Preparation of monodispersed oil-in-water emulsions by ceramic external membrane emulsification technique

In the present work, oil-in-water emulsions were prepared with toluene-water as working system, sodium lauryl sulfate as emulsifier, and α-Al₂O₃ ceramic membrane with pore size of 1.5 μm as emulsifying medium in a new submerged emulsification apparatus. The effects of stirring speed, transmembrane pressure and emulsifier concentration on the droplet size of emulsions and its distribution as well as the dispersed phase flux were studied. The experimental results showed that monodispersed oil-in-water emulsions could be obtained with the ceramic membrane emulsification system. With the increase of stirring speed and emulsifier concentration, mean droplet size and the span of the droplet size distribution decreased, and the dispersed phase flux hardly changed at the same time. However, mean droplet size and the span of the droplet size distribution increased, and the dispersed phase flux increased significantly with the increase of transmembrane pressure. A linear relationship between the dispersed phase flux and transmembrane pressure at low pressures was obtained.