有机-无机杂化型耐污染反渗透膜的制备及性能

Preparation and properties of organic-inorganic hybrid antifouling reverse osmosis membrane

采用溶胶-凝胶方法制备了聚乙烯醇(PVA)-γ-氨丙基三乙氧基硅烷(KH550)溶胶-凝胶修饰液,将其涂覆在聚酰胺(PA)反渗透膜表面得到改性的反渗透膜PA-KH550。利用ATR-FTIR、SEM、AFM、电极电位分析和接触角测试等方法分析了PA-KH550的结构与性能。实验结果表明,当KH550在修饰液中的含量为8 mg/mL时,所得PA-KH550-8的水通量达到45.3 L/(m^(2)·h),截盐率达到98.8%,粗糙度降至12.6 nm。KH550的引入提高了膜的亲水能力,修饰层有效的屏蔽作用使膜表面接近电中性。PA-KH550-8在牛血清白蛋白含量为1 mg/mL的污染水中连续运行12 h后,水通量下降率为13.6%,低于未改性的PA反渗透膜及PVA涂覆改性PA膜;经水洗后,PA-KH550-8的水通量可恢复至初始的95.0%,高于PA反渗透膜及PVA涂覆改性PA膜。

A sol-gel modification solution containing polyvinyl alcohol(PVA)andγ-aminopropyltriethoxy silane(KH550)was prepared by sol-gel method and coated on the surface of polyamide(PA)reverse osmosis(RO)membranes to prepare modified RO membrane PA-KH550.The structure and properties of the PA-KH550 were characterized by ATR-FTIR,SEM,AFM,streaming potential and static contact angle measurement.The results indicate that when the KH550 content in modification solution is 8 mg/mL,the PA-KH550-8 with a salt rejection rate of 98.8%,water flux of 45.3 L/(m^(2)·h)and roughness of 12.6 nm is obtained.The introduction of KH550 can improve the hydrophilic ability of the membrane,and the effective shielding of the modification layer made the surface of membrane close to electrical neutrality.PA-KH550-8 decreased about 13.6%of the initial flux after 1 mg/mL bovine serum albumin fouling for 12 h,which is lower than that of the unmodified PA RO membrane and PVA modified PA membranes.Furthermore,the flux recovery of the PA-KH550-8 reaches 95.0%after cleaning,which was much higher than that of PA RO membrane and PVA modified PA membranes.