Unexpected ionic transport behavior in hydrophobic and uncharged conical nanopores. (11th July 2018)

• Record Type: Journal Article
• Authors: Balme, Sebastien; Picaud, Fabien; Lepoitevin, Mathilde; Bechelany, Mikhael; Balanzat, Emmanuel; Janot, Jean-Marc
• Is Part Of: Faraday discussions. Volume 210(2018)
• Page Start: 69
• Page End: 85
• Publication Date: 2018-07-11
• Subjects: Chemistry -- Periodicals; Metallurgy -- Periodicals; Electrochemistry -- Periodicals; 540
• DOI: 10.1039/c8fd00008e
• Languages: English
• ISSNs: 1359-6640

Abstract

Abstract : We investigated ionic transport behavior in the case of uncharged conical nanopores. We observed unexpected ionic transport behaviour, which is attributed to a predominant effect of slippage due to water organization at the solid/liquid interface. Abstract : We investigated ionic transport behavior in the case of uncharged conical nanopores. To do so, we designed conical nanopores using atomic layer deposition of Al2 O3 /ZnO nanolaminates and then coated these with trimethylsilane. The experimental results are supported by molecular dynamics simulations. The ionic transport reveals an unexpected behavior: (i) a current rectification and (ii) a constant conductance at low salt concentration which are usually reported for charged conical nanopore. To explain these results, we have considered different assumptions: (i) a default of functionalization, (ii) the adsorption anion and (iii) the slippage. The first one was refuted by the study of the poly-l -lysine transport through the nanopore. To verify the second assumption, we investigate the effect of pH on the current rectification and the molecular dynamics simulations. Finally our study demonstrates that the unexpected ionic transport is provided to a predominant effect of slippage due to the water organization at the solid/liquid interface.