Ionic Current Rectification in Organic Solutions with Quartz Nanopipettes

Abstract

The study of behaviors of ionic current rectification (ICR) in organic solutions with quartz nanopipettes is reported. ICR can be observed even in organic solutions using quartz pipettes with diameters varied from several to dozens of nanometers, and the direction of ICR is quite different from the ICR observed in aqueous phase. The influences of pore size, electrolyte concentration, and surface charge on the ICR have been investigated carefully. Water in organic solutions affects the direction and extent of ICR significantly. Mechanisms about the formation of an electrical double layer (EDL) on silica in organic solutions with different amount of water have been proposed. An improved method, which can be employed to detect trace water in organic solutions, has been implemented based on Au ultramicroelectrodes with cathodic differential pulse stripping voltammetry.

Double layer effects in voltammetric measurements with scanning electrochemical microscopy (SECM)

“…The experimental curve shows good agreement with a simulated surface charge density of +10 mC m -2 ( Figure 2). This result is consistent with previously reported ICR studies at quartz nanopipettes in various organic media which also described the effect of tip size, electrolyte concentration and water content on the response [59]. The significance of EDL effects on the tip voltammetric response was explored herein by solution of the Nernst-Planck and Poisson equations in COMSOL Multiphysics (vide supra).…”

Track‐Etched Nanopore/Membrane: From Fundamental to Applications

“…These parameters usually relate to properties of electrolyte solutions, external forces, etc. It includes ion valence, [ 162,182 ] anions, [ 183 ] pressure, [ 184 ] scan rate, [ 185 ] ionic liquids, [ 186 ] solvents, [ 187 ] wettability, [ 116,188 ] and temperature. [ 189 ] They can also co‐influence ICR by combining several parameters which make it sometime complex to fully understand ion transport properties.…”

Tetraalkylammonium Cations Conduction through a Single Nanofluidic Diode: Experimental and Theoretical Studies

“…4(C). Shao and co-workers have also found that glass nanopipettes exposed to low concentrations of tetraphenylarsonium tetraphenylborate (TPAsTPB) show an inversion in the current rectification characteristics because of the adsorption of bulky cations (TPAs + ) on the pore surface [23]. As expected, the current rectification decreases at high concentrations (250 and 500 mM) and the nanopore exhibits a quasi-ohmic behavior.…”

“…Also, Yin et al have studied transport phenomena at the nanoscale using organic solvents where the electrolyte ions adsorbed on the pore surface can cause charge inversion and current rectification [23]. We propose now to describe experimentally and theoretically the transport of organic cations through single conical pores.…”