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Developing anode materials with high specific capacity and cycling stability is vital for improving thin‐film lithium‐ion batteries. Thin‐film zinc oxide (ZnO) holds promise due to its high specific capacity, but it suffers from volume changes and structural stress during cycling, leading to poor battery performance. In this research, we ingeniously combined polytetrafluoroethylene (PTFE) with ZnO using a radio frequency (RF) magnetron co‐sputtering method, ensuring a strong bond in the thin‐film composite electrode. PTFE effectively reduced stress on the active material and mitigated volume change effects during Li+ ion intercalation and deintercalation. The composite thin films are thoroughly characterized using advanced techniques such as X‐ray diffraction, scanning electron microscopy, and X‐ray photoelectron spectroscopy for investigating correlations between material properties and electrochemical behaviors. Notably, the ZnO/PTFE thin‐film electrode demonstrated an impressive specific capacity of 1305 mAh g−1 (=7116 mAh cm−3) at a 0.5C rate and a remarkable capacity retention of 82% from the 1st to the 100th cycle, surpassing the bare ZnO thin film (50%). This study provides valuable insights into using binders to stabilize active materials in thin‐film batteries, enhancing battery performance. [ABSTRACT FROM AUTHOR]

Multi‐walled carbon nanotubes (MWCNTs) with excellent physiochemical properties have been recently applied to energy/power generation and storage systems encompassing polymer electrolyte membrane fuel cells (PEMFCs). However, there is a lack of investigations of the properties of MWCNT composites themselves under the actual operating conditions of systems. In this paper, MWCNTs/polytetrafluoroethylene (PTFE) composites were fabricated as electric and hydrophobic components for energy/power systems. The electrical properties, heating behavior, hydrophobicity, and water evaporation behavior of the composites are characterized within the operating voltage ranges of PEMFC. With 50% MWCNT content, the conductivity and the contact angle were 11.83 S/cm, and the contact angle 128.1°, respectively. The MWCNT/PTFE composite film showed a linear temperature rise with voltages and rapid temperature saturation within 40 s. The rate in the initial heating range was measured at 0.5°C/s for the voltage of 0.5 V. The voltage increase induced an exponential decrease in the height of water droplets on the composite surface. The evaporation rate increased almost 10‐fold, from 0.013 mm/min at 0.0 V to 0.12 mm/min at 1.0 V. The proposed characteristics of the functional composite provide insights into the material requirements for electrochemical devices, including PEMFC. Highlights: Multi‐walled carbon nanotube/polytetrafluoroethylene composites can be applied to energy storage and power generation.Key properties of the composites are proposed for polymer electrolyte membrane fuel cell (PEMFC) operating conditions.The composite has a fast heating by high conductivity and temperature uniformity.Water‐vapor transformation under PEMFC operating voltage is quantified. [ABSTRACT FROM AUTHOR]

Antibacterial fiber mats play a crucial role in inhibiting the spread of bacteria and preventing bacterial transmission. While polytetrafluoroethylene (PTFE) exhibits excellent biological inertness, the lack of antibacterial properties in pure PTFE fiber mats has diminished their competitiveness. In this study, we developed an antibacterial fiber mat with high breathability and moisture permeability by introducing silver nanoparticles (Ag NPs) into a PTFE emulsion through electrospinning. In this study, five sets of concentration gradients from 1% to 5% were set up, and the comparison revealed that the best PTFE/Ag NPs composite fiber mat (PA fiber mat) performance was achieved at 3% Ag NPs concentration. Compared to PTFE fiber mats without Ag NPs loading and conventional expanded membranes (ePTFE), it demonstrated antibacterial rates of 97.1% against Escherichia coli (E. coli) and 97.0% against Staphylococcus aureus (S. aureus), a moisture permeability performance of 15,500 ± 304 g(m2·12h)−1, and excellent breathability. The fiber mat exhibited not only outstanding antibacterial capabilities but also a water contact angle of 137.6°, an elongation at break of approximately 260.92%, and a tensile strength of about 1.84 MPa. These properties offer great promise for PA fiber mats in antibacterial fabric applications including medical masks and protective clothing. [ABSTRACT FROM AUTHOR]

Polymer gears are often used in power transmission due to their numerous advantages. Heat accumulates on polymer gears during operation. Over time, this accumulated heat leads to damage; and shortens the service life of the gears. To prevent this, various fillers are added to the polymer materials. These fillers help to dissipate the heat generated on the gears. In this study, 25% glass fibers, 35% carbon powder, and 60% bronze particles were added to the polytetrafluoroethylene (PTFE) matrix to determine the wear behavior of gears. The properties of the matrix and the filler mainly influence the wear behavior of PTFE composites. The study showed that all composite gears with filler have better wear resistance than pure PTFE gears due to their better thermal stability. After the tests, it was found that the gears made of PTFE + 35% carbon additive had about 12 times better wear rates than those made of pure PTFE. Based on the average temperature values of the experiment, it was found that the mass temperature of gears made of 35% carbon-doped PTFE is about 38-39% lower than that of pure PTFE. This study contributes to the standard studies on heat build-up, thermal damage, and wear of gears made of polymers with different fillers and ratios.

The hybrid nanofluid (HNF) flow consists of polymer/CNT matrix nanocomposite material (MNC) across coaxial cylinders is numerically described in this study. The HNF flow is inspected under the consequences of thermal radiation, exponential heat source/sink and viscous dissipation. The HNF is prepared by adding polymer/CNT MNC in water. MNCs are highly productive elements with unique designs and properties. The MNCs are widely used in biomedicine and electrical applications due to their exceptional thermophysical properties. Based on their exceptionally high electrical conductivity, CNT/polymer nanoparticles (NPs) are also utilized as shielding for electrostatic discharge and electromagnetic interference (EMI). The HNF flow is modeled with the help of energy, continuity, and momentum equations. MATLAB package bvp4c is used to numerically handle the modeled equations. It has been perceived that the intensifying numbers of polymer/CNT MNC will lessen the fluid velocity and temperature profile in cases of both nanofluid and HNF. [ABSTRACT FROM AUTHOR]

Triboelectric generators (TEGs) stemming from the triboelectric phenomena, are promising for energy harvesting due to their high output power and efficiency. Analysis of the tribo material selection for TEGs has suggested that energy generation is linked to heterogeneous and homogeneous materials found at opposite ends of the triboelectric series. Current research has identified that the triboelectric phenomenon also exists from contact between identical tribo materials with the advancement of surface modification. However, a comparison of composite and identical homogeneous TEGs has yet to be reported. For this research, organic polymer membranes Polyamide-6 (PA6) and Polytetrafluoroethylene (PTFE) were evaluated. The membranes were cut into samples of varying dimensions to build three sets of TEGs for comparison. Two identical sets of four sampled TEGs were fabricated using the same membrane (i.e., PA6-PA6 and PTFE-PTFE); in contrast to a composite set of four sampled TEGs made from the two distinct membranes (i.e., PA6-PTFE). By repeatedly sampling the TEGs in sliding mode at a speed of 0.2 m/s and with a vertical force of 9.8 N an open circuit voltage (Voc) was generated and recorded. As a result, the Voc of the identical TEGs was compared to the Voc of the composite TEG in which the tribo materials are located at opposite ends of the triboelectric series. It was also observed that the Voc increased almost linear in relation to the surface area of the TEGs; thus, suggesting that the surface area of the TEG can influence significantly the Voc to a great extent. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of micro-nano rough structures on the performance of polytetrafluoroethylene (PTFE) superhydrophobic coatings on cement concrete-based substrates, this study considered the rough structures on the concrete surface and the micro-nano rough structures constructed using micrometer-level diamond, silicon carbide, alumina powder, and nanometer-level hydrophobic silica powder. Contact angle measurements and scanning electron microscopy (SEM) were used to characterize the wettability and micro-structure of PTFE coatings on various rough structures. Additionally, the slip resistance and wear resistance of the coatings were evaluated. The results showed that a two-step fabrication process, involving the construction of micro-nano rough structures followed by PTFE coating modification, achieved the highest superhydrophobic performance. The best results were obtained when micrometer-level and nanometer-level powders were combined, with the performance improving as the dosage increased, with a recommended ratio of 1: 1 and a particle size ratio controlled within the range of 60-120 times. Among different rough structures, diamond showed the best performance, followed by silicon carbide and corundum. After concrete surface treatment with chiseling, all the coatings met the requirements for slip resistance, and after 1000 cycles of reciprocal friction on the test surface using a wet wheel abrasion tester, the superhydrophobicity remained above 85%. This study provides insights into the mechanisms by which micro-nano rough structures affect coating performance and can guide the preparation of practical, high-performance PTFE superhydrophobic coatings. [ABSTRACT FROM AUTHOR]

A novel manufacturing technique has been developed to enhance the compliance of expanded polytetrafluoroethylene (ePTFE) for vascular graft applications. This new method involves modifying the existing processing procedures by introducing an additional expansion step while using a lower temperature during the first expansion stage. The new process results in the production of highly compliant ePTFE grafts without the need for supplementary additives or inherent material alterations. Tensile testing in both the longitudinal and circumferential directions as well as cyclical tensile testing were conducted to characterize the mechanical properties of double‐expanded ePTFE grafts prepared using varying expansion ratios. The double‐expanded ePTFE grafts consistently outperformed the prevailing, single‐expanded counterparts in both tensile stress tests and cyclical assessments of its elastic compliance. Notably, the double‐expanded ePTFE samples exhibited the desirable, biomimetic "toe‐region" and an elastic strain capacity of up to 50%, comparable to native vascular materials. Scanning electron microscopy (SEM) imaging was used to examine the morphological characteristics of the wavy fibers within the double‐expanded PTFE samples, which contributed to the enhanced compliance that is needed for vascular graft applications. Highlights: A new process has been developed for expanded polytetrafluoroethylene (ePTFE).This new process involves an additional expansion step at a lower temperature.This new process results in the production of highly compliant ePTFE grafts.Double‐expanded D‐ePTFE grafts outperform the single‐expanded counterparts.D‐ePTFE grafts exhibit an elastic strain capacity similar to native vasculature. [ABSTRACT FROM AUTHOR]

The aim of this study is to prepare epoxy/polytetrafluoroethylene (PTFE)/glass fiber (GF) composites (EPGs) with the unique characteristics of low friction and high wear resistance based on triglycidyl isocyanurate (TGIC). The tribological properties of composites with different filler ratios under different working conditions were systematically studied. At the maximum filler content of 40 wt% PTFE, the minimum coefficient of friction (COF) and wear rate reached 0.079 and 0.45 - 10°6 mm³/N-m. The hardness decreased by 44.2% and the density increased by 18.3%. The worn surfaces and transfer films were observed and analyzed by scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS). The increasing tendency of velocity and amplitude is beneficial to reduce the carbon-rich region and further enhance the formation of transfer films. It is proved that the tribological properties of TGIC-based epoxy composites are higher than those of other types of epoxy composites. This study offers great insight into the tribological applications of TGIC-based epoxy composites. Highlights • Epoxy/PTFE/GF composites (EPGs) were prepared using TGIC as the base material. • EPGs have good mechanical and tribological properties. • The COF of EPG3 reaches 0.079 and the wear rate becomes 0.45 x 10°6 mm3/(N-m). • The increasing tendency of velocity and amplitude is beneficial to reduce the carbon-rich region and further enhance the formation of transfer films. [ABSTRACT FROM AUTHOR]

In the era of advanced wearable electronic devices, the triboelectric nanogenerators (TENGs) as energy harvesting and self-powered sensing units hold great promise. Selecting appropriate triboelectric material is the crucial factor to optimize the performance of TENG, while polytetrafluoroethylene (PTFE) stands out as a highly versatile option among the various materials. In this study, we present an ultrafine nanofibrous PTFE (NF-PTFE) films prepared by novel in-situ fibrillation strategy as the triboelectric material in TENG devices. The innovative processing methodology facilely addresses the dilemma between high porosity and fine pore size of traditional porous PTFE films, meanwhile achieves exceptional mechanical strength, hydrophobicity, air permeability, and chemical resistance of the films. With the integration of nanofibrous PTFE films into contact-separation mode TENG and droplet-based TENG, these devices realize the peak electrical output of 131 V/10.8 µA and 54 V/14 µA with great durability, which surpass the performance of TENGs using traditional expanded PTFE films. Furthermore, a smart glove capable of recognizing hand gestures is proposed, which demonstrates the versatility, flexibility, and practicality of this material for potential use in smart devices. This reported NF-PTFE film provides insights for the design of high-performance TENG device for advanced wearable electrical applications. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) has been widely used as a lubrication additive for reducing friction and wear; however, the hydrophobic nature of PTFE restricts its application in eco-friendly water-based lubrication systems. In this study, for the first time, we designed novel PTFE@silica Janus nanoparticles (JNs) to meet the requirement for additives in water-based lubricants, which have excellent dispersion stability in water attributed to the unique amphiphilic structure. By introducing the lubrication of the aqueous dispersion of the JNs with a concentration of 0.5 wt%, the coefficient of friction (COF) and wear volume were reduced by 63.8% and 94.2%, respectively, comparing to those with the lubrication of pure water. Meanwhile, the JNs suspension also exhibits better lubrication and wear-resistance performances comparing to commercial silica and PTFE suspensions. The excellent tribological behaviors of PTFE@silica JNs as nano-additives could be attributed to the synergetic effect of the two components, where the PTFE provided lubrication through the formed tribofilms on the friction pairs, and the rigid silica further enhanced the wear-resistance performance. Most importantly, the unique structure of JNs makes it possible to use PTFE as an additive in water-lubrication systems. Our study shed light on the design and application of novel JNs nanomaterials as additives to meet the requirements of future industrial applications. [ABSTRACT FROM AUTHOR]

In orthodontic treatment, to achieve efficient tooth movement, it is important to reduce the frictional force between the wire and the bracket, especially the binding friction that occurs when the angle between the wire and the bracket is large. Electroless nickel–polytetrafluoroethylene (Ni-PTFE) coating is a coating technology used to deposit PTFE particles with a low coefficient of friction on the coating surface to provide a low-friction surface for metallic materials. The purpose of this study was to investigate the effect of Ni-PTFE-coated orthodontic wires on the frictional force between brackets. The surface morphology, surface roughness, and frictional properties of Ni-PTFE-coated stainless steel wires and Ni-Ti wires were evaluated. The results demonstrate that the Ni-PTFE coating reduced the frictional force between the orthodontic wires and brackets, despite the increased surface roughness. Even when the angle between the wire and bracket was increased, assuming binding friction, the frictional force was reduced by the Ni-PTFE coating. This suggests that the friction between the wire and the bracket was suppressed by the PTFE particles deposited on the wire surface in contact with the bracket. [ABSTRACT FROM AUTHOR]

Polymer gears are often used in power transmission due to their numerous advantages. Heat accumulates on polymer gears during operation. Over time, this accumulated heat leads to damage; and shortens the service life of the gears. To prevent this, various fillers are added to the polymer materials. These fillers help to dissipate the heat generated on the gears. In this study, 25% glass fibers, 35% carbon powder, and 60% bronze particles were added to the polytetrafluoroethylene (PTFE) matrix to determine the wear behavior of gears. The properties of the matrix and the filler mainly influence the wear behavior of PTFE composites. The study showed that all composite gears with filler have better wear resistance than pure PTFE gears due to their better thermal stability. After the tests, it was found that the gears made of PTFE + 35% carbon additive had about 12 times better wear rates than those made of pure PTFE. Based on the average temperature values of the experiment, it was found that the mass temperature of gears made of 35% carbon-doped PTFE is about 38-39% lower than that of pure PTFE. This study contributes to the standard studies on heat build-up, thermal damage, and wear of gears made of polymers with different fillers and ratios. [ABSTRACT FROM AUTHOR]

Type II endoleak is the most frequent complication after endovascular abdominal aneurysm repair. Polytetrafluoroethylene and polyester (PE) are the two most commonly used graft materials in endovascular aneurysm repair (EVAR) devices. Biological properties of the material might influence the appearance and persistence of type II endoleak (T2EL). Therefore, the aim of this study was to evaluate potential differences in the prevalence of T2EL after EVAR between polytetrafluoroethylene (PTFE) and PE endografts in patients electively treated for an infrarenal abdominal aortic aneurysm. A single-center, retrospective, observational study was conducted between January 2011 and January 2022. Preoperative, procedural, and follow-up data were derived from electronic health records. Imaging included computed tomography scans, and/or duplex ultrasound examination. The primary end point was the prevalence of T2EL diagnosed within 1 year after EVAR. Secondary end points included the prevalence of T2EL throughout follow-up, early (≤30 days) and late (>30 days) T2EL, the rate of T2EL disappearance during the follow-up period, the prevalence of type I and III endoleak, and T2EL-related reinterventions. Follow-up was available for 394 patients, 245 in the PE and 149 in the PTFE group. The prevalence of T2EL diagnosed within 1 year after endovascular repair was 11.8% in the PE group and 21.5% in the PTFE group (P =.010). There was no significant difference in early (≤30 days) and late (>30 days) T2EL between groups (P =.270 and P =.311). There was no difference in the freedom from endoleak type II reinterventions between groups (P =.877). The prevalence of T2EL after elective EVAR is significantly higher with the use of PTFE-based endografts compared with PE-based endografts. This difference is mostly based on T2EL diagnosed after 30 days of follow-up. [ABSTRACT FROM AUTHOR]

Tribological applications of polytetrafluoroethylene (PTFE) are often limited by technological complexity to overcome its poor wear resistance. Here, a PTFE/polyetheretherketone (PEEK) heterolayer (HL) was proposed and evaluated as a new solid lubrication solution. Pin-on-disk tribometry found the lowest friction coefficient (μ) of 0.031 and ultralow wear for the PEEK/HL under typical conditions. The friction coefficient of the HL surpasses those of the state-of-the-art polymeric coatings/composites by at least 200%, and approaches that of highly lubricated interfaces. Mechanistic investigations revealed multi-length physical and chemical heterogeneity of the HL that best facilitates a tribofilm with high subsurface stability and surface instability. The technological simplicity and robustness of the HL's high lubricity make it a promising new type of solid lubrication toward greater reliability and longevity. [ABSTRACT FROM AUTHOR]

In order to enhance the wear resistance of 6061 aluminum alloy, the MAO-PVA/PTFE self-lubricating composite coating was prepared on the surface of aluminum alloy using microarc oxidation (MAO) technology and solgel technique. Scanning electron microscopy and X-ray diffraction were employed to analyze the morphological properties and structures of the single MAO coating and the composite coating. Energy-dispersive spectroscopy was utilized to examine the elements present on the surface and within the wear track. Ball and disk friction tests were conducted to evaluate the wear resistance of the composite coating. Furthermore, the comprehensive friction performance of the composite coating was investigated across a range of speed variations (1 to 2.5 cm/s) and load variations (1 to 7 N). The test results revealed that the PVA-PTFE film covered the surface of the MAO coating, effectively sealing the micropores. Compared to the single MAO coating, the average coefficient of friction (COF) of the composite coating decreased significantly from 0.549 to 0.139, resulting in improved wear resistance. Moreover, the COF of the composite coating decreased with increasing velocity and load. Subsequently, the wear mechanisms of both the single MAO coating and the composite coating were discussed. The main wear mechanisms observed in the MAO coating were adhesive wear and abrasive wear, while the MAO-PVA/PTFE composite coating exhibited minimal fatigue and oxidation wear. Consequently, the composite coating effectively enhanced the wear resistance of the aluminum alloy, leading to an improved service life. [ABSTRACT FROM AUTHOR]

A new type of composite lubricant was prepared and its friction and wear characteristics were studied. The lubricant formula was optimized through the uniform design method, a model was established with SPSS and Matlab softwares, and results were analyzed by Intuitive analysis and regression analysis. The polytetrafluoroethylene (PTFE) was added to prepare a new type of composite lubricant p2, the lubricant contact friction status was analyzed to determine whether the friction coefficient of the contact surface had significantly reduced, and various properties of the metal were further analyzed. The results show that friction coefficients of lubricant p2 added with PTFE have reduced by 51.26% and 29.81% compared with dry friction and lubricant pi respectively. Observing the morphology of the wear scars, it is found that the friction film can make the metal flow more uniform during the forming process, reduce the deformation force, and effectively avoid a variety of forming defects. [ABSTRACT FROM AUTHOR]

Abstract Tribological applications of polytetrafluoroethylene (PTFE) are often limited by technological complexity to overcome its poor wear resistance. Here, a PTFE/polyetheretherketone (PEEK) heterolayer (HL) was proposed and evaluated as a new solid lubrication solution. Pin-on-disk tribometry found the lowest friction coefficient (μ) of 0.031 and ultralow wear for the PEEK/HL under typical conditions. The friction coefficient of the HL surpasses those of the state-of-the-art polymeric coatings/composites by at least 200%, and approaches that of highly lubricated interfaces. Mechanistic investigations revealed multi-length physical and chemical heterogeneity of the HL that best facilitates a tribofilm with high subsurface stability and surface instability. The technological simplicity and robustness of the HL’s high lubricity make it a promising new type of solid lubrication toward greater reliability and longevity.

Recently, the lubricating devices for the feed systems of computer numerical control (CNC) machine tools supply oil periodically because programmable logic controller and macro are adopted for designing oil supply for the present CNC machine tools, causing lack or overdose lubrication. This study attempts to discuss and design the optimum lubrication cycle timing for the feed system under the experimental conditions of different loads and feed rates. The parameters of the servomotor are monitored by utilizing an intelligent module, the changes in the current and torque of the servomotor are obtained, and then a lubrication module is created with the Stribeck friction model, a modeling that utilizes response surface methodology. The increase in feed rate will cause increasing current and torque, and the current and torque for the load 35 kg were 11 and 13%, respectively. Finally, different loads and feed rates are imported to determine optimal lubrication timing. According to a long-term validation, the oil supply frequency is improved by over 80% without influencing the feed system accuracy, and the traditional lubrication module is compared with the lubrication module. Long time test is 8 h, and the rate of improvement is 87.5%, the cost of lubricating oil is reduced, and green manufacturing is met. An appropriate oil supply system is provided for the circle.

Lithium-ion batteries (LIBs) have recently become popular for energy storage due to their high energy density, storage capacity, and long-term cycle life. Although binders make up only a small proportion of LIBs, they have become the key to promoting the transformation of the battery preparation process. Along with the development of binders, the battery manufacturing process has evolved from the conventional slurry-casting (SC) process to a more attractive solvent-free (SF) method. Compared with traditional LIBs manufacturing method, the SF method could dramatically reduce and increase the energy density due to the reduced preparation steps and enhanced electrode loading. Polytetrafluoroethylene (PTFE), as a typical binder, has played an important role in fabricating high-performance LIBs, particularly in regards to the SF technique. In this paper, the development history and application status of PTFE binder was introduced, and then its contributions and the inherent problems involved in the SF process were described and analyzed. Finally, the viewpoints concerning the future trends for PTFE-based SF manufacturing methods were also discussed. We hope this work can inspire future research concerning high-quality SF binders and assist in promoting the evolution of the SF manufacturing technology in regards to LIBs. [ABSTRACT FROM AUTHOR]

Arterial thoracic outlet syndrome (aTOS) due to subclavian arterial compression at the thoracic outlet, represents the least common type of TOS (< 1%) among the three: neurogenic (nTOS), venous (vTOS), and arterial (aTOS), and it requires surgical intervention in almost all the cases, being a constant threat to limb if remains untreated. This study analyses all aTOS patients admitted and managed at two vascular centres, over a span of 8 years. In our study, we had twenty-four limbs with arterial TOS, distributed among 23 patients (bilateral cervical rib in one), mean age of presentation was 38.85 years with male predominance. Fourteen out of 24 limbs (58.33%) had chronic, eight (33.33%) had an acute presentation and two limbs (8.34%) were asymptomatic. Rest pain was the most common symptom seen in 10 (41.67%) limbs. Complete/partial cervical rib was observed in 37.5% (9/24) and 62.5% (15/24) of cases, respectively. All patients of aTOS underwent thoracic outlet decompression (TOD): as a standalone procedure in five, combined with reinforced synthetic interposition graft in 10, and with thrombectomy by Seldinger technique using a Fogarty catheter, in eight patients. Three patients (12.5%) developed post-op complications: arm haematoma, Graft Thrombosis, and haemothorax; however, no limb loss or mortality was observed during the period of follow-up. Considering the unusual and varied presentation, limb and life-threatening complications of aTOS, early detection, and appropriate management (Open/Endovascular/Hybrid) is of paramount importance for optimal outcome. [ABSTRACT FROM AUTHOR]

Large defects in the congenital diaphragmatic hernia (CDH) are treated by prosthetic materials, most frequently polytetrafluoroethylene (PTFE), with high complications. The purpose of this study is to develop a novel electrospun double-faced prosthesis that will minimize these surgical complications. Polyamide 6 (PA-6) and thermoplastic polyurethane (TPU) nanofibers were prepared by solution electrospinning, and room temperature vulcanized silicone (RTV) was used in electrospinning by dip-coating to develop a double-faced membrane. The results demonstrate that the duration of electrospinning and thickness of silicone layers influence the morphology of the bilayer scaffolds. Electrospun bilayer polyamide 6/silicone and thermoplastic polyurethane/silicone scaffolds are fabricated as potential substitutes for prosthetic membrane applications in this study. The morphology, topography, mechanical, and biological properties of these electrospun meshes have been reported to make adequate conclusions in in vitro studies. The morphological characterizations show two distinct layers of electrospun and silicone layer which can mimic the morphology of PTFE prosthesis. However, the mechanical results of the developed TPU/Silicone membrane demonstrate improved mechanical properties. In addition, the biological tests confirm the biocompatibility of the developed prosthesis. [ABSTRACT FROM AUTHOR]

Abstract Polytetrafluoroethylene (PTFE) has been widely used as a lubrication additive for reducing friction and wear; however, the hydrophobic nature of PTFE restricts its application in eco-friendly water-based lubrication systems. In this study, for the first time, we designed novel PTFE@silica Janus nanoparticles (JNs) to meet the requirement for additives in water-based lubricants, which have excellent dispersion stability in water attributed to the unique amphiphilic structure. By introducing the lubrication of the aqueous dispersion of the JNs with a concentration of 0.5 wt%, the coefficient of friction (COF) and wear volume were reduced by 63.8% and 94.2%, respectively, comparing to those with the lubrication of pure water. Meanwhile, the JNs suspension also exhibits better lubrication and wear-resistance performances comparing to commercial silica and PTFE suspensions. The excellent tribological behaviors of PTFE@silica JNs as nano-additives could be attributed to the synergetic effect of the two components, where the PTFE provided lubrication through the formed tribofilms on the friction pairs, and the rigid silica further enhanced the wear-resistance performance. Most importantly, the unique structure of JNs makes it possible to use PTFE as an additive in water-lubrication systems. Our study shed light on the design and application of novel JNs nanomaterials as additives to meet the requirements of future industrial applications.

Polytetrafluoroethylene (PTFE) is a potential candidate for the fabrication of flexible electronics devices and electronics with applications in various extreme environments, mainly due to its outstanding chemical and physical properties. However, to date, the utilization of PTFE in printing trials has been limited due to the material's low surface tension and wettability, which do not ensure good adhesion of the printing ink at the level of the substrate. Within this paper, successful printing of PTFE is realized after pre-treating the surface of the substrate with the help of dielectric barrier discharge non-thermal plasma. The efficiency of the pre-treatment is demonstrated with respect to both silver- and carbon-based inks that are commercially available, and finally, the long-lasting pre-treatment effect is demonstrated for periods of time spanning from minutes to days. The experimental results are practically paving the way toward large-scale utilization of PTFE as substrate in fabricating printed electronics in harsh working environments. After 3 s of plasma treatment of the foil, the WCA decreased from approximately 103° to approximately 70°. The resolution of the printed lines of carbon ink was not time dependent and was unmodified, even if the printing was realized within 1 min from the time of applying the pre-treatment or 10 days later. The evaluation of the surface tension (σ) measured with Arcotest Ink Pink showed an increase in σ up to 40 < σ < 42 mN/m for treated Teflon foil and from σ < 30 mN/m corresponding to the untreated substrate. The difference in resolution was distinguishable when increasing the width of the printed lines from 500 μm to 750 μm, but when increasing the width from 750 μm to 1000 μm, the difference was minimal. [ABSTRACT FROM AUTHOR]

Herein, polytetrafluoroethylene (PTFE) is evaluated as a reinforcement agent in material extrusion (MEX) additive manufacturing (AM), aiming to develop nanocomposites with enhanced mechanical performance. Loadings up to 4.0 wt.% were introduced as fillers of polylactic acid (PLA) and polyamide 12 (PA12) matrices. Filaments for MEX AM were prepared to produce corresponding 3D-printed samples. For the thorough characterization of the nanocomposites, a series of standardized mechanical tests were followed, along with AFM, TGA, Raman spectroscopy, EDS, and SEM analyses. The results showed an improved mechanical response for filler concentrations between 2.0 and 3.0 wt.%. The enhancement for the PLA/PTFE 2.0 wt.% in the tensile strength reached 21.1% and the modulus of elasticity 25.5%; for the PA12/PTFE 3.0 wt.%, 34.1%, and 41.7%, respectively. For PLA/PTFE 2.0 wt.%, the enhancement in the flexural strength reached 57.6% and the modulus of elasticity 25.5%; for the PA12/PTFE 3.0 wt.%, 14.7%, and 17.2%, respectively. This research enables the ability to deploy PTFE as a reinforcement agent in the PA12 and PLA thermoplastic engineering polymers in the MEX AM process, expanding the potential applications. [ABSTRACT FROM AUTHOR]

Shallow Hilbert curve patterns with easily programmable texture density were selected for laser texturing of stainless steel substrates. Two different texture path segment lengths (12 and 24 µm) and four different laser power percentages (5%, 10%, 15%, and 20%) were investigated. The textured and smooth substrates were coated with thin polydopamine/polytetrafluoroethylene (PDA/PTFE) coatings for tribological property assessment. The effects of texture density (texture area coverage) and laser power on the durability and friction of the coated surfaces were studied. Laser texturing the substrates improved the coating durability up to 25 times, reduced the friction coefficient, and prevented coating global delamination. The textures fabricated with a laser power of 15% and a texture path segment length of 12 µm yielded the best coating durability. The textures provided the interlocking for the PTFE coating and thus prevented its global delamination. Furthermore, the PTFE inside the texture grooves replenished the solid lubricant worn away in the wear track and prolonged the coating wear life. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) was mixed with silicon carbide nanoparticles in various quantities to create thin films. Long-term UV light exposure to the PTFE films was used to study the effects of SiC NPs as a photo-stabilizer by assessing changes in weight loss and surface shape. Comparing PTFE films with various SiC NP concentrations to the blank film, very little variation was seen. AFM and optical microscopy were also used to analyze the surface morphology of films. When PTFE films with additives were compared to blank film, there were hard to observe any negative changes brought due to photo-degradation. Additionally, the surfaces appeared more uniformly smooth hence SiC NPs work well as photo-stabilizers to impede photo-degradation, particularly 0.0005 gm weight. Silicon carbide nanoparticles absorb ultraviolet light, bind polymeric chains, scavenge radical moieties, and degrade peroxide residues.

Abstract Shallow Hilbert curve patterns with easily programmable texture density were selected for laser texturing of stainless steel substrates. Two different texture path segment lengths (12 and 24 µm) and four different laser power percentages (5%, 10%, 15%, and 20%) were investigated. The textured and smooth substrates were coated with thin polydopamine/polytetrafluoroethylene (PDA/PTFE) coatings for tribological property assessment. The effects of texture density (texture area coverage) and laser power on the durability and friction of the coated surfaces were studied. Laser texturing the substrates improved the coating durability up to 25 times, reduced the friction coefficient, and prevented coating global delamination. The textures fabricated with a laser power of 15% and a texture path segment length of 12 µm yielded the best coating durability. The textures provided the interlocking for the PTFE coating and thus prevented its global delamination. Furthermore, the PTFE inside the texture grooves replenished the solid lubricant worn away in the wear track and prolonged the coating wear life.

Molecular models and sandwiched friction models of pure PTFE and h‐BN/PTFE composite were respectively constructed to investigate the enhancement of mechanical and tribological performances of the polytetrafluoroethylene (PTFE) matrix by incorporating the hexagonal boron nitride (h‐BN) nanosheets as reinforcements. The simulation results indicate that increases of 36.4% in the Young's modulus, 23.6% in the bulk modulus, and 37.3% in the shear modulus of the PTFE matrix are achieved respectively by the incorporation of h‐BN nanosheets. Decreases of 3.48% and 10.27% in the Poisson's ratio and the ratio of bulk modulus to shear modulus of the PTFE matrix are also observed due to the incorporation of h‐BN nanosheets, which shows that the ductility of the PTFE matrix could be somewhat decreased with the addition of h‐BN nanosheets. Additionally, decreases of 69.23% and 69.06% in the coefficient of friction and friction stress of the PTFE matrix are obtained respectively with the introduction of h‐BN nanosheets. To provide in‐depth insight into the internal reason for these findings, the interaction energy between the PTFE matrix and h‐BN nanosheets, the MSD and diffusion coefficient of PTFE chains, and the RDF of carbon and fluorine atoms in the PTFE backbone chains were evaluated and interpreted accordingly. [ABSTRACT FROM AUTHOR]

Freezing on asphalt roads affects driving safety. Spraying salt on roadways pollutes the environment. Mechanical deicing requires significant human and financial resources. This paper proposes a new approach to realize autonomous anti-icing of asphalt pavement, an acrylic/polytetrafluoroethylene coating (APC). The contact angle of a water droplet on the APC surface is 155.392°. Moreover, the freezing time of water droplets on the APC-coated asphalt mixture is 1.5 times longer than that of the uncoated asphalt mixture. Moreover, the skid resistance test results show that APC can increase the road friction coefficient, which is 1.2 times that of ordinary pavement. The water permeability test results confirm that APC can prevent water from penetrating into the road surface. In summary, APC improves the anti-icing performance of asphalt pavements and exhibits excellent anti-slip and waterproof properties. [ABSTRACT FROM AUTHOR]

In orthodontic treatment, to achieve efficient tooth movement, it is important to reduce the frictional force between the wire and the bracket, especially the binding friction that occurs when the angle between the wire and the bracket is large. Electroless nickel–polytetrafluoroethylene (Ni-PTFE) coating is a coating technology used to deposit PTFE particles with a low coefficient of friction on the coating surface to provide a low-friction surface for metallic materials. The purpose of this study was to investigate the effect of Ni-PTFE-coated orthodontic wires on the frictional force between brackets. The surface morphology, surface roughness, and frictional properties of Ni-PTFE-coated stainless steel wires and Ni-Ti wires were evaluated. The results demonstrate that the Ni-PTFE coating reduced the frictional force between the orthodontic wires and brackets, despite the increased surface roughness. Even when the angle between the wire and bracket was increased, assuming binding friction, the frictional force was reduced by the Ni-PTFE coating. This suggests that the friction between the wire and the bracket was suppressed by the PTFE particles deposited on the wire surface in contact with the bracket.

Efficient transportation requires minimal frictional resistance. Skidding has become an alternative method of transporting heavy structures in recent years. The static coefficient of friction plays an important role in determining whether the piston force in the thrust direction is sufficient to counteract the horizontal frictional force caused by the structure’s weight. This study aimed to determine various static coefficient of friction values for PolyTetraFluoroEthylene (PTFE) and glass-reinforced PTFE-C15 materials on steel skids. The research presents the influence of lubrication and the reduction of surface roughness on the static coefficient of friction. We designed six combinations of experiments for 10 repetitions for PTFE and PTFE-C15 under dry, oiled, and oil lubrication with added weight conditions. An inclined plane method was used to investigate and compare the coefficients of friction values of pure PTFE and glass-reinforced PTFE-C15 materials on a steel surface. The steel surface roughness was reduced by grinding to an average Ra value of 2.8 to minimize adhesion, which created a vacuum effect during the test. The application of added weight onto the specimens overcame the vacuum effect. PTFE-C15 in oil lubrication with added weight demonstrated the lowest coefficient of friction. However, it is noteworthy that pure PTFE had better performance than PTFE-C15 when both were oil-lubricated. These results provide essential data for precise engineering calculations to determine the required piston force and total number of pistons for loading heavy structures.

Dump trucks are widely used in the construction industry. When sand is discharged from a dump truck bed, the friction with the bed causes sand to remain on the bed. Therefore, it is desirable to develop a technology to adhere low-friction fluororesin to the steel plates of a truck bed. This study develops a technique for directly joining dissimilar materials, namely steel and polytetrafluoroethylene (PTFE), using one-sided seam welding and investigates the effects of heat input and pressure conditions on joining quality. The joining conditions that affect joining quality are examined. The results show that tensile shear strength tends to increase with increasing heat input. Furthermore, it is found that the amount of PTFE deformation and the fracture morphology during tensile testing change with roller pressurization. For a one-sided seam welding machine, the anchor effect occurs between the electrodes with roller pressurization but does not occur without roller pressurization. It is also found that the type of anchor effect (dense or dispersed) depends on whether roller pressure is applied. Furthermore, it is suggested that the amount of deformation of PTFE during tensile testing is different caused by the different form of occurrence of the anchor effect. It was assumed that the fracture morphology of PTFE changed as the amount of deformation increased during the tensile test, approaching the elongation limit of PTFE. Furthermore, when the rollers were cooled to increase the cooling function of the rollers, the number of anchors was found to be lower than when the rollers were not cooled. This result suggested that the thermal contraction of the PTFE during cooling causes the PTFE in the concave area to peel off. From these results, it is assumed that the reason for the dispersed anchor effect is due to the influence of heat removal by the roller pressurization.

The aim of the work was to investigate the possible biodegradation of such stable plastics as fluorated acrylic copolymer Protacryl-M and polytetrafluoroethylene—teflon (PTFE)—that are widely applied in medicine for prosthetics in dentistry and orthopedics. Our tasks were as follows: To select a suitable marine biological object (multicellular invertebrate) To develop a method for delivering microplastic particles (MP) of selected plastics to the gastrointestinal tract (GIT) of an experimental animal To develop a technique for separating MP particles from animal feces To develop a technology for multiple passages of MP particles through the gastrointestinal tract of an animal To select methods and techniques for determining the degradation of the surface of MP particles after passing through the gastrointestinal tract of the animal The effect of a biological agent on the types of plastic above is considered using marine gastropods of the genus Littorina (in particular, the periwinkle L. brevicula) as a model organism widely distributed in the marine intertidal zone. [ABSTRACT FROM AUTHOR]

Guided bone regeneration (GBR) has become a clinically standard modality for the treatment of localized jawbone defects. Barrier membranes play an important role in this process by preventing soft tissue invasion outgoing from the mucosa and creating an underlying space to support bone growth. Different membrane types provide different biological mechanisms due to their different origins, preparation methods and structures. Among them, collagen membranes have attracted great interest due to their excellent biological properties and desired bone regeneration results to non-absorbable membranes even without a second surgery for removal. This work provides a comparative summary of common barrier membranes used in GBR, focusing on recent advances in collagen membranes and their biological mechanisms. In conclusion, the review article highlights the biological and regenerative properties of currently available barrier membranes with a particular focus on bioresorbable collagen-based materials. In addition, the advantages and disadvantages of these biomaterials are highlighted, and possible improvements for future material developments are summarized. [ABSTRACT FROM AUTHOR]

The influence of polytetrafluoroethylene (PTFE) processing in sc-CO2 and sc-PFO above the melting point on the microstructure and characteristics of phase transitions is studied using high-resolution scanning electron microscopy and differential scanning calorimetry (DSC). It is shown that, depending on the crystallization conditions, after the processing of PTFE in the supercritical fluid, the formation of a microstructure with a radial orientation of fibrils atypical for this polymer is possible. The processing of PTFE in the supercritical fluid leads to an irreversible increase in the heat of melting and crystallization and, accordingly, to an increase in the degree of crystallinity by 1.5–2 times compared to the initial values. The growth in the crystallinity is explained by a change in the microstructure of the PTFE melt in the supercritical fluid: the release of a part of segments of macromolecules from physical knots during the process of swelling and plasticization of the polymer matrix. Disentanglement of such knots that limit molecular mobility contributes to an increase in the number of macromolecular units involved in the formation of crystalline domains and to an irreversible increase in the degree of crystallinity. [ABSTRACT FROM AUTHOR]

Achieving optimal thermal performance in large membrane-enclosed buildings presents a significant challenge. Aerogel mats offer potential for enhanced insulation, but their effectiveness in varying seasonal conditions is yet to be fully determined. The current study investigates the thermal performance of an enclosed dome with double-layered PTFE membrane roof integrated with aerogel-glass wool insulation mats. This research utilizes field experiments to assess indoor thermal comfort and numerical model to evaluate the effectiveness of the dome's insulation capabilities during summer and winter conditions. The Aerogel integrated areas show a difference of 10.26/3.72 °C for summer/winter while that of 9.36/3.22 °C for glass wool-integrated areas. An online thermal comfort tool utilized maximum indoor temperature values during both seasons obtained from numerical results indicating that winter comfort falls within ASHRAE comfort range with PMV value −0.48 but summer conditions require enhancements. Additionally, the study assessed the insulation's effectiveness using Maximum Reduction in Temperature (MRT), Decay Factor (DF), and Time Delay (TD) indicators. Results showed significant thermal lag, with peak temperature delays of up to 3.1 h in summer and 2.2 h in winter. Notable temperature differences between the dome's inner and outer surfaces, alongside 28 % and 27 % DF reductions during summer and winter, respectively, demonstrated the roof insulation's effectiveness. These findings support the use of both experimental and numerical methods to develop thermal management practices that improve sustainable building design, emphasizing occupant comfort and energy efficiency. [ABSTRACT FROM AUTHOR]

Lithium-ion batteries (LIBs) have recently become popular for energy storage due to their high energy density, storage capacity, and long-term cycle life. Although binders make up only a small proportion of LIBs, they have become the key to promoting the transformation of the battery preparation process. Along with the development of binders, the battery manufacturing process has evolved from the conventional slurry-casting (SC) process to a more attractive solvent-free (SF) method. Compared with traditional LIBs manufacturing method, the SF method could dramatically reduce and increase the energy density due to the reduced preparation steps and enhanced electrode loading. Polytetrafluoroethylene (PTFE), as a typical binder, has played an important role in fabricating high-performance LIBs, particularly in regards to the SF technique. In this paper, the development history and application status of PTFE binder was introduced, and then its contributions and the inherent problems involved in the SF process were described and analyzed. Finally, the viewpoints concerning the future trends for PTFE-based SF manufacturing methods were also discussed. We hope this work can inspire future research concerning high-quality SF binders and assist in promoting the evolution of the SF manufacturing technology in regards to LIBs.

Hilbert curve patterns were laser-textured on both stainless steel substrates and polytetrafluoroethylene (PTFE) thin coatings by applying 15% and 5% of the 2.3-W full laser power, respectively. The nanomechanical and tribological behavior of both smooth and laser-textured PTFE coatings on both smooth and laser-textured stainless steel substrates were studied. It was found that laser-texturing thin PTFE coatings reduced the hardness of PTFE coatings and prevented the coating from tearing under nanoindenter scratches. Furthermore, laser-texturing on both PTFE coatings and the stainless steel substrate improved the coating wear life 29 times compared to the wear life of the control sample without any laser textures.

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The problem of bacterial contamination through surfaces is important for the food industry. In this regard, there is a growing interest in new coatings based on nanoparticles that can provide a long-term antibacterial effect. Aluminum oxide nanoparticles are a good candidate for such coatings due to their availability and good biocompatibility. In this study, a coating containing aluminum oxide nanoparticles was produced using polytetrafluoroethylene as a polymer matrix—a polymer that exhibits excellent mechanical and physicochemical properties and it is not toxic. The obtained coatings based on "liquid Teflon" containing various concentrations of nanoparticles (0.001–0.1 wt%) prevented the bacterial growth, and they did not exhibit a cytotoxicity on animal cells in vitro. Such coatings are designed not only to provide an antibacterial surface effect, but also to eliminate micro damages on surfaces that inevitably occur in the process of food production. [ABSTRACT FROM AUTHOR]

All-nanofiber self-powered device was fabricated using simple, low-cost, safe, and scalable solution blow spinning (SBS) technology for real-time respiratory monitor and timely identification of respiratory obstruction clinically. Polytetrafluoroethylene (PTFE) and polyamide-66 (PA66) nanofibers were selected as triboelectric pairs, owing to strong ability to gain electrons of PTFE and supply electrons of PA66. Poly (ethylene oxide) (PEO) was added to regulate spinning solution viscosity and prepare PTFE/PEO nanofibers, and the morphology and diameter distribution of nanofibers were discussed. PTFE nanofiber film was obtained after the decomposition of PEO in PTFE/PEO nanofiber and melt flow of PTFE pellets in a limited region, and possessed a tensile strength of 1.05 MPa and elongation at a break of 288.58%. Later, PTFE/PA66 all-nanofiber self-powered device was constructed containing PA66 nanofibers, and Au deposition film was used as electrodes by magnetron sputtering. The as-obtained device showed robust electrical performance with an open circuit voltage of ∼ 110 V at a loading force of 10 N, a short-circuit current of ∼ 5 uA at a loading force of 10 N and a frequency of 4 Hz, a maximum power density of 562 mW·m−2, and a current of 3.1 uA at a loading resistance of 30 MΩ. Based on the triboelectric mechanism, the device possessed stable response and effective sensibility for stimuli, was used to monitor human breathing conditions, prevent suffocation, and distinguish slow, normal, and fast breathing, with an output voltage of ∼ 0.08 V perceived in one normal respiratory circle. [ABSTRACT FROM AUTHOR]