Chemical Durability Studies of Perfluorinated Sulfonic Acid Polymers and Model Compounds under Mimic Fuel Cell Conditions

2007 ◽  
Vol 40 (24) ◽  
pp. 8695-8707 ◽  
Author(s):  
Chun Zhou ◽  
Miguel A. Guerra ◽  
Zai-Ming Qiu ◽  
Thomas A. Zawodzinski, ◽  
David A. Schiraldi
Keyword(s):  
Fuel Cell ◽  
Sulfonic Acid ◽  
Chemical Durability ◽  
Model Compounds ◽  
Perfluorinated Sulfonic Acid

Fuel Cell Perfluorinated Sulfonic Acid Membrane Degradation Correlating Accelerated Stress Testing and Lifetime

2012 ◽  
Vol 112 (11) ◽  
pp. 6075-6103 ◽  
Author(s):  
Marianne P. Rodgers ◽  
Leonard J. Bonville ◽  
H. Russell Kunz ◽  
Darlene K. Slattery ◽  
James M. Fenton
Keyword(s):  
Fuel Cell ◽  
Sulfonic Acid ◽  
Stress Testing ◽  
Membrane Degradation ◽  
Perfluorinated Sulfonic Acid

Dynamic Emergence of Nanostructure and Transport Properties in Perfluorinated Sulfonic Acid Ionomers

2020 ◽  
Author(s):  
Adlai Katzenberg ◽  
Debdyuti Mukherjee ◽  
Peter J. Dudenas ◽  
Yoshiyuki Okamoto ◽  
Ahmet Kusoglu ◽  
...  
Keyword(s):  
Rate Constant ◽  
Sulfonic Acid ◽  
Mass Fraction ◽  
Gas Permeability ◽  
Transport Processes ◽  
Segmental Mobility ◽  
The Matrix ◽  
Swelling Rate ◽  
Ion Conducting ◽  
Perfluorinated Sulfonic Acid

<p>Limitations in fuel cell electrode performance have motivated the development of ion-conducting binders (ionomers) with high gas permeability. Such ionomers have been achieved by copolymerization of perfluorinated sulfonic acid (PFSA) monomers with bulky and asymmetric monomers, leading to a glassy ionomer matrix with chemical and mechanical properties that differ substantially from common PFSA ionomers (e.g., Nafion™). In this study, we use perfluorodioxolane-based ionomers to provide fundamental insights into the role of the matrix chemical structure on the dynamics of structural and transport processes in ion-conducting polymers. Through <i>in-situ</i> water uptake measurements, we demonstrate that ionomer water sorption kinetics depend strongly on the properties and mass fraction of the matrix. As the PFSA mass fraction was increased from 0.26 to 0.57, the Fickian swelling rate constant decreased from 0.8 s<sup>-1</sup> to 0.2 s<sup>-1</sup>, while the relaxation rate constant increased from 3.1×10<sup>-3</sup> s<sup>-1</sup> to 4.0×10<sup>-3</sup>. The true swelling rate, in nm s<sup>-1</sup>, was determined by the chemical nature of the matrix; all dioxolane-containing materials exhibited swelling rates ~1.5 - 2 nm s<sup>-1</sup> compared to ~3 nm s<sup>-1</sup> for Nafion. Likewise, Nafion underwent relaxation at twice the rate of the fastest-relaxing dioxolane ionomer. Reduced swelling and relaxation kinetics are due to limited matrix segmental mobility of the dioxolane-containing ionomers. We demonstrate that changes in conductivity are strongly tied to the polymer relaxation, revealing the decoupled roles of initial swelling and relaxation on hydration, nanostructure, and ion transport in perfluorinated ionomers. </p>

scholarly journals Bi-Functional Composting the Sulfonic Acid Based Proton Exchange Membrane for High Temperature Fuel Cell Application

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1000
Author(s):  
Guoxiao Xu ◽  
Juan Zou ◽  
Zhu Guo ◽  
Jing Li ◽  
Liying Ma ◽  
...  
Keyword(s):  
High Temperature ◽  
Fuel Cell ◽  
Composite Membrane ◽  
Sulfonic Acid ◽  
Elevated Temperatures ◽  
Mechanical Stability ◽  
Strong Dependence ◽  
Proton Exchange ◽  
Nafion Membrane ◽  
Silica Nanofiber

Although sulfonic acid (SA)-based proton-exchange membranes (PEMs) dominate fuel cell applications at low temperature, while sulfonation on polymers would strongly decay the mechanical stability limit the applicable at elevated temperatures due to the strong dependence of proton conduction of SA on water. For the purpose of bifunctionally improving mechanical property and high-temperature performance, Nafion membrane, which is a commercial SA-based PEM, is composited with fabricated silica nanofibers with a three-dimensional network structure via electrospinning by considering the excellent water retention capacity of silica. The proton conductivity of the silica nanofiber–Nafion composite membrane at 110 °C is therefore almost doubled compared with that of a pristine Nafion membrane, while the mechanical stability of the composite Nafion membrane is enhanced by 44%. As a result, the fuel cell performance of the silica nanofiber-Nafion composite membrane measured at high temperature and low humidity is improved by 38%.

Spectroscopic Studies of Heteropoly Acid-doped 3M Perfluorinated Sulfonic Acid Polymer Membranes

2019 ◽  
Vol 1 (6) ◽  
pp. 255-262 ◽  
Author(s):  
Andrew M. Herring ◽  
Fanqin Meng ◽  
Matthew Frey ◽  
Steve Hamrock ◽  
John Turner ◽  
...  
Keyword(s):  
Sulfonic Acid ◽  
Heteropoly Acid ◽  
Polymer Membranes ◽  
Spectroscopic Studies ◽  
Perfluorinated Sulfonic Acid
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