Development of highly stable n-Heptadecane/water-based phase change emulsion with mixed surfactant for thermal management applications

Phase change material (PCM) emulsions have grown in popularity due to their versatility and various thermal management applications. Therefore, new PCM materials and emulsion compositions have been investigated to enhance their functionality and widen their range of applications. In the present work, PCM emulsion was formulated using n-heptadecane as a dispersed phase, DI-water as base fluid, and sodium dodecyl sulfate and Brij30 as surfactant. The effect of mixed surfactants on the stability and other thermophysical properties of the PCM emulsions were investigated. The emulsions with mixed surfactants show excellent stability when compared to single surfactants. The average droplet size of the PCM emulsion was 102.8 nm with a phase change tem-perature and latent heat of fusion of 18.9 degrees C and 14.17 Jg(-1), respectively, for 10 wt% PCM concentration. The thermal conductivity was decreased by about 16.4 %, and the viscosity increased by nearly 128 % when compared with DI-water for the 10 wt% dispersed phase emulsion with mixed surfactants. The gravimetric and structural studies confirm the stability of dispersed phase and base fluid in the presence of surfactant. Overall, it can be concluded that the PCM emulsion with mixed surfactant can be a potential heat transfer medium with improved heat storage and transportation capacity.