Fabrication, characterisation and heat transfer study on microencapsulation of nano enhanced phase change material
Abstract Phase change materials (PCM) are used to trap the solar energy thereby contributing to a green environment. The current study focuses on synthesis of paraffin microcapsules with metal oxide nanoparticles suspended inside the shell using ultrasound assisted in situ polymerisation for thermal energy storage system. Scanning Electron Microscope (SEM) images exhibited perfect morphology of capsules with uniform shape. Average particle size was found ranging between 60 65 mm. Fourier Transform Infrared spectroscopy (FT IR) spectrum designated no new peaks with absence of chemical interaction. Differential Scanning Calorimeter (DSC) thermograms showed a minor change in melting and solidification temperatures with substantial drop in latent heat of 9% (Alumina) 11.9% (Copper oxide) and 5.4% (Titanium oxide) compared to pure encapsulated paraffin. The conductivity got intensified by 21% (Alumina) 49% (Copper oxide) and 59.38% (Titanium oxide) compared to pure encapsulated paraffin. Thermogravimetric Analysis (TGA) thermograms indicated that paraffin capsules could endure temperature up to 350 degC with minor loss in weight. The heat transfer study of microcapsules showed that capsule with copper oxide nanoparticle took less time to complete one thermal cycle compared to other samples. Characterisation results suggest that the paraffin capsules with nanoparticles can be employed as PCM in thermal energy storage applications.