[EN] Electrolyte mixtures in aqueous solutions are central to biophysical chemistry and chemical engineering. In many cases, ions are confined to nanoscale volumes with surface electrical charges. Here, we analyze ...[+]
[EN] Electrolyte mixtures in aqueous solutions are central to biophysical chemistry and chemical engineering. In many cases, ions are confined to nanoscale volumes with surface electrical charges. Here, we analyze experimentally the additivity of ionic currents across negatively charged conical nanopores in mixed electrolyte solutions. These pores show an asymmetric axial distribution of carboxylic acid groups on the pore surface, which gives rectified current (I)-voltage (V) curves when a single-pore membrane is bathed by two symmetrical aqueous solutions at neutral pH values. We consider KCl, LiCl, NaCl, CsCl, CaCl2, and K2SO4 pure electrolytes as well as the mixed electrolyte systems LiCl + KCl, NaCl + KCl, CsCl + KCl, CaCl2 + KCl, and K2SO4 + KCl for concentrations ranging from 2 to 500 mM and applied voltages between -2 V and 2 V. The difference between the sum of the pure electrolyte currents and the mixed electrolyte current is studied in terms of the electrolyte concentration, the sign of the applied voltage in the current-voltage curves, and the mixed electrolyte type. (C) 2022 Elsevier B.V. All rights reserved.[-]
info:eu-repo/grantAgreement/AEI//PID2021-126109NB-I00//Proyectos de Generación de Conocimiento 2021/
Agradecimientos:
Financial support from the Ministerio de Economia y Competitividad, under project PID2021-126109NB-I00, the European Regional Development Funds, and the Hessen State Ministry of Higher Education, Research and the Arts, ...[+]
Financial support from the Ministerio de Economia y Competitividad, under project PID2021-126109NB-I00, the European Regional Development Funds, and the Hessen State Ministry of Higher Education, Research and the Arts, Germany, under the LOEWE project iNAPO is gratefully acknowledged. We thank Prof. Antonio Alcaraz and Dr. Maria Queralt-Martin for helpful suggestions. Spe-cial thanks to Prof. C. Trautmann and Dr. E. Toimil Molares (GSI, Material Research Department) for their support with the irradia-tion experiments. The heavy ion irradiation is based on a UMAT experiment, which was performed at the X0-beamline of the UNI-LAC at the GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany) in the frame of FAIR Phase-0.[-]