Water Uptake and Interfacial Structural Changes of Thin Film Nafion® MembranesMeasured by Neutron Reflectivity for PEM Fuel Cells

Published

October 1, 2008

Author(s)

Vivek Srinivasamurthi, Joseph A. Dura, Sushil K. Satija, Charles F. Majkrzak

Abstract

Nafion thin films (500 Å) spin coated onto the Pt and Au layers on Si are investigated for water uptake and swelling. Neutron Reflectometry data demonstrate that these structures are composed of nafion layers which differ from their bulk properties in terms of their scattering length density and water uptake. However, as the relative humidity is increased, the amount of water in the layers increases for a Nafion on Au and is comparable to that observed on bulk nafion membranes only up to 80 % RH. However, the Nafion on Pt reaches complete hydration at 96% RH. Although, a single layer model was able to fit the NR data obtained on nafion under vapor conditions, only a bilayer model, with an outer less hydrated nafion and an inner more hydrated nafion layer, was able to fit the data in liquid water.

Citation

ECS Transactions

Volume

16

Issue

2

Pub Type

Journals

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Keywords

PEM fuel cells, nafion, water uptake, neutron reflectometry

Citation

Srinivasamurthi, V. , Dura, J. , Satija, S. and Majkrzak, C. (2008), Water Uptake and Interfacial Structural Changes of Thin Film Nafion® MembranesMeasured by Neutron Reflectivity for PEM Fuel Cells, ECS Transactions, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=610035 (Accessed April 29, 2024)