Evolution of Ionomer Morphology from Dispersion to Film: An in Situ X-ray Study

Dudenas, Peter J.; Kusoglu, Ahmet

doi:10.1021/acs.macromol.9b01024

Title: Evolution of Ionomer Morphology from Dispersion to Film: An in Situ X-ray Study

Abstract

Ion-conducting polymers (ionomers) have been extensively studied in solution, as membranes and substrate-supported thin films for various electrochemical energy-conversion devices, including fuel cells and electrolyzers. Formation of an ionomer film from a solution, however, is not well understood, despite its importance for fabrication of electrodes in energy devices. Here, the evolution of the perfluorinated sulfonic acid morphology upon casting from a solution is observed using in situ grazing-incidence small- and wide-angle X-ray scattering. Aggregate interactions in dispersion directly impact the hydrophilic-domain network of the cast film and the onset of crystallization occurs simultaneously with the solution-to-film transition but continues to evolve on different time scales. In addition, confinement is shown to induce anisotropic morphology at multiple length scales. These results show promise for elucidating the role of casting parameters, drying protocols, and ionomer-solvent interactions in governing film morphology and open new avenues for establishing structure/processing/property relationships for ionomer films and modifying their transport functionality at catalytic interfaces.

Authors:

Dudenas, Peter J. ^[1];

^[2]

Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Publication Date:: Tue Oct 08 00:00:00 EDT 2019

Research Org.:: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Sustainable Transportation Office. Hydrogen Fuel Cell Technologies Office

OSTI Identifier:: 1594934

Grant/Contract Number:: AC02-05CH11231

Resource Type:: Accepted Manuscript

Journal Name:: Macromolecules

Additional Journal Information:: Journal Volume: 52; Journal Issue: 20; Journal ID: ISSN 0024-9297

Publisher:: American Chemical Society

Country of Publication:: United States

Language:: English

Subject:: 30 DIRECT ENERGY CONVERSION; Morphology; Thin films; Hydrophilicity; Solvents; Ionomers

Citation Formats


                    Dudenas, Peter J., and Kusoglu, Ahmet. Evolution of Ionomer Morphology from Dispersion to Film: An in Situ X-ray Study.  United States: N. p., 2019. 
Web.  doi:10.1021/acs.macromol.9b01024.

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                    Dudenas, Peter J., & Kusoglu, Ahmet. Evolution of Ionomer Morphology from Dispersion to Film: An in Situ X-ray Study.  United States.  https://doi.org/10.1021/acs.macromol.9b01024

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                    Dudenas, Peter J., and Kusoglu, Ahmet. Tue .  
"Evolution of Ionomer Morphology from Dispersion to Film: An in Situ X-ray Study".  United States.  https://doi.org/10.1021/acs.macromol.9b01024.  https://www.osti.gov/servlets/purl/1594934.

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@article{osti_1594934,

  title        = {Evolution of Ionomer Morphology from Dispersion to Film: An in Situ X-ray Study},

  author       = {Dudenas, Peter J. and Kusoglu, Ahmet},

  abstractNote = {Ion-conducting polymers (ionomers) have been extensively studied in solution, as membranes and substrate-supported thin films for various electrochemical energy-conversion devices, including fuel cells and electrolyzers. Formation of an ionomer film from a solution, however, is not well understood, despite its importance for fabrication of electrodes in energy devices. Here, the evolution of the perfluorinated sulfonic acid morphology upon casting from a solution is observed using in situ grazing-incidence small- and wide-angle X-ray scattering. Aggregate interactions in dispersion directly impact the hydrophilic-domain network of the cast film and the onset of crystallization occurs simultaneously with the solution-to-film transition but continues to evolve on different time scales. In addition, confinement is shown to induce anisotropic morphology at multiple length scales. These results show promise for elucidating the role of casting parameters, drying protocols, and ionomer-solvent interactions in governing film morphology and open new avenues for establishing structure/processing/property relationships for ionomer films and modifying their transport functionality at catalytic interfaces.},

  doi          = {10.1021/acs.macromol.9b01024},

  journal      = {Macromolecules},

  number       = 20,

  volume       = 52,

  place        = {United States},

  year         = {Tue Oct 08 00:00:00 EDT 2019},

  month        = {Tue Oct 08 00:00:00 EDT 2019}

}

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https://doi.org/10.1021/acs.macromol.9b01024

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Cited by: 22 works

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Figures / Tables:

Figure 1: (a) Schematic of in-situ printing technique for monitoring ionomer film morphology. (b) Composite GIXS linecuts showing evolution of morphology across lengthscales. (c) Schematic of Nafion aggregate and core-shell cylinder model used to fit the solution data.

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