纳米结晶体Ni0.5Zn0.5Fe2O4对高氯酸铵热行为及分解反应动力学的影响

采用差示扫描量热法(DSC)、热重和微分热重(TG-DTG)及固相原位反应池/快速扫描傅立叶变换红外联用技术(hyphenated in situ thermolysis/RSFTIR)研究了纳米结晶体Ni_0.5Zn_0.5Fe₂O₄与高氯酸铵(AP)组成的混合物的热行为和分解反应动力学。结果表明：Ni_0.5Zn_0.5Fe₂O₄使得AP的低、高温分解放热峰温分别提前17.44 K和27.74 K，并使得对应的分解热分别增加3.7 J·g^-1和193.7 J·g^-1。Ni_0.5Zn_0.5Fe₂O₄并不影响AP的晶转温度和晶转热。Ni_0.5Zn_0.5Fe₂O₄使得AP的TG曲线出现3个阶段，并使得后2个失重阶段的初始和终止温度都有所提前。凝聚相分解产物分析表明Ni_0.5Zn_0.5Fe₂O₄加速了凝聚相AP的分解及氨气的释放。含Ni_0.5Zn_0.5Fe₂O₄的AP的高温分解反应的动力学参数E_a=238.88 kJ·mol^-1，A=1018.59 s^-1，动力学方程可表示为dα/dt=10^18.99(1-α)-ln(1-α)]^3/5e^-2.87×104T。始点温度(T_e)和峰顶温度(T_p)计算得出AP的热爆炸临界温度值分别为:574.83 K和595.41 K。分解反应的活化熵(ΔS^≠)、活化焓(ΔH^≠)和活化能(ΔG^≠)分别为:109.61 J·mol^-1·K^-1、236.49 kJ·mol^-1及172.58 kJ·mol^-1。

Effect of Nanocrystal Ni0.5Zn0.5Fe2O4 on Thermal Behavior and Decomposition Reaction Kinetics of Ammonium Perchlorate

The thermal behavior and non-isothermal decomposition reaction kinetics of the mixture of the nanocrystal Ni0.5Zn0.5Fe2O4 and ammonium perchlorate (AP) were investigated by differential scanning calorimetry(DSC), thermogravimetry and differential thermogravimetry (TG-DTG), and the hyphenated technique of in situ thermolysis cell with rapid-scan Fourier transform infrared spectroscopy (in situ thermolysis/RSFTIR). The results show that Ni0.5Zn0.5Fe2O4 can decrease the low-temperature and the high-temperature exothermic peak temperatures of AP by 17.44 K and 27.74 K, respectively, and increase the decomposition heats of the two exothermic peaks by of AP. Ni0.5Zn0.5Fe2O4 makes AP shown three mass-loss processes, and it can decrease the initial and terminated temperatures of the last two mass-loss stages. The condensed phase decomposition product analysis shows that Ni0.5Zn0.5Fe2O4 accelerates the decomposition of condensed AP and the release of the gaseous NH3. The kinetic of Ni0.5Zn0.5Fe2O4/AP can be described as: dα/dt =10 18.99 (1-α) -ln (1 -α)] 3/5 e -2.87entropy of activation (△S≠), enthalpy of activation (△H≠), and free energy of activation (△G≠) of the decomposition reaction are 109.61 J· mol-1· K-1, 236.49 kJ· mol-1, and 172.58 kJ· mol-1, respectively.