Modelling droplet formation in cross-flow membrane emulsification

In the present paper we illustrate applications of a new set of force balance equations able to predict the average size of a droplet forming during cross-flow membrane emulsification processes. These balance equations allow to correlate the droplet diameters with the advancing and receding contact angles along the droplet-pore contact line. When the drops detach directly from the pore outlet without an appreciable neck formation (i.e. excluding very low cross-flow velocities) the predicted droplet diameters are in quantitative agreement with those observed in experiments. Using the model the influence of the process parameters can be effectively investigated, allowing optimization of the emulsification conditions to achieve a desired product.

In this contribution, we present a novel force balance applied to cross-flow membrane emulsification that allowed to correlate the diameters of a droplet with the advancing and receding contact angles along the droplet-pore contact line. From the force equilibrium study some interesting conclusions can be drawn: • a predictable limiting droplet diameter (Dc) can be identified that effectively represents the droplet sizes obtained during a CDME when the particles detach directly from the pore outlet; • the theoretical relation between the diameter of the droplets, stuck on the pore border, and the advancing and receding contact angles is useful to evaluate the influence of the average cross-flow velocity on the droplet detachment dynamic.