Process for making a membrane M comprising the following steps: a) preparing a copolymer C, wherein said copolymer C comprises blocks of at least one polyarylene ether A and blocks of polyalkylene oxide PAO, wherein the content of polyethyleneoxide in copolymer C is 30 to 90% by weight and wherein copolymer C is prepared in a solvent L to yield solution S; b) providing a dope solution D comprising at least one polymer P; c) mixing solution S and dope solution D; d) preparing a membrane by bringing the mixture of solution S and dope solution D into contact with at least one coagulating agent.