STRACT Phase change material (PCM) emulsions have played increasingly important roles in many industrial fields as thermal energy storage media and heat transfer fluids. Precise size control of PCM emulsions is an important prerequisite for achieving consistent and repeatable performances. The present study introduced a novel co-flow microfluidic method to prepare uniform PCM emulsions in a controllable and reproducible manner. The droplet formation and size distribution of PCM emulsions were recorded in real time by a highspeed camera. The formation mode transition and droplet size variation were investigated by changing the flow rates of dispersed PCM and continuous water phases. The results showed that PCM emulsions with high uniformity and monodispersity can be attained in the squeezing and dripping modes, and the emulsion size increases with increasing flow rate of dispersed PCM and decreasing flow rate of continuous water. This study can provide technology support for future application of microfluidics in size-control of PCM emulsions.
Keywords PCM emulsion, Co-flow microfluidic, Droplet formation, Size distribution