Abstract Carbon nanotubes (CNTs) are important building blocks to produce high-performance membranes. However, the strong hydrophobicity significantly hinders their applications in aqueous systems. Herein, we demonstrate, for the first time, that atomic layer deposition (ALD) is an efficient and flexible method to upgrade the permselectivity of CNT-based membranes. We ALD-deposit ZnO on fabrics of multi-walled carbon nanotubes. ZnO grows on the CNT surface as nanoparticulates initially and then forms conformal layers wrapping the CNTs. The originally hydrophobic surface of CNTs is progressively turned to be highly hydrophilic with rising ALD cycles. The deposition of ZnO on CNTs significantly promotes the surface wettability of the CNT membranes on one hand, and endows the membrane an enhanced mechanical stability on the other. The CNT membranes exhibit simultaneously upgraded water permeability and retention in the ultrafiltration category after ALD for moderate cycle numbers. With ever increased ALD cycles, the retention is further improved while the water permeability is decreased due to the competing effect of the increased hydrophilicity and narrowed pores. The strategy of “ALD on CNT substrates” is expected to produce other robust membranes with additional functionalities dependent on the materials to be deposited by ALD.

中文翻译：

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金属氧化物在碳纳米管织物上的原子层沉积，用于坚固、亲水的超滤膜

摘要 碳纳米管 (CNT) 是生产高性能膜的重要组成部分。然而，强疏水性显着阻碍了它们在水性体系中的应用。在此，我们首次证明原子层沉积 (ALD) 是一种有效且灵活的方法，可提高 CNT 基膜的选择性渗透性。我们在多壁碳纳米管织物上 ALD 沉积 ZnO。ZnO 最初以纳米颗粒的形式在 CNT 表面上生长，然后形成包裹 CNT 的共形层。随着 ALD 循环的增加，CNT 最初的疏水表面逐渐变成高度亲水的。ZnO在碳纳米管上的沉积一方面显着提高了碳纳米管膜的表面润湿性，另一方面赋予膜增强的机械稳定性。在中等循环次数的 ALD 后，CNT 膜在超滤类别中同时表现出提高的水渗透性和保留率。随着 ALD 循环次数的增加，由于亲水性增加和孔隙变窄的竞争效应，保留率进一步提高，而透水性降低。“碳纳米管基板上的 ALD”策略有望生产具有附加功能的其他坚固膜，这取决于 ALD 沉积的材料。