Studies of the thermal behavior of Nafion® membranes treated with aluminum(III)

The effect of aluminum countercations on the thermal behavior of Nafion (R)-117 membrane was studied by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and accelerating rate calorimetry (ARC (R)). Aluminum countercations exchanged into a Nafion (R)-117 membrane were found to adversely affect the thermal properties of the membrane. The aluminum cations may give rise to a catalytic decomposition of the perfluoroalkylether (PFAE) side chains of the Nafion (R). This result, together with some previously reported data, indicate that not just the size of the countercations, but the properties of the countercations themselves can also have a very strong effect on ionomer properties. (c) 2005 Published by Elsevier Ltd.