Interfacial polymerization technology was employed to immobilize silver (Ag) nanoparticles on the surface of commercial polyethersulfone (PES) membrane to develop antibacterial and antifouling ultrafiltration membrane. Ag nanoparticles were prepared from the reduction of silver nitrate (AgNO₃) by sodium borohydride in the presence of polyethyleneimine (PEI) as the stabilizer. The encapsulated Ag nanoparticles in the PEI solution were embedded into the PEI membrane when trimesoyl chloride solution was used to crosslink the PEI solution with the PES membrane, forming Ag-polyamide (PA) networks through the interfacial polymerization reaction. Experimental results showed that the membrane prepared with 50 mmol/L of AgNO₃ and 20 mmol/L of PEI had the optimized antibacterial effect against Escherichia coli. Bacterial concentration and species were also investigated. Exiguobacterium aestuarii and Staphylococcus aureus which are gram-positive bacteria, needed significantly more time for the Ag-PA/PES membrane to kill the bacteria completely when compared to E.coli and Vibrio coralliilyticus which are gram-negative bacteria. This study showed that Ag nanoparticles impregnated in membrane surfaces were 100% effective in killing various types of marine bacteria and bacteria in the seawater collected off Sentosa Island in Singapore. These membranes exhibit excellent antibacterial and antifouling properties which can be used to kill bacteria in ballast water and seawater.

中文翻译：

---

压载水界面聚合浸渍银纳米颗粒抗菌超滤膜

采用界面聚合技术将银（Ag）纳米粒子固定在商用聚醚砜（PES）膜表面，开发抗菌防污超滤膜。在聚乙烯亚胺 (PEI) 作为稳定剂的存在下，通过硼氢化钠还原硝酸银 (AgNO ₃ )制备银纳米颗粒。当使用均苯三甲酰氯溶液将 PEI 溶液与 PES 膜交联时，PEI 溶液中封装的 Ag 纳米粒子嵌入 PEI 膜中，通过界面聚合反应形成 Ag-聚酰胺 (PA) 网络。实验结果表明，50 mmol/L AgNO ₃和20 mmol/L PEI制备的膜具有最佳的抑菌效果。大肠杆菌。还研究了细菌浓度和种类。与革兰氏阴性菌大肠杆菌和溶珊瑚弧菌相比，作为革兰氏阳性菌的Exiguobacterium aestuarii和金黄色葡萄球菌需要更多的时间让 Ag-PA/PES 膜完全杀死细菌。这项研究表明，浸渍在膜表面的银纳米粒子可以 100% 有效地杀死各种类型的海洋细菌和新加坡圣淘沙岛收集的海水中的细菌。这些膜表现出优异的抗菌和防污性能，可用于杀死压舱水和海水中的细菌。