Polytetrafluoroethylene Surface Research Articles

SEM AND IN VIVO STUDY OF ADHESION CHARACTERISTICS OF TITANIUM AND POLYTETRAFLUOROETHYLENE SURFACES HEALING SCREWS

Background: The long-term maintenance of implants and the prostheses they support depends on many factors. Specifically, the patient's biotype is important where the presence of a significant thickness of keratinized gingiva should ensure the presence of a real biological seal, whose formation is also influenced by the healing screw. The healing screws normally used are made of titanium; however, their cost induces the dentist to use them for improper single use. The possibility of using materials other than titanium such as polytetrafluoroethylene (PTFE) for the construction of healing screws can therefore be advantageous. Objectives: The aim of this experimental clinical study is to test new PTFE healing screws by exploiting their chemical-physical characteristics and undoubted economic advantages. Materials and methods: 10 patients were taken into consideration and 2 implants were inserted in each. In each patient in the second phase, a titanium healing screw and a PTFE healing screw were inserted. After 7 days, they were removed to allow analysis under an electron microscope. Results: SEM analysis of the screws showed that the PTFE surface has the ability to accumulate much less organic material than the titanium control screws. Furthermore, PTFE healing screws have been shown to reduce the level of inflammation induced by reuse compared to traditional healing screws. Conclusions: the reduced cost of the PTFE screw, together with the intrinsic characteristics of the material, represent promising characteristics, which can make their use advantageous in clinical practice.

Adhesive strength of ice on solid surfaces under dynamic heating condition

A clear and comprehensive understanding of the dynamic changes in ice adhesion during the operation of thermal de-icing systems on an airplane can help in realizing safer operation of these systems. In this study, we aim to elucidate the ice adhesion decay pattern on different materials under thermal de-icing conditions. Molds are used to form ice on the surfaces of aluminum alloy, stainless steel, titanium alloy, and polytetrafluoroethylene (PTFE), and then their initial and dynamic ice adhesive strengths are measured. The effects of surface roughness and heating rate are also explored. The results show that the residual adhesive strength is almost linearly proportional to the instant temperature before it rises to −0.5 °C for the three types of metallic surfaces. However, for PTFE surfaces, instead of a reduction in the adhesive strength caused by heat, adhesive failure occurs due to the high stress induced by thermal deformation of the substrate. Under dynamic heating conditions, the impact of substrate’s roughness on the adhesive strength is significantly weakened, and the heating rate has a minor effect on the relationship between adhesive strength and instant temperature.

Recombinant Production of Hydrophobin DewA in Pichia pastoris and Determination of Its Functions

Background Hydrophobins have great potential in many biotechnological applications due to changing surface characteristics. In recent years, although there has been a significant increase in the biotechnological applications of hydrophobins, industrial production has still not been achieved due to yield problems. Therefore, more studies are needed on the recombinant production of hydrophobins. In this work, the recombinant production of class I hydrophobin DewA from Aspergillus nidulans, which is determined to have high contact angle in the literature, was aimed. As a result, DewA protein was recombinantly produced using P. pastoris X-33 strain under AOX1 promoter by transferring into pPICZα-A vector. Results The optimal culture condition for DewA expression was obtained at 1% methanol concentration as 77 mg/L in 96 hour. Recombinant DewA has been proven to change the surface characteristics on the teflon and glass surfaces. Then, the surface stability of the protein was evaluated by applying hot SDS and UV to these surfaces. The surface-coated DewA was resistant to hot SDS application on both glass and teflon surfaces; in the UV application, it was understood that while the protein was degraded by UV exposure on glass surfaces, it preserved its structure on teflon surfaces. Conclusions In the study, the DewA protein of A.nidulans was cloned into the pPICZα-A vector and recombinantly produced in the P.pastoris X-33 strain for the first time.

Secondary roughness effect of surface microstructures on secondary electron emission and multipactor threshold for PTFE-filled and PI-filled single ridge waveguides

Secondary electron yield (SEY) is a dominant factor in determining the multipactor threshold. In this study, we analyzed the secondary roughness effect of surface microstructures for plastic dielectric on SEY reduction and multipactor mitigation. A single ridge waveguide (SRW) operating in Ku-band, filled with polytetrafluoroethylene (PTFE) or polyimide (PI), was designed with a dielectric–metal multipactor gap. By employing a femtosecond laser, periodic microstructures were fabricated on PTFE and PI surfaces to suppress SEY. The SEY peak values of PTFE and PI decreased from 2.05 to 1.40 and 1.37 to 1.07 by the porous surface. The surface morphologies and cross-sectional images of the porous PTFE and PI demonstrated the existence of secondary roughness structures. Via simulation, we obtained multipactor thresholds of 8496 W, 12 374 W, and 9397 W for the SRWs filled with untreated PTFE surface, ideal porous surface (without secondary roughness), and real porous surface (with secondary roughness). Similar works were implemented for the PI-filled SRWs, resulting in simulated multipactor thresholds of 7640 W, 11 327 W, and 9433 W. The results indicate that the multipactor effect may not be effectively suppressed under the influence of secondary roughness structures such as plastic velvet and foam. Besides, simulation works indicated that the radio frequency electric field could extract secondary electrons from the microstructures, weakening the mitigation effect of microstructures on multipactor. The impact of surface charging on electron motion was also analyzed by considering energy distribution. It was suggested that the surface microstructures of plastic dielectrics lead to a decrease in the surface charge density and the electrostatic field strength, weakening the self-extinguishing effect and lowering the multipactor threshold. This study provides an in-depth analysis of the effect of secondary roughness on SEY and multipactor for organic dielectrics, which makes significant sense for the further investigation of dielectric multipactor.

Electrostatic Field in Contact‐Electro‐Catalysis Driven C−F Bond Cleavage of Perfluoroalkyl Substances

AbstractPerfluoroalkyl substances (PFASs) are persistent and toxic to human health. It is demanding for high‐efficient and green technologies to remove PFASs from water. In this study, a novel PFAS treatment technology was developed, utilizing polytetrafluoroethylene (PTFE) particles (1–5 μm) as the catalyst and a low frequency ultrasound (US, 40 kHz, 0.3 W/cm2) for activation. Remarkably, this system can induce near‐complete defluorination for different structured PFASs. The underlying mechanism relies on contact electrification between PTFE and water, which induces cumulative electrons on PTFE surface, and creates a high surface voltage (tens of volts). Such high surface voltage can generate abundant reactive oxygen species (ROS, i.e., O2⋅−, HO⋅, etc.) and a strong interfacial electrostatic field (IEF of 109~1010 V/m). Consequently, the strong IEF significantly activates PFAS molecules and reduces the energy barrier of O2⋅− nucleophilic reaction. Simultaneously, the co‐existence of surface electrons (PTFE*(e−)) and HO⋅ enables synergetic reduction and oxidation of PFAS and its intermediates, leading to enhanced and thorough defluorination. The US/PTFE method shows compelling advantages of low energy consumption, zero chemical input, and few harmful intermediates. It offers a new and promising solution for effectively treating the PFAS‐contaminated drinking water.

Electrostatic Field in Contact-Electro-Catalysis Driven C-F Bond Cleavage of Perfluoroalkyl Substances.

Perfluoroalkyl substances (PFASs) are persistent and toxic to human health. It is demanding for high-efficient and green technologies to remove PFASs from water. In this study, a novel PFAS treatment technology was developed, utilizing polytetrafluoroethylene (PTFE) particles (1-5 μm) as the catalyst and a low frequency ultrasound (US, 40 kHz, 0.3 W/cm2) for activation. Remarkably, this system can induce near-complete defluorination for different structured PFASs. The underlying mechanism relies on contact electrification between PTFE and water, which induces cumulative electrons on PTFE surface, and creates a high surface voltage (tens of volts). Such high surface voltage can generate abundant reactive oxygen species (ROS, i.e., O2⋅-, HO⋅, etc.) and a strong interfacial electrostatic field (IEF of 109~1010 V/m). Consequently, the strong IEF significantly activates PFAS molecules and reduces the energy barrier of O2⋅- nucleophilic reaction. Simultaneously, the co-existence of surface electrons (PTFE*(e-)) and HO⋅ enables synergetic reduction and oxidation of PFAS and its intermediates, leading to enhanced and thorough defluorination. The US/PTFE method shows compelling advantages of low energy consumption, zero chemical input, and few harmful intermediates. It offers a new and promising solution for effectively treating the PFAS-contaminated drinking water.

Wall loss of semi-volatile organic compounds in a Teflon bag chamber for the temperature range of 262–298 K: mechanistic insight on temperature dependence

Abstract. ​​​​​​​Teflon bag chambers have long been used for investigating atmospheric chemical processes, including secondary organic aerosol formation. The wall-loss process of gas-phase species in Teflon bag chambers has typically been investigated at around room temperature. Recent laboratory studies started employing Teflon bag chambers at sub-273 K conditions for simulating wintertime and upper-tropospheric environments. However, temperature dependence in vapor-wall-loss processes of semi-volatile organic compounds (SVOCs) in a Teflon bag chamber has not been well investigated. In this study, we experimentally investigated wall-loss processes of C14–C19 n-alkanes in a 1 m3 Teflon bag for the temperature range of 262 to 298 K. Enhanced wall losses of the tested n-alkanes were observed following the decrease in temperature. For instance, 65 %​​​​​​​ of C14 n-alkane was lost to the wall 15 h after injection at room temperature, while the corresponding value was 95 % at 262 K. The experimental data were analyzed using a two-layer kinetic model, which considers both absorption of gas-phase species to the surface layer of the Teflon wall and diffusion to the inner layer. The experimental data demonstrated that absorption of gas-phase species by the surface layer was enhanced at lower temperatures. The temperature dependence in absorption was well accounted for using the equilibrium-dissolution model of organic compounds to the Teflon surface by considering reduced saturation vapor pressure at lower temperatures. On the contrary, diffusion of n-alkanes from the surface to the inner layer slowed down at reduced temperatures. Mechanistic studies on these processes will need to be conducted in the future to quantitatively predict the influence of temperature-dependent wall-loss processes of SVOCs on laboratory experimental results.

Identification of chemical species on plasma-treated polytetrafluoroethylene surface by ab-initio calculations of core-energy-level shift in X-ray photoelectron spectra

X-ray photoelectron spectroscopy (XPS) measurements and ab-initio calculations of the XPS chemical shift were performed to identify chemical species on plasma-treated polytetrafluoroethylene (PTFE) surfaces. The obtained C1s-XPS and O1s-XPS spectra confirmed the generation of oxygen-containing functional groups on plasma-treated PTFE surfaces. We investigated the effect of the substitution of F atoms in a CF2– chain by H atoms on the C1s core level binding energy in PTFE; our calculations showed that the C1s core level binding energy is linearly dependent on the number of substituted F atoms. This finding enables us to infer the number of substituted F atoms from the experimentally observed C1s-XPS spectra. We deconvoluted the experimentally observed C1s-XPS spectra of the plasma-treated PTFE surfaces using the calculated binding energies of various functional groups. It is impossible to reproduce the C1s-XPS spectra using the C1s core level binding energies of functional groups in the CF2– chain. However, they can be well reproduced by adding the calculated binding energies of the functional groups in the CH2– chain, indicating the substitution of the F atoms by the H atoms by plasma treatment. Furthermore, the time-of-flight secondary ion mass spectrometry confirmed the existence of H atoms on the plasma-treated PTFE surfaces.

Enhancing gamma irradiation resistance by a‐C film treatment on polytetrafluoroethylene (PTFE) surface

Polytetrafluoroethylene (PTFE) solid self‐lubricating materials exhibit inferior tribological properties in the gamma‐irradiated environment. In this paper, amorphous hydrogen‐free carbon (a‐C) film was deposited on the PTFE polymer surface by magnetron sputtering, and the a‐C/PTFE samples were irradiated with gamma ray at a maximum dose of up to 5 MGy. The evolution of the structure and nanomechanical and tribological properties of a‐C/PTFE with different irradiation doses were investigated. The structural analyses reveal that the microstructure of a‐C films irradiated at 5 MGy doses is stable. Due to the covering of the a‐C film, significant cracks appear at the surface of the a‐C/PTFE sample only when the irradiation dose reaches 5 MGy. Before and after irradiation, the nanohardness and Young's modulus of the a‐C/PTFE are significantly higher than those of PTFE. The mechanical properties of PTFE are improved by a‐C film surface treatment. The friction experiments show that the average friction coefficients of both a‐C/PTFE and PTFE remain stable around 0.175 with increasing irradiation dose. When the irradiation dose is within 1 MGy, frictional behaviors occur only on the surface of a‐C films, and the wear rate of a‐C/PTFE is as low as 9.3 × 10−5 mm3/N.m, which is significantly lower than that of PTFE. The method of a‐C film treatment on the PTFE surface can dramatically improve the irradiation resistance of PTFE.

Preparation of Polytetrafluoroethylene Superhydrophobic Materials by Femtosecond Laser Processing Technology.

In recent years, superhydrophobic surfaces have attracted significant attention due to their promising applications, especially in ice prevention, reduction in air resistance, and self-cleaning. This study utilizes femtosecond laser processing technology to prepare different surface microstructures on polytetrafluoroethylene (PTFE) surfaces. Through experiments, it investigates the relationship between the solid-liquid contact ratio and surface hydrophobicity. The shape of water droplets on different microstructure surfaces is simulated using ANSYS, and the relationship between surface microstructures and hydrophobicity is explored in the theoretical model. A superhydrophobic surface with a contact angle of up to 166° was obtained by machining grooves with different spacings in polytetrafluoroethylene sheets with femtosecond laser technology. Due to the micro- and nanostructures on the surface, the oleophobicity of the processed oleophilic PTFE surface is enhanced.

Visualizing Water Monomers and Chiral OH-(H2O) Complexes Infiltrated in a Macroscopic Hydrophobic Teflon Matrix.

Insights into the interaction of fluoroalkyl groups with water are crucial to understanding the polar hydrophobicity of fluorinated compounds, such as Teflon. While an ordered hydrophobic-like 2D water layer has been demonstrated to be present on the surface of macroscopically hydrophobic fluorinated polymers, little is known about how the water infiltrates into the Teflon and what is the molecular structure of the water infiltrated into the Teflon. Using highly sensitive femtosecond sum frequency generation vibrational spectroscopy (SFG-VS), we observe for the first time that monomeric H2O and chiral OH-(H2O) complexes are present in macroscopically hydrophobic Teflon. The species are inhomogeneously distributed inside the Teflon matrix and at the Teflon surface. No water clusters or single-file water "wires" are observed in the matrix. SFG free induction decay (SFG-FID) experiments demonstrate that the OH oscillators of physically absorbed molecular water at the surface dephase on the time scale of <230 fs, whereas the water monomers and hydrated hydroxide ions infiltrated in the Teflon matrix dephase much more slowly (680-830 fs), indicating that the embedded monomeric H2O and OH-(H2O) complexes are decoupled from the outer environment. Our findings can well interpret ultrafast water permeation through fluorous nanochannels and the charging mechanism of Teflon, which may tailor the desired applications of organofluorines.

Hydrophilic Nature of Polytetrafluoroethylene through Modification with Perfluorosulfonic Acid-Based Polymers

Polytetrafluoroethylene (PTFE), commercially known as Teflon, is a fluoropolymer with a structure containing (CF2–CF2)n. It has high resistance to acids, alkalis and corrosive chemicals. PTFE is hydrophobic in nature with a water contact angle of 140°. Being hydrophobic in nature is a knotty problem, particularly in electrical applications, as it may lead to short circuits and result in reducing the lifetime of electrical equipment. Herein we describe the surface modification of PTFE from hydrophobic to hydrophilic without altering its bulk property. The surface hydrophilicity is achieved by two different techniques, viz., polymer coating (aquivion and nafion) and plasma treatment. Several characterization techniques including FTIR, Raman, XPS, WCA and SEM were used to analyze the surface of PTFE. It was found that 5% of the polymer solution and N2 plasma treatment for 2 min can produce huge differences in the surface property, as evidenced by the reduction in water contact angle from 140° (neat Teflon) to 80° (surface-modified Teflon). The surface morphology of neat PTFE is completely changed and collapsed as evidenced by the SEM images. The FTIR, Raman and XPS analyses confirm the presence of additional hydrophilic functional groups after the polymer coating and plasma treatment. Hence, this method represents a unique approach to modifying the surface property of Teflon, while maintaining its bulk property.

Percolative Charge Transport on Electrified Surface of Polytetrafluoroethylene

Percolative Charge Transport on Electrified Surface of Polytetrafluoroethylene

Visualization of Charge Dynamics when Water Droplets Bounce on a Hydrophobic Surface.

Visualizing the motion of water droplets and understanding their electrification behavior holds significance for applications related to droplet transport, self-cleaning, and anti-icing/deicing and for providing a comprehensive explanation of the solid-liquid triboelectrification mechanism. Here, by constructing microcolumnar structures on the polytetrafluoroethylene surface, a water droplet-based single electrode triboelectric nanogenerator was fabricated for visualizing charge dynamics when a water droplet bounces on a hydrophobic surface. The motion state of the water droplet is closely linked to its electrification behavior through the integration of a high-speed camera and an ammeter. The electrification behavior stemming from the bounce of the water droplet is dynamically captured in real-time. The results show that the magnitude and polarity of the electrical signal have strong dependence on the motion state of the water droplet. For instance, when a water droplet approaches or moves away from the substrate in a single direction, a unipolar electrical signal is generated. However, when the water droplet reaches its limit in the initial motion direction, it signifies a static equilibrium state, resulting in the electrical signal being at zero. Furthermore, we examine the impact of factors such as impact speed, drop contact area, contact line spreading/retraction speed, and impact angle on electrification. Finally, based on the close relationship between poly(ethylene oxide) (PEO) droplet bounce dynamics and electrical signals, the bouncing details of PEO droplets with different concentrations are tracked by electrical signals. This study digitally presents the whole process of droplet bounce in situ and provides a means for monitoring and tracking droplet movement.

The roles of undercooling degree and materials surface configuration in the growth mechanism of ice layer caused by micro-droplets

Effect mechanisms of the undercooling degree and the surface configuration on the ice growth characteristics were revealed under micro-droplets icing conditions. Preferential ice crystals appear firstly on the surfaces due to the randomness of icing, and obtain growth advantages to form protruding structures. Protruding structures block the incoming droplets from contacting the substrates, causing voids around the structures. The undercooling degree mainly affects the density and the growth rate of preferential ice crystals. With the increase of undercooling degree, the preferential ice crystals have higher density and growth rate, resulting in stronger growth advantage and higher porosity. The surface configuration affects the growth mode, and the ice layer grows with uniform mode, spreading mode and structure-induced mode on the aluminum, smooth Polytetrafluoroethylene (PTFE) and rough PTFE surface respectively, causing the needle-like, ridge-like and cluster-like ice crystals. The rough structures effectively improve the porosity of the ice layer, which is beneficial for optimizing the icephobic property of the materials. This paper provides important theoretical guidance for the design of subsequent icephobic materials.

Electrospun PTFE nanofibrous composite membranes featuring a fiber network structure for organic solvent nanofiltration (OSN)

The practical implementation of organic solvent nanofiltration (OSN) was still hindered by the drawback of substrate swelling and dissolution in organic solvents. As the substrate of nanofiltration membranes, polytetrafluoroethylene (PTFE) had gained increasing attention due to its stable chemical characteristics. However, it was difficult to construct functional nanofiltration layers on the surface of PTFE due to its hydrophobicity induced by its intrinsic low surface energy, resulting into poor adhesion between substrate and functional layer. In this study, a polydopamine (PDA)-PA/PTFE composite nanofiltration membrane with a three-layer was fabricated by utilizing the poly (tetrafluoroethylene-hexafluoropropylene) (FEP) resins as the pore structure regulator of the PTFE substrate with fiber network structure, and PDA as the surface modifier of the PTFE substrate. The resultant composite nanofiltration membrane exhibited a notable rejection rate of 96.26 % for Rose Bengal (RB), and a long-term stable ethanol permeance of 2.28 (L·m−2·h−1·bar−1). After continuous filtration for 48 h, soaking in polar organic solvents (DMF) for 20 days, and circulating experiments exhibiting excellent solvent resistance and long-term stability. These results provided a useful strategy for the application of PTFE nanofiber substrates in the OSN field.

Confined assembly of size-tunable silver nanoprisms on flexible Teflon tapes as highly active SERS hotspots for ultralow-level sensing of DNA and glucose

The design of smart and advanced sensors facilitates highly sensitive optical detection platforms for biomolecules. Herein, we attempted the confined assembly of silver nanoprisms (SNPs) on hydrophobic Teflon tapes to design a highly flexible and ultrasensitive biosensing platform for DNA and glucose. We investigated the sensor characteristics including morphological, optical, and SERS activities as a function of nanoparticle size. Pyramidal SNPs were synthesized, whose size was tuned by varying the bromide ion concentrations. The size of SNPs was decreased with an increase in bromide ion concentrations, where quasi-spherical nanoparticles were formed at higher bromide content. The hydrophobic Teflon surface caused considerable constrain during the evaporation of nanoparticle suspension, leading to highly confined SNPs. SERS activities of Teflon/SNP sensors were tuned by varying the size of SNPs, where a size of ∼34 nm exhibited the highest signal enhancement. The optimum Teflon/SNP sensor showed an enhancement factor of 1.3 × 109 with high stability and excellent reproducibility. Teflon/SNP sensor was further exploited to detect DNA and glucose in a label-free method, exhibiting sensitivities of approximately 13.6 fg/µL and 5 µM, respectively. Real-time monitoring of DNA and glucose from saliva was also investigated. Teflon/SNP substrates were found to be excellent biosensing platforms for ultralow-level sensing of biomolecules in a rapid and cost-effective manner.

Stability of plasma improved adhesive property of polytetrafluoroethylene surface

In this study, the authors investigated the wettability change of atmospheric-pressure-cold-plasma (APCP)-treated polytetrafluoroethylene (PTFE) surfaces with time under different storage temperatures and pressures, and the results indicate that low temperature can hinder wettability recovery. After storage for 5 days, the water contact angle (WCA) of PTFE stored at room temperature (25°C) recovered from 19 ± 2 to 54 ± 2°, while the WCA of PTFE stored at low temperature (−10°C) increased to just 42 ± 3°. Then, the mechanism contributing to the slower wettability recovery was investigated by analyzing surface chemical compositions through X-ray photoelectron spectroscopy and observing surface morphologies using atomic force microscopy. After 15-day storage, the oxygen (O) and nitrogen (N) contents decreased obviously, while the fluorine (F) content increased. The fluorine content of the sample stored at low temperature was 20% less than that of the sample stored at room temperature. In contrast, surface micromorphologies were unchanged during storage, and the surface roughness R a of each sample was around 7 nm. Finally, peel strength tests were conducted on APCP-treated PTFE surfaces stored at different temperatures, and the surfaces stored at low temperature maintained better adhesive properties. After 15 days of storage, the adhesive strength could still reach 400 N/m, which was 376% higher than that of the untreated surface. The research results are expected to facilitate practical applications of APCP modification and PTFE surfaces significantly.

Tribological properties of differently shaped zinc‐based metal‐organic framework particles reinforced epoxy resin composites

AbstractIn this work, two zinc‐based metal–organic frameworks (Zn‐MOFs) with different morphologies were successfully produced by the surfactant‐mediated synthesis method. They were grown on the Polytetrafluoroethylene (PTFE)/polydopamine (PDA) to prepare PTFE/PDA/Zn‐MOFs fiber fabrics. Then the epoxy resin (EP) matrix was poured onto fabrics to prepare EP/PTFE/PDA/Zn‐MOF. PTFE was modified by introducing a PDA adhesion layer, which can provide absorption sites for Zn‐MOFs growth and improve the bonding strength with EP. The microscopic morphologies and structures of the PTFE and modified PTFE were studied. Compared with pure EP, the friction coefficient and specific wear rate of the EP/PTFE/PDA/ZnMOF2 composite were reduced by 67% and 91%, and the EP/PTFE/PDA/ZnMOF1 composite were reduced by 55% and 88%, respectively, which were due to the loading of ZnMOF2 onto the PTFE surface, improving the interfacial bonding between the PTFE and EP matrix and can prevent the PTFE fabric from coming out of the EP matrix. ZnMOF2 also presents its structural advantage: the unique thin layer structure plays a vital role in friction and wear reduction.

Rapid Transformation in Wetting Properties of PTFE Membrane Using Plasma Treatment.

In this paper, we describe the surface modification of polytetrafluoroethylene (PTFE) through the plasma treatment process. Several parameters including different active gases, RF power, distance between the plasma source and sample, and plasma duration were optimized to reduce the hydrophobic nature of PTFE. Three different active gases were used (i.e., N2, O2, and (Ar+H2)); N2 was effective to reduce the hydrophobicity of PTFE within a shorter plasma duration of 2 min. Several surface characterizations including ATR-FTIR, water contact angle, FE-SEM, and XPS were utilized to verify the neat and modified PTFE surface after plasma treatment. The plasma treatment using N2 as an active gas improved the wettability of the PTFE membrane, showing a water contact angle of 109.5° when compared with the neat PTFE (141.9°). The SEM images of plasma-treated PTFE showed greater modifications on the surface indicating non-uniform fiber alignment and torn fibers at several places. The obtained results confirm the fact that plasma treatment is an effective way to modify the PTFE surface without altering its bulk property.