D-酪氨酸接枝改性PAN超滤膜的制备及其抗生物污染机制研究

膜生物污染是超滤膜在水处理应用过程中的主要挑战之一。传统的膜亲水改性不能有效抑制生物膜在膜表面的形成，对膜生物污染控制效果较差。D-酪氨酸能够抑制微生物在膜表面黏附并促进生物膜解聚，如果利用D-酪氨酸对超滤膜进行改性以构建抗污染表面，可从根本上控制膜的生物污染。基于此，本项目拟在超滤膜表面化学接枝可抑制生物污染的D-酪氨酸，D-酪氨酸中的羧基和羟基还可提高膜表面亲水性，实现超滤膜抗生物污染和抗有机物污染性能的同时提高。利用聚丙烯腈（PAN）超滤膜表面的腈基为反应基团，经水解和羧基酰胺化两步反应，在膜表面共价接枝D-酪氨酸分子，制备改性层结构稳定的抗污染PAN超滤膜。探究D-酪氨酸功能分子的引入，对PAN超滤膜结构、物化性能、分离性能和抗污染性能的影响规律；阐明D-酪氨酸对膜抗生物污染性能的作用机制。本项目的研究将为抗污染超滤膜的制备提供新的设计思路和理论依据。

Biofouling poses one of the most serious challenges to ultrafiltration membrane technologies for water purification and reclamation. Traditional hydrophilic modification for membranes has been always employed to control biofouling, but with less effective due to the biofilm re-growth onto membrane surface. D-tyrosine (D-Tyr) possesses unique features to inhibit microbial attachment onto solid surfaces and trigger mature biofilm disassemble, which has showed great potential in membrane biofouling control. In this project, D-Tyr will be utilized as a surface-functionalized material to modify polyacrylonitrile (PAN) ultrafiltration membranes, aiming to improve their anti-biofouling capability and hydrophilicity. The nitrile grouping in PAN membranes will be employed as the reactive groups. After tew-step process of nitrile grouping hydrolysis and carboxylic amidation，D-Tyr will be grafted onto membrane surface via covalent binding. The effects of D-Tyr on the characteristics of modified PAN membranes towards morphologic structure, physicochemical properties, separation performance as well as anti-biofouling capability will be studied. Meanwhile, the involved anti-biofouling mechanisms will be investigated also. It is expected that the proposed investigation can offer new insights into the fabrication of anti-biofouling ultrafiltration membranes.