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Flow-assisted Dielectrophoresis: A Low Cost Method for the Fabrication of High Performance Solution-processable Nanowire Devices
Published on: December 7, 2017
Ion specific hydration in nano-confined electrical double layers
Z Zachariah1, R M Espinosa-Marzal2, M P Heuberger1
1Laboratory for Surface Science and Technology, Department of Materials, ETH Zürich, Switzerland; Laboratory for Advanced Fibers, Empa Materials Science & Technology, St. Gallen, Switzerland.
Abstract:
We probe counter-ion specific effects in nano-confined electrical-double-layers (EDLs) by means of direct force measurements across a model slit pore in the extended surface forces apparatus. By variation of solution composition, we compare four different counter-ions with dissimilar hydration properties, namely Na+, K+, Cs+ as well as H3O+, all confined between (001) mica surfaces. We discuss the results in terms of a recently proposed π-transition model, evoking hydrated ion layering as the recurrent structural element in highly confined EDLs. We demonstrate that the π-transition essentially proceeds in multiple steps in coherence with the event of single- or multiple- hydrated-ion layering.
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