An experimental investigation to the thermal conductivity enhancement of paraffin wax as a phase change material using diamond nanoparticles as a promoting factor

According to the increasing energy needs in the last decades, application of Phase Change Materials (PCMs) as a new phenomenon for temperature control, energy storage and management in this arena has been investigated in recent years. One of the common and wide spread applied phase change materials with a flexible melting point, nontoxic and noncorrosive and large latent heat is paraffin wax. However, the application of this type of PCM is limited due to its low thermal conductivity. To improve the thermal conductivity of paraffin based PCM, diamond-nanoparticles is used as an additive in microencapsulation of the paraffin wax coated with gelatin-Gum Arabic. For the preparation of the microcapsules complex coacervation method was employed. The measurement of the efficiency of microencapsulation was done by conducting heating test and washing the microcapsules with toluene. Appearance and size of manufacturing microscopes are investigated by using an optical microscope. Thermal properties of the samples were calculated by differential scanning calorimetry (DSC) test. Finally, the influence of microencapsulation parameters such as emulsification time, core to shell ratio and additive percentage on the microencapsulation efficiency and thermal conductivity, stability, and the latent heat of the resulting composite materials were discussed and compared with the properties of the pure microcapsules without nano-particles.