Multiphysics study on cement-based composites incorporating green biobased shape-stabilized phase change materials for thermal energy storage

Two types of eco-friendly shape-stabilized phase change materials (SSPCMs) were developed in this study. Biobased PCMs were impregnated into the pore structure of recycled expanded glass granules and coated with silica fume particles using a 4-step vacuum impregnation method. The morphological and thermal properties of the fabricated SSPCMs along with their effects on the hydration, microstructural, mechanical, and thermal properties of cement-based composites were characterized through a set of multiphysics tests including isothermal calorimetry, compressive and tensile strength, capillary water absorption, 3D image analysis of mu CT scans, and thermoregulating tests. It was found that coating PCM-integrated EG granules with porous silica fume particles can further mitigate the risk of leakage and increase the impregnation capacity of SSPCM composites, thus attaining desirable latent heat capacity. Furthermore, the incorporation of the developed environmentally friendly SSPCMs into concrete can maintain desirable mechanical strength, while achieving considerable thermal energy storage capacity, which can moderate indoor temperature fluctuations, thus yielding substantial HVAC energy savings.