Attapulgite: a promising natural mineral as carrier material for fatty acids phase change material

The pristine attapulgite (Atta) was pretreated by thermal and acid activation process in order to improve the loading capacity of phase change material (PCM). A series of pretreated Atta-based composite PCM was prepared combined with different kind of fatty acids. The XRD, FT-IR and XRF results shown that the pretreated process increased the purity of Atta as well as the SEM micrographs and BET results indicated that the porosity of Atta slightly increased after pretreating. What`s more, XRD and FT-IR results of the composites PCMs shown good chemical compatibility. DSC results indicated that the composite PCMs of AH-Atta/Lauric acid (LA), AH-Atta/Palmitic acid (SA) and AH-Atta/Docosanoic acid (DA) melted at 42.8 °C, 1.4 °C and 75.2 °C with the latent heat of 94.6 J g−1, 107.5 J g−1 and 84.6 J g−1 at the maximum loading of 51.0%, 50.8% and 51.3%, respectively. In addition, TGA results and 200 thermal cycles test results proved the good thermal stability and reliability of the samples. Based all above results, the prepared composite PCMs have good potential application in energy conservation buildings at different function temperature.