Study On The Heat Storage Performance Of Quaternary Ammonium Tetrachorometallates [NR₄]₂MCl₄

Phase change materials storage and release heat by solid-solid phase transition. It isalkylammonium tetrachorometallate （Ⅱ） that has so many advantages such as large latentheat, small degree of supercooling, non-toxic, good thermal stability, good reversibility, smallvolume rate. The phase change enthalpy and appropriate phase change temperature are thebasis of the thermal storage applications. In order to improve the phase change enthalpy ofthis kind of material, we changed the alkyl hydrocarbon chain, the [R–NH3]+were replacedfor [R–N （CH3）3]+. This paper researched the heat storage performance of quaternaryammonium tetrachorometallate（Ⅱ）. The main contents are as follows:In the first part: a series of [n-CnH2n+1N（CH3）3]2ZnCl4（n=8,10,12,14,16,18） and[n-（C18H37）2N（CH3）2]2ZnCl4were synthesized, element analysis, IR spectra, X-ray diffractionand Scanning electron microscopy （SEM） were used to characterize them. The thermalperformance was characterized by TG and DSC.In the second part, the single crystal of the compound of [CH3（CH2）13NH3]2ZnCl4wassynthesized element analysis, IR spectra, X-ray diffraction and Scanning electron microscopy（SEM） and TG were used to characterize it.In the third part, the binary system phase diagram of [C16H37N（CH3）3]2MC14and[C₁₈H₃₇N（CH₃）₃]₂MC14（M=Zn,Co）,[C18H37N（CH3）3]2ZnC14and[(C₁₈H₃₇₂N（CH₃）₂]₂ZnC14were drawed by DSC and XRD.In the last part, the heat of combustion of the a series of [n-CnH2n+1N（CH3）3]2ZnCl4（n=8,10,12,14,16,18） were measured by oxygen bomb calorimeter, andStandard molar enthalpy of combustion and Standard molar enthalpy of formation wereobtained.