Experimental Study on Thermal Property of Alkali Treated CNT-Based Composite as Phase Change Materials

Abstract

The nanocomposites were prepared by adding the multi-walled carbon nanotubes (CNTs) to the melting palmitic acid to improve the thermal transfer property. Mechanochemical reaction was used to treat CNTs for dispersing into organic matrix easily. The treated CNTs were introduced hydoxide radical functional groups on the surfaces during ball milling with the potassium hydroxide. And they were successfully dispersed into the palmitic acid matrix without any surfactant. The resulted nanocomposites were stable and homogeneous. The thermal conductivities and latent heat capacities of these nanocomposites were measured using a transient hot wire apparatus and a differential scanning calorimetric instrument. Nanotube composites, containing a small amount of CNTs, have substantially higher thermal conductivities than the base palmitic acid matrix, with the enhancement increasing with the mass fraction of CNTs in both liquid state and solid state. While the latent heat capacities turned out a reverse with the CNT loadings.