Finite Thickness Effects on Nafion Water Uptake and Ionic Conductivity at Hydrophilic Substrate Interfaces, and Implications for PEMFC Performance
Steven C. DeCaluwe, Joseph Dura
The effect of film thickness on water uptake in ultra-thin Nafion films is probed via in situ neutron reflectometry for a series of 10 samples with thicknesses ranging from 7 - 103 nm, and the resulting effects on ionic conductivity. The water uptake in the lamellae and the bulk-like layer varies non-monotonically, decreasing as the equivalent Nafion thickness increases from 7 nm to 12 nm, increasing with increasing film thickness for equivalent Nafion thicknesses ranging from 12 nm-60 nm, and then constant for films with equivalent thickness ≥. Composition depth profiles are used to predict the anisotropic ionic conductivities, which are used in a flooded-agglomerate model of PEMFC catalyst layers to predict the effect of lamellar structure transport properties on PEMFC performance.
and Dura, J.
Finite Thickness Effects on Nafion Water Uptake and Ionic Conductivity at Hydrophilic Substrate Interfaces, and Implications for PEMFC Performance, Electrochemical Society Transactions, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=923923
(Accessed September 25, 2023)