Fabrication of Stearic Acid/Silicon Dioxide Composite Shape-Stabilized Phase Change Materials for Thermal Energy Storage

Abstract

Stearic acid/silicon dioxide composite shape-stabilized phase change materials with different mass fraction of stearic acid have been successfully prepared using sol-gel methods. In such an organic/inorganic composite structure, the stearic acid was used as the filling material that is the latent heat storage phase change material (PCM), and the silicon dioxide acted as the matrix material which prevented the leakage of the melted stearic acid. The structure, morphology, thermal properties, thermal conductivity of the composite PCM were determined by X-ray powder diffraction (XRD), Fourier transform infrared (FT-IR) spectra, Scanning electron microscope (SEM) and Differential scanning calorimetry (DSC). The results show that the form-stable composite PCM has the optimal effect, preventing the leakage of stearic acid from the matrix of silicon dioxide, emerges when the composite containing 50% (mass fraction) stearic acid. The latent heat and melting temperature of the corresponding composite PCM is measured as 85.7J/g and 52.2 °C respectively. Meanwhile, the thermal conductivity of the composite PCM could be improved effectively by using silicon dioxide as a supporting material.