Abstract: The present disclosure provides a flat-sheet polyamide membrane comprising a first major surface and a second major surface and a separation layer and a porous substructure in the cross section of the membrane between the first major and the second major surface, wherein the average pore size diameter in the separation layer is smaller than the average pore size diameters on the first and second major surfaces, wherein the average pore size diameter on the first major surface is larger than the average pore size diameter on the second major surface, wherein the separation layer is closer to the second major surface than to the first major surface. The present disclosure further provides a method for producing such membranes and a use of the membranes for nanofiltration or ultrafiltration purposes.

Abstract: The present disclosure provides a flat-sheet polyamide membrane comprising a first major surface and a second major surface and a separation layer and a porous substructure in the cross section of the membrane between the first major and the second major surface, wherein the average pore size diameter in the separation layer is smaller than the average pore size diameters on the first and second major surfaces, wherein the average pore size diameter on the first major surface is larger than the average pore size diameter on the second major surface, wherein the separation layer is closer to the second major surface than to the first major surface. The present disclosure further provides a method for producing such membranes and a use of the membranes for nanofiltration or ultrafiltration purposes.

Abstract: Hydrophilic flat-sheet membrane based on a hydrophobic first polymer from the group consisting of aromatic sulfone polymers and a hydrophilic second polymer, wherein the membrane has a thickness in the range between 30 and 200 ?m, a first and a second surface and a supporting layer having a three-dimensional sponge-like network structure, wherein the supporting layer has a first cover layer on the side thereof facing the first surface and a second cover layer on the side thereof facing the second surface, which cover layers are formed integrally with the supporting layer, and wherein the first and second surfaces have approximately oval or circular openings which penetrate the first and second cover layers, respectively, and are connected to the supporting layer, wherein the average diameter of the openings in the surfaces differ by a factor of less than 2, wherein the three-dimensional network structure of the supporting layer is made up of thick branches and a continuous pore system, and the predominant pro

Abstract: Hydrophilic flat-sheet membrane based on a hydrophobic first polymer from the group consisting of aromatic sulfone polymers and a hydrophilic second polymer, wherein the membrane has a thickness in the range between 30 and 200 ?m, a first and a second surface and a supporting layer having a three-dimensional sponge-like network structure, wherein the supporting layer has a first cover layer on the side thereof facing the first surface and a second cover layer on the side thereof facing the second surface, which cover layers are formed integrally with the supporting layer, and wherein the first and second surfaces have approximately oval or circular openings which penetrate the first and second cover layers, respectively, and are connected to the supporting layer, wherein the average diameter of the openings in the surfaces differ by a factor of less than 2, wherein the three-dimensional network structure of the supporting layer is made up of thick branches and a continuous pore system, and the predominant pro