Microencapsulation of Phase Change Materials for Thermal Energy Storage in Building Application

This paper presents an investigation on microencapsulation of paraffin as a phase change materials (PCMs) for application in buildings. Encapsulated PCM particles were prepared by suspension-like polymerization technique. The effect of surfactant concentration and mass ratio of PCM to monomer on the final characteristics and performance of the microcapsules were investigated. The distribution of particle size, morphology surface, thermal energy storage and thermal stability of the synthesis microcapsules were analyzed using particle size analyser (PSA), optical microscope, differential scanning calorimeter (DSC) and thermal gravimetric analyzer (TGA) respectively. Results show that 1 wt% of PVA and 1.5 mass ratio of PCM (RT21) to monomer had a good compromise between particle surface morphology and PCM mass content of 65 %. In addition, results obtained from a differential scanning calorimeter (DSC) show that microcapsules prepared using the above method have a thermal energy storage capacity of 85.8 J/g, peak melting temperature of 22 C and mean volume particle diameter of 15 μm. TGA analysis indicated that the PCM microcapsules degrade in two steps and had good chemical stability.