Preparation of Small Droplet Size Monodispersed Emulsions at High Production Rate by Continuous Intramembrane Premix Emulsification Method

Abstract

A novel method of emulsion preparation by intramembrane premix membrane emulsification without preliminary emulsification was developed for the preparation of monodispersed oil-in-water (O/W) and water-in-oil-in-water (W/O/W) emulsions with small droplet size and high disperse phase content at high productivity. The dispersed phase and the continuous phases were simultaneously permeated through Shirasu Porous Glass (SPG) membranes with mean pore sizes of 5, 10, and 20 µm at a membrane permeation rate over 50 m³/m² h. Monodispersed emulsions with disperse phase content of 25 to 95% by volume, mean droplet size to the mean pore size ratio of 1.2 to 0.26, and with droplet size distribution (span) of 0.4 to 0.6 were prepared. The emulsion droplet size decreased with membrane permeation rate, continuous phase viscosity and the number of membrane permeation cycles. A composite W/O/W emulsion with an average droplet size of 10.4 µm, a span of 0.5 and of disperse phase content of 50% by volume was also prepared in a sequence of consecutive steps without integrating the preliminary emulsification step by high-shear homogenization.