Phase Diagram Prediction of the System Mg(NO3)2-MgCl2-H2O as Phase Change Materials

The modified BET thermodynamic model was applied to predict phase diagram of the system Mg(NO3)(2)-MgCl2-H2O from 273 to 373 K, in which two eutectic points were found. The exothermal and endothermal behavior of the predicted eutectic points were measured and the results showed that the ternary eutectic point Mg(NO3)(2)center dot 6H(2)O(45.6%)-Mg(NO3)(2)center dot 2H(2)O(29.6%)-MgCl2 center dot 6H(2)O(24.8%) has poor energy-storage ability, while another binary eutectic point Mg(NO3)(2)center dot 6H(2)O(61.6%)-MgCl2 center dot 6H(2)O(38.4%) has good exothermal and endothermal ability near the melting temperature with melting heat 136.8 J.g(-1) determined by differential thermal analysis (DTA), and is expected to be used for the potential phase change material.