Development and performance evaluation of metal organic frameworks and biochar encapsulated coconut oil shape stabilized biobased phase change materials

Phase change materials (PCMs) are promising materials for building thermal management and energy storage, however, leakage remain major concern. In this study, three different carriers including MOF-808, modified defective MOF-808, and 4.5 mm biochar were investigated for the encapsulation of coconut oil as a bio-based PCM. The MOF materials were synthesized via a solvothermal method, while biochar was prepared through grinding and sieving. Shape stabilized phase change materials (SSPCMs) were prepared using a vacuum impregnation technique. The prepared samples were characterized using SEM, BET, PXRD, FTIR, XPS, TGA, DSC, and leakage tests to evaluate their morphological, chemical, and thermal properties. Results show that all prepared SSPCM samples exhibit good chemical stability with successful impregnation of PCM within the carriers. However, SSPCM/Biochar demonstrates better thermal stability and performance, with a higher latent heat capacity of 66.08 J/g, improved ability to eliminate leakage for up to 1 h, and the least leakage signs over 24 h of continuous heating at 60 °C. These results show that biochar can be a more effective carrier for encapsulating coconut oil PCM compared to the proposed MOF materials, offering strong potential for sustainable building thermal energy storage applications.