Preparation and thermal characteristics of caprylic acid based composite as phase change material for thermal energy storage

The present work is focused on the phase change behavior of the lately prepared caprylic acid based composite as phase change materials (PCMs) for thermal energy storage. The composite PCMs were prepared with caprylic acid as base material whereas, CuO, ZnO, Ag and graphene oxide (GO) are used as supporting materials. The 0.5 weight fraction (wt%) of CuO, ZnO, Ag and GO nanoparticles (NPs) were dispersed in caprylic acid, separately aiming to assess the maximum enhancement of thermal conductivity. The morphological structure was found by using field emission scanning electron microscopy (FESEM) and crystalloid phase was studied by x-ray diffraction. The phase change properties of base PCM and composite PCMs were determined by using differential scanning calorimetry (DSC) analyses. Enhancement of thermal conductivity of caprylic acid with 0.5 wt% of CuO, ZnO, Ag and GO NPs separately, was estimated as 36%, 43%, 52%, and 87%, respectively when compared to caprylic acid alone. The results obtained from the experiment proved that freezing and melting times of the composite PCMs using GO were less while comparing to the rest. Thus, GO based composite PCM can be considered as one of the suitable candidates for low temperature thermal energy storage application.