Hoffmann EM, Fischer D, Thoma M, Damm C, Lobaz V, Zhigunov A, Peukert W (2020)
Publication Language: English
Publication Status: Published
Publication Type: Journal article, Original article
Publication year: 2020
Book Volume: 582
Pages Range: 883-893
Journal Issue: Pt B
DOI: 10.1016/j.jcis.2020.08.058
Performance of a proton exchange membrane fuel cell (PEMFC) is significantly determined by the structure and composition of the electrode layer. Electrode layers are formed from inks consisting of platinum-doped carbon black particles, perfluorosulfonic acid (PFSA) ionomer and a dispersing solvent. Interaction between these materials mainly influences suspension stability, ionomer conformation and therewith layer morphology. We characterize the interplay between a short sidechain (SSC) PFSA ionomer (Aquivion® D79-25BS) and a solvent mixture (diacetone alcohol (DAA) and water with different weight ratios) by using Hansen solubility/dispersibility parameters (HSP) and by experimental tests. It was found that HSPs are well suitable to describe the ionomer/solvent interactions. In particular, the HSP difference in terms of the hydrogen bonds is responsible for the poor affinity between ionomer and solvent at low DAA concentrations. With increasing DAA content the affinity between ionomer and solvent increases as indicated by better matching HSPs. For an ionomer concentration of 4 wt%, Aquivion always forms molecular solutions for all DAA-in-water mixing ratios. Self-organization of the ionomer molecules changes from densely packed/collapsed molecules with highly deprotonated sulfonic acid side groups at low DAA concentrations to unfolded Aquivion molecules with a low dissociation degree of the sulfonic acid groups at high DAA concentrations.
APA:
Hoffmann, E.-M., Fischer, D., Thoma, M., Damm, C., Lobaz, V., Zhigunov, A., & Peukert, W. (2020). Impact of DAA/water composition on PFSA ionomer conformation. Journal of Colloid and Interface Science, 582(Pt B), 883-893. https://doi.org/10.1016/j.jcis.2020.08.058
MLA:
Hoffmann, Eva-Maria, et al. "Impact of DAA/water composition on PFSA ionomer conformation." Journal of Colloid and Interface Science 582.Pt B (2020): 883-893.
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