Preparation of BaSO4-shelled microencapsulated phase change materials for thermal regulation and X-ray shielding of phosphogypsum composites

In this study, a novel microencapsulated phase change material (MPCMs) with barium sulfate (BaSO4) as the shell and a phase change material as the core was successfully synthesized by microencapsulation. While maintaining its inherent thermal energy storage performance, the incorporation of the high-atomic-number element barium endowed the MPCMs with excellent ionizing radiation shielding capability. Thermal performance evaluation showed that the phase transition temperature of the MPCMs was 35.78 °C and the encapsulation ratio reached 72.28%, demonstrating outstanding thermal stability and heat storage capacity. In addition, MPCMs with different mass fractions were incorporated into a phosphogypsum matrix for environmental temperature regulation tests. The results showed that the MPCMs could significantly slow down the temperature variation rate of the composites and greatly improve their thermal durability. Meanwhile, ionizing radiation shielding experiments confirmed that the introduction of MPCMs effectively enhanced the radiation resistance of phosphogypsum-based composites. The novel multifunctional MPCMs prepared in this study provide an innovative route for the comprehensive utilization of phosphogypsum and the development of new multifunctional building materials.