A series of Nafion-clay nanocomposite membranes were synthesized and characterized. To minimize any adverse effects on ionic conductivity the clay nanoparticles were H+ exchanged prior to mixing with Nafion. Well-dispersed, mechanically robust, free-standing nanocomposite membranes were prepared by casting from a water suspension at 180 °C under pressure. SAXS profiles reveal a preferential orientation of Nafion aggregates parallel to the membrane surface, or normal plane. This preferred orientation is induced by the platy nature of the clay nanoparticles, which tend to align parallel to the surface of the membrane. The nanocomposite membranes show dramatically reduced methanol permeability, while maintaining high levels of proton conductivity. The hybrid films are much stiffer and can withstand much higher temperatures compared to pure Nafion. The superior thermomechanical, electrochemical and barrier properties of the nanocomposite membranes are of significant interest for direct methanol fuel cell applications. © 2009 Elsevier Ltd. All rights reserved.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-C1-018-02
Acknowledgements: We acknowledge the financial support of the Cornell Fuel Cell Institute funded by DOE. EPG acknowledges the support of Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.