Better latent heat and specific heat of stearic acid with magnetite/graphene nanocomposite addition for thermal storage application

In our previous study, the addition of Magnetite (Fe₃O₄) into Stearic acid (Sa) as an organic phase change material (PCM) shows an enhancement in the latent heat for thermal energy storage applications. The latent heat of the PCM can also be increased by adding graphene material. Therefore, in this research, the thermal properties of Sa have been studied by the sonication method for several different concentrations of Fe₃O₄/Graphene nanocomposite additions. The structural properties of all of the samples were observed by X-Ray diffraction (XRD). Melting-solidifying behavior and specific heat value were measured by differential scanning calorimetry (DSC). The thermal degradation process of all samples was investigated by thermogravimetric analysis (TGA). Based on the DSC results, the presence of Fe₃O₄/Graphene in the Sa enhances the latent heat up to 20%. The specific heat value of the mixture was also found to be increased as the concentration of Fe₃O₄/Graphene to Sa increased. The TGA results show a lowered thermal degradation process of the Sa by the addition of the Fe₃O₄/Graphene which indicates a higher thermal stability of the mixture. In conclusion, the results demonstrate that the addition of Fe₃O₄/Graphene to Sa improves both the sensible heat and the latent heat of the mixture which are very important for thermal energy storage applications.