Microencapsulated oleic–capric acid/hexadecane mixture as phase change material for thermal energy storage

Abstract

Thermal energy storage systems provide efficiency in order to have better utilization of energy sources while protecting the environment. Thermal energy storage can be classified as sensible and latent heat storage. The storage of latent heat allows a greater density of energy storage with a narrow temperature range during phase change. Phase change materials (PCMs) are important novel materials, which are used as the storage of thermal energy as latent heat, and can provide utilization of waste heat energy. In this study, the capric acid and oleic acid mixture containing hexadecane were encapsulated as the core with styrene–divinylbenzene copolymer shell by emulsion polymerization technique. Thermal properties of fatty acid microcapsules were characterized by differential scanning calorimetry and thermogravimetric analysis and also their morphology and structure were examined by scanning electron microscopy, polarized optical microscopy and Fourier transform infrared spectroscopy (FT-IR), respectively. The heat storage property of microencapsulated PCM was tested in a horizontal air flow channel system equipped with a flat heating plate, air fan and air flow sensors. The microencapsulated PCM was prepared successfully, and results of the analysis presented that this material is promising candidate for potential heating and cooling system applications.