE surface during the triboelectric electrification of water droplets was modeled. The rate of ion transfer between water droplets and hydrophobic surfaces depends linearly on the actual liquid–solid contact area. The charge saturation value of a solid surface is related to its ionic binding sites and the dielectric properties. The study promotes the development of reusable electret filters, and advances the understanding of the triboelectric properties of droplets on hydrophobic surfaces.
研究领域:
材料科学
·
环境科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Yang Xiao,Lin Zhang,Bin Wei,ChangFeng Lu,Ling Li
Generally, modification of materials by adding multiple types of nano particles could cause dispersion problems, generally limited the performance improvement effect. Herein, we report the modification of UHMWPE materials by organic-inorganic core-shell particles with PTFE as the core and Al(OH) 3 as the shell, which prepared by in-situ polymerization of sodium bicarbonate and aluminum sulfate solution . Core-shell particles were filled in UHMWPE matrix and sintered into composite by spark plasma sintering (SPS). The mechanical and tribological properties of the composites were characterized by tensile compression testing machine, universal micro tribometer (UMT-5), three-dimensional white light interferometer and scanning electron microscope (SEM). The results showed that the addition of core-shell structural materials effectively improved the tribological properties (friction coefficient decreased by 40%, wear rate decreased by 30%) and mechanical properties (compression strength increased by 2.4 times) of the composites. It was demonstrated that the inorganic framework provided strength to improve the mechanical properties and wear resistance of materials, and the organic phase was used as a lubricating phase to reduce the friction coefficient of materials. Surface treatment of core-shell particles both improved the binding between particles and matrix and decreased the formation of agglomerations, thus significantly reducing ploughing phenomena’s effect produced by abrasive wear of agglomeration
研究领域:
材料科学
·
机械工程
✓ 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）