Optical properties and swelling of thin film perfluorinated sulfonic-acid ionomer
Document Type
Article
Publication Date
7-2019
Department
Department of Mechanical Engineering-Engineering Mechanics
Abstract
Perfluorinated sulfonic-acid (PFSA) ionomers are members of a class of ion-conductive polymers that are commonly used in both membranes and catalyst layers in polymer-electrolyte fuel cells. Transport properties of thin film ionomers and their deviation from bulk properties are still unclear. Label free, high-speed Surface Plasmon Resonance imaging (SPRi) is proposed to simultaneously measure refractive index and thickness of a 30 nm thick Nafion film at relative humidity of 3%, 36%, and 93% . The result shows the thickness of the thin film increases with increasing the relative humidity. The refractive index of the thin Nafion film decreases from 1.310±0.003 to 1.228±0.003 when the relative humidity increases from 3% to 93%. The drop in optical properties of 30 nm thick Nafion film, indicates the void part of hydrated Nafion film is filled with a mixture of water and water vapor.
Publication Title
ECS Transactions
Recommended Citation
Ahangar, S. B.,
Bellur, K.,
Medici, E. F.,
Tajiri, K.,
Allen, J. S.,
&
Choi, C. K.
(2019).
Optical properties and swelling of thin film perfluorinated sulfonic-acid ionomer.
ECS Transactions,
92(8), 197-204.
http://doi.org/10.1149/09208.0197ecst
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p/1856