Morphology of hydrated as-cast Nafion revealed through cryo electron tomography

Frances I. Allen, Luis R. Comolli, Ahmet Kusoglu, Miguel Modestino, Andrew M. Minor, Adam Z. Weber

Research output: Contribution to journalArticle


Nafion is an ion-containing random copolymer used as a solid electrolyte in many electrochemical applications thanks to its remarkable ionic conductivity and mechanical stability. Understanding the mechanism of ion transport in Nafion, which depends strongly on hydration, therefore requires a complete picture of its morphology in dry and hydrated form. Here we report on a nanoscale study of dry versus hydrated as-cast 100 nm Nafion membranes using analytical transmission electron microscopy (TEM) and cryogenic TEM tomography, respectively. For the dry membrane, spherical clusters ∼3.5 nm in diameter corresponding to the hydrophilic sulfonic-acid-containing phase are identified. In contrast, cryo TEM tomography of the hydrated membrane reveals an interconnected channel-type network, with a domain spacing of ∼5 nm, and presents the first nanoscale 3D views of the internal structure of hydrated Nafion obtained by a direct-imaging approach. (Figure Presented).

Original languageEnglish (US)
Pages (from-to)1-5
Number of pages5
JournalACS Macro Letters
Issue number1
Publication statusPublished - 2015


ASJC Scopus subject areas

  • Organic Chemistry
  • Materials Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry

Cite this

Allen, F. I., Comolli, L. R., Kusoglu, A., Modestino, M., Minor, A. M., & Weber, A. Z. (2015). Morphology of hydrated as-cast Nafion revealed through cryo electron tomography. ACS Macro Letters, 4(1), 1-5.