Elastic properties of colloidal crystals

Abstract

The shear modulus of colloidal dispersions was calculated by assuming the purely repulsive Derjaguin-Landau-Verwey-Overbeek (DLVO) potential and the Sogami potential containing a short-range repulsion and long-range attraction. These two potentials gave practically the same shear moduli, which were in a good agreement with the observed values. This agreement indicates that the DLVO potential (and hence Yukawa potential) need not always be considered the only correct one in contrast to the widely accepted view. Attention was drawn to recent experimental data obtained by metallurgical microscope, laser scanning microscope, and dynamic light scattering, which showed a definite contribution of a long-range attractive interparticle interaction.