Data from "Breakdown of Nernst-Einstein Relation in Carbon Nanotube Porins"

Full dataset from the manuscript, including data from all main text, extended data, and supplementary materials sections. <br> Abstract: For over 100 years, the Nernst-Einstein relation has provided a universal link between a charged particle electrophoretic mobility and its diffusion coefficient. Here, we report experimental measurements of diffusive and electrophoretically-driven K⁺ ion transport in narrow pores of 0.8 nm diameter single-wall carbon nanotubes (CNTs), which indicate that the Nernst-Einstein relation breaks down by over three orders of magnitude in these channels. To explain these findings, we carried out all-atomistic molecular dynamics simulations using polarizable force fields that showed that the K⁺ ion diffusion in the narrow pore of the CNT in the presence of a single file water chain was at least three orders of magnitude slower than the K⁺ ion diffusion in bulk solution. Intriguingly, the simulations also revealed a novel mechanism for electrophoretic transport of K⁺ ions where the single file water chain disintegrated in the presence of applied electric fields, forming distinct ion-water clusters, which then traversed the CNT at significantly higher velocities. Finally, we demonstrate that although the individual ion-water clusters still obey the Nernst-Einstein relation, the overall relation breaks down because of two distinct ion transport mechanisms for concentration gradient-driven versus electric field-driven ion flows in these channels.

本数据集包含该手稿的全部数据，涵盖正文、补充数据及辅助材料章节中的所有数据。摘要：百余年来，能斯特-爱因斯坦关系（Nernst-Einstein relation）为带电粒子的电泳迁移率与其扩散系数之间建立了普适性关联。本研究针对直径0.8 nm的单壁碳纳米管（single-wall carbon nanotubes, CNTs）狭窄孔道内的钾离子（K⁺）扩散与电泳驱动输运过程开展实验测量，结果表明，在该孔道中能斯特-爱因斯坦关系的偏离程度超过三个数量级。为阐释上述实验发现，我们采用极化力场开展了全原子分子动力学模拟，结果显示，当孔道内存在单链水分子链时，碳纳米管孔道内钾离子的扩散速率相较于体相溶液中的钾离子扩散速率至少慢三个数量级。有趣的是，模拟结果还揭示了一种全新的钾离子电泳输运机制：在外加电场作用下，单链水分子链发生解离，形成独立的离子-水团簇，这些团簇随后以显著更高的速度穿过碳纳米管孔道。最后，我们证实，尽管单个离子-水团簇仍遵循能斯特-爱因斯坦关系，但由于浓度梯度驱动与电场驱动的离子输运在该孔道内存在两种截然不同的机制，整体的能斯特-爱因斯坦关系不再成立。