基于3,7-二硝基-1,3,5,7-四氮杂双环[3.3.1]壬烷(DPT)在HNO3-N H4N O3及HNO3中两种硝解机理,分别通过实验和理论计算方法对NH+4在DPT硝解反应中的作用进行了研究。将三种不同的铵盐(NH4)2H PO4,(NH4)2SO4和CH3C O O N H4添加到硝解体系...基于3,7-二硝基-1,3,5,7-四氮杂双环[3.3.1]壬烷(DPT)在HNO3-N H4N O3及HNO3中两种硝解机理,分别通过实验和理论计算方法对NH+4在DPT硝解反应中的作用进行了研究。将三种不同的铵盐(NH4)2H PO4,(NH4)2SO4和CH3C O O N H4添加到硝解体系中,考察了NH+4对HM X产率的影响。结果表明,与NH4N O3的作用相似,以上三种铵盐可提高HM X产率,提高率分别为41.5%、37.4%和20.7%。在不同的HNO3-铵盐体系中,当N H+4与DPT的摩尔比接近10时,HM X的产率均达到最大值,分别为56.3%、52.2%和35.5%。对比了HNO3-铵盐和H N O3-硝酸盐体系中D PT硝解反应的结果,发现N H+4对HM X产率的提高起主导作用。采用密度泛函理论(DFT)对NH+4在DPT硝解反应过程中的作用机理进行了理论解释,得出HNO3/N H+4体系中D PT硝解反应的活化能为133.95 k J·m ol-1,低于HNO3体系中的376.73 k J·mol-1。展开更多
Molecular dynamics simulations on octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine （HMX） at 303-383 K and atmospheric pressure are carried out under NPT ensemble and COMPASS force field, the equilibrium structures a...Molecular dynamics simulations on octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine （HMX） at 303-383 K and atmospheric pressure are carried out under NPT ensemble and COMPASS force field, the equilibrium structures at elevated temperatures were obtained and showed that the stacking style of molecules don＇t change. The coefficient of thermal expansion （CTE） values were calculated by linear fitting method. The results show that the CTE values are close to the experimental results and show anisotropy. The total energies of HMX cells with separately increasing expansion rates （100%-105%） along each crystallographic axis was calculated by periodic density functional theory method, the results of the energy change rates are anisotropic, and the correlation equations of energy change-CTE values are established. Thus the hypostasis of the anisotropy of HMX crystal＇s thermal expansion, the determinate molecular packing style, is elucidated.展开更多
Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scannin...Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that B-HMX microparticle in different average size (2-9.5um) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.展开更多
文摘基于3,7-二硝基-1,3,5,7-四氮杂双环[3.3.1]壬烷(DPT)在HNO3-N H4N O3及HNO3中两种硝解机理,分别通过实验和理论计算方法对NH+4在DPT硝解反应中的作用进行了研究。将三种不同的铵盐(NH4)2H PO4,(NH4)2SO4和CH3C O O N H4添加到硝解体系中,考察了NH+4对HM X产率的影响。结果表明,与NH4N O3的作用相似,以上三种铵盐可提高HM X产率,提高率分别为41.5%、37.4%和20.7%。在不同的HNO3-铵盐体系中,当N H+4与DPT的摩尔比接近10时,HM X的产率均达到最大值,分别为56.3%、52.2%和35.5%。对比了HNO3-铵盐和H N O3-硝酸盐体系中D PT硝解反应的结果,发现N H+4对HM X产率的提高起主导作用。采用密度泛函理论(DFT)对NH+4在DPT硝解反应过程中的作用机理进行了理论解释,得出HNO3/N H+4体系中D PT硝解反应的活化能为133.95 k J·m ol-1,低于HNO3体系中的376.73 k J·mol-1。
文摘Molecular dynamics simulations on octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine （HMX） at 303-383 K and atmospheric pressure are carried out under NPT ensemble and COMPASS force field, the equilibrium structures at elevated temperatures were obtained and showed that the stacking style of molecules don＇t change. The coefficient of thermal expansion （CTE） values were calculated by linear fitting method. The results show that the CTE values are close to the experimental results and show anisotropy. The total energies of HMX cells with separately increasing expansion rates （100%-105%） along each crystallographic axis was calculated by periodic density functional theory method, the results of the energy change rates are anisotropic, and the correlation equations of energy change-CTE values are established. Thus the hypostasis of the anisotropy of HMX crystal＇s thermal expansion, the determinate molecular packing style, is elucidated.
基金the National Natural Science Foundation of China (No. 29376233).
文摘Microparticle formation and crystallization rate of 1,3,5,7-tetranitro-l,3,5,7-tetraazacyclooctane (HMX) in acetone solution using supercritical carbon dioxide antisolvent (GAS) recrystallization were studied. Scanning electronic microscopy, X-ray diffraction and infrared radiation were used to examine particle size, crystallinity and chemical structure. The results show that B-HMX microparticle in different average size (2-9.5um) and with narrow size distribution were obtained by controlling the expansibility, expansion speed, initial concentration and temperature during recrystallization of HMX. The formation of nuclei may be a main cause of consumption of solute when the solution is expanded rapidly enough and the equilibrium concentration is lower, in which almost monodisperse microparticle can be obtained.
