*2.8. Ionic Exchange Capacity Determination*

Membrane samples (~250 mg) were dried at 120 ◦C for 3 h, weighed and then equilibrated in 20 mL of 0.1 M NaCl overnight to exchange the membrane protons with Na+ ions. The solution was titrated, in the presence of the membrane, with 0.01 M NaOH through a Radiometer automatic titrimeter (TIM900 TitraLab, Radiometer Copenhagen, Denmark), according to the equilibrium point method. The reported Ionic Exchange Capacity (IEC) values are the average of five replicate titrations [16].
