Highly Selective Ionic Transport through Subnanometer Pores in Polymer Films

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• 作者：Qi Wen ; Dongxiao Yan ; Feng Liu ; Mao Wang ; Yun Ling ; Pengfei Wang ; Patrick Kluth ; Daniel Schauries ; Christina Trautmann ; Pavel Apel ; Wei Guo ; Guoqing Xiao ; Jie Liu ; Jianming Xue and Yugang Wang
• 刊名：Advanced Functional Materials
• 出版年：2016
• 出版时间：August 23, 2016
• 年：2016
• 卷：26
• 期：32
• 页码：5796-5803
• 全文大小：1342K
• ISSN：1616-3028

文摘

Novel transport phenomena through nanopores are expected to emerge as their diameters approach subnanometer scales. However, it has been challenging to explore such a regime experimentally. Here, this study reports on polymer subnanometer pores exhibiting unique selective ionic transport. 12 μm long, parallel oriented polymer nanopores are fabricated in polyethylene terephthalate (PET) films by irradiation with GeV heavy ions and subsequent 3 h exposure to UV radiation. These nanopores show ionic transport selectivity spanning more than 6 orders of magnitude: the order of the transport rate is Li⁺>Na⁺>K⁺>Cs⁺>>Mg²⁺>Ca²⁺>Ba²⁺, and heavy metal ions such as Cd²⁺ and anions are blocked. The transport can be switched off with a sharp transition by decreasing the pH value of the electrolyte. Structural measurements and molecular dynamics simulations suggest that the ionic transport is attributed to negatively charged nanopores with pore radii of ≈0.3 nm, and the selectivity is associated with the dehydration effect.