Preparing polymer membrane with isoporous separation-active layer, useful e.g. in filtration module, comprises e.g. spreading casting solution having solvent, to form film, evaporating solvent portion near surface and precipitating membrane

摘要

Preparing polymer membrane having an isoporous separation-active layer, preferably an ultrafiltration- or nanofiltration membrane, comprises preparing a casting solution comprising at least one solvent, in which at least one amphiphilic block copolymer having at least two different polymer blocks, and at least one salt of a main group element of second main group, are dissolvable, spreading the casting solution to form a film, evaporating a portion of the solvent near the surface during standing period, and precipitating a membrane by immersing the film in a precipitation bath. Preparing polymer membrane having an isoporous separation-active layer, preferably an ultrafiltration- or nanofiltration membrane, comprises (a) preparing a casting solution comprising at least one solvent, in which at least one amphiphilic block copolymer having at least two different polymer blocks, and at least one salt of a main group element of second main group, are dissolvable, where one of the polymer blocks forms complexes with the main group element, (b) spreading the casting solution to form a film, (c) evaporating a portion of the solvent near the surface during standing period, and (d) precipitating a membrane by immersing the film in a precipitation bath comprising at least one non-solvent for the block copolymer. An independent claim is also included for the polymer membrane having isoporous separation-active layer, produced by the above method, exhibiting a ratio of maximum pore diameter and minimum pore diameter of less than 3.