Water scarcity and inadequate membrane selectivity have spurred interest in biomimetic desalination membranes, in which biological or synthetic water channels are incorporated in an amphiphilic bilayer. As low channel densities (0.1 to 10%) are required for sufficient water permeability, the amphiphilic bilayer matrix will play a critical role in separation performance. We determine selectivity limits for biomimetic membranes by studying the transport behavior of water, neutral solutes, and ions through the bilayers of lipid and block-copolymer vesicles and projecting performance for varying water channel densities. We report that defect-free biomimetic membranes would have water/salt permselectivities ~10⁸-fold greater than current desalination membranes. In contrast, the solubility-based permeability of lipid and block-copolymer bilayers (extending Overton's rule) will result in poor rejection of hydrophobic solutes. Defect-free biomimetic membranes thus offer great potential for seawater desalination and ultrapure water production, but would perform poorly in wastewater reuse. Potential strategies to limit neutral solute permeation are discussed.

中文翻译：

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仿生海水淡化膜的选择性渗透极限。


缺水和膜选择性不足激发了人们对仿生海水淡化膜的兴趣，其中生物或合成水通道被纳入两亲双层中。由于足够的水渗透性需要低通道密度（0.1至10%），因此两亲双层基质将在分离性能中发挥关键作用。我们通过研究水、中性溶质和离子通过脂质和嵌段共聚物囊泡双层的传输行为并预测不同水通道密度的性能来确定仿生膜的选择性限制。我们报告说，无缺陷的仿生膜的水/盐选择性渗透率比现有的脱盐膜高约 10 ⁸倍。相反，脂质和嵌段共聚物双层的基于溶解度的渗透性（扩展奥弗顿规则）将导致疏水性溶质的排斥性较差。因此，无缺陷的仿生膜为海水淡化和超纯水生产提供了巨大的潜力，但在废水回用方面表现不佳。讨论了限制中性溶质渗透的潜在策略。