The Effect Of Electric Field On The Nucleation And Crystallization Of HMX

Nucleation and crystallization under electric field is a new research trend which has been widely used in chemical,biological,pharmaceutical,food,energy and other fields in the past 20 years due to the flexible of controlling the nucleation by electric field,but it is untouched in the energetic materials field.HMX is the most widely known nitramine explosive by its good comprehensive performance and high-energy,and it has great research value among the energetic materials.In this paper,the HMX nucleation under DC electric field and AC electric field is explored by theoretical and simulation.The research of this paper is as follow:1.The variations of bond-length and bond-angle are caused by the electron transfer of HMX molecule which is stimulated by the applied electric field,and that resulting in the conformational change of HMX molecule.With the electric field intensity increases,the excited of electron gets easier and the conformation has greater change.In this research,there is none chemical bond break under the electric field intensity from 0 to 0.004 a.u.2.The intensity of DC electric field has more influence on the HMX nucleation than that of the direction of DC electric field.With the increase of electric field intensity,the ability of HMX nucleation is changed,and the time for reaching equilibrium is significantly shorten.The direction of electric field affects the nucleation or dissolution of HMX to some extent,but it can not change its trend.The total dipole moment of HMX molecule increases with the increase of electric field intensity,and its direction has a small angle with the direction of electric field.3.The HMX nucleation is mostly promoted by the effect of high current frequency under the AC electric field,and it can also improve the nucleation rate of HMX.However,the nucleation promoting of HMX starts to change as nucleation inhibiting when the ultra-high current frequency(over a critical value of current frequency)is applied.The influence of electric field intensity on HMX nucleation is greatly weakened by the current frequency,which has a major impact on HMX nucleation.The total dipole moment of HMX molecules under AC electric field is extremely close to that under no electric field,and it is almost unchanged with the increases of current frequency.The direction of total dipole moment of HMX molecules and the direction of AC electric field form a large angle,it nearly perpendicular to the direction of electric field.This reveals the nature that the polarization effect of electric field is greatly weakened by the current frequency.