H2O2-microwave treated graphite stabilized stearic acid as a composite phase change material for thermal energy storage

Flake graphite (FG) was treated by microwave radiation in hydrogen peroxide solution and used to support stearic acid (SA) to synthesize SA/FG composites for thermal energy storage. The thermostability of the SA/FG was measured via TG-DSC, revealing they have good thermal stability up to 230 degrees C. The thermal properties of the composites were changed by varying the radiation time, and the SA/FG(3) composite with the longest FG treatment time showed a higher latent heat value (61.05 J g(-1) for melting and 61.00 J g(-1) for freezing), and greater crystallinity (F-c, 98.34%) than other samples according to the analysis of DSC. The SA/FG(3) composite had a good thermal reliability after thermal cycling tests. The thermal conductivity of SA/FG(3) (3.18 W m(-1) k(-1)) was 12.2 times higher than that of pure SA. Furthermore, the mechanism of the enhanced performance of SA/FG(3) was further revealed by monitoring functional groups of the surface of FG and demonstrated on the atomic-scale. Infrared imaging showed SA/FG(3) possessed superior thermal-regulated properties. Therefore, all these thermal properties indicate SA/FG(3) has potential for application in thermal energy storage systems.