Fabrication and performance of an agar-aerogel composite membrane for polymer electrolyte membrane fuel cells

摘要

In this study, we proposed a new type of proton conducting polymer membrane based on agar and polyethylene oxide (PEO) containing silica aerogel. Stable silica aerogel slurry was prepared from agar/PEO aqueous solutions with ethanol, and the composite membrane was fabricated by standard gel casting. The obtained agar/PEO composite membranes were translucent and exhibited a very smooth surface. From cross-sectional SEM observations, silica aerogel particles were found to be homogeneously distributed in the agar/PEO matrix. The ionic conductivity of the composite membranes was estimated to be approximately 1 x 10(-3) S cm(-1) at room temperature, and it was further improved by thermal treatment at 150 degrees C and surface modification in a hexamethyldisilazane (HMDS)/n-hexane solution.