ABSTRACT
A disperse system consists of fine insoluble or only slightly soluble particles distributed throughout a continuous medium. According to the terminology recommended by IUPAC the two-phase solid-in-liquid systems are dispersions when the particles have colloidal dimensions and suspensions when the particles exceed colloidal dimensions, while still being buoyant. A colloidal dispersion whose dispersed phase is nonpolymeric in nature is termed a sol. The procedures employed for the characterization of dispersion depend on the specific objective of the investigation. The stability of dispersion depends, among other variables, on the solvent used as the dispersion medium. The choice of the solvent depends, in addition to the particle-solvent interactions, on the volatility, toxicity, flammability, odor, and price of the solvent. A solvent used as the dispersion medium can be characterized by its chemical composition, dielectric constant, refractive index, boiling point, surface tension, and viscosity.
