Synthesis and Characterization of Enhanced Proton-Conducting Nafion<sup>® </sup>117- Silica Composite Membranes for Fuel Cell Applications DOI
Mayetu Segale, Touhami Mokrani, Rudzani Sigwadi

et al.

Journal of nano research, Journal Year: 2024, Volume and Issue: 82, P. 95 - 116

Published: April 8, 2024

Nafion ® /silica nanocomposite membranes were prepared by impregnation method from 117 and sol-gel pre-synthesized n-octadecyl-trimethoxy silane (C 18 TMS) coated silica nanoparticles. The scanning electron microscope (SEM) of pristine particles displayed monodispersed nanospheres with diameters ranging 150-350 nm; while Brunauer-Emmett-Teller (BET) analysis presented 760 m 2 /g BET surface area, a micropore-mesopore bimodal distribution micropore systems respective pore volume at 14.6 Å 17.0 (2.01 x 10 -3 cm 3 /g.Å), as well the prolific mesopores centered 29.5 (5.64 -2 /g.Å). Characterization based on SEM, Fourier transform infrared spectroscopy (FTIR), thermogravimetric (TGA), x-ray diffraction (XRD), tensile stress exhibited varying morphology loadings, structural interaction between membrane support ion exchanger, thermal stabilities (up to 330 °C), crystalline nature, reasonable mechanical stability membranes. maximum water uptake (44.8 %) proton conductivity (1.14 x10 S/cm) obtained low /SiO (5%) loaded membrane. While both composite improved reduction in methanol permeability, 2.43x10 -07 /s 80 °C was high (10%) loading. Improved substantiate exchange capacity (IEC) 1.81 meq.g -1 when compared IEC 0.93 [pristine ] 1.46 [Nafion (10%)]. increase value may be due acid functionalization additional sulfonic groups surrounded hydrophilic segments nanosilica, which improves properties coupled great retention capabilities indicated that could utilized for medium temperature fuel cells. Keywords: Fuel cells; membrane; SiO nanofillers; permeability;

Language: Английский

Direct Defluorination and Amination of Polytetrafluoroethylene and Other Fluoropolymers by Lithium Alkylamides DOI Creative Commons
Guillaume Herlem, Yaëlle Roina, Mathieu Frégnaux

et al.

Molecules, Journal Year: 2024, Volume and Issue: 29(13), P. 3045 - 3045

Published: June 26, 2024

Polytetrafluoroethylene (PTFE) and, by extension, fluoropolymers are ubiquitous in science, life, and the environment as perfluoroalkyl pollutants (PFAS). In all cases, it is difficult to transform these materials due their chemical inertness. Herein, we report a direct amination process of PTFE some such polyvinylidene fluoride (PVDF) Nafion lithium alkylamide salts. Synthesizing reactants extemporaneously between metal an aliphatic primary di- or triamine that also serves solvent leads rapid nucleophilic substitution moiety when contact with fluoropolymer. Moreover, alkylamides dissolved suitable solvents other than amines can react fluoropolymers. This highly efficient one-pot opens way for further surface bulk modification if needed, providing easy, inexpensive, fast experiment protocol on large scales.

Language: Английский

Citations

1
Remediation of Fluoride-Contaminated Wastes: Chelator-Assisted Washing and Subsequent Immobilization Using CaO and H3PO4 DOI

Tomoya Mizuishi,

Shafiqur Rahman,

Kaori Mitsuboshi

et al.

Chemosphere, Journal Year: 2024, Volume and Issue: unknown, P. 143431 - 143431

Published: Sept. 1, 2024

Language: Английский

Citations

1
TFE Terpolymers: Once Promising – Are There Still Perspectives in the 21st Century? Part II: Processing, Properties, Applications DOI
Salim Ok, Martin Steinhart,

Bruno Améduri

et al.

Macromolecular Rapid Communications, Journal Year: 2024, Volume and Issue: 45(23)

Published: Oct. 1, 2024

Abstract Tetrafluoroethylene (TFE) terpolymers have emerged as advantageous substitutes for polytetrafluoroethylene (PTFE). Therefore, they are being considered alternatives to PTFE in many application areas. The advantages of TFE include their facile processability at elevated temperatures, solubility some polar organic solvents, inertness against aqueous acids, bases and a large number mostly nonpolar low dielectric constant, refractive index well useful electro‐ thermochemical properties. This review on focuses processing including shaping surface modification selected properties wettability, properties, mechanical response behavior, chemical stability, degradability. Applications use elastomeric sealing material, liner cladding layer material membranes, microfluidic devices, photonics, photovoltaics, energy storage, harvesting, sensors, nanothermitic composites will be discussed. concludes with discussion the future potential scientific challenges addressed by research terpolymers.

Language: Английский

Citations

1
A Critical Update on the Design of Dense Ion‐Conducting Membranes for Redox Flow Batteries DOI

Francesca Niccolai,

Elisa Guazzelli,

Zakaria El Koura

et al.

Advanced Sustainable Systems, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 27, 2024

Abstract Recent progress in the design and preparation of dense ion‐conducting membranes, to improve redox flow batteries (RFBs) performance are critically examined. The ideal membrane has balance a high ionic conductivity, low crossover ion/redox‐active species, coulombic voltage efficiencies. Several ion exchange membranes analyzed, with focus on proton (PEMs), that most mature technology RFBs, led by gold standard Nafion. Key developments include synthesis tailored (co)polymers, post‐functionalization commercially available ones, formation techniques like electrospinning, polymer blending, additions organic inorganic fillers, surface modification. Dense, asymmetric composite reported discussed. effects properties macromolecular parameters (polymer backbone, type length side chains, acidity ion‐exchanging group) highlighted. Correlations between chemical structure, discussed, targeting trade‐off selectivity overall RFB cell. Although significant steps forward development were made, improvements electrochemical long‐term stability, while reducing costs, still challenging necessary large‐scale application RFBs.

Language: Английский

Citations

1
Synthesis and Characterization of Enhanced Proton-Conducting Nafion<sup>® </sup>117- Silica Composite Membranes for Fuel Cell Applications DOI
Mayetu Segale, Touhami Mokrani, Rudzani Sigwadi

et al.

Journal of nano research, Journal Year: 2024, Volume and Issue: 82, P. 95 - 116

Published: April 8, 2024

Nafion ® /silica nanocomposite membranes were prepared by impregnation method from 117 and sol-gel pre-synthesized n-octadecyl-trimethoxy silane (C 18 TMS) coated silica nanoparticles. The scanning electron microscope (SEM) of pristine particles displayed monodispersed nanospheres with diameters ranging 150-350 nm; while Brunauer-Emmett-Teller (BET) analysis presented 760 m 2 /g BET surface area, a micropore-mesopore bimodal distribution micropore systems respective pore volume at 14.6 Å 17.0 (2.01 x 10 -3 cm 3 /g.Å), as well the prolific mesopores centered 29.5 (5.64 -2 /g.Å). Characterization based on SEM, Fourier transform infrared spectroscopy (FTIR), thermogravimetric (TGA), x-ray diffraction (XRD), tensile stress exhibited varying morphology loadings, structural interaction between membrane support ion exchanger, thermal stabilities (up to 330 °C), crystalline nature, reasonable mechanical stability membranes. maximum water uptake (44.8 %) proton conductivity (1.14 x10 S/cm) obtained low /SiO (5%) loaded membrane. While both composite improved reduction in methanol permeability, 2.43x10 -07 /s 80 °C was high (10%) loading. Improved substantiate exchange capacity (IEC) 1.81 meq.g -1 when compared IEC 0.93 [pristine ] 1.46 [Nafion (10%)]. increase value may be due acid functionalization additional sulfonic groups surrounded hydrophilic segments nanosilica, which improves properties coupled great retention capabilities indicated that could utilized for medium temperature fuel cells. Keywords: Fuel cells; membrane; SiO nanofillers; permeability;

Language: Английский

Citations

0