Subcooling in PCM emulsions—Part 1: Experimental

Many phase change materials (PCM) tend to subcool in microscopic geometries, even if they show negligible subcooling in macroscopic geometries. This paper presents an experimental study on subcooling and nucleation in paraffin-in-water emulsions. Different material systems with the average droplet size from 0.2 to 12.5 μm were prepared and analyzed. An increased subcooling up to 15 K was observed for small droplets. The paraffin, surfactant and nucleating agent also have impacts on the subcooling. The nucleation theory and the evaluation of the experimental results will be presented in Part 2.