ACS Publications. Most Trusted. Most Cited. Most Read
My Activity

AFM Imaging of Adsorbed Nafion Polymer on Mica and Graphite at Molecular Level

View Author Information
Electrochemical Energy Research Laboratory, GM Research and Development, 10 Carriage Street, Honeoye Falls, New York 14472-1039, United States
Department of Chemistry and Biomolecular Science, Clarkson University, 8 Clarkson Avenue Potsdam, New York 13699-5810, United States
§ Trison Business Solutions, Honeoye Falls, New York 14472-1039, United States
Tel.: 315-268-3807. Fax: 315-268-6610. E-mail: [email protected]
Cite this: Langmuir 2011, 27, 16, 10157–10166
Publication Date (Web):July 7, 2011
Copyright © 2011 American Chemical Society

    Article Views





    Other access options


    Abstract Image

    Perfluorosulfonic acid ionomer (PFSA, specifically Nafion at EW = 975 g/mol) was visualized at the single molecule level using atomic force microscopy (AFM) in liquid. The diluted commercial Nafion dispersion shows an apparent Mw = 1430 kg/mol and Mw/Mn = 3.81, which is assigned to chain aggregation. PFSA aggregates, imaged on mica and HOPG during adsorption from EtOH–H2O solvent at pH(e) 3.0 (below isoelectric point), showed a stable, segmented rod-like conformation. This structure is consistent with earlier NMR, SAXS/SANS, and TEM results that support a stiff helical Nafion conformation with long persistence length, a sharp solvent–polymer interface, and an extension of the sulfonated side chain into solution. Adsorption of Nafion structures on HOPG was observed at even higher pH(e) from EtOH due to screening of the repulsive electrostatic interaction in lower dielectric constant solvent, while the chain adopted an expanded coil conformation. These measurements provided direct evidence of the chain aggregation in EtOH–H2O solution and revealed their equilibrium conformations for adsorption on two model surfaces, highly ordered pyrolitic graphite (HOPG) and mica. The commercial Nafion dispersion was autoclaved at 0.10% w/w in nPrOH/H2O = 4:1 v/v solvent at 230 °C for 6 h to give a single-chain dispersion with Mw = 310 kg/mol and Mw/Mn = 1.60. The autoclaved chains adopt an electrostatically stabilized compact globule conformation as observed by AFM imaging of the single PFSA molecules after rapid deposition on mica and HOPG at a low surface coverage.

    Read this article

    To access this article, please review the available access options below.

    Get instant access

    Purchase Access

    Read this article for 48 hours. Check out below using your ACS ID or as a guest.


    Access through Your Institution

    You may have access to this article through your institution.

    Your institution does not have access to this content. You can change your affiliated institution below.

    Cited By

    This article is cited by 35 publications.

    1. Yasuhiro Shiraishi, Masahiro Jio, Koki Yoshida, Yoshihiro Nishiyama, Satoshi Ichikawa, Shunsuke Tanaka, Takayuki Hirai. Nafion-Integrated Resorcinol-Formaldehyde Resin Photocatalysts for Solar Hydrogen Peroxide Production. JACS Au 2023, 3 (8) , 2237-2246.
    2. Yuting Guo, Takuya Mabuchi, Gaoyang Li, Takashi Tokumasu. Morphology Evolution and Adsorption Behavior of Ionomers from Solution to Pt/C Substrates. Macromolecules 2022, 55 (11) , 4245-4255.
    3. Yuta Okamoto, Kenjirou Higashi, Takeshi Morita, Keisuke Ueda, Sayaka Mukaide, Junpei Takeda, Masatoshi Karashima, Yukihiro Ikeda, Kunikazu Moribe. Nanostructure and Molecular-Level Characterization of Aminoalkyl Methacrylate Copolymer and the Impact on Drug Solubilization Ability. Molecular Pharmaceutics 2021, 18 (11) , 4111-4121.
    4. Takuya Mabuchi, Sheng-Feng Huang, Takashi Tokumasu. Influence of Ionomer Loading and Substrate Wettability on the Morphology of Ionomer Thin Films Using Coarse-Grained Solvent Evaporation Simulations. Macromolecules 2021, 54 (1) , 115-125.
    5. Atefeh Tarokh, Kunal Karan, Sathish Ponnurangam. Atomistic MD Study of Nafion Dispersions: Role of Solvent and Counterion in the Aggregate Structure, Ionic Clustering, and Acid Dissociation. Macromolecules 2020, 53 (1) , 288-301.
    6. Ahmet Kusoglu and Adam Z. Weber . New Insights into Perfluorinated Sulfonic-Acid Ionomers. Chemical Reviews 2017, 117 (3) , 987-1104.
    7. Mahdi Ghelichi and Michael H. Eikerling . Conformational Properties of Comb-Like Polyelectrolytes: A Coarse-Grained MD Study. The Journal of Physical Chemistry B 2016, 120 (10) , 2859-2867.
    8. Daiane Damasceno Borges, Gerard Gebel, Alejandro A. Franco, Kourosh Malek, and Stefano Mossa . Morphology of Supported Polymer Electrolyte Ultrathin Films: A Numerical Study. The Journal of Physical Chemistry C 2015, 119 (2) , 1201-1216.
    9. Pengcheng Liu, Daijun Yang, Bing Li, Cumman Zhang, Pingwen Ming. Recent progress of catalyst ink for roll-to-roll manufacturing paired with slot die coating for proton exchange membrane fuel cells. International Journal of Hydrogen Energy 2023, 48 (51) , 19666-19685.
    10. Xiaohui Yan, Zhiling Xu, Shu Yuan, Aidi Han, Yuanting Shen, Xiaojing Cheng, Yuwei Liang, Shuiyun Shen, Junliang Zhang. Structural and transport properties of ultrathin perfluorosulfonic acid ionomer film in proton exchange membrane fuel cell catalyst layer: A review. Journal of Power Sources 2022, 536 , 231523.
    11. Yuqing Guo, Fengwen Pan, Wenmiao Chen, Zhiqiang Ding, Daijun Yang, Bing Li, Pingwen Ming, Cunman Zhang. The Controllable Design of Catalyst Inks to Enhance PEMFC Performance: A Review. Electrochemical Energy Reviews 2021, 4 (1) , 67-100.
    12. Nagappan Ramaswamy, Swami Kumaraguru, Roland Koestner, Timothy Fuller, Wenbin Gu, Nancy Kariuki, Deborah Myers, Peter J. Dudenas, Ahmet Kusoglu. Editors’ Choice—Ionomer Side Chain Length and Equivalent Weight Impact on High Current Density Transport Resistances in PEMFC Cathodes. Journal of The Electrochemical Society 2021, 168 (2) , 024518.
    13. Jaqueline S. da Silva, Sabrina G. M. Carvalho, Rodrigo P. da Silva, Ana C. Tavares, Ulrich Schade, Ljiljana Puskar, Fabio C. Fonseca, Bruno R. Matos. SAXS signature of the lamellar ordering of ionic domains of perfluorinated sulfonic-acid ionomers by electric and magnetic field-assisted casting. Physical Chemistry Chemical Physics 2020, 22 (24) , 13764-13779.
    14. Bruckner, Giesselmann. The Lyotropic Analog of the Polar SmC* Phase. Crystals 2019, 9 (11) , 568.
    15. Xuanxuan Zhang, Yajing Kan. Adsorption of the Nafion Polymers on Mica Substrate in Water. 2019, 337-340.
    16. Makoto Yamaguchi, Takeshi Terao, Akihiro Ohira, Naoki Hasegawa, Kazuhiko Shinohara. Size and shape of Nafion particles in water after high‐temperature treatment. Journal of Polymer Science Part B: Polymer Physics 2019, 57 (13) , 813-818.
    17. Ahmet Kusoglu. Ionomer Thin Films in PEM Fuel Cells. 2019, 417-438.
    18. Simon E. Wawra, Martin Thoma, Johannes Walter, Christian Lübbert, Thaseem Thajudeen, Cornelia Damm, Wolfgang Peukert. Ionomer and protein size analysis by analytical ultracentrifugation and electrospray scanning mobility particle sizer. European Biophysics Journal 2018, 47 (7) , 777-787.
    19. Ahmet Kusoglu. Ionomer Thin Films in PEM Fuel Cells. 2018, 1-23.
    20. Ahmet Kusoglu. Ionomer Thin Films in PEM Fuel Cells. 2018, 1-23.
    21. Kenji Kudo, Ryosuke Jinnouchi, Yu Morimoto. Humidity and Temperature Dependences of Oxygen Transport Resistance of Nafion Thin Film on Platinum Electrode. Electrochimica Acta 2016, 209 , 682-690.
    22. Ahmet Kusoglu, Thomas J. Dursch, Adam Z. Weber. Nanostructure/Swelling Relationships of Bulk and Thin‐Film PFSA Ionomers. Advanced Functional Materials 2016, 26 (27) , 4961-4975.
    23. Tetsuya Mashio, Atsushi Ohma, Takashi Tokumasu. Molecular Dynamics Study of Ionomer Adsorption at a Carbon Surface in Catalyst Ink. Electrochimica Acta 2016, 202 , 14-23.
    24. Š. Hovorka, A. Randová, T. Borbášová, P. Sysel, H. Vychodilová, L. Červenková-Šťastná, L. Brožová, J. Žitka, J. Storch, M. Kačírková, P. Drašar, P. Izák. Permeability and diffusion coefficients of single methyl lactate enantiomers in Nafion® and cellophane membranes measured in diffusion cell. Separation and Purification Technology 2016, 158 , 322-332.
    25. Hidenori Kuroki, Takanori Tamaki, Takeo Yamaguchi. Nanostructural Control and Performance Analysis of Carbon-Free Catalyst Layers Using Nanoparticle-Connected Hollow Capsules for PEFCs. Journal of The Electrochemical Society 2016, 163 (8) , F927-F932.
    26. P-É A Melchy, M H Eikerling. Theory of fracture formation in a heterogeneous fibrillar membrane. Journal of Physics: Condensed Matter 2015, 27 (32) , 325103.
    27. Alena Randová, Lidmila Bartovská, Štěpán Hovorka, Marie Kačírková, Hana Vychodilová, Zuzana Sedláková, Lucie Červenková Šťastná, Libuše Brožová, Jan Žitka, Petr Sysel, Jiří Brus, Pavel Drašar, Pavel Izák. Sorption of enantiomers and alcohols into Nafion® and the role of air humidity in the experimental data evaluation. Separation and Purification Technology 2015, 144 , 232-239.
    28. Anna Kowalewska, Maria Nowacka, Adam Tracz, Tomasz Makowski. Supramolecular self-assembly of linear oligosilsesquioxanes on mica – AFM surface imaging and hydrophilicity studies. Soft Matter 2015, 11 (24) , 4818-4829.
    29. S. Iqbal, N. Podgaynyy, M. Ahmed, G.A. Attard, H. Baltruschat. Surface morphological studies of Nafion®/Pt(100) interface. Electrochimica Acta 2014, 144 , 141-146.
    30. Isai Gonzalez Martinez, Tanja Vidaković-Koch, Rafael Kuwertz, Ulrich Kunz, Thomas Turek, Kai Sundmacher. Analysis of a novel chlorine recycling process based on anhydrous HCl oxidation. Electrochimica Acta 2014, 123 , 387-394.
    31. P.-É. A. Melchy, M. H. Eikerling. Physical theory of ionomer aggregation in water. Physical Review E 2014, 89 (3)
    32. Adam Z. Weber, Rodney L. Borup, Robert M. Darling, Prodip K. Das, Thomas J. Dursch, Wenbin Gu, David Harvey, Ahmet Kusoglu, Shawn Litster, Matthew M. Mench, Rangachary Mukundan, Jon P. Owejan, Jon G. Pharoah, Marc Secanell, Iryna V. Zenyuk. A Critical Review of Modeling Transport Phenomena in Polymer-Electrolyte Fuel Cells. Journal of The Electrochemical Society 2014, 161 (12) , F1254-F1299.
    33. Akihiro Ohira, Seiichi Kuroda, Hamdy F. M. Mohamed, Bruno Tavernier. Effect of interface on surface morphology and proton conduction of polymer electrolyte thin films. Physical Chemistry Chemical Physics 2013, 15 (27) , 11494.
    34. Tatsuya Nakajima, Takanori Tamaki, Hidenori Ohashi, Takeo Yamaguchi. Introduction of Size-Controlled Nafion/ZrO 2 Nanocomposite Electrolyte into Primary Pores for High Pt Utilization in PEFCs. Journal of The Electrochemical Society 2013, 160 (2) , F129-F134.
    35. Tanja Vidakovic-Koch, Isai Gonzalez Martinez, Rafael Kuwertz, Ulrich Kunz, Thomas Turek, Kai Sundmacher. Electrochemical Membrane Reactors for Sustainable Chlorine Recycling. Membranes 2012, 2 (3) , 510-528.

    Pair your accounts.

    Export articles to Mendeley

    Get article recommendations from ACS based on references in your Mendeley library.

    Pair your accounts.

    Export articles to Mendeley

    Get article recommendations from ACS based on references in your Mendeley library.

    You’ve supercharged your research process with ACS and Mendeley!

    STEP 1:
    Click to create an ACS ID

    Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

    Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

    Please note: If you switch to a different device, you may be asked to login again with only your ACS ID.

    Your Mendeley pairing has expired. Please reconnect