title: Electrohydrodynamics near hydrophobic surfaces.
abstract: We show that an electro-osmotic flow near the slippery hydrophobic surface depends strongly on the mobility of surface charges, which are balanced by counterions of the electrostatic diffuse layer. For a hydrophobic surface with immobile charges, the fluid transport is considerably amplified by the existence of a hydrodynamic slippage. In contrast, near the hydrophobic surface with mobile adsorbed charges, it is also controlled by an additional electric force, which increases the shear stress at the slipping interface. To account for this, we formulate electrohydrodynamic boundary conditions at the slipping interface, which should be applied to quantify electro-osmotic flows instead of hydrodynamic boundary conditions. Our theoretical predictions are fully supported by dissipative particle dynamics simulations with explicit charges. These results lead to a new interpretation of zeta potential of hydrophobic surfaces.
authors.affiliation: A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, 119071 Moscow, Russia.|Department of Physics, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.
authors.forename: S R
authors.initials: SR
authors.lastname: Maduar
authors.affiliation: A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, 119071 Moscow, Russia.|Department of Physics, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.|Federal Research and Clinical Center of Pediatric Hematology, Oncology and Immunology, 1 Samora Machel street, 117997 Moscow, Russia.|Center for Theoretical Problems of Physicochemical Pharmacology RAS, 38A Leninsky Prospect, 119991 Moscow, Russia.
authors.forename: A V
authors.initials: AV
authors.lastname: Belyaev
authors.affiliation: School of Physics and CASL, University College Dublin, Belfield, Dublin 4, Ireland.
authors.forename: V
authors.initials: V
authors.lastname: Lobaskin
authors.affiliation: A.N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, 31 Leninsky Prospect, 119071 Moscow, Russia.|Department of Physics, M. V. Lomonosov Moscow State University, 119991 Moscow, Russia.|DWI-Leibniz Institute for Interactive Materials, RWTH Aachen, Forckenbeckstraße 50, 52056 Aachen, Germany.
authors.forename: O I
authors.initials: OI
authors.lastname: Vinogradova
mesh_terms: D057446:Hydrodynamics; D057927:Hydrophobic and Hydrophilic Interactions; D008956:Models, Chemical; D009997:Osmotic Pressure; D055672:Static Electricity; D013499:Surface Properties