Power-law electrokinetic behavior as a direct probe of effective surface viscosity

Yuki Uematsu*, Roland R. Netz, Douwe Jan Bonthuis

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


An exact solution to the Poisson-Boltzmann and Stokes equations is derived to describe the electric double layer with inhomogeneous dielectric and viscosity profiles in a lateral electric field. In the limit of strongly charged surfaces and low salinity, the electrokinetic flow magnitude follows a power law as a function of the surface charge density. Remarkably, the power-law exponent is determined by the interfacial dielectric constant and viscosity, the latter of which has eluded experimental determination. Our approach provides a novel method to extract the effective interfacial viscosity from standard electrokinetic experiments. We find good agreement between our theory and experimental data.

Original languageEnglish
Pages (from-to)11-15
Number of pages5
JournalChemical Physics Letters
Publication statusPublished - 1 Jan 2017
Externally publishedYes


  • Electric double layer
  • Electrokinetics
  • Interfacial slip
  • Liquid-solid interface

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry


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