Abstract
By a membrane emulsification method, four kinds O/W emulsions with very narrow distribution of droplet size were prepared. The creaming rate of the emulsions for various volume fractions (φ) were measured accurately by the Image-Analysis Method. The obtained creaming rate did not agree with both the values calcurated by using Buscall's equation for monodisper sion of latex and those obtained by Uχ= Uο/ηsys, where Uο is Stoke's value for Newtonian fluid under gravity and ηsys is the viscosity of emulsion determined by Mooney's theoretical equation or Sherman's empirical equation. It was found that the creaming rate of the emulsion could be presented by the equation Uχ=Uο/exp (A [η] φ) for a wide range of φ, where [η] is the intrinsic viscosity of the emulsion and A is a correction coefficient for the individual intrinsic viscosity for emulsions with different radius. Furthermore, this eqation is also applicable to monodispersed hard spheres (latex) from 0 to 0.3 of φ.
