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Hybridization of Nafion membranes by the infusion of functionalized siloxane precursors

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journal contribution
posted on 02.08.2007, 15:30 by Marino Lavorgna, Leno Mascia, Giuseppe Mensitieri, Marianne Gilbert, Giuseppe Scherillo
Polysiloxane modified hybrid membranes were prepared by introducing pre-swelled commercial Nafion membrane into a sol-gel precursor solution, consisting of a pre-hydrolyzed mixture of tetraethoxysilane (TEOS) and a mercaptan functionalized organoalkoxysilane. The structure of the polysiloxane network was changed by altering the ratio of the two silane components within the precursor solution. The mercaptosilane modifier was used to provide an additional source of acidic Bronsted sites through the oxidisation of the mercaptan groups to sulfonic acid groups. The physical and chemical properties of the hybrid membranes were examined by TGA, FTIR and SEM analysis. The water vapour sorption and proton conductivity characteristics were evaluated at temperatures up to 70°C and with water activity in the region of 0.4 to 1. It was found that the polysiloxane network alters the water vapour sorption mechanism of the Nafion membrane, resulting in an increase in the equilibrium amount of water absorbed in the middle range of water activity (0.4-0.6). At the same time, the increased water absorption capability produced a concomitant increase in ionic conductivity at low water activities.

History

School

  • Aeronautical, Automotive, Chemical and Materials Engineering

Department

  • Materials

Citation

LAVORGNA, M. ... et al (2007). Hybridization of Nafion membranes by the infusion of functionalized siloxane precursors. Journal of membrane science, 294 (1-2), pp. 159-168

Publisher

© Elsevier

Publication date

2007

Notes

This article was published in the journal, Journal of membrane science [© Elsevier] and is available at: http://www.sciencedirect.com/science/journal/03767388

ISSN

0376-7388

Language

en