Porous PTFE Research Articles

Highly flexible SCOF proton exchange membrane reinforced with PTFE to enhance fuel cell power density

Sulfonated covalent organic frameworks (SCOFs) facilitate rapid proton conduction through densely ordered sulfonic acid groups, however, the brittleness of COFs self-supporting membranes often makes potential difficulty in fuel cell assembly and limits their power density. Herein, a highly flexible SCOF proton exchange membrane is developed through in-situ growth of a continuous BD(SO3H)2-COF microphase within porous PTFE networks. The strong hydrogen bonding between PTFE and BD(SO3H)2-COF contributes to the defect-free morphology of the BD(SO3H)2/PTFE membrane. The reinforce of PTFE network makes the membrane extremely high flexibility, achieving an elongation at break of 124.4% even with a remarkably high SCOF mass proportion of 90 wt.% (BD(SO3H)2/PTFE-0.9). This allows the membrane to be folded repeatedly, even in dry state. The swelling ratio in water at 80 °C is effectively restricted to 8.6%, even with a high ion exchange capacity of 3.6 mmol g-1 and a water uptake of 68.2%. The densely ordered sulfonic acid groups in continuous BD(SO3H)2-COF microphase contribute to a high proton conductivity up to 249.2 mSꞏcm-1 at 80°C, approximately 1.5 folds that of Nafion 212. As a result, the BD(SO3H)2/PTFE-0.9 membrane achieves a fuel cell power density of 1195.3 mWꞏcm-2 at 80°C, along with a high open circuit voltage of 1.01 V, surpassing the-state-of-the-art COF-based proton exchange membranes. This work provides a novel strategy to fabricate COFs into flexible and size scalable membranes, enhancing the performance of fuel cells.

Developing high-flux dense Janus membrane with robust wetting and scaling resistance: A systematic comparison with Omniphobic membranes

Membrane wetting, scaling and low flux are challenging obstacles for membrane distillation (MD). However, the lack of advanced membranes capable of achieving both high flux and high wetting/scaling resistance constrains MD potential applications. Herein, a dense Janus membrane (JM) was facilely developed by co-depositing a dense PVA/PDA layer on a highly porous PTFE substrate to overcome this dilemma and systematically compared with omniphobic PTFE substrates with varied pore sizes for the first time. Results showed that, unlike flux-resistance “trade-off” observed for PTFE substrates, dense JM effectively resisted 0.4 mM SDS at a high flux of 56.8 LMH and retarded membrane scaling by 20 mM oversaturated gypsum. Robust wetting resistance was primarily attributed to the sieving effect of the sub-nanometer surface layer, which greatly protected substrate from SDS adsorption and feed intrusion, and was less affected by severe surface concentration polarization and relatively low substrate LEP than PTFE substrates. Strongly polar PVA/PDA layer provided a much more thermodynamically unfavorable continuous interface for gypsum adhesion than PTFE substrates, which played a key role in determining anti-scaling behavior. In contrast, gypsum still tended to rapidly cause membrane scaling in stagnant zones within PTFE substrates when flux was increased. This study shall provide new insights in designing high-performance membranes for robust hypersaline wastewater treatment, and highlighting dense JMs with a macroporous substrate and a highly hydrophilic dense surface layer as ideal alternatives.

Novel zirconium phosphate/MXene/ionic liquid membranes for PEM fuel cells operating up to 145°C

In this work, zirconium phosphate, MXene, and a hexyl-based ionic liquid were incorporated into a porous PTFE polymer to synthesize novel composite proton exchange membranes (PEM) for fuel cell applications. The synthesized composite membranes were evaluated for their conductivity at temperatures above the boiling point of water as well as their water uptake properties, thermal stability, surface morphology, and structural characteristics via several characterization techniques. It was observed that the inclusion of MXene had a direct impact on the thermal stability of these membranes and caused substantial structural modifications within the membrane’s matrix. The fabricated membranes displayed a high proton conductivity at room temperature, reaching a peak of approximately 10−2 S/cm when all materials were combined. The membranes exhibited good proton conductivity of 10−4 S/cm at high temperature ranges up to 145℃ and appeared to be stable at higher temperatures, as thermogravimetric analyses showed. The results reported here demonstrate the suitability of the MXene-based synthesized membranes for hydrogen-fueled PEM fuel cell applications. This, in turn, will contribute to enhanced energy efficiency and cleaner energy transition.

A durable, breathable, and weather-adaptive coating driven by particle self-assembly for radiative cooling and energy harvesting

The imperative to attain net-zero emissions emphasizes energy conservation. Radiative cooling stands out as a compelling technology in this pursuit for its self-sufficiency and cost-effectiveness. However, the radiative cooling faces the challenge in varied weather, including high ultraviolet (UV), cloudy and rainy days, primarily due to instability of radiative cooling materials and mono-energy conservation mechanism. To address this issue, a durable, breathable, and weather-adaptive coating (porous PTFE coating) has been developed through assembling polyfluortetraethylene (PTFE) nanoparticles enabled by the differential interaction in a binary-solvent system. The porous PTFE coating exhibits high solar reflectivity (94%) and thermal emissivity (93%), which results from the precisely tunable assembly of PTFE nanoparticles, forming a desired porous morphology. This design serves as effective scattering, achieving a sub-ambient cooling effect of approximately 5 ℃ at midday. With an outstanding UV protection factor (UPF) of 179.15, the porous PTFE coating sustained stability after 40 days exposure to solar radiation. Leveraging the porous PTFE coating's exceptional negative triboelectric effect, an engineered high-performance droplet electricity nanogenerator (DEG) achieves a notable power density of 153.8 mW/m2, revealing significant potential for raindrop energy harvesting on rainy days. The versatile porous PTFE coating, with its exceptional weather adaptation and UV stability, holds promise for diverse applications, advancing sustainable and efficient energy solutions with reliability in varying conditions.

PTFE-reinforced pore-filling proton exchange membranes with sulfonated poly(ether ether ketone)s and poly(aryl ether sulfone)s

It is a technical challenge to improve the dimensional and chemical stability of pore-filling proton exchange membranes (PEMs) filled with high-sulfonated poly(ether ether ketone) (SPEEK) electrolytes. To solve this issue, double-electrolyte pore-filling PTFE PEMs were prepared by co-filling sulfonated poly(aryl ether sulfone) (SPAES) and SPEEK in this work. Utilizing ethanol hydrophilic pre-treatment, the double-electrolyte can be efficiently and uniformly infused into the porous PTFE, resulting in a compact, homogeneous and defect-free membrane. The existence of low-sulfonated SPAES40 in the double-electrolyte demonstrates a quite positive effect on inhibiting the dissolution of high-sulfonated SPEEK70 at high temperatures and controlling membrane swelling. Consequently, the PTFE/SPEEK-SPAES membrane shows 103.4 % higher proton conductivity, 33.6 % and 21.5 % lower in-plane and through-plane swelling than the control PTFE/SPEEK70 membrane at 90 °C. Moreover, heat treatment further enhances the mechanical and antioxidant characteristics of the membrane by forming –SO2- crosslinking. The resulting thermally cross-linked membrane exhibits 76.5 % lower oxidation mass loss, 70.4 % and 38.2 % higher elongation at break and tensile stress than the control PTFE/SPEEK70 membrane. After 48 h fuel cell operation, the output voltage of the PTFE/SPEEK-SPAES(1:1)* membrane only decreases by 3.6 %, which is better than the control PTFE/SPEEK70 membrane (46.2 %). This proves that a double-electrolyte pore-filling membrane is an efficient and facile method to strengthen the stability of PEMs.

Development of a Carbon Nanotube-Enhanced FAS Bilayer Amphiphobic Coating for Biological Fluids.

This study reports the development of a novel amphiphobic coating. The coating is a bilayer arrangement, where carbon nanotubes (CNTs) form the underlayer and fluorinated alkyl-silane (FAS) forms the overlayer, resulting in the development of highly amphiphobic coatings suitable for a wide range of substrates. The effectiveness of these coatings is demonstrated through enhanced contact angles for water and artificial blood plasma fluid on glass, stainless steel, and porous PTFE. The coatings were characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), atomic force microscopy (AFM), and contact angle (CA) measurements. The water contact angles achieved with the bilayer coating were 106 ± 2°, 116 ± 2°, and 141 ± 2° for glass, stainless steel, and PTFE, respectively, confirming the hydrophobic nature of the coating. Additionally, the coating displayed high repellency for blood plasma, exhibiting contact angles of 102 ± 2°, 112 ± 2°, and 134 ± 2° on coated glass, stainless steel, and PTFE surfaces, respectively. The presence of the CNT underlayer improved plasma contact angles by 29%, 21.7%, and 16.5% for the respective surfaces. The presence of the CNT layer improved surface roughness significantly, and the average roughness of the bilayer coating on glass, stainless steel, and PTFE was measured to be 488 nm, 301 nm, and 274 nm, respectively. Mechanistically, the CNT underlayer contributed to the surface roughness, while the FAS layer provided high amphiphobicity. The maximum effect was observed on modified glass, followed by stainless steel and PTFE surfaces. These findings highlight the promising potential of this coating method across diverse applications, particularly in the biomedical industry, where it can help mitigate complications associated with device-fluid interactions.

Porous Polyethylene Supports in Reinforcement of Multiblock Hydrocarbon Ionomers for Proton Exchange Membranes.

Hydrocarbon (HC)-based block copolymers have been recognized as promising candidates for proton exchange membranes (PEMs) due to their distinct hydrophilic-hydrophobic separation, which results in improved proton transport compared to that of random copolymers. However, most PEMs derived from HC-based ionomers, including block copolymers, encounter challenges related to durability in electrochemical cells due to their low mechanical and chemical properties. One method for reinforcing HC-based ionomers involves incorporating the ionomers into commercially available low surface tension PTFE porous substrates. Nevertheless, the high interfacial energy between the hydrocarbon-based ionomer solution and PTFE remains a challenge in this reinforcement process, which necessitates the application of surface energy treatment to PTFE. Here, multiblock sulfonated poly(arylene ether sulfone) (SPAES) ionomers are being reinforced using untreated PE on the surface, and this is compared to reinforcement using surface-treated porous PTFE. The PE support layer exhibits a lower surface energy barrier compared to the surface-treated PTFE layer for the infiltration of the multiblock SPAES solution. This is characterized by the absence of noticeable voids, high translucency, gas impermeability, and a physical and chemical stability. By utilizing a high surface tension PE support with a comparable value to the multiblock SPAES, effective reinforcement of the multiblock SPAES ionomers is achieved for a PEM, which is potentially applicable to various hydrogen energy-based electrochemical cells.

Construction of PTFE/Nafion Composite Membrane with Ultrathin Graphene Oxide Layer for Durable Fuel Cells

The long‐term operation of polymer electrolyte membrane fuel cells (PEMFCs) relies heavily on the durability of the perfluorinated sulfonic acid (PFSA, e.g., Nafion) membrane against chemical and mechanical degradation. To mitigate mechanical degradation, the introduction of a reinforcing matrix, such as a porous PTFE sheet, is employed. However, completely impregnating the PFSA ionomer into the PTFE sheet through the conventional blade‐coating method using a highly viscous ionomer solution proves challenging. This limitation results in decreased mechanical and proton transport properties. To reduce proton transport resistance, thinner membrane thickness is desirable, although it increases the amount of gas crossover, which generates radicals and accelerates the chemical degradation of the membrane. In this study, a spraying process utilizing a low viscous‐solvent‐rich ionomer solution is experimentally optimized to construct a well‐impregnated PTFE/Nafion membrane and analyzed using a simple theoretical droplet‐spreading model. Furthermore, an ultrathin graphene oxide (GO) layer is introduced during the membrane fabrication process with the same spraying technique for reducing gas crossover while minimizing performance loss. The membrane electrode assembly (MEA) with the prepared PTFE/Nafion membrane‐incorporated ultrathin GO layer shows significantly greater durability and initial performance compared to the conventional MEA.

Construction of high performance sulfonated aromatic block copolymer/PTFE composite membrane for pervaporation desalination

Pervaporation (PV) has great prospect in desalination of hypersaline water and its application is still limited by lack of high performance membrane with high water flux and good sustainability. This study reported a method of constructing thin film composite (TFC) membrane consisting of sulfonated aromatic polymer (SAP) active layer and porous PTFE substrate for PV desalination. The TFC membrane was fabricated by hydrophilic modification of PTFE support, followed by coating polystyrene-grafted SEBS on the support and post-sulfonation. The modification of PTFE by a strong oxidant introduced oxygen-containing group and tuned its wettability for better adhesion with the active layer. Polystyrene-grafting on SEBS endowed more aromatic groups for sulfonation to attain highly hydrophilic S-SEBS-g-PSt active layer carrying rich sulfonic acid groups. At a higher sulfonation degree (SD) of 60%, the adhesion strength between the active layer and the support was increased to over 1 MPa, and meanwhile the microphase separation of S-SEBS-g-PSt was enhanced with enlarged and more continuous hydrophilic micro-domain and improved water permeation. An ultra-high water permeance of 109, 000–438, 400 GPU was achieved at 45–85 °C. The outstanding performance of this membrane indicates the promising potential of the SAP composite membrane for practical application.

Leaves of Cannabis sativa and their trichomes studied by DESI and MALDI mass spectrometry imaging for their contents of cannabinoids and flavonoids.

In recent years, industrial production of Cannabis sativa has increased due to increased demand of medicinal products based on the plant. In these medicinal products, it is mainly the contents of cannabinoids like THCA and CBDA which are of interest, but also the flavonoids of C. sativa have pharmaceutical interest. The primary aim is to study the distribution of the different cannabinoids in leaves of C. sativa and specifically to which extent they are located on the trichomes found on the surface of C. sativa leaves. Desorption electrospray ionization (DESI) and matrix assisted laser desorption ionization (MALDI) mass spectrometry imaging (MSI) provide non-targeted imaging of numerous compounds in the same experiment. Therefore, the distribution of flavonoids is also mapped in the same experiments. Fan leaves from C. sativa were imaged in the lateral dimension using direct DESI-MSI as well as indirect DESI-MSI via a porous PTFE surface using pixel sizes of 150-200 μm. For cross sections of sugar leaves, MALDI-MSI was performed at 20 μm pixel size. From indirect DESI-MSI experiments, a connection was made between the cannabinoid CBGA and capitate-stalked trichomes. Other cannabinoids like THCA/CBDA (isomers, which are not resolved in an MSI experiment) were also detected in the capitate-stalked trichomes, but in addition to this also in the small glandular trichomes. MALDI-MSI experiments on cross sections of sugar leaves confirmed that the cannabinoids were not an integral part of the leaf tissue itself, but originated from the trichomes on the surface of the leaf. The study provides visual evidence that the cannabinoids are produced and accumulated in the trichomes of C. sativa leaves.

PTFE nanocoating on Cu nanoparticles through dry processing to enhance electrochemical conversion of CO2 towards multi-carbon products

Solvent-free synthesis of porous PTFE thin film coated Cu nanocomposite for selective multi-carbon production from electrochemical CO2 reduction.

Application of Mass Spectrometry Imaging in Evaluating the Spatial Distribution of Aminoacids and Sugars in Basil Leaves upon Long-Time Exposure to Cadmium

Basil samples (Ocimum basilicum Lameaceae) were exposed to cadmium and analyzed on porous PTFE membrane, and TLC plate substrates by desorption electrospray ionization mass spectrometry imaging (DESI-MSI) for amino acids and sugars identification. The TLC plate was the best substrate for analysis of the basil leaves, with high-definition images, small extract scattering, low mass deviations, and excellent reliability in the spatial distribution of the analytes. DESI-MSI analysis identified 13 images of ions putatively annotated as amino acids and sugars with high accuracy (mass deviation between -1.97 to 1.42 ppm) in contaminated and non-contaminated leaves. In general, the amino acids and sugars (proline, histidine, glutamine, arginine, homoarginine, theanine, hexose sugars, and disaccharides) accumulated preferably in basil leaves as a defense mechanism against exposure to cadmium. Asparagine, tyrosine, glutamic acid, and phenylalanine were inhibited when exposed to the toxic element. The images obtained in this study demonstrated the spatial distribution and accumulation of amino acids and sugars in basil leaves as a response to cadmium contamination, confirming that DESI-MSI is a valuable and promising tool for metabolomics studies in plants exposed to toxic metals.

ODP179 Development of Derivatization-free ID-LC/MS/MS Method for Simultaneous Measurement of Human Serum Monosaccharides

Abstract According to the CDC's National Diabetes Statistics Report for 2020, it is estimated that 34.2 million, 10.5% of the U. S. population, have diabetes. High fructose intake has also been associated with increased de novo lipogenesis in the liver leading to non-alcoholic fatty liver disease (NAFLD). Emerging evidence suggests that measuring fructose, galactose, and other saccharides in addition to glucose may be helpful for diagnosis of metabolic disorders and other diseases. Therefore, there is a need for an accurate and precise laboratory method for measuring serum monosaccharide panels. Traditional monosaccharide assays used in patient care often can only quantitate one monosaccharide at a time. We aim to develop a high-throughput analytical method for simultaneous measurement of serum monosaccharides that is suitable for large scale epidemiologic studies. Our assay is based on a derivatization-free ID-LC/MS/MS procedure. Certified primary reference materials of monosaccharides from NIST (Gaithersburg, MD) were used for assay calibration. The serum samples were spiked with 13 C labeled internal standards. The monosaccharides were isolated from serum matrix by acetonitrile protein precipitation and filtration in 96-well filter plate (0.2um, porous PTFE). Aliquot of the acetonitrile filtrate was applied on an AB SCIEX Triple Quad™ 6500 LC/MS/MS system for analysis. The monosaccharides including glucose, galactose, fructose, mannose, and potential interferences were resolved from each other on Unison UK Amino column (3×250mm) eluted with acetonitrile and water gradient. Selective reaction monitoring in negative electrospray ionization mode was used for quantitation of monosaccharides in the samples. The measurement ranges covered 10–402 mg/dL for glucose, which is sufficient to monitor the serum glucose levels in normal, hypo-, and hyperglycemia patient samples. Using 4 levels of NIST SRM 965b (values assigned using GC-MS based reference measurement procedure), the method demonstrated excellent measurement accuracy of over 98% for serum glucose. The imprecision of serum glucose measurement was within 3%. Imprecision and accuracy of lower abundant serum monosaccharides were lower than 6% and above 96%, respectively. The application of 96-well format filter plate and automated liquid handler system significantly improves the throughput of sample preparation. The current analytical method can be used to simultaneously measure the concentrations levels of a panel of serum monosaccharides with appropriate accuracy and precision. Free of derivatization, simple sample procedure and application of automation system significantly improves throughput of the assay which are suitable for routine serum monosaccharides assay in clinical laboratories and for large biomonitoring studies. Presentation: No date and time listed

Scale like Co(OH)2/CoOOH modified platinum catalytic gas diffusion electrode and its application in ammonia detection

Platinum (Pt) is sputtered on porous PTFE membrane as the basic electrode. Cobalt hydroxide catalyst is deposited on the porous platinum/PTFE electrode by an electrochemical assisted deposition method with ammonia gas employed as precipitant. SEM image of the catalyst shows an integration of scale like flake of about 0.5 micrometer in diameter. The XRD analysis suggested that the catalyst is a mixture of β-Co(OH)2 and CoOOH. The mixture is regard as the effective constituent in the ammonia electrode reaction according to the electrochemical analysis. The cyclic voltammogram indicate that at higher than 0.4V (v.s. saturated HgO/Hg electrode reference) the catalytic activity of the working electrode increased significantly. With the modified electrode as working electrode and a pure platinum electrode as assistant electrode, a four electrodes sensor is established to measure ammonia in air successfully.

3D porous PTFE membrane filled with PEO-based electrolyte for all solid-state lithium–sulfur batteries

3D porous PTFE membrane filled with PEO-based electrolyte for all solid-state lithium–sulfur batteries

Liquid-solid triboelectric nanogenerators for a wide operation window based on slippery lubricant-infused surfaces (SLIPS)

Triboelectric nanogenerators (TENG) have emerged as suitable devices that are suitable to harvest widely abundant and renewable blue energy. However, a major drawback in related deployments include the reliability of the system when operating in variable atmospheric conditions. To address this limitation, we propose the integration of slippery lubricant-infused porous surfaces (SLIPS) as key TENG component. For instance, we combine SLIPS with transistor-inspired architectures to develop a robust single-electrode triboelectric nanogenerator (SLIPS-SE-TENG) that is shown to operate effectively under extreme temperature and humidity. For this purpose, we use the energy of water droplets (as in rain) impacting a surface to generate the electrical energy output. Our theoretical calculations and atomic force microscopy measurements show that a small volume of lubricant per surface area (4 μL/ per cm2 of porous PTFE) is sufficient to produce a low water contact angle hysteresis, leading to efficient energy conversion, provided the droplet’s moving velocity on the surface surpasses a threshold (0.3 mm/s). As such, we demonstrate SLIPS-SE-TENG to generate an instantaneous short-circuit current of 3 μA (charge density 8.8 nC/cm2). Importantly, we address the limitations of TENG fabricated with traditional superhydrophobic surfaces, affording a device that works normally and stably in harsh environments, under freezing temperatures or high humidity.

Spray-coated tough thin film composite membrane for pervaporation desalination

Water flux of pervaporation (PV) desalination membranes can be increased by reducing thickness of the selective layer and/or reducing the resistance of the support layer. However, low resistant support layer typically has large surface pores that requires a thick selective layer to avoid fracture. To solve this problem, we used poly(acrylic acid-co-2-acrylamido-2-methyl propane sulfonic acid) (P(AA-AMPS)) to crosslink PVA to improve the mechanical property of the coating layer. The PVA layer was deposited on to a highly porous PTFE substrate via spray-coating. By optimizing the spray-coating conditions, a thin and defect-free P(AA-AMPS) crosslinked PVA/PTFE composite membrane with a selective layer thickness of 1.1 μm was prepared. The water flux of the composite membrane reached to 256.6 ± 31.3 kg/(m2 h) at 75 °C with a NaCl rejection rate over 99.9% when desalinating a 3.5 wt.% NaCl solution. The membrane flux is higher than all reported PV desalination membranes.

Experimental study of gas diffusion layers nonlinear orthotropic behavior

One of the most important components of PEMFC is the gas diffusion layer (GDL), owing to its key role in the reactant diffusion, water management, thermal and electron conductivity. Therefore, the GDL must have an optimal stiffness to ensure these transport functions during numerous hydrothermal cycles. The understanding of its behavior is still a remaining issue. Its orthotropic mechanical behavior requires a series of mechanical characterizations in the plane of the fibers and out of plane. In addition, there are different manufacturing processes for GDL in sheet or roll form to optimize its functional properties. A macro porous layer (MPL) or different PTFE contents might be added by different manufacturers to optimize its performance. In this study, we have performed several mechanical tests differentiating between in plane and out of plane properties in order to characterize different GDLs available on the market. All of the experimental work has been done in the machine (MD) and cross machine direction (CD) according to the fiber orientation. The different GDL types were then classified into categories presenting similar mechanical response.

3D printed field-deployable microfluidic systems for the separation and assay of Pu in nuclear forensics.

A compact field-deployable microfluidic system has been developed to improve timelines for the rapid analysis of debris in post-detonation nuclear forensics. We used a high-resolution 3D printer to miniaturize typical laboratory-based procedures into a fieldable platform. Microfluidic half-modules were produced for the purification of Pu from excess U, along with a portable alpha chamber for the following isotopic analysis of the Pu stream. A porous PTFE membrane is soaked with a hydrophobic tributyl phosphate (TBP) solution and is placed between two half-modules; separation is performed as a liquid-liquid extraction in an extraction channel across this membrane, where the forward and back-extractions occur within one complete module. Following separation, a 100 μL sampling of the Pu-bearing stream is injected into a small-footprint 3D printed alpha chamber for isotopic assay via alpha spectrometry as part of an online process. In this first demonstration of microfluidic separation coupled with online alpha spectrometry, high extraction yields have been obtained for Pu (98.9 ± 4.0)% and U (97.5 ± 2.5)%. The process uses less than 800 μL of solution with separation chemistry complete within 45 minutes and subsequent alpha spectrometry initiating 25 minutes after separation.

Surface hydrophilization toward the proton conductive porous PTFE substrate impregnating SPEEK for polymer electrolyte membranes

Porous poly(tetrafluoroethylene) (PTFE) substrate was impregnated with sulfonated poly(ether ether ketone) (SPEEK) molecules to synthesize the reinforced polymer electrolyte membranes with high dimensional stability and high proton conductivity. During the hydrophilization of the hydrophobic PTFE pore surface with hydroquinone/polyethyleneimine mediator for feasible impregnation of SPEEK molecules, alendronic acid was introduced along to enhance the proton conductivity of the membrane. The chemical composition, morphology, and hydrophilicity of the membrane were examined by XPS, FESEM, and water contact angle measurements to analyze its surface modification effect. Water uptake, swelling ratio, mechanical strength, and proton conductivity of the pore filled membranes were investigated for their application of fuel cell. While the swelling ratio of pore filled membrane was even lower than that of Nafion117 at all temperatures (<15% even at 80 °C), its proton conductivity was comparable to that of Nafion 117. The tensile strength of pore filled membrane, 23.13 MPa, was much higher than that of the pristine SPEEK70 membrane, 12.4 MPa, but similar to that of Nafion in hydrated states.