Theoretical prediction and experimental determination of room-temperature phase change materials using hydrated salts as agents

A BET thermodynamic model and its recently modified version were applied to predict the phase diagrams of the systems NH4NO3-LiNO3-H2O and NaNO3-LiNO3-Mg(NO3)(2)-H2O, in which two eutectic points were found with melting point at temperatures between 15 A degrees C and 25 A degrees C. Simple experiments were designed to measure the exothermal and endothermal behavior of the predicted phase change materials. The experimental results showed that the theoretically predicted materials possess excellent exothermal and endothermal behavior at room temperatures. Besides, the fusion and solidification heats of the predicted phase change materials were measured.