二氧化碳GAS法重结晶细化HMX成核速率研究

Nucleation Rate of Ultrafine HMX Recrystallized by Carbon Dioxide Gas Anti-solvent Method

采用CO2气体抗溶剂法（GAS）对奥克托今（HMX）重结晶细化过程进行了研究。运用紫外分光光度计测定了压力为10—35MPa条件下，HMX在CO2-丙酮体系中的过饱和度，进而利用成核速率方程计算得到了HMX的成核速率。利用扫描电子显微镜（SEM）表征了HMX样品形貌，通过扫描电镜照片统计分析，得到了HMx粒子平均粒度及粒径分布。结果表明，随着压力的升高，HMX在CO2-丙酮体系中过饱和度逐渐增加，表现出非常高的成核速率，可以达到10 24数量级。不同压力下所得HMX粒子形貌、粒度及粒径分布也有较大差别。从成核速率角度进行理论分析，表明高压条件（35MPa）相对低压条件（5～15MPa）而言，能量更多的消耗在成核阶段，从而有利于形成形貌规整、粒度小、粒径分布较窄的HMX颗粒。

During the process of recrystallizing ultrafine HMX by gas anti-solvent （GAS） method,the ultraviolet-visible detector was used to measure the supersaturation degree of HMX in CO2 and acetone system at 10 -35 MPa,and the nucleation rate equation was used to calculate the nucleation rate of HMX. The ultrafine HMX was characterized by scanning electronic microscope （SEM）. Results show that the supersaturation degree of HMX in CO2 and acetone system increases with increasing of the pressures. ＇Also,the nucleation rates of HMX are very high,can reach to 10 24 orders of magnitude. From results of SEM , there are some obvious differences in particle morphology,size and size distribution of HMX. Analyzing from the view of nucleation rates,there is more energy consumed in nucleation stage at relatively high pressure （35 MPa） than that at low pressure （5 -15 MPa）,which contributes to formation of HMX particles with regular morphology,small size,narrow size distribution.