Fabrication of polysulfone membrane with sponge-like structure by using different non-woven fabrics

The porous support layer with sponge-like structure has been widely used in thin-film composite (TFC) membranes. A series of polysulfone (PSf) support membranes with different sponge-like structure were fabricated via non-solvent induced phase separation (NIPS) method. The influences of membrane fabrication parameters including coagulation bath temperature, relative humidity, pre-evaporation time and membrane thickness on PSf membrane properties were systematically explored. The sponge-like-structured PSf membranes were formed while the coagulation bath temperature, relative humidity, pre-evaporation time and membrane thickness were 60 °C, 20%, 30 s, and 60 μm, respectively. Additionally, three types of polyethylene terephthalate (PET) non-woven fabrics (NWFs) with different properties were selected to study the influencing mechanism on PSf membrane with sponge-like structure. It was found that the PSf membrane (PSf-NWF-01) formed on more hydrophilic PET NWFs exhibited higher porosity (63%) and excellent performances (with a pure water flux of 463.69 L/(m2·h) and the BSA rejection of 97.58%), which was caused by a higher adhesion existed between more hydrophilic NWF surface and PSf casting solution. Moreover, the PSf-NWF-01 membrane also exhibited the highest flux recovery ratio of 88.59% and the lowest irreversible fouling of 11.41%. This work academically clarified the influence mechanism of PET NWFs properties on spongy-like PSf membranes, which also had theoretical guidance for selecting appropriate PET NWFs for the preparation of PSf membranes in industry.