The Effect of Copper Oxide Nanoparticles on the Effective Thermal Conductivity of Solid Eicosane-Based Nanostructure-Enhanced Phase Change Materials

Conference Name: 49th Annual Technical Meeting of the Society of Engineering Science
Location: Atlanta, Georgia, USA
Date: 10/2012

List of Authors:

Mahdi Nabil , Jay M. Khodadadi

Abstract

Copper oxide (CuO) nanoparticles, stabilized by sodium oleate acid (SOA), were used to enhance the thermal conductivity of eicosane (C20H42) as the base PCM (phase change material). Thermal conductivity measurements of NePCM (nano-structure enhanced phase change material) samples were performed using transient plane source (TPS) technique. The dependence of thermal conductivity on temperature, method of solidification and the loading of CuO nanoparticles were investigated. At first, liquid samples (0, 1, 2, 5 and 10 wt%) were poured into small diameter molds and were degased within a vacuum oven. The molds were then subjected to either ambient solidification or ice-water bath freezing method. With the aid of a controllable temperature bath, measurements were conducted at various temperatures between 10 and 35°C for the solid samples. At each temperature, three different runs were performed and the standard deviation of data was less than 5%. Measured thermal conductivity data of the composites were found to be nearly independent of the measurement temperature for a given loading of CuO nanoparticles regardless of the solidification scheme. Irrespective of the solidification method, as the melting temperature was approached, thermal conductivity data of the solid disks rose sharply for both sets of experiments. The composites prepared using the ice-water bath solidification scheme consistently exhibited lower values of thermal conductivity when compared to the samples which prepared under ambient solidification method. TEM analysis for solid samples was performed as well to explain the phenomenon from the crystal structure point of view.