Approximate Expressions for Double Layer Interaction at Moderate Potential

✍ Scribed by Wang Haoping; Jin Jun

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 89 KB
• Volume: 177
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1996.0047

✦ Synopsis

can be obtained if the interaction energy is expressed as a According to the suggestion of Sader et al., who replaced the series function of g Å tanh(Y/4) instead of Y and derived the reduced surface potential Y Å e c 0 /kT by the effective reduced interaction energy correct to g 4 . Later, Ohshima and Kondo surface potential Y (h) Å 4e kh /2 tanh 01 [e 0 kh /2 tanh(Y/4)] (where (6), in accordance with Honig et al.'s suggestion, propose a c 0 is the surface potential of particles, k is Boltzmann's constant, systematic method for obtaining the interaction energy in power T is the absolute temperature, e is the proton charge, h is the senes of g. distance of closet approach between the spheres, k is the Debye In all the above approaches, the interaction energy between screening parameter), we return to the double layer interaction at two parallel plates has been solved fairly well for low or modermoderate potential under constant surface potential and derive a ate surface potential. However, for spherical colloidal particles, formula for the interaction energy between two parallel plates, valid up to the moderate to high potential regime. Using an im-the above authors all just resorted to Derjaguin's method (7), proved Derjaguin approximation we derive formulae for interacthe expressions given are only applicable to large ka and small tion energy and force for identical spherical colloidal particles, kh (where a is the radius of the sphere, h is the distance of which are more accurate than the formulae of Sader et al. at closet approach between the spheres, and k is the Debye screenmoderate potential.