Preparation and application of low-temperature binary eutectic lauric acid-stearic acidSiO2 phase change microcapsules

Most phase change materials developed in current research have high phase change temperatures, making them challenging to use in buildings. To solve this problem, the microencapsulated phase change materials (MPCMs) with low eutectic temperature were prepared by interfacial polymerization using binary eutectic of lauric acid (LA) and stearic acid (SA) as the core material and silica as the shell material. And the phosphogypsum-based phase change microcapsules (PG-MPCM) were prepared. Morphology, structure and thermal properties of microcapsules have been investigated. The differential scanning calorimetry (DSC) results indicate that the melting and freezing temperatures of MPCMs prepared under optimal conditions are 27.9 °C and 28.3 °C, and the latent heats of melting and freezing are 170.3 J/g and 155.7 J/g. The thermogravimetry (TG) analysis results confirm that the microcapsules have good thermal stability. There is no significant change in the latent heat of the microcapsules phase change after 300 melting/freezing cycling. The heat storage performance shows that PG-MPCMs have good heat energy storage capacity and temperature regulation ability. In general, the LA-SA/SiO2 microcapsule is suitable as the energy storage material for buildings.