A coupled effect of dehydration and electrostatic interactions on selective ion transport through charged nanochannels. Issue 39 (2nd October 2018)

• Record Type: Journal Article
• Authors: Wang, Mao; Shen, Wenhao; Ding, Siyuan; Wang, Xue; Wang, Zhong; Wang, Yugang; Liu, Feng
• Is Part Of: Nanoscale. Volume 10:Issue 39(2018)
• Page Start: 18821
• Page End: 18828
• Publication Date: 2018-10-02
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c8nr04962a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : The interplay between dehydration and electrostatic interactions leads to a switch in ion selectivity in nanochannels as the surface charge density increases. Abstract : Selective ion transport is an essential feature of biological ion channels. Due to the subnanometer size and negatively charged surface of ion channels, the ion selectivity is affected by both dehydration effects and electrostatic interactions. Their coupled effect on selective ion transport, however, has been elusive. Here, using molecular dynamics simulations, we study ion (Li + and Mg 2+ ) transport through subnanometer carbon nanotubes (CNTs) with varying charge densities. Our results indicate that the dehydration effect governs the ionic transport at low surface charge densities, hence the nanochannel shows a selectivity for Li + ions. In contrast, the nanochannel switches to a selectivity for Mg 2+ ions as the electrostatic interaction between the cations and the negatively charged wall dominates the transport at high surface charge densities.