Abstract This study introduces a thin-film composite (TFC) membrane with a dual-layered nanocomposite substrate synthesized using a dual-blade casting approach for application in osmotic power generation by the pressure-retarded osmosis (PRO) process. The approach incorporates halloysite nanotubes (HNTs) into the bottom polymer substrate layer and graphene oxide (GO) on the top layer substrate, on which a thin polyamide active layer is formed. The fabricated membrane substrate showed highly desirable membrane substrate properties such as a high porosity, opened-bottom surface, suitable top-skin surface morphology for subsequent active layer formation and high mechanical strength, which are essential for high-performance PRO processes. At a GO loading of 0.25 wt% and HNT loading of 4 wt%, the power density (PD) of the nanocomposite membrane was 16.7 W/m2 and the specific reverse solute flux (SRSF) was 2.4 g/L operated at 21 bar applied pressure using 1 M NaCl as draw solution and deionized water as feed, which is significantly higher than the those for a single-layered or commercial PRO membrane. This membrane performance was observed to be stable in the pressure cycle test and under long-term operation. The membrane substrate with HNTs incorporated exhibited high fouling resistance to sodium alginate and colloidal silica foulants, with the PD decreasing by 17% after 3 h of operation, compared to a membrane substrate without HNTs and commercial PRO membranes, which decreased by 26% and 57%, respectively. A fluorescence microscope study of the membranes subjected to feed water containing Escherichia coli confirmed the good antibacterial properties of the dual-layered TFC membrane. The study provides an attractive alternative approach for developing PRO membranes with high PD and fouling resistance.

中文翻译：

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包含氧化石墨烯和埃洛石纳米管的双层纳米复合膜具有高渗透功率密度和抗污染性

摘要 本研究介绍了一种具有双层纳米复合基材的薄膜复合 (TFC) 膜，该膜采用双叶片浇铸方法合成，用于压力延迟渗透 (PRO) 工艺的渗透发电。该方法将埃洛石纳米管 (HNT) 结合到底部聚合物衬底层和顶层衬底上的氧化石墨烯 (GO)，在其上形成薄的聚酰胺活性层。制造的膜基材显示出非常理想的膜基材特性，例如高孔隙率、开放的底面、适合后续活性层形成的表皮表面形态和高机械强度，这些都是高性能 PRO 工艺必不可少的。在 0.25 wt% 的 GO 负载和 4 wt% 的 HNT 负载下，纳米复合膜的功率密度 (PD) 为 16。7 W/m2 和特定反向溶质通量 (SRSF) 为 2.4 g/L，在 21 bar 的应用压力下使用 1 M NaCl 作为驱动溶液和去离子水作为进料，这显着高于单层或商用 PRO 膜。该膜性能在压力循环试验和长期运行中均表现稳定。含有 HNTs 的膜基材对海藻酸钠和胶体二氧化硅污染物表现出高抗污染性，与没有 HNTs 和商用 PRO 膜的膜基材相比，运行 3 小时后 PD 降低了 17%，后者分别降低了 26% 和 57 ％， 分别。对含有大肠杆菌的进水的膜进行荧光显微镜研究，证实了双层 TFC 膜的良好抗菌性能。