Luminescence Probe Studies of Nafion Polyelectrolytes

Results of luminescence probe studies of solutions of the polyelectrolytes obtained upon dissolving Nafion are reported. The primary objective of this work was to study the nature of the interactions between these anionic polyelectrolytes and their counterions. Both 1100 and 1200 equivalent weight Nafion were studied; solutions of these Nafions were prepared using a procedure developed in this laboratory. These luminescence probe studies have shown that strong binding to the Nafion polyelectrolytes occurs when both hydrophobic and electrostatic interactions are possible. Hence, Nafion preferentially binds hydrophobic cations such as , methylviologen, and auramine O over simple inorganic cations such as H+, Na+, and Mg2+. The implications of this unusual ion exchange selectivity to transport properties of Nafion films and membranes are discussed.