Thermal Properties of Phase Change Composites Containing Ferric Oxide Nanoparticles

We prepared a series of homogeneous nanocomposites by suspending Fe₂O₃ nanoparticles into paraffin wax (PW) matrix. Fe₂O₃/PW nanocomposites have reduced both solid-solid phase change latent heat capacity (L_s-s ) and solid-liquid phase change latent heat capacity (L_s-l ) with an increase in the mass fraction of Fe₂O₃ nanoparticles. There is almost equable solid-solid phase change temperature (T_s-s ) between PW and Fe₂O₃/PW composites, as well as melting temperature (T_s-l ). Fe₂O₃ nanoparticle addition leads to substantial enhancement in the thermal conductivity of Fe₂O₃/PW and the enhancement ratio increases with the nanoparticle loading. Thermal conductivity of Fe₂O₃/PW composite with 3.0 wt% nanoparticles is about 0.27 W/(m·K) at 15 °C, which close to that of γ-Al₂O₃/PW with 5.0 wt% nanoparticles but higher than that of ZnO/PW containing 5.0 wt% nanoparticles. At 60 °C, Fe₂O₃/PW has higher thermal conductivity than γ-Al₂O₃/PW and ZnO/PW contained with same fraction of nanoparticles.