Comparative study on the effect of surface-modified nanoparticles on PCM for solar energy applications

This study focuses on the critical role of paraffin, an important phase change material (PCM) known for its high thermal capacity, for thermal energy storage in solar energy applications with respect to experimental thermodynamics. Nanoparticles and surfactants were used for enhancing the properties of PCMs. An experimental setup was established, and the effect of oleic acid (OA) as a surfactant on PCM was thoroughly examined. The effect of metallic oxide-based nanoparticles (Al₂O₃, MgO, SiO₂, ZnO, Fe₂O₃ and Cu₂O) on the thermal properties of paraffin was experimentally investigated. The mass fraction was kept constant at 2.5% to explore the best nano-enhanced phase change material (NePCM). The effect of the homogeneous distribution was also studied in detail. SEM analysis showed that OA improved the homogeneity of the NePCM. The Cu₂O-doped sample had the best thermal conductivity value in samples with and without OA, improving by 66% and 58%, respectively. The charging and discharging times of all NePCM decreased when compared to pure paraffin. The highest latent heat capacity was detected in ZnO-doped sample. The findings indicate that NePCM with OA outperforms NePCM without OA in terms of thermal performance, showcasing its potential for enhancing energy efficiency in solar energy applications.