Preparation, characterization and determination of thermal energy storage properties of microcrystalline cellulose/methyl stearate/graphene nanopellet composite phase change material

In this thesis study, microcrystalline cellulose (MCS)/methyl stearate (MtS)/graphene nanolayer (GnT) composites were produced as new phase change materials using the facile vacuum impregnation method. In these composites, MCS was utilized as the supporting material, MtS as the phase change material (PCM), and GnT as the thermal conductor. Additionally, the effect of GnT loading ratio in the composite structure on MtS, as well as its impact on other properties such as chemical structure, latent heat, thermal stability, crystal structure, morphological structure, and heat storage and release, were investigated. By employing MCS-GnT hybrid structure as the supporting material in the thermally stable composite, a high MtS loading ratio of 65% by weight was achieved. This composite exhibited the highest heat storage-release performance with a thermal conductivity performance of 0.51 W/mK. The enhanced thermal conductivity was confirmed by reductions in melting-freezing times and infrared thermal image capture analysis. DSC results indicated that this composite melted at 35.32 ℃ with a melting enthalpy of 147.97 J/g. The proposed MC/MtS/GnP composite offered excellent cycle stability after 1000 melting-freezing cycles, along with high thermal stability. All test results demonstrate significant potential of the prepared MCS/MtS/GnT composites for various low-temperature thermal energy storage (TES) applications