分子动力学模拟三乙烯二胺准晶体的可控晶体生长

Controllable crystal growth in triethylenediamine quasicrystals using molecular dynamics simulation

由于三乙烯二胺结晶均匀度和大小不一,且传统结晶工艺不可控,严重影响了其使用性能,且制约了后续产品的研发。采用分子动力学模拟,研究了三乙烯二胺在温度253~413 K下的准晶生长。通过研究准晶的势能、分子排布、密度、扩散系数、径向分布函数和N—N原子的取向性来表征影响效果。模拟结果表明:三乙烯二胺准晶体随着温度的升高,总势能逐渐增加;各温度下准晶体的生长受晶种影响很小;在温度333 K下,该准晶体的密度最大,为1.13 g/cm^(3),且该温度下准晶体的均一性最好,即N—N原子与z轴正半轴夹角分布在72.5~73.5°范围内所占的百分比最大,峰值为3.13。

Due to the different uniformity and size of triethylenediamine crystallization,and uncontrollable process of traditional crystallization,the performance is seriously affected and the research and development of subsequent products is restricted.The quasicrystals growth in triethylenediamine at a temperature range of 253~413 K was studied using molecular dynamics simulations.The effect was characterized by the potential energy,molecular arrangement,density,diffusion coefficient,radial distribution function and orientation of N—N atoms.The simulation results show that the potential energy of triethylenediamine quasicrystals increases with the increase of temperature.The quasicrystal growth is minimally affected by the seed crytal at each temperature.At the temperature of 333 K,the quasicrystals have the highest density of 1.13 g/cm^(3),and the homogeneity of quasicrystals is best.The percentage for the angle between N—N atoms and the z-axis positive half axis in the range of 72.5~73.5°is the largest,with a ratio of 3.13 at 333 K.