Preparation and properties of phase change ceramisite loaded with inorganic salt hydrate

Abstract

Phase change ceramisite (PCC) was prepared by vacuum adsorption method using inorganic CaCl2·6H2O (CCH) as phase change material. Effects of loading in ceramsite on super–cooling of CCH during liquid–solid phase change process and surface–sealing treatment of PCC on properties of the cement–based composite phase change material were investigated. The results showed that the amount of CCH adsorbed in ceramsite was significantly higher compared to that of capric acid (CA), and the supercooling degree of CCH during liquid–solid phase change can be greatly reduced after being loaded in ceramisite. By simple clading with cement and PEG, the salt hydrate cannot be effectively sealed within ceramisite. The dewdrops appeared on the surface after exposed in the air for 3 d for claded with cement, and expansive cream–like substance was found on the surface after exposed in the air for one month for claded with PEG, leading to a destruction of PCC. After further loaded with capric acid or oily paint, incorporation of both PCC in cement–based materials can effectively lower the temperature rise during hydration. However, the hardened composite showed leakage of CA for the former case whereas no leakage appeared for the ceramisite coated by using oily paint.