The preparation, characterization and modification of a new phase change material: CaCl2·6H2O–MgCl2·6H2O eutectic hydrate salt

The preparation, characterization and modification of eutectic hydrate salt (CaCl 2 ·6H 2 O–MgCl 2 ·6H 2 O) as a new phase change material (PCM) were investigated in this paper. CaCl 2 ·6H 2 O was prepared using industrial grade calcium chloride (CaCl 2 ), and then 10, 15, 20 and 25   wt% MgCl 2 ·6H 2 O was added into CaCl 2 ·6H 2 O respectively in order to obtain CaCl 2 ·6H 2 O–MgCl 2 ·6H 2 O eutectic hydrate salt PCM. The modification of CaCl 2 ·6H 2 O-25   wt% MgCl 2 ·6H 2 O material was designed by a uniform experimental method to select the efficient nucleating and thickening agents. The results show that SrCl 2 ·6H 2 O and SrCO 3 can be effective nucleating agents , and hydroxyethyl cellulose (HEC) is an excellent thickener. For CaCl 2 ·6H 2 O-25   wt% MgCl 2 ·6H 2 O material with 3   wt% SrCl 2 ·6H 2 O, 1   wt% SrCO 3 and 0.5   wt% HEC, the supercooling is reduced to 2   °C, and its phase change temperature and latent heat are 21.4   °C and 102.3   J/g, respectively.