Sa. Palkar et Am. Lenhoff, ENERGETIC AND ENTROPIC CONTRIBUTIONS TO THE INTERACTION OF UNEQUAL SPHERICAL DOUBLE-LAYERS, Journal of colloid and interface science, 165(1), 1994, pp. 177-194
The potential energy as a function of distance is obtained for the dou
ble-layer interaction of two spherical colloidal particles. The Poisso
n-Boltzmann equation is solved numerically, using a collocation techni
que, for two spheres having various sizes and for constant potential a
nd constant charge boundary conditions. The potential distribution is
determined and then used to find the change in the electrical energy,
the entropy, and the chemical part of the free energy as the two parti
cles are brought into contact from infinity. Various approximate metho
ds used previously, depending on surface conditions and geometry, are
found to work quite well for the constant potential case, but for the
constant charge case, they are not adequate for most of the parameter
space. The interaction energy profiles are found to be functions of th
e curvature of the interacting spheres, and the dependence is quite st
rong for the constant charge case, in which the relative magnitudes of
the electrical energy and entropy change significantly as the radii o
f the interacting spheres are changed for a fixed Debye length. (C) 19
94 Academic Press, Inc.