Carbon nanotubes (CNTs) are promising for realizing ultrafast membranes with implications to molecular separations and beyond. However, it is a big challenge to harness the potential of CNTs for designing scalable yet high-performance membranes. Here we systematically explore the role of loading and vacuum-assisted alignment of CNTs for improving the desalination performance of polyamide (PA) based thin-film composites. To rule out the dispersion instability issues, we focused on carboxylated single-walled CNTs (SWCNTs) commercially available in the market. After applying a pre-treatment for cleaning, we deposited SWCNTs on porous polysulfone supports by vacuum filtration and coated a PA layer on top via interfacial polymerization. Morphological assessments supported by polarized Raman microspectroscopy allowed the quantification of SWCNT alignment. At an optimum SWCNT loading, which we found critical for alignment, the water permeability of resulting membranes significantly improved without compromising NaCl selectivity. Also, we achieved an improved boric acid selectivity, arguably owing to the hydrophobic nature of nanotube channels. Moreover, nanotubes promoted resistance against chlorine degradation and improved mechanical strength. Vacuum deposition is instrumental for infiltrating SWCNTs into the support layer, but a mat layer forms between the support and PA layers when SWCNT loading exceeds the limit that the support pores can accommodate. Given that we use ordinary SWCNTs and a scalable methodology (vacuum-assisted infiltration), the developed membranes are promising for practical applications.

碳纳米管 (CNT) 有望用于实现对分子分离及其他方面具有影响的超快膜。然而，利用碳纳米管的潜力来设计可扩展但高性能的膜是一个巨大的挑战。在这里，我们系统地探索了碳纳米管的加载和真空辅助排列在提高聚酰胺（PA）基薄膜复合材料的脱盐性能方面的作用。为了排除分散不稳定性问题，我们专注于市场上市售的羧化单壁碳纳米管 (SWCNT)。在应用清洁预处理后，我们通过真空过滤将 SWCNT 沉积在多孔聚砜载体上，并通过界面聚合在顶部涂覆 PA 层。偏振拉曼显微光谱支持的形态学评估允许对 SWCNT 对齐进行量化。在我们发现对排列至关重要的最佳 SWCNT 负载下，所得膜的透水性显着提高，而不会影响 NaCl 的选择性。此外，我们还提高了硼酸的选择性，这可以说是由于纳米管通道的疏水性。此外，纳米管提高了对氯降解的抵抗力并提高了机械强度。真空沉积有助于将 SWCNT 渗透到支撑层中，但是当 SWCNT 负载超过支撑孔可以容纳的极限时，在支撑层和 PA 层之间会形成垫层。鉴于我们使用普通的 SWCNT 和可扩展的方法（真空辅助渗透），