Micro-morphology of DP and the prepared paraffin/DP composite PCM was observed by using scanning electron microscopy
(SEM) instrument (JEOL, JSM-6390). Chemical compatibility of paraffin/DP composite PCM was studied by using Fourier transform infrared spectroscopy (FT-IR, Bio-Rad FTS 6000) analysis method. The wavenumber range of FT-IR used was from 4000 cm1 to 400 cm1.