Thermophysical properties of three-dimensional palygorskite based composite phase change materials

Abstract

In order to enhance the loading capacity of palygorskite (Pal) and further understand the relationship between pore size of carrier and thermal properties of mineral-based phase change materials (PCMs), series of three-dimensional palygorskite carriers and corresponding composite PCMs (CPCMs) were fabricated. The morphology, structural characteristics and thermal properties of the support and composite PCMs were determined by various techniques. The effects of support microstructure on the thermo physical properties of CPCMs were also discussed. The results revealed that the isocyanate functionalized palygorskite can be covalently bonded by dihydric alcohol to form three-dimensional Pal-based carrier. The pore diameter of the carrier varies with the chain length of dihydric alcohol. Since covalent bonding and surface functionalization can prevent the agglomeration of palygorskite crystals, thermal energy storage performance of stearic acid/three-dimensional palygorskite is increased by 67.4% to 100.7% within the scope of the study compared with that of stearic acid/palygorskite. The phase change temperature and latent heat of the composite phase change material have a linear correlation with pore size of support. This study is expected to be helpful for designing mineral-based porous carrier and providing guidance for optimizing CPCMs.