Issue 28, 2016

A self-protection phenomenon in the Nafion membrane when it breathes in methanol-saturated air

Abstract

Ex situ characterizations based on TGA and XRD techniques revealed that MeOH vapor had little influence on the Nafion microstructures. To reveal the underlying mechanism, in this study, we designed new FTIR-based equipment to track in situ the microstructural changes of a bulk Nafion membrane in MeOH-saturated air. First, an interesting MeOH-breathing phenomenon was found in the ionic domains of Nafion. It demonstrated that there existed a dynamic equilibrium between the sorption and desorption processes of MeOH vapor in Nafion. Second, the FTIR results also detected the high stability of the hydrophobic regions of Nafion in MeOH vapor. The super-acid –CF2–SO3H always retained a small quantity of bonded H2O (H+(H2O)n) inside the Nafion membrane. MeOH vapor was absorbed first into the hydrophilic regions, however, the interactions between –CF2–SO3H and MeOH vapor were much weaker than those between –CF2–SO3H and H+(H2O)n. Therefore, a protective layer composed of residual water formed in the lumen of the hydrophilic ionic domains of Nafion, which protected its hydrophobic regions from the MeOH attack. Hereby, the self-protection ability of Nafion in MeOH vapor was detected for the first time. This work gave a new insight into the complex interplay between Nafion and MeOH vapor.

Graphical abstract: A self-protection phenomenon in the Nafion membrane when it breathes in methanol-saturated air

Supplementary files

Article information

Article type
Paper
Submitted
11 May 2016
Accepted
23 Jun 2016
First published
23 Jun 2016

Phys. Chem. Chem. Phys., 2016,18, 19440-19450

A self-protection phenomenon in the Nafion membrane when it breathes in methanol-saturated air

K. Feng, B. Tang and P. Wu, Phys. Chem. Chem. Phys., 2016, 18, 19440 DOI: 10.1039/C6CP03176E

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements