Flow-induced surface charge heterogeneity in electrokinetics due to Stern-layer conductance coupled to reaction kinetics

Werkhoven, B. L. (author), Everts, Jeffrey Christopher (author), Samin, S. (author), Roij, R. van (author)

We theoretically study the electrokinetic problem of a pressure-induced liquid flow through a narrow long channel with charged walls, going beyond the classical Helmholtz-Schmolukowski picture by considering the surprisingly strong combined effect of (i) Stern-layer conductance and (ii) dynamic chargeregulating rather than fixed surface charges. We find that the water flow induces, apart from the well-known streaming potential, also a strongly heterogeneous surface charge and zeta potential on chemically homogeneous channel walls. Moreover, we identify a novel steady state with a nontrivial 3D electric flux with 2D surface charges acting as sources and sinks. For a pulsed pressure drop our findings also provide a first-principles explanation for ill-understood experiments on the effect of flow on interfacial chemistry [D. Lis et al., Science 344, 1138 (2014)].

• Language: English
• Keywords: electrokinetics, surface phenomena, hydrodynamics
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Author Accepted Manuscript
• Publisher: American Physical Society
• Year: 2018
• Number of pages: Str. 264502-1-264502-6
• Numbering: Vol. 120, iss. 26
• PID: 20.500.12556/RUL-101750
• UDC: 537.36
• ISSN on article: 0031-9007
• DOI: 10.1103/PhysRevLett.120.264502
• COBISS.SI-ID: 3210852
• Publication date in RUL: 03.07.2018

Record is a part of a journal

• Title: Physical review letters
• Shortened title: Phys. rev. lett.
• Publisher: American Physical Society
• ISSN: 0031-9007
• COBISS.SI-ID: 1282575

Secondary language

• Language: Slovenian
• Keywords: elektrokinetika, površinski pojavi, hidrodinamika

Projects

• Funder: EC - European Commission
• Funding programme: H2020
• Project number: 795377
• Name: Topological Colloidal Double Layers
• Acronym: TCDL