Novel nanocomposite membranes were prepared with sulfonated polyoxadiazole and different amounts of sulfonated dense and mesoporous (MCM-41) silica particles. It has been shown that particle size and functionality of sulfonated silica particles play an important role when they are used as fillers for the development of polymer electrolyte nanocomposite membrane for fuel cells. No significant particle agglomerates were observed in all nanocomposite membranes prepared with sulfonated dense silica particles, as analyzed by SEM, AFM, TGA, DMTA and tensile tests. The Tg values of the composite membranes increased with addition of sulfonated silica, indicating an interaction between the sulfonic acid groups of the silica and the polyoxadiazole. Constrained polymer chains in the vicinity of the inorganic particles were confirmed by the reduction of the relative peak height of tan δ. A proton conductivity of 0.034 S cm-1 at 120 °C and 25% RH, which is around two-fold higher than the value of the pristine polymer membrane was obtained.
Bibliographical noteFunding Information:
D. Gomes thanks the Helmholtz-Hochschul-Nachwuchsgruppe Projekt (VH-NG-323) for supporting this research. R. Marschall gratefully acknowledges a Georg-Christoph-Lichtenberg scholarship by the Ministry of Science and Culture of the German State of Lower Saxony, and financial support from the DFG (WA 1116/15, SPP 1181). The authors thank H. Böttcher for the dynamic mechanical thermal analyses and tensile tests, S. Nowak for the TGA measurements, K. Prause for the SEM images and S. Bolmer for the AFM topographies. The cooperation was initiated in the frame of the CARISMA Coordination Action.
- Fuel cell
- Proton conductivity
- Sulfonated silica
ASJC Scopus subject areas
- General Materials Science
- Physical and Theoretical Chemistry
- Filtration and Separation