论文标题
水和离子转移到狭窄的碳纳米管：外部和内部的作用
Water and Ion Transfer to Narrow Carbon Nanotubes: Roles of Exterior and Interior
论文作者
论文摘要
狭窄的碳纳米管（CNT）脱盐水，模仿生物膜的水通道，但是选择性背后的物理学，尤其是膜嵌入CNT对水和离子转移的影响，尚不清楚。在这里，我们报告了$ ab $ $ $ $ INITIO $分析水和k $^+$和cl $^ - $^ - $离子从溶液到空和水填充0.68 nm cnts的能量，用于周围矩阵的不同介电常数$ε$。以$ 1 \leqε<\ infty $计算的转移能允许将转移能的透明分解为三个主要贡献：与CNT结合，内部CNT水合和矩阵的介电偏振。后者与$ε$相反，并为两种离子的订单$ 10^2 $/$ε$ kj/mol，这可能会将离子转移从有利转移到不利，具体取决于离子，$ε$和CNT直径。这可能对基于纳米渠道的设备的设计和调整选择性具有广泛的影响。
Narrow carbon nanotubes (CNTs) desalinate water, mimicking water channels of biological membranes, yet the physics behind selectivity, especially, the effect of the membrane embedding CNTs on water and ion transfer, is still unclear. Here, we report $ab$ $initio$ analysis of the energies involved in transfer of water and K$^+$ and Cl$^-$ ions from solution to empty and water-filled 0.68 nm CNTs, for different dielectric constants $ε$ of the surrounding matrix. The transfer energies computed for $1 \leq ε< \infty$ permit a transparent breakdown of the transfer energy to three main contributions: binding to CNT, intra-CNT hydration, and dielectric polarization of the matrix. The latter scales inversely with $ε$ and is of the order $10^2$/$ε$ kJ/mol for both ions, which may change ion transfer from favorable to unfavorable, depending on ion, $ε$, and CNT diameter. This may have broad implications for designing and tuning selectivity of nanochannel-based devices.
