Non-Newtonian Flow of Water-in-Oil Emulsions

Abstract

Abstract In order to obtain information on the dispersion state of W/O type emulsions, the steady-flow viscosity in a wide shear range has been studied using a capillary type viscometer. Emulsions prepared by using Arlacel 83 or Arlacel 60, are classified according to the kind of hydrocarbon used as the suspending fluid, i.e., benzene, cyclohexane, liquid paraffin, isopropyl myristate, and squalane systems, respectively. Although all systems show the so-called shear thinning flow, shear dependence of the viscosity is not only influenced by the disperse phase concentration and emulsifier concentration, but is also much effected by the kind of suspending fluid. Such non-Newtonian behavior is observed markedly in benzene systems. It may thus be assumed that the water droplets in benzene have a tendency to form a large aggregate not easily redispersed under shear. The formation of aggregate may be facilitated by the disturbance of the orientation of the adsorbed emulsifier molecules at the interface due to the mutual interaction between the π-electron in benzene molecule and the emulsifier molecule.