Electrical properties of charged cylindrical and spherical surfaces in a general electrolyte solution
Journal
Langmuir
Journal Volume
15
Journal Issue
19
Pages
6244-6255
Date Issued
1999
Author(s)
Kuo Y.-C.
Abstract
The electrical properties of a system containing cylindrical or spherical charged surfaces in a general a-b electrolyte solution are analyzed theoretically. Two perturbation methods, one for low to medium potentials and the other for medium to high potentials, are proposed for the resolution of the Poisson-Boltzmann equation governing the spatial variation of the electrical potential. The results obtained are used to derive the basic thermodynamic properties of an electrical double layer, which include Helmholtz free energy, entropy, and surface excess of co-ions. The rate of convergence of the perturbation solution is satisfactory: if the second-order solution is adopted, the deviations in the electrical potential and the thermodynamic properties examined are less than 5%. The results obtained facilitate subsequent prediction of the behavior of a dispersed system, for example, its critical coagulation concentration and stability.
Type
journal article