Study of a thermal regulation mortar incorporating phase change microcapsules for overheating reduction underground engineering

A phase change energy storage mortar (PEM) for use in underground refuge enclosures was prepared by incorporating phase change microcapsules in this study. To improve microcapsules' heat resistance, thermal compactness, and shell structure strength, paraffin @ MUF/SiO2 microcapsules were prepared by in situ polymerization using nano-SiO2 as the silicon source. The introduction of nano-SiO2 does not change the crystal structure and chemical structure of the microcapsules and Paraffin@MUF/SiO2 exhibits a better core inclusion rate and thermal stability. Although introducing microcapsules reduces the thermal conductivity and mechanical properties of the PEM specimens, it gives the PEM better thermal insulation and regulation functions. Overall, the development of PEM has a broad application prospect in underground cooling projects.