Synthesis and characterization of microencapsulated phase change materials and their applications in the heat exchanger

The scope of this study is to produce suitable materials for latent heat storage systems by encapsulation of the selected organic phase change materials into silica shell. Polyethylene glycol (PEG) with molecular weight 600 g/mol and paraffin were selected as phase change materials for encapsulation. It was tried to obtain the most efficient microcapsule using tetraethyl orthosilicate (TEOS), sodium metasilicate, and silica-alumina particles as silica sources. Characterizations of samples were done with Scanning Electron Microscope (SEM), optical microscope, and Differential Scanning Calorimetry (DSC) analyses. According to these analyses, the suitable sample was tried in the heat exchanger to control its applicability. Suitable powder samples were obtained as a result of the experiments which were carried out using TEOS and silica-alumina particles with the particle size of 40-180 µm. It was indicated that the samples with the content of PEG and TEOS which was obtained by interfacial polycondensation method has the best encapsulation ratio with the latent heat of 83.55 J/g. It was proved that obtained sample which had the best encapsulation ratio can be used as PCM through the heat exchanger experiment.