聚多巴胺-聚乙烯亚胺改性反渗透膜制备与表征

饮用水短缺和水污染问题严重影响着人类和社会的发展。反渗透技术提供了一种高效经济的方法来生产纯水和处理废水,以缓解这个问题。但是,反渗透膜的污染尤其是生物污染严重制约着其高效应用。膜表面改性技术是提升膜抗污染性能的最常用手段,通过多巴胺盐酸盐(DA)在聚酰胺反渗透膜表面自聚,生成超薄聚多巴胺涂层(PDA),进一步利用PDA涂层上的活性基团将聚乙烯亚胺(PEI)接枝到反渗透膜表面,得到稳定持久的PDA-PEI改性反渗透膜。通过对改性膜的XPS测试,亲水性和抗菌性试验,得到以下结论:PDA成功涂层于反渗透膜表面,且PEI成功接枝于PDA涂层表面;PDA-PEI改性增大了膜表面的亲水性,提升了反渗透膜抗污染的能力,使其具有了一定的抗菌能力。

Fabrication and characterization of a reverse osmosis membrane modified by polydopamine-polyethylenimine

Shortage of clean drinking water and water pollution are two of the biggest challenges to human and social development. Reverse osmosis technology can provide an high-efficient and economical way to produce pure water and treat wastewater and mitigate water resources problem. However, this promising water treatment technology is often hampered by the bio-fouling of membrane. And membrane surface modification techniques are the most common method to promote anti-fouling performance of membrane. In this study, through the auto-agglutination of self-polymerization of dopamine (DA) on the membrane surface, a super-thin PDA film can be formed and the PDA film can provide a large number of active groups for the subsequent PEI grafting. With the successful grafting, we can get stable and durable PDA-PEI modified reverse osmosis membrane. The successful modification including the formation of PDA and its surface-grafting of PEI are confirmed by X-ray photoelectron spectroscopy (XPS). The test shows that modification enhanced the surface hydrophilicity. Furthermore, the simulated fouling and antibiosis experiments were done. The results showed that the modification enhanced the membrane anti-fouling and antibacterial properties.