Process optimisation of rotating membrane emulsification through the study of surfactant dispersions

In this study, a rotating membrane emulsification setup incorporating a 6.1 μm pore diameter Shirasu porous glass membrane was used to produce oil-in-water emulsions. The processing conditions varied between 0.2 and 1.5 bar for the transmembrane pressure and shear rates at the membrane surface between 0.6 s−1 and 104.6 s−1 were generated. All emulsions consisted of 10 vol.% of sunflower oil stabilised by one of four different surfactants (Tween 20, Brij 97, lecithin and sodium dodecyl sulphate) of either 0.1 wt.% or 1 wt.% concentration. A novel approach for emulsification processing was introduced which incorporates high hydrophilic–lypophilic balance, non-ionic surfactants within the dispersed phase rather than the continuous phase. A reduction in droplet size by at least a factor of 3 for the same formulation can be achieved without significant hindrance on disperse phase flux. This therefore suggests a possible strategy for further process optimisation.