Membrane comprising a blend of polyarylethersulfone and polyaryletherketone and method for manufacturing thereof

A method [method (MQ)] for the manufacture of a membrane [membrane (Q)] comprising at least one porous layer [layer LQ)], said method comprising:

• (I) providing a composition [composition (C)] comprising:
• (a) at least one poly(aryl ether ketone) (PAEK) polymer,
• (b) at least one poly(aryl ether sulfone) (PAES) polymer, and
• (c) at least one compound [compound(S)] comprising a sulfonate or carboxylate salt of a metal selected from the group consisting of alkaline metals, alkaline-earth metals, aluminum, iron, zinc, nickel, copper, palladium and silver;
• (II) processing said composition (C) to provide pellets;
• (III) melt extruding the pellets obtained in step (II), thus providing a precursor layer [layer (LP)];
• (IV-a) contacting said layer (LP) as obtained in step (III) with at least one organic solvent, thus providing an intermediate porous layer [layer (L−iQa)], or (IV-b1) contacting said layer (LP) as obtained in step (III) with water, thus providing a first intermediate porous layer [layer (L−iQb)];
• (IV-b2) contacting said layer (L−iQb) with at least one organic solvent, thus providing a second intermediate porous layer [layer (L−iQb2)];
• (V) contacting said layer (L−iQa) as obtained in step (IV-a) or said layer (L−iQb2) as obtained in step (IV-b2) with water, thus providing a porous layer [layer (LQ)].