Application of modern concepts in liquid state theory to concentrated particle dispersions

Theories on liquid structure properties are applied to concentrated colloidal dispersions in nonpolar media. Light scattering experiments on microemulsions (W/O) with benzene and toluene as the continuous phases are characterized in terms of a hard sphere repulsion and a perturbative attraction. The origin of the attraction and the influence of polydispersity on particle size are discussed. Light scattering of crosslinked PMMA-latex particles in benzene as a function of scattering angle showed structure formation at higher latex concentrations. The results were discussed in terms of the structure factor S(K), susceptibility χ(K) and the radial distribution function g(r) of the particle centres. The latex behaves as an “expanded” liquid structure. This structure formation was also reflected in the diffusion coefficient measured by quasi-elastic light scattering.