Thermophysical characterization and reliability analysis of binary composite nano doping on stearic acid-acetamide eutectic PCM

Abstract

Organic phase change materials (PCM) have been extensively studied and employed for thermal energy storage applications, especially in the last decade. Wide range of melting temperature with high latent heat of fusion and absence of super cooling have made them highly desirable for energy storage applications, yet their intrinsic low thermal conductivity has been a major drawback in practical implementation. This study intends to address this and study the thermophysical characteristics of an organic PCM through composite nano doping. Stearic acid-acetamide eutectic PCM with a melting temperature of 65.73 °C and a latent heat of 203.72 J/g, was incorporated with a binary blend of Aluminum Oxide nanoparticles and multi-walled carbon nanotubes (MWCNT). The addition of metallic oxide and carbonaceous nanoparticles increased the melting temperature of the eutectic mixture by 2.9 °C and a highly advantageous increment in latent heat of fusion by 10% was observed, due to the improved molecular interaction introduced by the nanoparticles. Composite nano doping enhanced the thermal conductivity of the eutectic PCM by a 132.7% and also resulted in high optical absorption properties. The prepared eutectic mixtures were chemically stable and the eutectic PCM showed an improved final degradation temperature and thermal stability, with composite nano doping. Thermal reliability was analyzed through accelerated thermal cycling test and the eutectic mixtures could retain their thermal characteristics and chemical stability even after 500 thermal cycles. Composite nano doping proved to be a reliable thermophysical characteristics enhancement technique for organic eutectic PCM.