Abstract Increasing demand for affordable desalinating water has stimulated the vigorous development of reverse osmosis (RO) membranes. To date, the performance of polymeric membranes is limited by the permeability–selectivity trade-off: more permeable membranes lead to a less ideal selectivity and vice versa. Significant efforts have been made to identify new classes of ultra-permeable nanoporous membranes, but such trade-off can still be commonly observed. In this study, we identify the key role of the surface uniformity and chemistry of permeation channels inside nanoporous membranes in mitigating the trade-off. By using highly tunable aluminosilicate nanotubes (AlSiNTs) as a model system, this study demonstrates that, by properly designing the interior surface of AlSiNTs, the materials can offer not only higher water permeability but also a better ability to reject salts. Detailed investigations on the capacity, dynamics, energetics, and distribution of water as well as the free energy landscapes for water molecules and ions are also carried out to understand the permeation mechanisms of species at an atomic level. The outcomes obtained herein can provide guidelines for the rational design of nanotube-based membranes, or porous materials in general, to achieve more efficient and effective desalination processes.

中文翻译：

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利用反渗透海水淡化膜的内表面功能化来减轻渗透性-选择性权衡：基于纳米管的膜的分子模拟

摘要 对经济实惠的淡化水的需求不断增加，刺激了反渗透（RO）膜的蓬勃发展。迄今为止，聚合物膜的性能受到渗透性 - 选择性权衡的限制：更高的渗透性导致不太理想的选择性，反之亦然。已经做出重大努力来确定新类别的超渗透纳米多孔膜，但这种权衡仍然可以普遍观察到。在这项研究中，我们确定了纳米多孔膜内部渗透通道的表面均匀性和化学性质在减轻权衡中的关键作用。通过使用高度可调的铝硅酸盐纳米管 (AlSiNTs) 作为模型系统，本研究表明，通过正确设计 AlSiNTs 的内表面，这些材料不仅可以提供更高的透水性，而且还具有更好的阻盐能力。还对水的容量、动力学、能量学和分布以及水分子和离子的自由能景观进行了详细研究，以在原子水平上了解物种的渗透机制。本文获得的结果可以为基于纳米管的膜或一般多孔材料的合理设计提供指导，以实现更有效的脱盐过程。