scholarly journals SAXS signature of the lamellar ordering of ionic domains of perfluorinated sulfonic-acid ionomers by electric and magnetic field-assisted casting

2020 ◽  
Vol 22 (24) ◽  
pp. 13764-13779
Author(s):  
Jaqueline S. da Silva ◽  
Sabrina G. M. Carvalho ◽  
Rodrigo P. da Silva ◽  
Ana C. Tavares ◽  
Ulrich Schade ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Sulfonic Acid ◽  
Saxs Pattern ◽  
Electric And Magnetic Field ◽  
The Matrix ◽  
Perfluorinated Sulfonic Acid

The origins of the matrix and ionomer peaks of Nafion SAXS pattern are revisited.

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>

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 Impact of the Composition of Alcohol/Water Dispersion on the Proton Transport and Morphology of Cast Perfluorinated Sulfonic Acid Ionomer Thin Films

ACS Omega ◽  
2021 ◽  
Author(s):  
Xiao Gao ◽  
Kentaro Yamamoto ◽  
Tomoyasu Hirai ◽  
Noboru Ohta ◽  
Tomoki Uchiyama ◽  
...  
Keyword(s):  
Thin Films ◽  
Proton Transport ◽  
Sulfonic Acid ◽  
Water Dispersion ◽  
Alcohol Water ◽  
Perfluorinated Sulfonic Acid

scholarly journals Orbital: An Electric and Magnetic Field

2021 ◽  
Vol 1893 (1) ◽  
pp. 012002
Author(s):  
M. Amin Mir
Keyword(s):  
Magnetic Field ◽  
Electric And Magnetic Field

Electric and magnetic field effects on the exciton localization in a modulation doped InGaAs/GaAs quantum well

2020 ◽  
Author(s):  
Geetanjali Vashisht ◽  
S. Haldar ◽  
S. Porwal ◽  
R. Kumar ◽  
V. K. Dixit
Keyword(s):  
Magnetic Field ◽  
Quantum Well ◽  
Magnetic Field Effects ◽  
Exciton Localization ◽  
Field Effects ◽  
Electric And Magnetic Field

scholarly journals Planar orientation of hydrophilic channels by biaxial deformation of perfluorinated sulfonic acid membranes for vanadium redox flow batteries

2021 ◽  
Vol 489 ◽  
pp. 229497
Author(s):  
Seonwoo Hwang ◽  
Doohee Lee ◽  
Yecheol Rho ◽  
Kyung Seok Yoon ◽  
Duk Man Yu ◽  
...  
Keyword(s):  
Sulfonic Acid ◽  
Redox Flow Batteries ◽  
Biaxial Deformation ◽  
Flow Batteries ◽  
Planar Orientation ◽  
Perfluorinated Sulfonic Acid ◽  
Vanadium Redox

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

Electric and magnetic field perturbations recorded by DEMETER satellite before seismic events of the 17th July 2006 M 7.7 earthquake in Indonesia

2009 ◽  
Vol 34 (5) ◽  
pp. 634-644 ◽  
Author(s):  
S. Bhattacharya ◽  
S. Sarkar ◽  
A.K. Gwal ◽  
M. Parrot
Keyword(s):  
Magnetic Field ◽  
Seismic Events ◽  
Demeter Satellite ◽  
Electric And Magnetic Field

Thermo-Optical Properties of Perfluorinated Sulfonic Acid Membranes: An Investigation of Hydration Based on Absorption Spectra

2017 ◽  
Vol 71 (11) ◽  
pp. 2504-2511 ◽  
Author(s):  
Daniele T. Dias ◽  
Guy Lopes ◽  
Tales Ferreira ◽  
Ivanir L. Oliveira ◽  
Caroline D. Rosa
Keyword(s):  
Sulfonic Acid ◽  
Room Temperature ◽  
Water Retention ◽  
Structural Changes ◽  
Optical Characterization ◽  
Scanning Calorimetry ◽  
Experimental Procedure ◽  
Nafion Membranes ◽  
Perfluorinated Sulfonic Acid

The Nafion membranes are widely used in electrochemical applications such as fuel cells, chlor-alkali cells, and actuators–sensors. In this work, the thermal-optical characterization of Nafion in acid form was performed by photoacoustic spectroscopy, thermogravimetry, and differential scanning calorimetry. In the experimental procedure three distinct hydration levels were considered: (1) pristine membrane (λ ≅ H2O/–SO3H ≅ 5.6); (2) swelling process (λ ≅ 17.4); and (3) drying at controlled room temperature after swelling process (λ ≅ 6.5). The discovered behaviors showed significant irreversible structural changes induced by water retention in the membrane. These structural changes depend on the water population present in the clusters and also affect the directional thermal diffusivity of the membrane irreversibly.

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