Synthesis and Characterization of Microencapsulated Paraffin Microcapsules as Shape-Stabilized Thermal Energy Storage Materials

This article presents the preparation and characterization of microencapsulated paraffin microcapsules with silicon dioxide (SiO2) shells as thermal energy storage materials. The microcapsules were prepared using a sol-gel method. Paraffin was used as the core material, and SiO2 prepared with methyl triethoxysilane (MTES) acted as the shell material. The morphology and particle size of the microcapsules were investigated using scanning electron microscopy (SEM). The chemical characterization of the microcapsules was measured using Fourier transform infrared spectroscope (FTIR). The crystalloid phase of the microcapsules was measured using X-ray diffraction (XRD). The thermal properties and thermal stability of the microcapsules were analyzed using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The FTIR, XRD, and SEM results showed that the paraffin was encapsulated in the shell of the SiO2. The DSC results indicated that the typical microcapsules melted at 57.96 degrees C with a latent heat of 156.86 kJ/kg and solidified at 55.78 degrees C with a latent heat of 144.09 kJ/kg at microencapsulation ratio of 82.2%. The TGA and DTG results showed that the microcapsules had good thermal stability. The SiO2 shells improved the thermal stability of the microcapsules.