Thermal characterization of net-like and form-stable ML/SiO2 composite as novel PCM for cold energy storage

Abstract

A novel phase change materials (PCMs) composite was fabricated by sol-gel method for cold energy storage. Methyl laurate (ML) as cold energy medium was preferred due to its appropriate phase change temperature (3.96 ℃) and high latent heat (210.1 J/g), and silica provided a complete external protection for the ML. Various techniques were used to characterize the as-prepared ML/SiO2 PCMs composite so as to investigate its structure and thermal properties, including scanning electron microscopy (SEM), fourier transforms infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). During the PCMs composite forming process, hydrogen bonds generated by the interaction of carboxyl group of ML, the silicon hydroxyl group of silica, and the hydroxyl groups of emulsifier PVA promoted the morphology change of the PCMs composite from sphere-like to net-like structure. The DSC results showed that the net-like PCMs melted at 6.71 ℃ with a latent heat of 151.3 J/g and solidified at -5.43 ℃ with a latent heat of 148.9 J/g. Besides, the PCMs composite exhibited outstanding chemical compatibility, thermal reliability and complete micromorphology. Thus, the prepared ML/SiO2 PCMs composite with novel net-like structure had great potential for cold energy storage.