Approximate analytic expression for the electrophoretic mobility of a cylindrical colloidal particle. Relaxation effect

Approximate Analytic Expression for the Electrophoretic Mobility of Moderately Charged Cylindrical Colloidal Particles

An approximate analytic expression for the electrophoretic mobility of an infinitely long cylindrical colloidal particle in a symmetrical electrolyte solution in a transverse electric field is obtained. This mobility expression, which is correct to the order of the third power of the zeta potential ζ of the particle, considerably improves Henry's mobility formula correct to the order of the first power of ζ (Proc. R. Soc. London, Ser. A 1931, 133, 106). Comparison with the numerical calculations by Stigter (J. Phys. Chem. 1978, 82, 1417) shows that the obtained mobility formula is an excellent approximation for low-to-moderate zeta potential values at all values of κa (κ = Debye-Hückel parameter and a = cylinder radius).

Effect of finite ion sizes in electric double layer mediated interaction force between two soft charged plates

A new theory quantifies the effect of finite ion size in osmotic pressure (Πosm) between two soft charged plates.