Work

Morphology of Hydrated As-Cast Nafion Revealed through Cryo Electron Tomography

Year: 2014

Type: article

Abstract: 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.

Source: ACS Macro Letters

DOI: 10.1021/mz500606h

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

Institutions: Lawrence Berkeley National Laboratory, Molecular Foundry, University of California, Berkeley

Language: English

Topic: Fuel Cells and Related Materials

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500

Funders: Fuel Cell Technologies Program, Basic Energy Sciences