Preparation and properties of CaCl₂^.6H₂O/silica aerogel composite phase change material for building energy conservation

To meet the national demand for energy conservation and emission reduction, a shape-stable CaCl(2)(.)6H(2)O /silica aerogel composite phase change material (CPCM) for building energy storage was successfully developed. The CPCM was formed by using modified CaCl(2)(.)6H(2)O composed of CaCl(2)(.)6H(2)O (main PCM) and SrCl(2)(.)6H(2)O (nucleating agent) as PCM, and silica aerogel as carrier via physical blending method. The structure and prop-erties of the CPCM were investigated by various techniques. The results showed that compositing of modified CaCl(2)(.)6H(2)O with silica aerogel could significantly reduce the thermal conductivity, effectively prevent leakage as well as lessen supercooling. The obtained CPCM with 75 wt% modified CaCl(2)(.)6H(2)O had suitable phase transition temperature (27.0 degrees C) with high latent heat (110.9 J(.)g(-1)), acceptable supercooling degree (1.6 degrees C), low thermal conductivity (0.1954 W/(m(.)K)) as well as excellent thermal reliability. The results obtained make the CPCM in this work promising for use in building thermal insulation materials.