POLYAMIDE FLAT SHEET MEMBRANES WITH MICROPOROUS SURFACE STRUCTURE FOR NANOPARTICLE RETENTION

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 themembrane 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. 本公开提供了一种聚酰胺平片膜，所述聚酰胺平片膜包括第一主表面和第二主表面，以及在所述膜的横截面中在所述第一主表面与所述第二主表面之间的分隔层和多孔亚结构，其中所述分隔层中的平均孔尺寸直径小于所述第一主表面和所述第二主表面上的平均孔尺寸直径，其中所述第一主表面上的平均孔尺寸直径大于所述第二主表面上的平均孔尺寸直径，其中与所述第一主表面相比，所述分隔层更靠近所述第二主表面。本公开还提供了一种用于生产此类膜的方法以及所述膜用于纳滤或超