An Experimental Test of the Ion Condensation Theory for Spherical Colloidal Particles

✍ Scribed by M. Quesada-Pérez; J. Callejas-Fernández; R. Hidalgo-Álvarez

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 89 KB
• Volume: 233
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.2000.7265

✦ Synopsis

This paper deals with the notion of ion condensation for spherical colloids and, more specifically, with a recent model developed to predict effective charges (Y. Levin, M. C. Barbosa, and M. N. Tamashiro, Europhys. Lett. 41, 123, 1998). Electrophoretic mobility measurements (carried out for a set of well-characterized latexes) were used to find out to what extent this theory is able to accounts for: (i) the insensitivity of mobility to surface charge, and (ii) the small values of electrokinetic charge found at low ionic strength. As the Levin theory was developed assuming no added salt, a previous discussion about the effect of additional electrolyte was needed. Contrary to what other authors have reported, our results do not support the above-mentioned theory.