Browse
Submit Data
Databases
API
Help

Dataset Information

29 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Sulfonated Polysulfone/TiO₂(B) Nanowires Composite Membranes as Polymer Electrolytes in Fuel Cells.

ABSTRACT: New proton conducting membranes based on sulfonated polysulfone (sPSU) reinforced with TiO₂(B) nanowires (1, 2, 5 and 10 wt.%) were synthesized and characterized. TiO₂(B) nanowires were synthesized by means of a hydrothermal method by mixing TiO₂ precursor in aqueous solution of NaOH as solvent. The presence of the TiO₂(B) nanowires into the polymer were confirmed by means of Field Emission Scanning Electron Microscopy, Fourier transform infrared and X-ray diffraction. The thermal study showed an increase of almost 20 °C in the maximum temperature of sPSU backbone decomposition due to the presence of 10 wt.% TiO₂(B) nanowires. Water uptake also is improved with the presence of hydrophilic TiO₂(B) nanowires. Proton conductivity of sPSU with 10 wt.% TiO₂(B) nanowires was 21 mS cm^-1 (at 85 °C and 100% RH). Under these experimental conditions the power density was 350 mW cm^-2 similar to the value obtained for Nafion 117. Considering all these obtained results, the composite membrane doped with 10 wt.% TiO₂(B) nanowires is a promising candidate as proton exchange electrolyte in fuel cells (PEMFCs), especially those operating at high temperatures.

SUBMITTER: Martinez-Morlanes MJ

PROVIDER: S-EPMC8234381 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Similar Datasets

Sulfonated Poly(Arylene Ether Sulfone) and Perfluorosulfonic Acid Composite Membranes Containing Perfluoropolyether Grafted Graphene Oxide for Polymer Electrolyte Membrane Fuel Cell Applications.

Project description:Sulfonated poly(arylene ether sulfone) (SPAES) and perfluorosulfonic acid (PFSA) composite membranes were prepared using perfluoropolyether grafted graphene oxide (PFPE-GO) as a reinforcing filler for polymer electrolyte membrane fuel cell (PEMFC) applications. PFPE-GO was obtained by grafting poly(hexafluoropropylene oxide) having a carboxylic acid end group onto the surface of GO via ring opening reaction between the carboxylic acid group in poly(hexafluoropropylene oxide) and the epoxide groups in GO, using 4-dimethylaminopyridine as a base catalyst. Both SPAES and PFSA composite membranes containing PFPE-GO showed much improved mechanical strength and dimensional stability, compared to each linear SPAES and PFSA membrane, respectively. The enhanced mechanical strength and dimensional stability of composite membranes can be ascribed to the homogeneous dispersion of rigid conjugated carbon units in GO through the increased interfacial interactions between PFPE-GO and SPAES/PFSA matrices.

| S-EPMC6403734 | biostudies-literature

Novel TiO2 Nanoparticles/Polysulfone Composite Hollow Microspheres for Photocatalytic Degradation.

Project description:Nanosized titanium oxide (TiO2) material is a promising photocatalyst for the degradation of organic pollutants, whereas the difficulty of its recycling hinders its practical application. Herein, we reported the preparation of a novel titanium oxide/polysulfone (TiNPs/PSF) composite hollow microspheres by the combination of Pickering emulsification and the solvent evaporation technique and their application for the photodegradation of methyl blue (MB). P25 TiO2 nanoparticles dispersed on the surface of PSF microspheres. The porosity, density and photoactivity of the TiNPs/PSF composite microsphere are influenced by the TiO2 loading amount. The composite microsphere showed good methyl blue (MB) removal ability. Compared with TiO2 P25, and PSF, a much higher MB adsorption speed was observed for TiNPs/PSF microspheres benefited from their porous structure and the electrostatic attractions between the MB+ and the negatively charged PSF materials, and showed good degradation efficiency. For TiNPs/PSF composite microsphere with density close to 1, a 100% MB removal (10 mg L-1) within 120 min at a catalyst loading of 2.5 g L-1 can be obtained under both stirring and static condition, due to well dispersing of TiO2 particles on the microsphere surface and its stable suspending in water. For the non-suspended TiNPs/PSF composite microsphere with density bigger than 1, the 100% MB removal can be only obtained under stirring condition. The removal efficiency of MB for the composite microspheres retained 96.5%, even after 20 cycles. Moreover, this composite microsphere also showed high MB removal ability at acidic condition. The high catalysis efficiency, excellent reusability and good stability make this kind of TiNPs/PSF composite microsphere a promising photocatalyst for the water organic pollution treatment.

| S-EPMC7865213 | biostudies-literature

Polymer and Composite Membranes for Proton-Conducting, High-Temperature Fuel Cells: A Critical Review.

Project description:Polymer fuel cells operating above 100 °C (High Temperature Polymer Electrolyte Membrane Fuel Cells, HT-PEMFCs) have gained large interest for their application to automobiles. The HT-PEMFC devices are typically made of membranes with poly(benzimidazoles), although other polymers, such as sulphonated poly(ether ether ketones) and pyridine-based materials have been reported. In this critical review, we address the state-of-the-art of membrane fabrication and their properties. A large number of papers of uneven quality has appeared in the literature during the last few years, so this review is limited to works that are judged as significant. Emphasis is put on proton transport and the physico-chemical mechanisms of proton conductivity.

| S-EPMC5551730 | biostudies-other

Durable and self-hydrating tungsten carbide-based composite polymer electrolyte membrane fuel cells.

Project description:Proton conductivity of the polymer electrolyte membranes in fuel cells dictates their performance and requires sufficient water management. Here, we report a simple, scalable method to produce well-dispersed transition metal carbide nanoparticles. We demonstrate that these, when added as an additive to the proton exchange Nafion membrane, provide significant enhancement in power density and durability over 100?hours, surpassing both the baseline Nafion and platinum-containing recast Nafion membranes. Focused ion beam/scanning electron microscope tomography reveals the key membrane degradation mechanism. Density functional theory exposes that OH• and H• radicals adsorb more strongly from solution and reactions producing OH• are significantly more endergonic on tungsten carbide than on platinum. Consequently, tungsten carbide may be a promising catalyst in self-hydrating crossover gases while retarding desorption of and capturing free radicals formed at the cathode, resulting in enhanced membrane durability.The proton conductivity of polymer electrolyte membranes in fuel cells dictates their performance, but requires sufficient water management. Here, the authors report a simple method to produce well-dispersed transition metal carbide nanoparticles as additives to enhance the performance of Nafion membranes in fuel cells.

| S-EPMC5583391 | biostudies-literature

ePTFE reinforced, sulfonated aromatic polymer membranes enable durable, high-temperature operable PEMFCs.

Project description:Sulfonated polyphenylene (SPP)-based ionomers have been developed for electrochemical applications in recent years due to their inherent thermal and chemical stability. However, the difficult synthesis, limited solubility, and rigid backbone obstructs their progress. Herein, a new monomer, 3,3″-dichloro-2',3',5',6'-tetrafluoro-1,1':4',1″-terphenyl (TP-f) with high polymerization reactivity was designed and polymerized with sulfonated phenylene monomer to prepare SPP-based ionomers (SPP-TP-f) with high ion exchange capacity up to 4.5 mequiv g-1. The resulting flexible membranes were more proton conductive than Nafion (state-of-the-art proton exchange membrane) even at 120°C and 20% RH. Unlike typical SPP ionomers, SPP-TP-f 5.1 was soluble in ethanol and thus, could be reinforced with double expanded polytetrafluorethylene thin layers to obtain SPP-TP-f 5.1/DPTFE membrane. SPP-TP-f 5.1/DPTFE showed superior fuel cell performance to that of Nafion, in particular, at low humidity (30% RH, > 100°C) and reasonable durability under the severe accelerated conditions combining OCV hold and humidity cycling tests.

| S-EPMC8379343 | biostudies-literature

Composite Sulfonated Polyether-Ether Ketone Membranes with SBA-15 for Electrochemical Energy Systems.

Project description:The aim of this work is the evaluation of a Sulfonated Poly Ether-Ether Ketone (S-PEEK) polymer modified by the addition of pure Santa Barbara Amorphous-15 (SBA-15, mesoporous silica) and SBA-15 previously impregnated with phosphotungstic acid (PWA) fillers (PWA/SBA-15) in order to prepare composite membranes as an alternative to conventional Nafion® membranes. This component is intended to be used as an electrolyte in electrochemical energy systems such as hydrogen and methanol Proton Exchange Membrane Fuel Cell (PEMFC) and Electrochemical Hydrogen Pumping (EHP). The common requirements for all the applications are high proton conductivity, thermomechanical stability, and fuel and oxidant impermeability. The morphology of the composite membranes was investigated by Scanning Electron Microscopy- Energy Dispersive X-ray Spectroscopy (SEM-EDS) analysis. Water Uptake (Wup), Ion Exchange Capacity (IEC), proton conductivity, methanol permeability and other physicochemical properties were evaluated. In PEMFC tests, the S-PEEK membrane with a 10 wt.% SBA-15 loading showed the highest performance. For EHP, the inclusion of inorganic materials led to a back-diffusion, limiting the compression capacity. Concerning methanol permeability, the lowest methanol crossover corresponded to the composites containing 5 wt.% and 10 wt.% SBA-15.

| S-EPMC7178128 | biostudies-literature

Characterization of Polyethylene-Graft-Sulfonated Polyarylsulfone Proton Exchange Membranes for Direct Methanol Fuel Cell Applications.

Project description:This paper examines polymer film morphology and several important properties of polyethylene-graft-sulfonated polyarylene ether sulfone (PE-g-s-PAES) proton exchange membranes (PEMs) for direct methanol fuel cell applications. Due to the extreme surface energy differences between a semi-crystalline and hydrophobic PE backbone and several amorphous and hydrophilic s-PAES side chains, the PE-g-s-PAES membrane self-assembles into a unique morphology, with many proton conductive s-PAES channels embedded in the stable and tough PE matrix and a thin hydrophobic PE layer spontaneously formed on the membrane surfaces. In the bulk, these membranes show good mechanical properties (tensile strength >30 MPa, Young's modulus >1400 MPa) and low water swelling (? < 15) even with high IEC >3 mmol/g in the s-PAES domains. On the surface, the thin hydrophobic and semi-crystalline PE layer shows some unusual barrier (protective) properties. In addition to exhibiting higher through-plane conductivity (up to 160 mS/cm) than in-plane conductivity, the PE surface layer minimizes methanol cross-over from anode to cathode with reduced fuel loss, and stops the HO• and HO?• radicals, originally formed at the anode, entering into PEM matrix. Evidently, the thin PE surface layer provides a highly desirable protecting layer for PEMs to reduce fuel loss and increase chemical stability. Overall, the newly developed PE-g-s-PAES membranes offer a desirable set of PEM properties, including conductivity, selectivity, mechanical strength, stability, and cost-effectiveness for direct methanol fuel cell applications.

| S-EPMC4704017 | biostudies-literature

Assessment of sulfonated homo and co-polyimides incorporated polysulfone ultrafiltration blend membranes for effective removal of heavy metals and proteins.

Project description:Sulfonated homo and co- polyimide (sPI) were synthesized with new compositional ratios, and used as additives (0.5?wt%, 0.75?wt%, and 1.0?wt%) to prepare blend membranes with polysulfone (PSf). Flat sheet membranes for ultrafiltration (UF) were casted using the phase inversion technique. Surface morphology of the prepared UF membranes were characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Surface charge of the membranes were determined by zeta potential, and hydrophilicity was studied by contact angle measurement. The contact angle of the membrane decreased with increasing sPI additive indicates increasing the hydrophilicity of the blend membranes. Filtration studies were conducted for rejection of heavy metals (Pb2+ and Cd2+) and proteins (pepsin and BSA). Blend membranes showed better rejection than pure PSf membrane. Among the blend membranes it was observed that with increasing amount of sPIs enhance the membrane properties and finally, PSf-sPI5 membrane with 1?wt% of sPI5 showed the improved permeability (72.1?L?m-2 h-1 bar-1), and the best rejection properties were found for both metal ions (?98% of Pb2+; ?92% of Cd2+) and proteins (>98% of BSA;?>?86% of Pepsin). Over all, this membrane was having better hydrophilicity, porosity and higher number of sites to attach the metal ions. Its performance was even better than several-reported sulfonic acid based UF membranes. All these intriguing properties directed this new UF membrane for its potential application in wastewater treatment.

| S-EPMC7184734 | biostudies-literature

Efficient Chitosan/Nitrogen-Doped Reduced Graphene Oxide Composite Membranes for Direct Alkaline Ethanol Fuel Cells.

Project description:Herein, we prepared a series of nanocomposite membranes based on chitosan (CS) and three compositionally and structurally different N-doped graphene derivatives. Two-dimensional (2D) and quasi 1D N-doped reduced graphene oxides (N-rGO) and nanoribbons (N-rGONRs), as well as 3D porous N-doped graphitic polyenaminone particles (N-pEAO), were synthesized and characterized fully to confirm their graphitic structure, morphology, and nitrogen (pyridinic, pyrrolic, and quaternary or graphitic) group contents. The largest (0.07%) loading of N-doped graphene derivatives impacted the morphology of the CS membrane significantly, reducing the crystallinity, tensile properties, and the KOH uptake, and increasing (by almost 10-fold) the ethanol permeability. Within direct alkaline ethanol test cells, it was found that CS/N rGONRs (0.07 %) membrane (Pmax. = 3.7 mWcm-2) outperformed the pristine CS membrane significantly (Pmax. = 2.2 mWcm-2), suggesting the potential of the newly proposed membranes for application in direct ethanol fuel cells.

| S-EPMC7916145 | biostudies-literature

Electrospun Nafion®/Polyphenylsulfone Composite Membranes for Regenerative Hydrogen Bromine Fuel Cells.

Project description:The regenerative H₂/Br₂-HBr fuel cell, utilizing an oxidant solution of Br₂ in aqueous HBr, shows a number of benefits for grid-scale electricity storage. The membrane-electrode assembly, a key component of a fuel cell, contains a proton-conducting membrane, typically based on the perfluorosulfonic acid (PFSA) ionomer. Unfortunately, the high cost of PFSA membranes and their relatively high bromine crossover are serious drawbacks. Nanofiber composite membranes can overcome these limitations. In this work, composite membranes were prepared from electrospun dual-fiber mats containing Nafion® PFSA ionomer for facile proton transport and an uncharged polymer, polyphenylsulfone (PPSU), for mechanical reinforcement, and swelling control. After electrospinning, Nafion/PPSU mats were converted into composite membranes by softening the PPSU fibers, through exposure to chloroform vapor, thus filling the voids between ionomer nanofibers. It was demonstrated that the relative membrane selectivity, referenced to Nafion® 115, increased with increasing PPSU content, e.g., a selectivity of 11 at 25 vol% of Nafion fibers. H₂-Br₂ fuel cell power output with a 65 μm thick membrane containing 55 vol% Nafion fibers was somewhat better than that of a 150 μm Nafion® 115 reference, but its cost advantage due to a four-fold decrease in PFSA content and a lower bromine species crossover make it an attractive candidate for use in H₂/Br₂-HBr systems.

| S-EPMC5456663 | biostudies-other