The heat transfer of phase change cold storage material regulated by magnetic field-induced surfactant-modified nano-Fe3O4

Sodium formate-potassium chloride water-based phase change materials are considered promising for cold energy storage due to their low cost and high latent heat. However, high supercooling and low thermal conductivity hinder their practical applications. The addition of magnetic metal nanoparticles can effectively enhance thermal conductivity and reduce supercooling of phase change materials, although nanoparticle dispersion remains problematic. Therefore, in this study, a physical blending method was used to modify nano-Fe₃O₄ with the surfactant CTAB, improving its dispersion in phase change materials. The prepared MPCMs-1.2 had the advantages of low phase transition temperature (−26.83 °C), high latent heat (228.2 J/g), and low supercooling (1.27 °C). After 50 thermal cycles, the latent heat of melting of MPCMs-1.2 decreased by only 2.02 %, indicating excellent cycle stability. Additionally, as the intensity of the alternating magnetic field increased, the solidification temperature of MPCMs-1.2 gradually increased, while the melting temperature decreased. The controllable phase transition heat transfer of MPCMs was achieved through the induction of CTAB-modified nano-Fe₃O₄ by the alternating magnetic field. Furthermore, MPCMs-1.2 was able to keep Carassius auratus refrigerated below −15 °C for 17.53 h. This study provides an effective solution for short-distance cold chain transportation of aquatic products.