Effects of Al2O3,CuO and TiO2 nanoparticles son thermal, phase transition and crystallization properties of solid-solid phase change material

This paper presents the effects of addition of Al2O3, CuO, and TiO2 nanoparticles on thermal, solid-solid phase transition and crystallization properties of pentaerythritol (PE). The PE added with 0.1 wt% of nanoparticles underwent 500 thermal cycles and characterized using TG-DTA, DSC, FTIR methods. The thermal conductivity of the PCM samples obtained using the T-history method. Thermal degradation kinetics of the PCM samples studied by using the Coats-Redfern technique. Crystallization behavior of PE added with Al2O3, CuO and TiO2 nano particles studied under non-isothermal condition. The addition of 0.1% of Al2O3, TiO2 and CuO nanoparticles to pentaerythritol caused respectively 1.46%, 2.56% and 2.52% decrease in heat flow value. After 500 thermal cycles, the enthalpy of solid-solid transition of PE, PE + 0.1% Al2O3, PE + 0.1% TiO2 and PE + 0.1% CuO were found to be decreasing by 8.8%, 10.14%, 13.1% and 11.89% respectively. The time needed to finish the process of crystallization decreased with rising cooling rate, and the relative crystallinity values of the PE added with 0.1% weight fractions of Al2O3, CuO and TiO2 were higher than that of pure PE. The addition of CuO nano particles resulted in the less time for 50% crystallization of PE compared to Al2O3 and TiO2 nanoparticles.