Stability studies of poly(vinyl chloride)-based polymer inclusion membranes containing Aliquat 336 as a carrier

► Polymer inclusion membranes' (PIMs) stability in aqueous solutions is studied. ► All PIMs are originally made of PVC and Aliquat 336 (R3MeN+Cl−). ► In some membranes the Cl− anion is replaced by NO3-, SCN−, ClO4-, Ac− and SO42-. ► PIMs lose (R3MeN+)nXn− to the aqueous phase to reach a stable composition. ► The loss is minimized or eliminated by increasing the aqueous concentration of Xn−.