Abstract:

In order to endow microporous polypropylene membrane (MPPM) with antibacterial ability and enhance its anti-pollution performance, the modified layer of chitosan quaternary ammonium salt was successfully constructed on the surface of MPPM membrane by covalent modification through photoinitiated graft polymerization of acrylic acid, amidation reaction of chitosan with polyacrylic acid, ring-opening addition of amino group of chitosan with 2,3-epoxypropyltrimethyl ammonium chloride. The construction process was confirmed by FTIR, XPS and fluorescein disodium salt staining analysis. The results of static water contact angle and water absorption experiment showed that the modified film has excellent surface wettability and water absorption, and the water absorption can reach 11.23mg/cm², which is 1123 times of that of unmodified MPPM. The antibacterial activity and stability of the modified membrane were tested with E. coli and S. aureus by plate count method. The results showed that the modified membrane had good antibacterial activity, with the antibacterial rate of 98% against E. coli and 100% against S. aureus, and the antibacterial effect was stable, thus having potential application prospect in the field of water treatment.

Key words: membranes, surface modification, separation, chitosan, antibacterial property

摘要：

为了赋予微孔聚丙烯膜（MPPM）抗菌能力，增强其抗污染性能，本文通过丙烯酸的光引发接枝聚合、壳聚糖与聚丙烯酸的酰胺化反应、壳聚糖胺基与2,3-环氧丙基三甲基氯化铵的开环加成，成功地在MPPM膜表面通过共价修饰技术构建了壳聚糖季铵盐修饰层。构建过程通过FTIR、XPS和荧光素二钠盐染色分析得到了证实。静态水接触角和吸水量实验结果表明，制得的修饰膜具有优异的表面润湿性和吸水性，吸水量可达11.23mg/cm²，为未修饰MPPM的1123倍。以大肠杆菌和金黄色葡萄球菌为代表，采用平板活菌计数法考察了修饰膜的抗菌性能和抗菌稳定性。研究结果表明，修饰膜具有良好的抗菌活性，对大肠杆菌的抗菌率可达98%，对金黄色葡萄球菌的抗菌率可达100%，且抗菌效果稳定，在水处理领域具有潜在的应用前景。

关键词: 膜, 表面修饰, 分离, 壳聚糖, 抗菌性能