Preparation of Polysulfone anion exchange membranes incorporated with Gemini cationic molecules

A series of anion exchange membranes were synthesized based on polysulfone incorporated with Gemini cationic surfactant as conductivity improving additives. The effect of addition of diethyl maleate bis[(dodecyldimethyl)chloride/ammonium bromide] (G_12–2-12) cationic surfactant with different content on the water uptake, swelling ratio, ion exchange capacity, mechanical property, conductivity, and alkaline stability of the membranes were all investigated and the aforementioned membranes were also characterized by FT-IR, TGA and SEM. The result revealed that water uptake, swelling ratio, ion exchange capacity, conductivity were increased with the increasing of G_12–2-12 content. The optimum P-X (X ≠ 0) membrane (W_G12–2-12% = 40) showed an IEC of 1.20 meq g⁻¹ with water uptake of 20.33% and hydroxide conductivity of 9.53 10⁻³ S cm⁻¹ obtained at 80 °C. Interestingly, these membranes displays outstanding thermal stability with stable up to 150 °C, good mechanical strength with tensile stress in the range of 40.75 MPa–25.16 MPa and excellent chemical stabilities of up to 120 h in 6 M KOH without obvious loss of anionic conductivity (≤5.0%).