Improved thermal energy storage behavior of polyethylene glycol-based NEOPCM containing aluminum oxide nanoparticles for solar thermal applications

In the present investigation, a novel composite of Polyethylene glycol (PEG) with molecular weight 10,000 (10 k) and aluminum oxide nanoparticle were prepared for solar thermal energy storage system. A composite of nanoparticles of Al₂O₃ in different mass fraction (1%, 2%, 3%, 4%, and 5%) and PEG 10,000 was prepared. The thermal properties of these composites and their chemical stability were studied by DSC and FT-IR analysis. The XRD technique was adopted for analyzing the crystallization of prepared composite materials. The TGA curves was also obtained and utilized to check the thermal stability of nano-enhanced organic phase change materials (NEOPCMs). The chemical and thermal reliability was tested by conducting an aging test on an in-housed designed thermal cycler for 1500 melt/freeze cycles. The results show that the thermal properties of the NEOPCMs do not change considerably after the thermal cycle test. An increment of 52.09% in thermal conductivity was found in the developed composite with 5% incorporation of nanoparticles. On the basis of results obtained, it can be ascertained that the composites possess significant thermal properties and are a good candidate for the latent heat thermal energy storage systems having temperature requirement around 60 °C such as solar water heater, etc.