Effects of porous silicon carbide supports prepared from pyrolyzed precursors on the thermal conductivity and energy storage properties of paraffin-based composite phase change materials

Abstract

In this work, novel shape-stabilized silicon carbide/paraffin composite phase change materials were prepared by a vacuum impregnation method. The silicon carbide increased the thermal conductivity of the composite, and its porous structure acted as the support material to improve the mechanical integrity of the composite. The pore sizes in the shape-stable silicon carbide matrix were easily adjusted by optimizing the pyrolytic conditions used to prepare the precursor. Composite phase change energy storage materials were prepared by impregnating the different porous silicon carbide support with paraffin. The prepared silicon carbide/paraffin composites were characterized with X-ray diffraction and scanning electronic microscopy. The results showed that the paraffin was adsorbed within the porous structure as well as on the surface of the SiC, and there was no chemical reaction between the two components. The results of differential scanning calorimetry analysis showed that the melting temperatures and latent heats of the composites were 58.36 °C and 89.76 J/g, respectively, and the thermal storage capacity of the composites was as high as 99.36 %. Notably, the thermal conductivity of the composite was as much as 4.28 times higher than that of pure paraffin. The excellent thermal conductivity and good thermal storage capacity of the composites prepared here make them promising materials for storing thermal energy in practical applications.