Preparation and Characterization of Fe ₃ O ₄ -Modified Graphene Oxide as Heat Transfer Additive for Paraffin Wax Applications

Introduction: In phase change thermal management systems, the development of magnetic phase change materials offers the possibility of effectively integrating passive and active heat control technologies. The low dispersibility of traditional heat transfer additives, the high interfacial thermal resistance with phase change matrices, and the restricted magnetic response characteristics are some of the current problems that must be resolved. Methods: To overcome these challenges, this study employed a co-precipitation method to composite magnetic nanoparticles Fe3O4 with graphene oxide (GO). The active sites on GO were functionalized with alkyl groups to prepare Fe3O4-modified graphene oxide (Fe3O4-MGO)/paraffin magnetic composite phase change materials. The morphology, structure, chemical composition, and thermal properties of the resulting magnetic composite phase change materials were tested and characterized. Results: The results indicated that Fe3O4-MGO exhibits good dispersibility in paraffin, which can enhance the thermal conductivity of the phase change material. The thermal conductivity of the composite phase change material with a Fe3O4-MGO mass fraction of 2.0% was measured to be 0.461 W/m·K, representing a 47.3% increase compared to pure paraffin. Additionally, Fe3O4-MGO demonstrated a certain phase change capability, with a phase change enthalpy reaching 70.35 kJ/kg. Conclusion: The findings of this study are expected to provide technical support for innovative applications of magnetic-controlled phase change thermal management.