Water in oil emulsions from hydrophobized metal membranes and characterization of dynamic interfacial tension in membrane emulsification

Hydrophobization of metal surfaces is reported based on silanization reactions. The aim was its application to metal porous membranes for the production of water in oil emulsions using a process known as membrane emulsification. A vertical oscillating membrane system was used to carry out drop formation experiments. It is shown that drop size can be tuned between 35 and 85. μm by changing just the surfactant concentration in the continuous phase. In addition, a method to determine the percentage of active pores during the membrane emulsification process is demonstrated. This method links knowledge acquired in the surfactant adsorption dynamics and drop expansion rate. Using this approach, pore velocity can be determined, which will help in determining the boundary between dripping and jetting from a pore. This study reinforces the importance of dynamic interfacial tension which must be considered in process design, and modelling purposes, particularly in two liquid phase systems using membranes such as membrane emulsification.