Synthesis Of Amphiphilic Comb Copolymer Containing PDMS And Application In Synergistic Antifouling Modification For PES Membrane

The polymer membranes, such as poly(ether sulfone), poly(vinylidene fluoride) are easily fouled due to the hydrophobic property, which decreses the separation efficiency and life span of the membrane. Therefore, it is necessary to improve the antifouling property of the membrane. Currently, it is an efficient way to improve the antifouling property of membrane by hydrophilic modification. However, the antifouling performance is limited when it confronted the various foulants and the complicated filtration condition. Some low surface energy materials, such as PTFE, organic silicone, possess antiadhesion, self-cleaning and fouling release ability. It is promising that the membrane surface will have excellent antifouling properties by synergistic antifouling modification (antifouling and fouling release). This study has designed and prepared the comb copolymer as modifier, achieving the engineering of lowfouling and high flux recovery PES membrane.In this study, a novel amphiphilic comb copolymer P(PEG-r-PDMS) with mixed hydrophilic and low surface energy side chains was synthesized by free radical polymerization method. The copolymers were blended with polyethersulfone (PES) to fabricate antifouling membranes through non-solvent induced phase separation (NIPS). The surface distribution of the hydrophilic PEG segments and hydrophobic PDMS segments on the membranes via surface segregation during NIPS process was confirmed by the X-ray photoelectron spectroscopy (XPS), the wetting property and the surface energy measurements. The binary-defense mechanisms from fouling resistant to fouling release for the membranes modified by amphiphilic copolymers P(PEG-r-PDMS) were investigated with bovine serum albumin (BSA) aqueous solution as a model foulant. The antifouling properties of the modified membrane, especially for membrane PES/P(PEG-r-PDMS)-31.3%(M4), was effectively improved in comparation with pure PES membrane (Mo). The flux decline rate of the membrane M4 was as low as 15.6%, and the flux recover ratio was up to 96.6%.Moreover, this study further prepared the organic-inorganic composite modified membrane, and investigated its iernary-defense mechanisms. Firstly, a novel amphiphilic comb copolymer P(PEG-PDMS-KH570) was synthesized by free radical polymerization.The cepolymer was blended with polyethersulfone (PES) and tetraethyl orthosilicate TEOS to fabricate antifouling membranes through non-solvent induced phase separation (NIPS). The surface segregation of the composite additive was confirmed by the SEM and AFM measurements. And the well diepension of the additive in the membrane was verified by the EDX image. The antifouling properties of the membrane PES/T@SiO2, especially for membrane PES/T@SiO2-4%, was effectively improved in comparation with other membranes. The flux decline rate was as low as 13.67%, and the flux recover ratio was up to 98.03%.