Low-Zeta-Potential Analytic Solution for the Electrophoretic Mobility of a Spherical Colloidal Particle in an Oscillating Electric Field

✍ Scribed by Christine S. Mangelsdorf; Lee R. White

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 432 KB
• Volume: 160
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1993.1397

✦ Synopsis

The equations developed by C. S. Mangelsdorf and L. R. White (J. Chem. Soc. Faraday Trans. 88, 3567 (1992)) to calculate the electrophoretic mobility of a solid, spherical colloidal particle subjected to an oscillating electric field are solved analytically for low zeta potential, (\zeta), to obtain the electrophoretic mobility correct to (\mathcal{O}\left(e \zeta / k_{\mathrm{B}} T\right)). Due to severe numerical cancellation of the exponential integrals, two forms of the analytic solution are presented which are numerically stable for different regions of (\kappa a) (where (a) is the particle radius and (\kappa^{-1}) is the Debye screening length). This low- (\zeta) analytic solution is valid for all frequencies, particle sizes, and electrolyte concentrations, and agrees to at least two significant figures with the "exact" results obtained by Mangelsdorf and White at (e \zeta / k_{\mathrm{B}} T=1(\zeta \approx 25 \mathrm{mV})). A program implementing this low-zeta analytic formula for the electrophoretic mobility is available from the authors. (1993 Academic Press, Inc.