Graphene oxide (GO), as an emerging nanofiller, is commonly incorporated into the polypiperazine amide (PPA) selective layer to enhance nanofiltration (NF) performance. However, GO’s dispersibility and compatibility present outstanding challenges for fabricating high-performance GO-incorporated NF membranes. In this study, polyvinyl alcohol (PVA) and GO were introduced into the aqueous solution at the same time to enhance the membrane performance by taking advantage of the synergetic effects of GO and PVA. GO’s dispersibility in aqueous solution and its compatibility within the PPA matrix were significantly improved because of the introduction of PVA. Furthermore, both PVA and GO contributed to the diffusion behavior of aqueous monomers for constructing defect-free, rougher, thinner, and more hydrophilic NF membranes. With the introduction of 100 ppm GO and 0.05 wt % PVA into the aqueous solution during the interfacial polymerization process, the optimal thin-film nanocomposite NF membrane exhibited a water flux of 84.2 LMH without reducing the salt rejections (97.6% for Na₂SO₄), which were 69.1 and 36.7% higher than the pristine thin-film composite (TFC)-blank and TFC-PVA membranes, respectively. Meanwhile, an excellent antifouling performance was achieved with a flux recovery rate of 92.1% because of the lower negative charge and excellent hydrophilicity of the membrane surface. This study develops a simple and effective approach to construct high-performance NF membranes.

中文翻译：

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氧化石墨烯与聚乙烯醇协同作用构建高性能纳滤膜的简便策略

氧化石墨烯（GO）作为一种新兴的纳米填料，通常掺入聚哌嗪酰胺（PPA）选择性层中以增强纳米过滤（NF）性能。但是，GO的分散性和相容性为制造高性能的掺有GO的NF膜提出了严峻的挑战。在这项研究中，聚乙烯醇（PVA）和GO同时引入水溶液中，以利用GO和PVA的协同作用增强膜性能。由于引入了PVA，大大提高了GO在水溶液中的分散性及其在PPA基质中的相容性。此外，PVA和GO均有助于水性单体的扩散行为，以构建无缺陷，更粗糙，更薄且更具亲水性的NF膜。₂ SO ₄），分别比原始的TFC-空白和TFC-PVA膜高69.1和36.7％。同时，由于较低的负电荷和优异的膜表面亲水性，因此具有优异的防污性能，通量回收率为92.1％。这项研究开发了一种构造高性能NF膜的简单有效的方法。