Electrical Fluctuations in Colloid and Ionic Solutions

✍ Scribed by José A. Fornés

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 334 KB
• Volume: 186
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1996.4620

✦ Synopsis

A solution of spherical charged particles 1 of radii a A method is developed in order to determine the natural electriimmersed in a symmetrical electrolyte solution of puntual cal thermal fluctuations and its spectral distribution across two ions, Fig. 1a.

points of a solution of ions or spherical charged particles immersed (b) A symmetrical electrolyte solution which ions have in an ionic solution. The electrical equivalent between two points a mean radius a, Fig. 1b.

of a solution is considered as a capacitor and a resistor in parallel.

In both cases are estimated the electrical fluctuations and

The method is applied within the Debye-Hu ¨ckel approximation their spectral distributions.

(linearized Poisson-Boltzmann equation), although it is valid in general. Among the results is the diminution of electrical fluctua-

II. ELECTRICAL FLUCTUATIONS IN SOLUTIONS tions as particle sizes increase; as a consequence, large particles produce electrical stabilization in their neighborhood. It can also

The Debye-Hu ¨ckel theory (13) for a symmetrical electrobe observed that fluctuations are not quite sensitive to ionic concenlyte of valence z with n ions per m 3 gives for the potential trations for large particles. When the size of the particles become negligible we obtain similar results with the already obtained using c(r) surrounding an spherical ion of charge Q Å ze 0 : the method of the mode expansion.