International Conference PhysicA.SPb/2023

The influence of surface charge on the ionic conductivity of the electrolyte in a nanochannel

M. V. Zhukov, O. M. Gorbenko, S. Yu. Lukashenko, I. D. Sapozhnikov, M. L. Fel'shtyn, S. V. Pichakhchi, A. O. Golubok

Institute for Analytical Instrumentation, Russian Academy of Sciences, St. Petersburg, Russia

Abstract: The flow of ion current in a nanochannel formed by a glass nanopipette close to a flat polymer surface at distances commensurate with or less than the diameter of its aperture ($\sim$ 100 nm) was studied. The gap between the pipette and the plane was controlled using the feedback loop of a scanning ion conductance microscope. An increase in ionic conductivity was detected as the nanopipette approached the surface. The axially symmetric pipette-plane system was considered as an adaptive T-shaped nanochannel. The dependence of the T-channel conductivity on the aperture size, temperature, and ion concentration was studied. It has been shown that the effect of increasing conductivity is due to the surface charge.

Keywords: nanopipette, scanning ion conductance microscope, nanochannel, peak effect, surface charge.

Received: 19.05.2023
Revised: 13.09.2023
Accepted: 30.10.2023

DOI: 10.61011/FTT.2023.12.56762.5110k

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