Investigation of glycerol-Ni(NO3)26H2O /perlite composites as form stable phase change materials

In this presented experimental research, composites of phase change materials (PCMs) were prepared by impregnating glycerol and nickel salt into the expanded perlite pores (EP). In this study, vacuum impregnation and wet impregnation methods were used. Glycerol and nickel salt were inserted to the pores of EP and during the phase transition the leakage of the glycerol and nickel salt were prevented. The characterization study of chemical structure and surface microstructure of the composite PCMs were performed by Fourier transformation infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Thermal properties were determined by differential scanning calorimeter (DSC) instrument. The melting temperature and latent heat were determined for prepared composite, as -8.3°C and 136 J/g for vacuum impregnation method. For wet impregnation method the melting point could not be measured because of the PCM mixture could not deposited into perlite by using this method. The FTIR analysis presented that no chemical reactions take place between the EP and prepared PCM mixture. SEM images showed that the glycerol nickel salt mixture dispersed uniformly into the EP pores. During the heating and cooling processes, leakage and impairment of the composite PCM were not detect. Consequently, the PCM composite obtained by vacuum impregnation method, can be used for thermal energy storage applications.