In order to theoretically study the growth morphology of dihydroxylammonium 5,5’-bistetrazole-1,1’-dio late(TKX-50)crystal in different solvent systems,crystal–solvent models were established,and then molecular dyn...In order to theoretically study the growth morphology of dihydroxylammonium 5,5’-bistetrazole-1,1’-dio late(TKX-50)crystal in different solvent systems,crystal–solvent models were established,and then molecular dynamics(MD)methods were adopted as a means to simulate particle motion.Modified attachment energy(MAE)model was employed to calculate the growth morphology of TKX-50.The simulation results demonstrate that COMPASS force field and RESP charge are suitable for molecular dynamics simulation of TKX-50.The morphologically dominant growth surfaces of TKX-50 in vacuum are(020),(011),(11–1),(100)and(120),respectively.In water(H_(2)O)and N,N-dimethylformamide(DMF)solvents,the(11–1)face is the largest in the habit face,the growth rate of(020)face becomes faster.With the increase of temperature,the aspect ratios of TKX-50 crystal in DMF solvent increase,and the areas of the(120)faces decrease.In ethylene glycol/H_(2)O mixed solvent system with volume ratio of 1/1,aspect ratio of TKX-50 is relatively small.In formic acid/H_(2)O mixed solvents with different volume ratios(1/4,1/3,1/2,1/1 and 2/1),aspect ratio of TKX-50 is relatively small when volume ratio is 1/2.展开更多
Important crystal faces that dominate the crystal morphology of royal demolition explosive （RDX） in vacuum were analyzed with the attachment energy （AE） method. Molecular dynamics （MD） simulations were used to c...Important crystal faces that dominate the crystal morphology of royal demolition explosive （RDX） in vacuum were analyzed with the attachment energy （AE） method. Molecular dynamics （MD） simulations were used to calculate the interaction energies between these crystal faces and different solvent molecules for an attachment energy correction. Growth habits in the presence of different solvents were generated. The results showed that some crystal faces in solutions became morphologically more important than that in vacuum while others became less important. Thus, crystal shape and surface property changed a lot with the variation of crystal faces. The results from calcula- tion were in agreement with those from the re-crystallization experiment, which indicated that cyclohexanone （CH） was a promising solvent to modify the crystal morphology of RDX for obtaining products with regular shape and high purity, while butyrolactone （BL） played a great role in improving the surface electrostatic property of RDX.展开更多
基金supported by Fundamental Research Program of Shanxi Province(20210302123055)and(201801D221035).
文摘In order to theoretically study the growth morphology of dihydroxylammonium 5,5’-bistetrazole-1,1’-dio late(TKX-50)crystal in different solvent systems,crystal–solvent models were established,and then molecular dynamics(MD)methods were adopted as a means to simulate particle motion.Modified attachment energy(MAE)model was employed to calculate the growth morphology of TKX-50.The simulation results demonstrate that COMPASS force field and RESP charge are suitable for molecular dynamics simulation of TKX-50.The morphologically dominant growth surfaces of TKX-50 in vacuum are(020),(011),(11–1),(100)and(120),respectively.In water(H_(2)O)and N,N-dimethylformamide(DMF)solvents,the(11–1)face is the largest in the habit face,the growth rate of(020)face becomes faster.With the increase of temperature,the aspect ratios of TKX-50 crystal in DMF solvent increase,and the areas of the(120)faces decrease.In ethylene glycol/H_(2)O mixed solvent system with volume ratio of 1/1,aspect ratio of TKX-50 is relatively small.In formic acid/H_(2)O mixed solvents with different volume ratios(1/4,1/3,1/2,1/1 and 2/1),aspect ratio of TKX-50 is relatively small when volume ratio is 1/2.
文摘It is reported that from March 1 st, 2005, the energy efficiency label will be attached on the household refrigerators and air conditioners in China.
文摘Important crystal faces that dominate the crystal morphology of royal demolition explosive （RDX） in vacuum were analyzed with the attachment energy （AE） method. Molecular dynamics （MD） simulations were used to calculate the interaction energies between these crystal faces and different solvent molecules for an attachment energy correction. Growth habits in the presence of different solvents were generated. The results showed that some crystal faces in solutions became morphologically more important than that in vacuum while others became less important. Thus, crystal shape and surface property changed a lot with the variation of crystal faces. The results from calcula- tion were in agreement with those from the re-crystallization experiment, which indicated that cyclohexanone （CH） was a promising solvent to modify the crystal morphology of RDX for obtaining products with regular shape and high purity, while butyrolactone （BL） played a great role in improving the surface electrostatic property of RDX.
