Abstract:

In order to enhance the nanofiltration performance of graphene oxide(GO) nanofiltration membrane, a large area GO nanofiltration membrane was prepared by electrostatic spraying technology. Further, combined with electrospinning technology, a PVA/GO nanofiltration membrane with composite sandwich structure was designed and prepared, which greatly improved the structural stability of the nanofiltration membrane. To further improve the nanofiltration performance of PVA/GO nanofiltration membrane, hydrophilic nanoparticles silica(SiO₂) was intercalated into GO, which increased the interlayer spacing of the GO nanofiltration membrane. Finally, the nanofiltration performance, structural stability, reusability and adsorption performance of the PVA/SiO₂/GO nanofiltration membrane(PS@GS-NF) with composite sandwich structure were studied. The results show that the steady-state pure water permeability coefficient of PS@GS-NF can reach as high as 21.1 L/(m²·h·bar), and the retention rate of organic dyes can be maintained as high as 98%. The sandwich structure also ensures that the PS@GS-NF has high structural stability. In addition, PS@GS-NF has excellent reusability and adsorption properties for positively charged organic dye molecules, with the recovery rate of 92% for pure water permeability, and the adsorption rate of 96% for positively charged methylene blue organic dye molecules.

Key words: graphene oxide, silicon dioxide, nanofiltration membrane, sandwich structure, water permeability coefficient, retention rate

摘要：

为了提高氧化石墨烯(GO)纳滤膜的纳滤性能,采用静电喷涂技术制备了大面积的GO纳滤膜,进一步结合静电纺丝技术,设计并制备了PVA/GO复合夹层结构纳滤膜,极大地提高了纳滤膜的结构稳定性。此外,为了进一步提高PVA/GO纳滤膜的纳滤性能,采用亲水性二氧化硅(SiO₂)纳米粒子插层GO,增大了GO纳滤膜的层间距。最后,对所制备的PVA/SiO₂/GO复合夹层结构纳滤膜(PS@GS-NF)的纳滤性能、结构稳定性、可重复利用性能和吸附性能进行研究。结果表明:PS@GS-NF的稳态纯水渗透系数高达21.1 L/(m²·h·bar),有机染料截留率的保持率高达98%。同时夹层结构还保证了PS@GS-NF具有较高的结构稳定性。此外,PS@GS-NF还具有良好的可重复利用性能和对带正电荷的有机染料分子具有良好的吸附性能,其纯水渗透系数恢复率可达92%,对带正电荷的亚甲基蓝有机染料分子的吸附率可达96%。

关键词: 氧化石墨烯, 二氧化硅, 纳滤膜, 夹层结构, 水渗透系数, 截留率