烷基咪唑离子液体C_nmimCl(n=4,6,8)对CL-20重结晶的影响  

Effect of Alkyl Imidazole Ionic Liquids C_nmim Cl(n=4,6,8) on CL-20 Recrystallization

作　　者：郑晓頔 朱艳丽[1] 董睿[1] 焦清介[1] 

机构地区：[1]北京理工大学爆炸科学与技术国家重点实验室,北京100081

出　　处：《物理化学学报》2016年第8期1950-1959,共10页Acta Physico-Chimica Sinica

基　　金：国家自然科学基金(51304024)资助项目~~

摘　　要：六硝基六氮杂异戊兹烷(CL-20)是高能量密度材料的典型代表之一。重结晶制备高品质CL-20的一个重要难题是晶体微观结构的调控。本文通过在CL-20重结晶过程中加入微量离子液体作为晶形控制剂,探究离子液体浓度、种类和添加方式(加入溶剂或者反溶剂)对CL-20晶体微观结构的影响规律。结果表明:通过改变离子液体的添加方式、种类和浓度,能够实现CL-20晶体尺寸和晶体形貌的调控。热分析结果表明:离子液体的加入可以使ε到γ晶型转变温度提前多达12.6°C;重结晶CL-20的分解峰温和热稳定性提高,放热量增加,最高可达1344 J?g^(-1)。溶剂中1-己基-3-甲基咪唑氯盐(Dmim Cl)的加入,能够结晶出没有尖锐棱边和角的类八面体形CL-20晶体,晶粒细小,分解峰温均提高了6°C以上,放热量均在1100 J?g^(-1)以上,是较理想的晶形控制剂。Hexanitrohexaazaisowurtzitane （CL-20） is considered to be a representative high energy density material. It is important to control the microstructure of the crystal during recrystallization to ensure the quality of CL-20. In this study, the effects of different types and concentrations of ionic liquids on CL-20 were investigated by adding them to the solvent or anti-solvent during recrystallization. Three types of ionic liquids acting as a morphology control additive can reduce the crystal size of recrystallized CL-20. Thermal analysis shows that most ionic liquids added to solvents or anti-solvents can increase the transition temperature from the ε crystal to the y crystal by up to 12.6 ℃, and the decomposition peak temperature increases so the thermal stability of CL-20 improves. The heat output increases to 1344 J·g^-1. When DmimCI is added into the solvent, recrystallized CL-20 has smaller particle size and an octahedral shape without sharp edges or agglomeration. With different concentrations of DmimCI in the solvent, the decomposition peak temperature of recrystallized CL-20 increases more than 6℃ and the heat output is more than 1100 J·g^-1. Therefore, DmimCI is an ideal morphology control additive.

关 键 词：CL-20 Ostwald规则 热分析 晶形控制剂 重结晶 离子液体 

分 类 号：O645.1[理学—物理化学]