Thermophysical parameters of organic PCM coconut oil from the T-history method and its variation with the chemical dopant

The thermophysical parameters of organic phase change material (PCM) of coconut oil (co_oil) with chemical dopant have been studied by analyzing the temperature vs time data during liquid-solid phase transition (solidification process) based on T-history method. The dopant consist of nanoparticles of graphite, CuO, and ZnO, each of them added separately to co_oil in 1 wt% and 2 wt%. The data of pure co_oil are taken as the comparison. Analysis of the data reveals the values of solid and liquid specific heats and the heat of fusion related to phase transition of co_oil+dopant. In general, we found that the solid specific heat tends to decrease with dopant concentration, while liquid specific heat tends to increase with dopant concentration with a rather small variation for all type of dopant. The heat of fusion, on the other hand, decreases with the increase of dopant concentration. The temperature dependent enthalpy shows that the solid-liquid phase transition of co_oil occurred with a temperature change, which might be due to its mixture composition. (paper)