Differential scanning calorimetry analysis of W/O emulsions prepared by miniature scale magnetic agitation and microfluidics



Understanding and modelling the mechanism of destabilisation of complex and opaque water-in-oil emulsions is very challenging. The purpose of our current study is to develop experiments to restrict the number of destabilisation mechanisms that take place in order to better understand their role in the evolution of model emulsions. We focused particularly on the effects of droplet size increase and of droplet sedimentation, which can be observed when the emulsion ages. The evolution of the water in oil emulsion was characterised by following the displacement of the water freezing transition with time by Differential Scanning Calorimetry. We present the results obtained on two different systems: first on emulsions prepared in a miniature cell with an integrated magnetic stirrer designed for experiments on ground and under microgravity conditions (FASES program). In addition, the first results obtained with a microfluidic device, in order to generate dispersed water droplets of uniform size and determine the most probable freezing temperature of the water droplets as a function of their size, are displayed.