Preparation and characterization of methyl palmitate/palygorskite composite phase change material for thermal energy storage in buildings

In this study, palygorskites (PALs) including raw PAL, acid-activated PAL and organic PAL were using as carrier to prepare methyl palmitate (MPA)/PAL composite phase change materials (PCM) by vacuum impregnation method (VIM) and direct impregnation method (DIM), respectively. The microstructure, thermal property and thermal stability of MPA/PAL composite were investigated. Scanning electron microscopy and N-2 adsorption-desorption measurement results of PAL indicated that acid treatment can remove the impurities inside the crystal bundles and then form a highly porous structure. The MPA was well incorporated into the holes and surface of PAL. The MPA/PAL composite prepared by VIM exhibited higher absorption ratio (46.32%) than that of DIM. The values of freezing latent heat for MPA/Raw PAL, MPA/H+-PAL and MPA/OPAL (prepared via VIM) were 51.31 J/g, 96.10 J/g and 81.96 J/g, respectively. The phase-change temperature of MPA/PAL composites was range from 22.29 degrees C to 24.5 degrees C. Moreover, the H+-PAL/MPA composite had good thermal reliability after 300 times thermal cycling test. Therefore, the MPA/PAL composite was an effective building material for reducing energy consumption. (C) 2019 Elsevier Ltd. All rights reserved.