Thermal conductivity investigation of titanium dioxide nanoparticles embedded paraffin wax for thermal energy storage applications

Abstract

To enhance the efficacy of thermal conversion systems, it is imperative to incorporate them with thermal energy storage mechanisms. Within the extensive selection of essential materials, phase change materials (PCMs) are identified as the top choice for the retention and later liberation of thermal energy, attributable to their notable latent heat of fusion. Generally, PCMs exhibit low thermal conductivity. Incorporating nano additives has been explored to improve the thermal characteristics of PCMs further. In our recent exploration, we augmented the thermal conductivity of paraffin wax using different mass concentration additions (1 wt. %, 3 wt. %, 5 wt. Titanium dioxide (TiO₂) nanoparticles exist at a percentage that is roughly 10 nm in diameter. Researchers have noted that introducing TiO₂ nanoparticles into the paraffin wax matrix affects the temperature at which phase changes occur. Also, the thermal conductivity in the resultant composites indicated a falling tendency as temperature increased, due to the increased surface interfacial thermal resistance between TiO₂ nanoparticles and the wax matrix. A notable enhancement in thermal conductivity, quantified at approximately 10% and 7%, was recorded through the utilisation of spherical and trapezoidal capsules, respectively, at a nanoparticle loading of 5 wt. The atmospheric conditions are 50±5% humidity and the temp is at 15°C.