Current research on thermal management systems focuses on aspects such as structural optimization of liquid cooling channels, with less research on the development of cooling media. Phase change emulsions, as latent heat functional fluids with significant potential, enhance heat transfer efficiency and temperature control in thermal management systems. However, the issues of significant supercooling and poor stability have hindered the further development of phase change emulsions. In this study, a highly stable, low-supercooling paraffin nano emulsion was successfully prepared by ultrasonication using SDBS, Span80, and Tween80 as composite surfactants and titanium dioxide nanoparticles as nucleating agents. It was found that the emulsion maintained excellent stability for 180 days of static stability and 200 thermal cycles without significant stratification. Subsequently, thermophysical property tests showed that the emulsion had a latent heat of phase transition of 45.48 J·g−1, and maintained good electrical insulating properties. The successful dispersion of 0.9 wt% titanium dioxide nanoparticles in the presence of SDBS resulted in a 77 % reduction in supercooling and a 20.5 % increase in thermal conductivity. Meanwhile, no instability was observed in the emulsion over 90 days of static stability test and 200 thermal cycles. The titanium dioxide-modified paraffin nano emulsions are characterized by high energy storage density, low supercooling, excellent stability, high thermal conductivity, and good electrical insulating properties, which give them significant potential as a cooling medium in thermal management systems.
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