Preparation and thermophysical properties of a novel form-stable CaCl2·6H2O/sepiolite composite phase change material for latent heat storage

• Published in: Journal of thermal analysis and calorimetry 2018, Vol.131 (1), p.57-63
• Main Authors: Cui, Weiwei, Zhang, Huanzhi, Xia, Yongpeng, Zou, Yongjin, Xiang, Cuili, Chu, Hailiang, Qiu, Shujun, Xu, Fen, Sun, Lixian
• Format: Article
• Language: English
• Subjects: Analytical Chemistry; Calcium chloride; Chemistry; Chemistry and Materials Science; Crystal structure; Differential scanning calorimetry; Enthalpy; Fourier transforms; Heat storage; Inorganic Chemistry; Latent heat; Measurement Science and Instrumentation; Phase change materials; Phase transitions; Physical Chemistry; Polymer Sciences; Sepiolite; Stability analysis; Thermal analysis; Thermal stability; Thermal transformations; Thermogravimetric analysis; Thermophysical properties
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-017-6170-2

In this work, CaCl 2 ·6H 2 O/sepiolite was successfully designed and synthesized as a novel form-stable composite phase change material by vacuum impregnation method, using sepiolite as a sustainer and CaCl 2 ·6H 2 O as phase change material. Scanning electron microscope and Fourier transform infrared spectroscopy measurements display that CaCl 2 ·6H 2 O is filled into the porous structure of sepiolite by physical interactions. Phase transformation behavior and thermal stability were revealed from differential scanning calorimetry and thermogravimetric analysis, respectively. Results show that the melting enthalpy of the composite phase change material containing 70% CaCl 2 ·6H 2 O can achieve 87.9 J g −1 , and the composite PCM has a good thermal stability in the temperature range from 25 to 100 °C. Meanwhile, the crystal structure of CaCl 2 ·6H 2 O is maintained in the porous structure of sepiolite observed by X-ray diffraction. It means that sepiolite reduces the super-cooling of CaCl 2 ·6H 2 O which ensures the good phase change behavior of the composites. These results exhibit that the CaCl 2 ·6H 2 O/sepiolite composite phase change material possesses high latent heat. Moreover, low cost of the sepiolite enables the composites to be a good candidate for latent heat storage.