Electrophoretic Mobility of Spherical Colloidal Particles in Concentrated Suspensions

✍ Scribed by Hiroyuki Ohshima

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 185 KB
• Volume: 188
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1997.4790

✦ Synopsis

for a swarm of spherical particles applicable for low z poten-A general mobility expression is derived for a swarm of identical tials and all ka values, showing that as ka decreases and/ spherical colloidal particles in concentrated suspensions on the or the particle volume fraction increases (the porosity debasis of S. Kuwabara's cell model [ J. Phys. Soc. Japan 14, 527 creases), the mobility rapidly decreases because of overlap-(1959)]. This expression, which is a function of ka ( k Å Debyeping of the electrical double layers around the particles. Hu ¨ckel parameter and a Å particle radius) and the particle vol-Kozak and Davis (13) extended the theory of Levine and ume fraction (or the porosity), tends to a mobility expression Neale (12) to the case of an array of circular cylinders. derived by S. Levine and G. H. Neale [J. Colloid Interface Sci. 47, Kozak and Davis (14, 15) also developed a more general 520 (1974)] for low z potentials and to that derived by M. W. theory for electrokinetics of concentrated suspensions and Kozak and E. J. Davis [J. Colloid Interface Sci. 129, 166 (1989)]

for the case of nonoverlapping double layers. A simple approxi-porous media that is applicable to all z potential values but mate mobility expression is derived with relative errors less than ignores double-layer overlap.

4%. ᭧ 1997 Academic Press

Levine and Neale's mobility formula (12), which is appli-Key Words: electrophoretic mobility; spherical particle; concencable for all ka values (with low z potentials), involves trated suspension.

tedious numerical integration and thus it is not always convenient for practical calculation of mobility values. Recently we proposed an approximation method to derive simple ana-