Potential of wood as thermal energy storage materials: Different characteristics depending on the hierarchical structure and components

Renewable biomaterials are in the spotlight as a potential solution to increasing global greenhouse gas emissions. The construction industry contributes up to 40% of greenhouse gas emissions, with building materials responsible for a major portion. Research on high-performance materials with small carbon footprints has been steadily progressing. Wood is a sustainable building material with a high carbon fixation. Wood can be divided into the hard core and outer bark, both of which are very useful as building materials. In this study, a phase change material (PCM) was applied using vacuum impregnation to compensate for the poor thermal performance of wood. The thermal energy storage capacity of wood can be enhanced by applying aPCM, which has excellent latent heat/heat storage performance. The difference in the structural and chemical compositions of the core and bark of wood also has a significant influence onPCM impregnation. The thermal performance of shape-stabilized PCMs (SSPCMs) was evaluated by comparing the hierarchical structures and components of wood (core and bark). The PCM loading performance was verified by impregnation and surface/morphological property conversion analyses. When the porous structure of wood is filled with the PCM, its surface properties change from hydrophilic to hydrophobic. This was analyzed by contact angle measurements. The SSPCM with cork showed a 49% efficiency compared with the n-octadecane, which indicates an outstanding performance compared with other biomaterial-based PCM composites.