School of Aeronautics and Institute of Extreme Mechanics, Northwestern Polytechnical University, Xi'an, 710072, China.
School of Physical Science and Technology, Northwestern Polytechnical University, Xi'an, 710072, China.
Nanoscale. 2023 Jun 1;15(21):9560-9566. doi: 10.1039/d3nr01156a.
When channels are scaled down to the size of hydrated ions, Coulomb interactions are enhanced in confinement, resulting in new phenomena. Herein, we found blockade of ionic transport in latent-track angstrom-scale channels governed by surface charge, fundamentally different from Coulomb blockade or Wien effects. The channels are non-conductive at low voltage, blocked by cations bound at the surface in confinement; however, they change to conductive with increasing voltage due to the release of bound ions. The increase in surface charge density gradually causes the conduction to be ohmic. Using Kramers' escape framework, we rationalized an analytical equation to describe the experimental results, uncovering new fundamental insights into ion transport in the smallest channels.
当通道缩小到水合离子的大小时，库仑相互作用在限制中增强，从而产生新的现象。在此，我们发现受表面电荷控制的潜在轨迹埃米尺度通道中的离子输运被阻断，这与库仑阻塞或维恩效应根本不同。在低电压下，通道不导电，被束缚在表面的阳离子在限制中被阻断；然而，随着电压的增加，由于结合离子的释放，它们变为导电。表面电荷密度的增加逐渐导致传导为欧姆。利用克拉默斯逃逸框架，我们推导出一个解析方程来描述实验结果，揭示了在最小通道中离子输运的新的基本见解。
