Salt Pumping by Voltage-Gated Nanochannels

Mario Tagliazucchi, Igal Szleifer*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

This Letter investigates voltage-gated nanochannels, where both the potential applied to the conductive membrane containing the channel (membrane potential) and the potential difference between the solutions at both sides of the membrane (transmembrane potential) are independently controlled. The predicted conductance characteristics of these fixed-potential channels dramatically differ from those of the widely studied fixed-charge nanochannels, in which the membrane is insulating and has a fixed surface charge density. The difference arises because the transmembrane potential induces an inhomogeneous charge distribution on the surface of fixed-potential nanochannels. This behavior, related to bipolar electrochemistry, has some interesting and unexpected consequences for ion transport. For example, continuously oscillating the transmembrane potential, while holding the membrane potential at the potential for which it has zero charge in equilibrium, creates fluxes of neutral salt (fluxes of anions and cations in the same direction and number) through the channel, which is an interesting phenomenon for desalination applications.

Original languageEnglish (US)
Pages (from-to)3534-3539
Number of pages6
JournalJournal of Physical Chemistry Letters
Volume6
Issue number18
DOIs
StatePublished - Aug 25 2015

Keywords

  • Nernst-Planck
  • bipolar diode
  • bipolar electrochemistry
  • desalinization
  • ion current
  • membrane
  • nanopore

ASJC Scopus subject areas

  • Materials Science(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Salt Pumping by Voltage-Gated Nanochannels'. Together they form a unique fingerprint.

Cite this