Modification Of Cardo Polyetherketone(PEK-C) Ultrafiltration Membrane With Zwitterionic Groups

Cardo polyetherketone (PEK-C) membrane has many desirable properties including thermostability, chemical stability, but the high hydrophobic of PEK-C membrane surface severely limits its application in separation. Hydrophobic membrane surface not only decreases water flux but also easily leads to membrane fouling. Sulfobetaine methacrylate (SBMA), as a strong hydrophilic monomer, is an ideal material for the membrane modification. Therefore, it is of great significance and practical value to apply it to the membrane modification to improve water flux and antifouling properties.Under the atmosphere, the UV irradiation was carried out to graft the hydrophilic monomer SBMA on PEK-C ultrafiltration membrane surface without photosensitizer. The effects of UV grafting conditions on the membrane hydrophilicity, the separation performance and antifouling property were studied. Results show that the increase of SBMA can raise the hydrophilicity to some extent, and it can improve the water flux and antifouling properties. The data of X-ray photoelectron spectroscopy (XPS) reveals the SBMA is successfully grafted onto the membrane surface.PEK-C membrane was grafted with Glycidyl methacrylate (GMA) by photografting, introducting epoxy groups to the membrane surface. Then, the modifited membrane was reacted with the Triethylenetetramine (TETA), Epichlorohydrin (ECH) or immersed into the Hydrobromic acid, introducting the initiator to the membrane surface. The membrane with initiator grafted SBMA via the surface-initiated atom transfer radical polymerization (SI-ATRP) to prepare antifouling membrane. The effects of grafting conditions on the membrane hydrophilicity were studied, and we got grafting process conditions of the best hydrophilic surface. XPS results also show the feasibility of grafting process.The effects of irradiation time on membrane performance was investigated by ultrafiltration experiments. The results show that when the irradiation time is30s, the modified membrane water flux reaches a maximum, then declines with the increase of time. The recovery rate of the modified membrane can reach90%under the certain irradiation time, much higher than the original membrane, and adsorption of BSA is greatly reduced. The results indicates the membrane grafted with SBMA not only enhances the flux of the membrane but also improves its antifouling performance.