Article
Engineering, Mechanical
Mingkun Xu, Zidan Wang, Lihe Guo, Liming Tao, Tianbao Ma, Tingmei Wang, Qihua Wang
Summary: Fabric composites are widely used in self-lubricating bearing liners, but their cryogenic tribological properties are poorly understood. This study investigates the tribological behavior of PTFE-based hybrid-fabric composites at cryogenic and ambient temperatures. The results show that the friction coefficients of the composites increase and wear decreases when the temperature decreases. Thermoplastic PEI adhesive exhibits better cryogenic lubrication performance compared to thermosetting PF resin. The excellent lubrication performance is attributed to the transfer film formed by PTFE fibers on the fabric surface.
Article
Materials Science, Multidisciplinary
Tianyu Guan, Michael D. Gilchrist, Fengzhou Fang, Nan Zhang
Summary: This study improves the lubrication and wear resistance of nickel composite moulds by co-depositing nano-sized polytetrafluoroethylene (PTFE) particles with nickel. The experimental results show that using nano-sized PTFE particles is more effective than micro-sized PTFE particles in improving the lubrication, mechanical, and tribological properties of the composite moulds.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Multidisciplinary
Sung-Jun Lee, Gang-Min Kim, Chang-Lae Kim
Summary: The purpose of this study was to enhance the tribological properties of PDMS by incorporating lubricants. The PDMS/lubricant composites (PLCs) with different ratios of PDMS and lubricant were analyzed for their chemical composition, physical/chemical bonding state, and mechanical properties. The friction coefficient initially decreased with increasing lubricant content, reaching a minimum value at a PDMS/lubricant ratio of 100:10. However, it gradually increased with further increase in the lubricant content. The PLCs with lubricant contents of 10% and higher exhibited decreased mechanical properties but reduced frictional resistance due to the self-lubricating effect.
Article
Materials Science, Characterization & Testing
Aswani Kumar Bandaru, Paul M. Weaver, Ronan M. O' Higgins
Summary: The study found that hygrothermal ageing reduces the wear resistance of glass/PTFE composites, with crystallinity decreasing as water uptake increases. The inclusion of a metal mesh improves the wear resistance of non-hybrid composites under the same ageing conditions.
Article
Chemistry, Multidisciplinary
Xiaotao Qiu, Aiqun Gu, Wenjian Tang, Siqi Tang, Zili Yu
Summary: In this study, various perfluoropolymers were used as additives to lubricate carbon fiber-reinforced polyphenylene sulfide composites, showing that the addition of FEP, PFA, or iPTFE could reduce friction coefficient compared to neat PTFE.
Article
Physics, Fluids & Plasmas
Hans Terwisscha-Dekker, Tadeus Hogenelst, Roland Bliem, Bart Weber, Daniel Bonn
Summary: Polytetrafluoroethylene (PTFE) is a highly slippery polymer with a low coefficient of friction compared to other polymers. Despite being nonsticky, PTFE leaves a material residue on the substrate while sliding.
Article
Engineering, Mechanical
Qihua Wang, Xiaoyue Wang, Xinrui Zhang, Song Li, Tingmei Wang
Summary: The tribological properties of materials have a complex and non-linear correlation under varying operational conditions. Therefore, using a data-driven approach to predict service capability is crucial for advancing material design and preparation in the field of tribology. In this investigation, the tribological performance and wear mechanism of PTFE composites were analyzed, and machine learning techniques were employed to predict tribological properties under different operational conditions. The gradient boosting regression (GBR) model showed excellent predictive performance, with R2 values of 82% and 91% for friction coefficient and wear rate, respectively. Furthermore, the Pearson correlation coefficient indicated that temperature and speed have a greater impact on friction coefficient and wear rate compared to load.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Mechanical
Mingkun Xu, Song Li, Tingmei Wang, Qihua Wang, Liming Tao, Peng Liu
Summary: In this study, a novel Nomex/polytetrafluoroethylene (PTFE) fabric composite with a hierarchical distribution of PTFE was developed by sintering a layer of PTFE/MoS2 coating. The tribological properties of the composite were investigated over a temperature range from -150 to 25 degrees Celsius. The results revealed a nonmonotonic relationship between the friction coefficient and temperature, which was attributed to the molecular conformation and mobility of PTFE.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Engineering, Chemical
Kylie E. Van Meter, Tomas F. Babuska, Christopher P. Junk, Kasey L. Campbell, Mark A. Sidebottom, Tomas Grejtak, Andrew B. Kustas, Brandon A. Krick
Summary: This study demonstrates that PTFE filled with iron-cobalt microparticles is an ultralow wear, magnetic, multifunctional tribological material. Compared to PTFE filled separately with iron or cobalt microparticles, PTFE filled with FeCo microparticles shows significantly improved steady-state wear behavior.
Article
Engineering, Mechanical
Jiang Wei, Wei Sun, Kun Liu, Xiaojun Liu, Jiaxin Ye
Summary: This study aims to further understand the origin of the interfacial surface energy gradient and its relationship with wear reduction by investigating the wear and environmental sensitivities of a 5 wt% PPS-PTFE composite. The results reveal that there is a scaling factor of approximately 1000 fold per mJ/m2 between wear rate and Delta gamma. It is also found that the interfacial energy gradient is influenced by transfer film adhesion and coverage, which is primarily determined by PTFE tribochemistry rather than PPS enrichment. Additionally, maintaining a moderate Delta gamma can minimize bulk wear and stabilize transfer films.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Liu Jian, Lu Fei, He Tiantian, Pang Xianjuan, Zhang Yongzhen
Summary: This paper focuses on the abnormal tribological damage and fluctuation of tribological performance in self-lubricating composites used in heavy load spherical plain bearings in the aerospace field. A reciprocating block on ring tribological test was conducted using the Nomex/PTFE fiber reinforced composite to investigate its wear evolution and tribological performance. The results indicate that, under high load conditions (above 90 MPa or 180 kN), the influence of oscillating frequency on material wear is significantly greater than that of load. Friction temperature is a key factor affecting the wear behavior of the material. High friction temperature weakens the friction and wear performance, leading to material failure in a short time. Thermal fatigue is the main tribological damage mode under high load and high frequency conditions, resulting in local wear.
MATERIALS RESEARCH EXPRESS
(2022)
Article
Engineering, Mechanical
Wei Sun, Qingrui Song, Kun Liu, Xiaojun Liu, Jiaxin Ye
Summary: The addition of nano-sized fillers can greatly reduce the wear rate of polytetrafluoroethylene by forming a protective transfer film. The wear reduction is influenced by the properties of the polymer wear surface and the roughness of the transfer film.
Article
Engineering, Mechanical
Jiaxing Wu, Jianxin Deng, Ying Meng, Shijie Wang, Ran Wang, Xuemu Li, Wei Sun
Summary: The research focused on improving the dry friction and wear performance of aluminum alloys through a combination of texturing pretreatments and lubricant films. The study showed that the sample with 100μm spacing texture and PTFE/PPS film exhibited the best anti-wear effect during dry reciprocating sliding, increasing wear life by 10% and reducing wear track width and adhesion width by 35% and 25%, respectively.
Article
Chemistry, Physical
Yuanjie Shu, Liaoliang Ke, Jie Su, Fei Shen
Summary: This experimental study focused on the fretting wear behavior of PVDF piezoelectric thin film against a Si3N4 ceramic sphere under air conditions. Results indicated that creep and plastic deformation led to noticeable wrinkles on the contact surface of the PVDF thin film, which could decrease its specific wear rate.
Article
Engineering, Mechanical
Diego Salvaro, Joao Marcos Warmling Dudy, Fabiana de Oliveira Palheta, Cristiano Binder, Aloisio Nelmo Klein, Guilherme Mariz de Oliveira Barra, Jose Daniel Biasoli de Mello
Summary: Improving the energy efficiency of mechanical systems and reducing the usage of lubricant oils and related additives are challenging tasks of the 21st century. The application of tribopolymers, such as PEEK, PAEK, and PTFE, is increasing due to their easy processing and lower density. This study investigates the effects of grinding processes and the incorporation of PTFE on the morphology, composition, and tribological properties of PAEK + PTFE blends.
Editorial Material
Engineering, Mechanical
Shelby R. Maddox, Arup Gangopadhyay, Hamed Ghaednia, Jiyu Cai, Xiaoxiao Han, Xiangbo Meng, Josue A. Goss, Min Zou
JOURNAL OF TRIBOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Chemistry, Inorganic & Nuclear
Yongqiang Liu, Xin Wang, Sujan Kumar Ghosh, Min Zou, Hua Zhou, Xianghui Xiao, Xiangbo Meng
Summary: This study investigates the thin film growth of lithium zirconium oxides (LixZryO or LZOs) and reveals the influence of hygroscopic nature of LiOH on the growth of LZOs. The research combines two individual atomic layer deposition (ALD) processes and applies various characterization techniques to analyze the LZO films. Furthermore, the study demonstrates that LZO coating films can significantly improve the performance of cathodes in lithium-ion batteries.
DALTON TRANSACTIONS
(2022)
Article
Materials Science, Coatings & Films
Dipankar Choudhury, Christopher Rincon, Ronghua Wei, Mourad Benamara, Min Zou
Summary: The study shows that depositing a DLC coating on a PDA and SiO2 nanoparticle composite underlayer significantly improves resistance to crack propagation and coating delamination. The PDA + SiO2/DLC coating demonstrated increased critical loads for crack propagation and delamination, with reduced wear track cross-sectional area and smaller cracks compared to a TMS/DLC coating.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Charles Miller, Min Zou
Summary: This study investigates the nanoscale deformation behavior and failure mechanisms of PDA/PTFE coatings under various scratch loads using a nanoindenter. The study reveals that PDA/PTFE coating failure is strongly correlated with the removal of PDA particles in the underlayer.
Article
Chemistry, Applied
Xin Wang, Jiyu Cai, Yang Ren, Mourad Benamara, Xinwei Zhou, Yan Li, Zonghai Chen, Hua Zhou, Xianghui Xiao, Yuzi Liu, Xiangbo Meng
Summary: This study reports the protective performance of a sulfide coating prepared by atomic layer deposition on nickel-rich LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes for the first time. The coating enhanced capacity retention, voltage stability, and rate capability of NMC811 significantly.
JOURNAL OF ENERGY CHEMISTRY
(2022)
Article
Biophysics
Diksha Shrestha, Jun Ou, Ariel Rogers, Amani Jereb, Deborah Okyere, Jingyi Chen, Yong Wang
Summary: In this study, we investigated the motion of Escherichia coli bacteria in microsphere-mimicked porous media. The density of microspheres affected bacterial velocity and directional changes, mainly due to collisions with the microspheres. We also established the correlation between bacterial trapping and geometric confinement imposed by the microspheres, and numerical simulations confirmed experimental observations.
COLLOIDS AND SURFACES B-BIOINTERFACES
(2023)
Article
Engineering, Biomedical
Firuze Soltani-Kordshuli, Dipankar Choudhury, Josue A. Goss, Mara Campbell, Evelyn Smith, Steven Sonntag, Isabelle I. Niyonshuti, Deborah Okyere, Mark S. Smeltzer, Jingyi Chen, Min Zou
Summary: Joint replacements have become common orthopedic procedures to address the demand for functional mobility. However, the durability of joint replacements, especially for younger patients, is a major concern. This study explored the use of microscale dimples on titanium implants to improve lubrication and reduce wear. The star-shaped dimples showed the best performance, significantly reducing wear and friction. The study also investigated bacterial colonization on dimpled surfaces and found that dimpling did not increase colonization, although the coating with antibacterial materials did not decrease it either. Overall, star-shaped dimpled titanium surfaces have the potential to be more durable orthopedic implants.
JOURNAL OF THE MECHANICAL BEHAVIOR OF BIOMEDICAL MATERIALS
(2023)
Article
Materials Science, Characterization & Testing
Firuze Soltani-Kordshuli, Charles Miller, Nathaniel Harris, Min Zou
Summary: In this study, Hilbert curve patterns were laser-textured on stainless steel substrates and PTFE thin coatings. The laser-textured PTFE coatings reduced the hardness of the coatings and prevented tearing under nanoindenter scratches. Additionally, laser-texturing on both PTFE coatings and the stainless steel substrate significantly improved the wear life of the coatings.
Article
Engineering, Mechanical
Firuze Soltani-Kordshuli, Nathaniel Harris, Min Zou
Summary: Texturing stainless steel substrates using shallow Hilbert curve patterns through laser processing can improve coating durability and friction performance. The best texture was achieved with a texture path segment length of 12 μm and laser power of 15%.
Article
Engineering, Manufacturing
Mahyar Afshar-Mohajer, Xingwei Yang, Rong Long, Min Zou
Summary: Micro/nano-hierarchical structures composed of nanohairs on top of micropillars were produced using high-resolution two-photon lithography additive manufacturing technique. Varying the tapering angle of the micropillar and the length of the nanohairs allowed control over the effective stiffness of the structures. In-situ monitoring of the structural deformation and frictional response revealed that changes in structure stiffness through 3D printing could affect the onset of sliding motion, friction force, and coupling between nanohair and micropillar deformation, providing new directions for friction and deformation control.
ADDITIVE MANUFACTURING
(2023)
Article
Chemistry, Physical
Prashant Acharya, Jiyun Hong, Ryan Manso, Adam S. S. Hoffman, Laszlo Kekedy-Nagy, Jingyi Chen, Simon R. R. Bare, Lauren F. F. Greenlee
Summary: Operando X-ray absorption spectroscopy (XAS) can be used to study the phase and structural changes of transition metal oxide electrocatalysts during electrocatalytic reactions. In this work, time-resolved changes in the Ni K-edge of a FeNiO (x) bimetallic nanoparticle electrocatalyst were successfully captured. The observed changes are related to the Ni redox transition and the phase transition from hydroxide to oxyhydroxide.
JOURNAL OF PHYSICAL CHEMISTRY C
(2023)
Article
Chemistry, Applied
Jiyu Cai, Zhenzhen Yang, Xinwei Zhou, Bingning Wang, Ana Suzana, Jianming Bai, Chen Liao, Yuzi Liu, Yanbin Chen, Shunlin Song, Xuequan Zhang, Li Wang, Xiangming He, Xiangbo Meng, Niloofar Karami, Baasit Ali Shaik Sulaiman, Natasha A. Chernova, Shailesh Upreti, Brad Prevel, Feng Wang, Zonghai Chen
Summary: Nickel-rich transition-metal oxides are considered promising cathode materials for high-energy-density lithium-ion batteries, but they face safety and cycle-life obstacles. The major issues originate from the unstable cathode-electrolyte interface and the mechanism of parasitic reactions on the cathode surface is not well understood.
JOURNAL OF ENERGY CHEMISTRY
(2023)
Article
Nanoscience & Nanotechnology
Jiyu Cai, Xinwei Zhou, Tianyi Li, Hoai T. Nguyen, Gabriel M. Veith, Yan Qin, Wenquan Lu, Stephen E. Trask, Marco-Tulio Fonseca Rodrigues, Yuzi Liu, Wenqian Xu, Maxwell C. Schulze, Anthony K. Burrell, Zonghai Chen
Summary: This study identifies the issues with silicon-based lithium-ion batteries during calendar aging and proposes strategies to improve battery life by suppressing parasitic reactions.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Biochemistry & Molecular Biology
Patrick M. Pysz, Julia K. Hoskins, Min Zou, Julie A. Stenken
Summary: This Perspective article discusses the potential of 3D printing technology in improving neuroscience measurement devices. It explores the use of 3D printing for device creation and the printing of peripheral objects required for functional devices. The most suitable 3D printing setup for microsampling devices with specific feature sizes is likely to involve 2-photon polymerization-based printers.
ACS CHEMICAL NEUROSCIENCE
(2023)
Article
Biochemistry & Molecular Biology
Benjamin Russell, Ariel Rogers, Ryan Yoder, Matthew Kurilich, Venkata Rao Krishnamurthi, Jingyi Chen, Yong Wang
Summary: Silver (Ag) in different forms has gained attention for its antimicrobial activities, especially as bacteria become more resistant to antibiotics. However, the mechanism of how Ag affects bacterial motility is not fully understood. In this study, we found that Ag+ ions significantly inhibited the motility of E. coli bacteria and increased the tumbling/pausing frequency. Using the hidden Markov model (HMM), we analyzed the results and found that Ag+ ions decreased the bacterial tumbling/pausing-to-running transition rate. This work provides new quantitative understanding of Ag-based antimicrobial agents in bacterial motility.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
