Fabrication Of Antifouling Interface Of Ultrafiltration Membrane And Study Of Its Separation Property

The ultrafiltration membrane separation technology is energy-saving and highly efficient. For solving fouling problem of polymeric membranes exits in bio-separation process, the research designed modifying agents and membrane formation method rationally, made the bioinspired fabrication of antifouling membranes to improve the antifouling property of ultrafiltration.With the method of chemical modification on surface of membrane, PAN control membrane was hydrolyzed. By reacting with ethanolamine, carboxylic acid groups turn to amine groups (-CONH-), which have superior performance.in the aspect of antifouling. The property of PAN modified membranes was studied in detail. The XPS and contract angel data results showed that PAN modified membrane might have better antifouling property with the increase of amine group on the membrane surface. The photos of scanning electron microscopy (SEM) confirmed that the morphology of PAN modified membrane did not changed. The results of Ultrafiltration proved that the modified membranes showed better antifouling property in competition with the PAN control membrane. The membranes could be used for several runs. A novel membrane material PAN-PFMA copolymer was synthesized, which is used to fabricate the interface of membrane. PAN-PFMA polymer membranes with different desolvation were prepared by a phase inversion method with different desolvation time. X-ray photoelectron spectroscopy (XPS) analysis characterized the increasing content of fluorine on the membrane surface. Scanning electron microscopy (SEM) observed the spongy morphology of the PAN-PFMA polymer membranes. The separation and antifouling property of the PAN-PFMA polymer membranes were efficiently improved with the increase of the desolvation time during the process of phase inversion.In order to improve surface coverage of PVP on membrane surface and further enhance antifouling property, silica-PVP nanocomposite was synthesized and used as a novel hydrophilic additive to modify PES membranes. TEM observation showed that PES membranes using additives of PVP and silica-PVP nanocomposite have similar asymmetric structure. XPS measurement indicated that the near-surface coverage of PVP for PES membrane with additive of silica-PVP nanocomposite is higher than that with additive of PVP. Protein ultrafiltration experiment also showed that the antifouling ability of PES membrane with additive of silica-PVP nanocomposite is stronger than that with additive of PVP. The hydrophilic modification with silica-PVP nanocomposite is appropriate method for improved antifouling property of PES ultrafiltration membranes.