The great potential of nanoporous membranes for water filtration and chemical separation has been challenged by the trade-off between selectivity and permeability. Here we report on nanoporous polymer membranes with an excellent balance between selectivity and permeability of ions. Our membranes are fabricated by irradiating 2-μm-thick polyethylene terephthalate Lumirror® films with GeV heavy ions followed by ultraviolet exposure. These membranes show a high transport rate of K+ ions of up to 14 mol h−1 m−2 and a selectivity of alkali metal ions over heavy metal ions of >500. Combining transport experiments and molecular dynamics simulations with a polymeric nanopore model, we demonstrate that the high permeability is attributable to the presence of nanopores with a radius of ~0.5 nm and a density of up to 5 × 1010 cm−2, and the selectivity is ascribed to the interaction between the partially dehydrated ions and the negatively charged nanopore wall.
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机译：选择性和渗透性之间的权衡挑战了纳米多孔膜在水过滤和化学分离中的巨大潜力。在这里，我们报道了具有选择性和离子渗透性之间极佳平衡的纳米多孔聚合物膜。我们的膜是通过用GeV重离子辐照2μm厚的聚对苯二甲酸乙二醇酯Lumirror®膜，然后进行紫外线照射制成的。这些膜显示出高达14 mol h -1 m -2 的K + 离子的高迁移率和碱金属离子的选择性超过500的重金属离子。将传输实验和分子动力学模拟与聚合物纳米孔模型相结合，我们证明了高渗透性归因于存在半径为〜0.5 nm且密度高达5×10 10 的纳米孔cm −2 ，选择性归因于部分脱水离子与带负电荷的纳米孔壁之间的相互作用。
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