Morphological Differences in Short Side Chain and Long Side Chain Perfluorosulfonic Acid Proton Exchange Membranes at Low and High Water Contents

2014 ◽  
Keyword(s):  
High Water ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Side Chain ◽  
Perfluorosulfonic Acid ◽  
Short Side ◽  
Acid Proton ◽  
Morphological Differences ◽  
Water Contents

scholarly journals Chemically stabilised extruded and recast short side chain Aquivion® proton exchange membranes for high current density operation in water electrolysis

2019 ◽  
Vol 578 ◽  
pp. 136-148 ◽  
Author(s):  
Stefania Siracusano ◽  
Claudio Oldani ◽  
Maria Assunta Navarra ◽  
Stefano Tonella ◽  
Lucia Mazzapioda ◽  
...  
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Water Electrolysis ◽  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Side Chain ◽  
High Current ◽  
Short Side

scholarly journals Effect of perfluorosulfonic acid side chains on oxygen permeation in hydrated ionomers of PEMFCs: Molecular dynamics simulation approach

2020 ◽  
Author(s):  
Sung Hyun Kwon ◽  
Haisu Kang ◽  
Young-Jun Sohn ◽  
Jinhee Lee ◽  
Sunbo Shim ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Water Content ◽  
Polymer Electrolyte Membrane ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Side Chain ◽  
Side Chains ◽  
Perfluorosulfonic Acid ◽  
Short Side ◽  
Water Contents

Abstract We prepared two types of perfluorosulfonic acid (PFSA) ionomers with Aquivion (short side chain) and Nafion (long side chain) on a Pt surface and varied their water contents (2.92 ≤ λ ≤ 13.83) to calculate the solubility and permeability of O2 in hydrated PFSA ionomers on a Pt surface using full atomistic molecular dynamics (MD) simulations. The solubility and permeability of O2 molecules in hydrated Nafion ionomers were greater than those of O2 molecules in hydrated Aquivion ionomers at the same water content, indicating that the permeation of O2 molecules in the ionomers is affected not only by the diffusion coefficient of O2 but also by the solubility of O2. Notably, O2 molecules are more densely distributed in regions where water and hydronium ions have a lower density in hydrated Pt/PFSA ionomers. Radial distribution function (RDF) analysis was performed to investigate where O2 molecules preferentially dissolve in PFSA ionomers on a Pt surface. The results showed that O2 molecules preferentially dissolved between hydrophilic and hydrophobic regions in a hydrated ionomer. The RDF analysis was performed to provide details of the O2 location in hydrated PFSA ionomers on a Pt surface to evaluate the influence of O2 solubility in ionomers with side chains of different lengths. The coordination number of C(center)–O(O2) and O(side chain)–O(O2) pairs in hydrated Nafion ionomers was higher than that of the same pairs in hydrated Aquivion ionomers with the same water content. Our investigation provides detailed information about the properties of O2 molecules in different PFSA ionomers on a Pt surface and with various water contents, potentially enabling the design of better-performing PFSA ionomers for use in polymer electrolyte membrane fuel cells.

Proton exchange membranes based on the short-side-chain perfluorinated ionomer

2005 ◽  
Vol 145 (2) ◽  
pp. 108-115 ◽  
Author(s):  
A. Ghielmi ◽  
P. Vaccarono ◽  
C. Troglia ◽  
V. Arcella
Keyword(s):  
Proton Exchange Membranes ◽  
Proton Exchange ◽  
Side Chain ◽  
Short Side

scholarly journals Superior Proton Exchange Membrane Fuel Cell (PEMFC) Performance Using Short-Side-Chain Perfluorosulfonic Acid (PFSA) Membrane and Ionomer

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 78
Author(s):  
Nana Zhao ◽  
Zhiqing Shi ◽  
Francois Girard
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Cell Performance ◽  
Superior Performance ◽  
Side Chain ◽  
Perfluorosulfonic Acid ◽  
Short Side ◽  
Fuel Cell Performance ◽  
Exchange Membrane

Optimization of the ionomer materials in catalyst layers (CLs) which sometimes is overlooked has been equally crucial as selection of the membranes in membrane electrode assembly (MEA) for achieving a superior performance in proton exchange membrane fuel cells (PEMFCs). Four combinations of the MEAs composed of short-side-chain (SSC) and long-side-chain (LSC) perfluorosulfonic acid (PFSA) polymers as membrane and ionomer materials have been prepared and tested under various temperatures and humidity conditions, aiming to investigate the effects of different side chain polymer in membranes and CLs on fuel cell performance. It is discovered that SSC PFSA polymer used as membrane and ionomer in CL yields better fuel cell performance than LSC PFSA polymer, especially at high temperature and low RH conditions. The MEA with the SSC PFSA employed both as a membrane and as an ionomer in cathode CL demonstrates the best cell performance amongst the investigated MEAs. Furthermore, various electrochemical diagnoses have been applied to fundamentally understand the contributions of the different resistances to the overall cell performance. It is illustrated that the charge transfer resistance (Rct) made the greatest contribution to the overall cell resistance and then membrane resistance (Rm), implying that the use of the advanced ionomer in CL could lead to more noticeable improvement in cell performance than only the substitution as the membrane.

scholarly journals Molecular dynamics simulation study on the effect of perfluorosulfonic acid side chains on oxygen permeation in hydrated ionomers of PEMFCs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sung Hyun Kwon ◽  
Haisu Kang ◽  
Young-Jun Sohn ◽  
Jinhee Lee ◽  
Sunbo Shim ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Water Content ◽  
Polymer Electrolyte Membrane ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Side Chain ◽  
Side Chains ◽  
Perfluorosulfonic Acid ◽  
Short Side ◽  
Water Contents

AbstractWe prepared two types of perfluorosulfonic acid (PFSA) ionomers with Aquivion (short side chain) and Nafion (long side chain) on a Pt surface and varied their water contents (2.92 ≤ λ ≤ 13.83) to calculate the solubility and permeability of O2 in hydrated PFSA ionomers on a Pt surface using full atomistic molecular dynamics (MD) simulations. The solubility and permeability of O2 molecules in hydrated Nafion ionomers were greater than those of O2 molecules in hydrated Aquivion ionomers at the same water content, indicating that the permeation of O2 molecules in the ionomers is affected not only by the diffusion coefficient of O2 but also by the solubility of O2. Notably, O2 molecules are more densely distributed in regions where water and hydronium ions have a lower density in hydrated Pt/PFSA ionomers. Radial distribution function (RDF) analysis was performed to investigate where O2 molecules preferentially dissolve in PFSA ionomers on a Pt surface. The results showed that O2 molecules preferentially dissolved between hydrophilic and hydrophobic regions in a hydrated ionomer. The RDF analysis was performed to provide details of the O2 location in hydrated PFSA ionomers on a Pt surface to evaluate the influence of O2 solubility in ionomers with side chains of different lengths. The coordination number of C(center)–O(O2) and O(side chain)–O(O2) pairs in hydrated Nafion ionomers was higher than that of the same pairs in hydrated Aquivion ionomers with the same water content. Our investigation provides detailed information about the properties of O2 molecules in different PFSA ionomers on a Pt surface and with various water contents, potentially enabling the design of better-performing PFSA ionomers for use in polymer electrolyte membrane fuel cells.

scholarly journals Improved Thermo-Mechanical Properties and Reduced Hydrogen Permeation of Short Side-Chain Perfluorosulfonic Acid Membranes Doped with Ti3C2Tx

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7875
Author(s):  
Panpan Guan ◽  
Jianlong Lei ◽  
Yecheng Zou ◽  
Yongming Zhang
Keyword(s):  
Mechanical Properties ◽  
Proton Conductivity ◽  
Composite Membrane ◽  
Hydrogen Permeation ◽  
Composite Membranes ◽  
Pem Fuel Cells ◽  
Proton Exchange ◽  
Side Chain ◽  
Perfluorosulfonic Acid ◽  
Short Side

Benefiting from its large specific surface with functional -OH/-F groups, Ti3C2Tx, a typical two-dimensional (2D) material in the recently developed MXene family, was synthesized and used as a filler to improve the properties of the short side-chain (SSC) perfluorosulfonic acid (PFSA) proton exchange membrane. It is found that the proton conductivity is enhanced by 15% while the hydrogen permeation is reduced by 45% after the addition of 1.5 wt% Ti3C2Tx filler into the SSC PFSA membrane. The improved proton conductivity of the composite membrane could be associated with the improved proton transport environment in the presence of the hydrophilic functional groups (such as -OH) of the Ti3C2Tx filler. The significantly reduced hydrogen permeation could be attributed to the incorporation of the impermeable Ti3C2Tx 2D fillers and the decreased hydrophilic ionic domain spacing examined by the small angle X-ray scattering (SAXS) for the composite membrane. Furthermore, improved thermo-mechanical properties of the SSC/Ti3C2Tx composite membrane were measured by dynamic mechanical analyzer (DMA) and tensile strength testing. The demonstrated higher proton conductivity, lower hydrogen permeation, and improved thermo-mechanical stability indicate that the SSC/Ti3C2Tx composite membranes could be a potential membrane material for PEM fuel cells operating above the water boiling temperature.

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