Conductivity of pure (air controlled) and air exposed hydroxide ion was compared using a unique sample preparation and conductivity measurements at controlled environment for a commercial FumasepÒ FAA anion exchange membrane. At 95%RH and 80°C, the membrane had conductivity value of 0.075 S/cm at the pure hydroxide form but reduced merely to 0.017 S/cm when the membrane was exposed to ambient CO2 for 2 days. A comparative anionic (OH-, CO32-, and HCO3- forms) conductivity study showed the reduced ionic conductivity value by ¼ of its pure form; closed to HCO3- forms of the membrane. This indicated the formation of ionic mixture of CO32-, HCO3,- and residual OH- ions in the hydroxide form of the membrane when exposed to air. The hydroxide ions also showed a smaller ionic energy of activation when compared to other anions indicating a smaller ionic transport energy barrier.
