Membrane emulsification modelling: how can we get from characterisation to design?

There has been an increasing interest in a new technique for making emulsions known as membrane emulsification, which uses a microporous membrane operated in cross-flow. The continuous phase is pumped along the membrane and sweeps away dispersed phase droplets forming from pore openings as shown in Fig. 1. The effects of process parameters in membrane emulsification have been studied, especially on a quantitative level. However, the physical mechanisms of droplet formation are still under investigation to better elucidate the roles of operating parameters, and finally model the process. This work reviews current developments and deficiencies in the modelling membrane emulsification processes.

In order to develop a predictive model for membrane emulsification processes, more work is required. Droplet detachment is more complicated than originally thought, but can be studied further by taking surface viscoelastic properties into account. The most important parameters in process design are well known and insight into their coupled effects will improve modelling work. With improved modelling and design, a number of interesting industrial applications can be realised such as controlled release system in parentheral pharmaceuticals and micro-encapsulation of flavours. Due to the low shear stresses and mild processing conditions, shear sensitive materials could be incorporated into a variety of novel formulations.