Development of microcapsules containing phase change material by coacervation method

In recent times, there has been a growing interest in the storage of energy for energy efficiency. Among the energy storage methods, thermal energy storage is the most economical and efficient. The latent heat storage method, a type of thermal energy storage, is implemented using Phase Changing Materials (PCMs). Phase Changing Materials undergo a transition from one phase to another within specific temperature ranges, enabling them to store thermal energy in the form of latent heat. Energy is stored during the melting or vaporization of a phase change material. When needed, the energy is recovered by the solidification or condensation of the phase change material. Microencapsulation has been developed to enhance the effective use of PCMs. The purpose of encapsulating Phase Changing Materials is to trap the active substance inside capsules, facilitating the phase change within the capsule. Microcapsules find applications in various fields such as textiles, construction, food, medical, logistics, and more. In the context of this thesis, microencapsulation processes were carried out using simple coacervation and complex coacervation methods. Chitosan and carboxymethyl cellulose were used as wall materials, while oleic acid and palm oil were used as core materials. Optical microscope analysis was conducted to determine the morphological features. Examination of the optical microscope images revealed that palm oil and oleic acid, forming the oil phase dispersed in water, created spherical droplets that dispersed, and as the oil content increased, the droplet sizes decreased. Fourier Transform Infrared Spectroscopy (FT-IR) and Thermogravimetric Analysis (TGA) results, when compared with the literature, indicated successful encapsulation of both palm oil and a mixture of palm oil and oleic acid through both simple and complex coacervation methods. Thermal properties of the obtained microcapsules were determined by performing Differential Scanning Calorimetry (DSC) analysis. The melting enthalpies of both microencapsulated oleic acid and palm oil-oleic acid microcapsules decreased significantly with encapsulation.