Structural, morphological and thermal properties of novel hybrid-microencapsulated phase change materials based on Fe2O3, ZnO and TiO2 nanoparticles for latent heat thermal energy storage applications

In this investigation, some kinds of novel organic-inorganic hybrid-microencapsulated phase change materials (hybrid-MEPCMs) were synthesized using paraffin as core and urea-formaldehyde (UF) polymer containing metal oxide nanoparticles as shell. 0.3, 1 and 3% wt/wt of metal oxide nanoparticles were used separately to prepare these composites. The use of hybrid materials composed of organic and inorganic materials constitutes a promising way to improve chemical and thermal properties of microencapsulated phase change materials. The prepared composites were characterized using Fourier Transform Infrared spectroscopy, X-Ray Diffraction, Scanning Electron Microscopy, Differential Scanning Calorimetry and Thermogravimetric analyses. The obtained results show that the synthesized hybrid-MEPCMs are in spherical and irregular forms, and present a rougher surface due to the presence of metal oxide nanoparticles which are scattered onto the surface of microcapsules or wrapped by UF shell material. They also indicate a probable improvement of hybrid-MEPCMs' thermal stability. In this work, the effects of the nature and the amount of metal oxide nanoparticles on structural, morphological and thermal properties of hybrid-MEPCMs were also discussed.