In order to maintain the stability of the crystal structure and appropriate crystal morphology of eutectic explosives,and then meet the better safety performance and charge requirements of eutectic,two crystallization methods,namely,cooling and solvent/anti solvent,were used to study the crystallization behavior of CL-20/MTNP eutectic in the different solvent sys-tems,including methanol,ethanol,n-propanol,acetone,cyclopentanone,3-methyl-2-butanone,ethyl acetate,ethyl buty-rate,DMSO,methanol/water(volume ratio is 2∶1)and cyclopentanone/ethanol(volume ratio is 1∶6).From this,the crystal products with different morphologies were obtained.XRD was used to analyze the crystal products.And theoretical cal-culations were conducted using the AE model and molecular dynamics in Materials Studio software,revealing the influence of solvents on crystal morphology and the reasons.Based on simulation and experimental results,solvent/anti solvent crystalliza-tion method was adopted,with methanol as the good solvent and water as the anti solvent,to optimize the crystallization con-ditions.The results show that the crystallization of CL-20/MTNP eutectic explosives in alcohols,esters,and ketones exhibit the trends of rod like,flake like,and block like,respectively,where the crystal surface area occupies the largest proportion.The crystal obtained by crystallization using DMSO as a solvent is not the eutectic explosives but a mixture of CL-20 and MTNP.Under the optimal conditions of a concentration of 0.017g/mL,a temperature of 55 ℃,and a drip rate of 1 mL/min,the eu-tectic crystal obtained has the smallest aspect ratio and good particle uniformity.The sensitivity of short rod-shaped crystals with regular shapes is much lower than that of both sheet-like and needle shaped crystals with sharp edges.Accordingly,the change in crystal morphology is mainly attributed to the varying strength of the interaction between the solvent and different crystal planes,and the morphology of cocrystal crystals play a significant role of sensitivity.
physical chemistrycocrystal explosivesCL-20/MTNP energetic cocrystalstability of crystal structurecrystal morphologycrystallization
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