Characterization of bio-nano doped phase change material (bio-nano/PCM) for building energy management

The energy consumed by buildings to maintain thermal comfort has been significantly high in recent years. It is attributed to the increased cooling/heating loads of the buildings, and it has been considered the most challenging factor in achieving net-zero buildings. Phase changing materials (PCM) have been proposed as prospective thermal energy storage materials, and they can be deployed to maintain the thermal comfort of the building in a passive manner if they are integrated with the building components appropriately. In this research, an organic bio-nano doped phase change material (bio-nano/PCM) has been synthesized and characterized for its thermophysical characteristics to analyze its suitability for building thermal management. Paraffin wax has been chosen as the PCM, and an in-house synthesized eggshell nanoparticle (derived from bio-wastes) has been deployed as the thermal characteristics-enhancing medium of the PCM. The waste eggshells are mechanically milled into nano-sized particles, and then they are blended with the PCM in different mass proportions (.0%, .5%, 1.0%, and 2.0%) to obtain bio-nano/PCMs. Then, the thermophysical characteristics of the bio-nano/PCMs have been studied using different instruments to assess the effect of bio-nanoparticles on the thermal storage performance of the base PCM. The results confirmed the consistent distribution of the bio-nanoparticles within the PCM matrix at lower mass fractions and the significant stability of bio-nano/PCMs, both in terms of chemical and thermal aspects. Further, the results exposed that the amalgamation of 1.0% bio-nanoparticles in PCM has pointedly suppressed the supercooling of the PCM and greatly amended the thermal conductivity of PCM to 53.33% without much distressing its latent heat, even after 500 thermal cycles. However, the inclusion of bio-nanoparticles above a 1.0% mass fraction significantly reduced the thermal storage capability of the PCM.