Performance Analysis of Polytetrafluoroethylene as Journal Bearing Material

ACS Appl. Electron. Mater.

Kang

Choi

et al. 2023

Despite the excellent performance of MXene−Ag nanowire (MA) composite transparent conductive electrodes (TCEs), they rapidly and severely degrade in ambient and humid environments. To address this critical issue, we developed conformal polytetrafluoroethylene (PTFE) passivation thin films prepared using magnetron sputtering at room temperature. Compared to the PTFE passivated electrode, the nonpassivated bare MA-composite electrode exhibited a considerably increased sheet resistance, and the electrode flexibility and electromagnetic interference (EMI) shielding efficiency (SE) degraded rapidly over time because the moisture and impurities severely oxidized the MXene layer in the harsh testing environment. However, the MA-composite electrode with PTFE passivation shows constant sheet resistance, transmittance, flexibility, and EMI SE, even after the 85 °C−85% relative humidity (RH) test. Compared to the nonpassivated MA-electrode-based thin film heaters (TFHs), the PTFE-passivated MA-composite electrode-based TFHs exhibited improved stability and reliability, indicating that the sputtered PTFE film effectively prevented the moisture and impurity penetration of the MA-composite electrodes.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Conformal Passivation of Self-Cleanable, Flexible, and Transparent Polytetrafluoroethylene Thin Films on Two-Dimensional MXene and Three-Dimensional Ag Nanowire Composite Electrodes

ACS Appl. Electron. Mater.

Kang

Choi

et al. 2023

“…Also, PTFE has enough thermal ability to withstand even 300 °C, lower surface energy, and self-lubrication property, so it is highly suitable for a thin film passivation of the flexible OMO electrode applied to flexible and transparent TFHs. [39,40] Despite the importance of OMO electrodes, the degradation mechanism of the OMO electrodes and their effective thin film passivation is still under investigation. To apply the OMO electrode in commercial TFHs equipped with smart windows for buildings and automobiles, high-quality thin film passivation prepared by a large area coating process to protect OMO against humidity and impurities should be developed.…”

Section: Introductionmentioning

confidence: 99%

Highly Transparent, Flexible, and Hydrophobic Polytetrafluoroethylene Thin Film Passivation for ITO/AgPdCu/ITO Multilayer Electrodes

Kang

2022

Adv Materials Inter

Transparent and flexible polytetrafluoroethylene (PTFE) thin film passivation for ITO/AgPdCu (APC)/ITO (IAI) electrodes is developed to prevent severe degradation and maintain the reliable performance of the flexible IAI electrodes. Also, oxygen ion beam treatment (IBT) on the surface of the IAI electrode improves the adhesion between the top ITO and PTFE passivation layer, as well as the performance of the passivation layer. The IAI electrode with PTFE passivation exhibits constant sheet resistance, transmittance, and flexibility, even after the 85 °C and 85% RH test. However, the bare IAI electrode shows a significant increase in sheet resistance and a decrease in transmittance and flexibility, owing to the incorporation of moisture and impurities into the IAI layer, and agglomeration of the APC layer. To demonstrate the feasibility of PTFE passivation, the performance of flexible and transparent thin film heaters (TFHs) with the bare IAI and PTEF/IAI samples are compared. The better stability and reliability of the PTFE/IAI‐based TFHs than the bare IAI‐based TFHs indicate that the PTFE film effectively prevents the introduction of moisture and impurities. The performance of the TFH with PTFE/IAI electrode implies that sputtered PTFE film is a promising transparent and flexible thin film passivation for high‐quality oxide‐metal‐oxide multilayer electrodes.

Surf. Topogr.: Metrol. Prop.

“…Ye et al (2016) declared that PTFE composites could generate uniform, cohesive, and protective transfer film on the composite's surface in dry sliding circumstances, improving the friction coefficient and wear rate [13]. However, poor mechanical properties and high wear rate of PTFE are considered as its disadvantages [14]. Weak resistance to wear and abrasion of PTFE leads to premature failure of machine parts [15,16].…”

Section: Introductionmentioning

confidence: 99%

Evaluating the tribological and mechanical properties of filament wound composite incorporated with PTFE fibers and tungsten carbide filler applicable for self-lubricating bearings

Shahramforouz

Hejazi

Taherizadeh

2021

In this paper, tribological and mechanical features of hybrid E-glass+polytetrafluoroethylene (PTFE)/epoxy and Kevlar+PTFE/epoxy self-lubricating composite bearings with different contents of PTFE yarns were studied. Tribological properties, such as friction coefficient, weight loss, and wear rate, were analyzed by using a linear reciprocating tribometer machine under two loads of 30 N and 40 N. For measuring mechanical characteristics of composite samples, the universal testing machine was applied. To investigate the worn surface and transfer film, a scanning electron microscope (SEM) was employed. EDS elemental analysis was also used to inspect the elemental content of the transfer film. To identify whether chemical changes have occurred in the structure of the composite or not, Fourier transform infrared spectroscopy (FTIR) was utilized. The results showed that composites including 20% glass+80% PTFE and 20% Kevlar+80% PTFE exhibited the most effective lubricating performance. The 20% Kevlar+80% PTFE composite has the lowest friction coefficient, and the transfer film remains more stable during the wear test. Transfer film with a large quantity of 'fluorine' and 'carbon' elements was formed on the surface and led to decrease the friction coefficient. It was concluded that the compressive strength of composite declines with increasing the wt.% of PTFE yarn by investigating the mechanical properties. Moreover, the tribological and mechanical properties of 20% Kevlar+80% PTFE composites filled with different wt.% of tungsten carbide (WC) (5%, 10%, 20%, and 30%) were studied. Among these composites, the sample filled with 20% WC filler showed superior tribological and mechanical properties compared to other samples.