Preparation and properties of porous diatomite-supported multi-walled carbon nanotubes with Na2SO4·10H2O-based phase change energy storage composites

The Na 2 SO 4 ·10H 2 O-based phase change energy storage materials (PCMs) were fabricated through vacuum impregnating and adsorbing the oxidized multi-walled carbon nanotubes (MWCNs) with diatomite. The Fourier Transform Infrared Spectroscopy results reveals that the existence of carboxyl and hydroxyl groups in MWCNs can increase its compatibility with PCMs. The vacuum impregnated to obtain the diatomite composite PCMs (PCMs-M-D) crystallize adhering to the treated diatomite (DI-2) observed from the scanning electron microscope. The PCMs-M-D displays negligible supercooling and the thermal conductivity reaches 0.97 W m −1 K −1 . Moreover, after 100 cycles of phase change, the melting latent heat loss is 1.43% and the solidification latent heat loss is 11.15%, showing good heat storage performance and chemical stability.