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Seminars
Functionalisation of Composite Membranes for Fuel Cells
Joe da Costa
ARC Centre for Functional Nanomaterials School of Engineering
University of Queensland, Australia
When: Wednesday, April 19, 2006
Time: 4:00 PM
Where: Sewell Hall, Room 309
Abstract:
The ARC Centre for Functional Nanomaterials is a multidisciplinary hub of scientists and engineers which was created by the Australian Research Council in 2003. Among several research areas of application (i.e. clean energy delivery, bio materials and drug delivery), the Centre has a research program in nanomaterials functionalisation for fuel cell technology. One aspect of our research program is to investigate the in situ formation of functionalised colloidal silica particles to inhibit the transport of methanol through Nafion by blocking sites necessary for methanol diffusion. These microstructural modifications have shown to reduce methanol crossover from 7.48x10-6 cm2s-1 for pure Nafion to 2.86 x10-6 cm2s-1 for nanocomposite Nafion membranes (Methanol 50% (v/v) solution, 75°C). Reduction in methanol permeability by one order of magnitude was also observed for polyaniline/Nafion/silica composite membranes whilst conductivities remained very close to Nafion values. Functionalised nanoparticles were also embedded in polyvinyl alcohol (PVA) polymer matrix, by dispersing phosphosilicate colloidal particles through a sol-gel process. Proton conductivities of up to 0.02 Scm-1 at 70 oC and 90% relativity humidity (RH) was obtained whilst methanol permeability was also reduced by a factor of 5-10 as compared with Nafion 117. This presentation further addresses the use of sol-gel processes to prepare inorganic proton conduction membranes, in particular that proton conductivities of 0.2 S.cm-1 (80%RH at 22oC) or 0.02 S.cm-1 (dry condition at 200oC) can be achieved.
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