MWCNT Grafted Long Chain Fatty Acids/Fatty Alcohols: A Novel Approach to have Higher Thermal Conductivity in Organic PCMs

Among the existing thermal heat storage techniques, latent heat thermal energy storage (LHTES) provides the highest energy storage density. It operates on the principle that the latent heat of fusion of most materials is much larger than their enthalpy change, which means that they can absorb and release energy efficiently during a change of phase. Thermal energy storage (TES) based on this phenomenon requires a suitable phase-change material (PCM) that undergoes a transformation in the temperature range needed for the desired application. It also requires a means of containment for the storage substance, and a suitable heat-carrying fluid for transferring the heat effectively from the heat source to the heat storage device. A TES systems economic performance depends substantially on its specific application and operational needs, including the number and frequency of storage cycles. Long chain fatty acids/fatty alcohol both natural and petrochemical sources. These organic materials have shown great application potential as PCM, due to several suitable properties such as, low supercooling, high heat capacity, low vapor pressure, non-toxic, good thermal and chemical stability, small volume change and self-nucleating behavior. However, like other organic PCMs it also suffers from lower thermal conductivity, which effects their application. To improve thermal conductivity, many scholars have used different techniques and materials, like, employing the fin type heat exchanger with an extended surface for thermal storage, adding metal fillings or the light carbon materials [10,11] etc.. In recent years, high thermal conductivity inorganic materials such as carbon nanotubes, silica fume, graphene oxide and activated montmorillonite featuring high specific surface areas and porous structure have been widely employed as supporting materials to prepare stable PCMs with higher thermal conductivity. After all these modification, the problem still persists, like agglomeration of fillers, ununiform distribution, etc., which at the end effect the thermal conductivity and overall performance. Therefore, to get a better solution to improve thermal conductivity of these organic PCMs, we will be grafting suitable functionalized MWCNT with long selected chain fatty acids/fatty alcohols. Carbon nanotubes have very good thermal conductivity, stability, and they can be functionalized easily, as required. Here the chance of inhomogeneous distribution and agglomeration can be eliminated at the same time thermal conductivity can be improved. These materials will be characterized for conformation of bonding, thermal conductivity, and stability.