Solution combustion synthesized copper foams for enhancing the thermal transfer properties of phase change material

Abstract Regardless of the high latent heat of organic phase change materials (PCMs) for thermal energy storage, their intrinsically low thermal conductivity has constrained their wide application. In order to improve the thermal conductivity of paraffin PCM, porous copper foams as supporting frameworks are fabricated by a simple solution combustion synthesis (SCS), using copper nitrate as oxidizer and starch as fuel. The SCS is conducted under inert atmosphere and the efficient exothermic reaction occurs at around 100 °C. At an optimal oxidant-fuel condition of 4.43 g copper nitrate to 2 g starch, a good porous copper scaffold is prepared, which is further shaped and sintered to form robust copper foams. Paraffin is infiltrated into the copper foams to form PCM composites and the thermophysical properties are analyzed. Due to the continuous copper skeleton as heat transfer path, the thermal conductivity of the composite is improved to 3.29 W m-1 K-1 from 0.25 W m-1 K-1 of pure paraffin. The enhanced heat transfer properties of PCM composites as-supported by the facilely SCS-derived copper foams can reinforce the application in solar thermal harvesting and thermal management.