2021 Volume 58 Issue 4 Pages 186-192
The theory is reviewed of the electrokinetics of spherical solid colloidal particles with a slip surface in an aqueous electrolyte solution. The effect of the hydrodynamic slip is characterized by the slipping length. The limiting case of zero slipping length corresponds to a hydrophilic surface. The slipping length increases as the hydrophobicity of the particle surface increases. General formulas together with approximate expressions are presented for the electrophoretic mobility, the electrical conductivity, the sedimentation velocity and potential, and the diffusion constant of particles with a slip surface. The magnitudes of the electrophoretic mobility and the sedimentation potential, in particular, are found to increase with increasing slipping length. A spherical solid colloidal particle with a slip surface is shown to be hydrodynamically similar to a liquid drop.
