Experimental Investigation on Binary Phase Diagram of the Thermotropic Phase Transitions Compounds (n‐CnH2n+1R3)2ZnCl4 |
| |
| Authors: | Kezhong Wu Xiaolong Sun Zhongyuan Duan Jing Ma Lei Chen Bei Ruan |
| |
| Affiliation: | Department of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, China, Tel: 86‐0311‐80787435 |
| |
| Abstract: | The thermotropic phase transitions compounds (n‐CnH2n+1R3)2ZnCl4 as well as a series of their binary mixtures were prepared by a solution reflux method from their ethanol solutions. The experimental subsolidus binary phase diagram of [n‐C18H37N(CH3)3]2ZnCl4‐[n‐(C18H37)2N(CH3)2]2ZnCl4 is constructed over the entire composition range by differential scanning calorimetry(DSC) and X‐ray. Experi‐ mental results indicate one stable intermediate phase [n‐C18H37N(CH3)3] [n‐(C18H37)2N(CH3)2]ZnCl4 at WC18C3Zn %=59.75 %, and two invariant three phase equilibria, which shows two eutectoid temperatures: Te1 at 310±1 K for eutectoid point WC18C3Zn %=36.24 %, Te2 at 313±1 K for eutectoid point WC18C3Zn %=80.17 %. These three noticeable solid‐solution ranges are α‐phase at the left, ?‐phase at the right, and ψ‐phase in the middle of the phase diagram. It is (n‐CnH2n+1R3)2ZnCl4 systems as phase change materials that are characterized the phase transition temperatures T in the range of 310 to 340 K, the transition enthalpies ΔH in the range of 38.40 and 168.72 J/g between two polymorphic forms. |
| |
| Keywords: | The quaternary ammonium tetrachlorozincate Phase change materials Differential scanning calorimetry Eutectoid temperature Phase diagram |
|
|
