Thermal Characterization of Eicosane/Graphite Nano-Composite-Based Phase Change Material

Abstract

Phase Change Materials (PCMs) have received much consideration as thermal energy storage systems due to their high storage capacity. However, their heat transfer rate is limited because of the low thermal conductivity. Incorporating of carbon-based nanoparticles into the matrix of PCMs with good dispersion can be an efficient way to solve their deficiency. In this research, graphite nanoparticles were homogeneously dispersed within the Eicosane PCM matrix to prepare a Nano-Enhanced PCM (NEPCM). The main objective is to determine the optimum amount of graphite to maximize the thermal properties of NEPCM composites. The Scanning Electron Microscopy (SEM) images of the prepared nanocomposites confirmed the excellent dispersion of graphite nanoparticles within the Eicosane layers through an ultrasonic bath-assisted homogenization procedure followed by solidification. In addition, Differential Scanning Calorimetry (DSC) and Thermal Conductivity Evaluation (TC) of the samples were conducted to determine their heat capacity and thermal diffusivity. The results illustrated that the more the number of graphite nanoparticles, the larger the number of collisions between graphite and Eicosane. As the nanoparticle content increased, the thermal conductivity and diffusivity were enhanced, as well. Numerically, the maximum thermal conductivity was 4.1 W/m K for the composite containing 10 wt% graphite, 15.66 times that of the pure Eicosane. Furthermore, increasing crystal growth and reducing heat capacity for the large number of nanoparticles in the composite were discussed. The significantly improved thermal properties of the prepared NEPCMs with an optimal nanoparticle content could make them applicable for different thermal management applications.

Keywords

• thermal conductivity
• phase change materials
• graphite nanoparticles
• morphological characterization