Crystal Growth of Urea and Its Modulation by Additives as Analyzed by All-Atom MD Simulation and Solution Theory
Crystal Growth of Urea and Its Modulation by Additives as Analyzed by All-Atom MD Simulation and Solution Theory
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全原子MD模拟和解理论分析尿素晶体生长及其添加剂调节
DOI：
10.1021/acs.jpcb.2c01764
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发表时间：
2022
期刊：
影响因子：
3.3
通讯作者：
and Nobuyuki Matubayasi
中科院分区：
文献类型：
--
作者：
Senri Tanaka;Naoki Yamamoto;Kento Kasahara;Yoshiki Ishii;and Nobuyuki Matubayasi
采用全原子分子动力学（MD）方法对尿素晶体（001）面和（110）面与水溶液接触的生长过程进行了模拟。一个结晶分子的局部环境中的结晶邻居的数量和相对于晶体表面的取向方面进行了处理，和生长表面的分子水平的不均匀性，通过分解的整体增长率到由本地结构和取向模式的条件下的贡献的总和来解决。（001）面和（110）面之间的生长机制的对比由局部贡献来证明，并且晶体的外层朝向液体区域的作用被指出对于（001）。以缩二脲、N，N-二甲基甲酰胺（DMF）和丙酮为原料，研究了液相中添加剂种类对尿素晶体生长的影响。生长被观察到更强烈地抑制缩二脲> DMF>丙酮的顺序，并且发现添加剂抑制的顺序是常见的，与结晶尿素的局部环境无关。这一发现意味着添加剂对晶体生长的影响可以通过处理平坦表面来预测，这是一种方便的原子分辨率详细分析系统。对应于添加剂的吸附的自由能，然后检查添加剂诱导的调制的生长速率。有人认为，吸附自由能相关的增长率的调制程度，和相互作用的组件，管理的吸附倾向进行了鉴定。
The crystal growth of urea was analyzed with all-atom molecular dynamics (MD) simulation for the (001) and (110) faces in contact with aqueous solutions. The local environment of a crystallizing molecule was treated in terms of the numbers of crystalline neighbors and the orientation relative to the crystal surface, and the molecular-level inhomogeneity of a growing surface was addressed by decomposing the overall rate of growth into a sum of the contributions conditioned by the local structure and orientation mode. The contrast of the growth mechanism between the (001) and (110) faces was then evidenced by the local contributions, and the roles of the outer layers of the crystal toward the liquid region were pointed out for (001). The effect of the additive species in the liquid on the crystal growth of urea was investigated with biuret,N,N-dimethylformamide (DMF), and acetone. The growth was observed to be suppressed more strongly in the order of biuret > DMF > acetone, and it was found that the ordering of suppression by the additive is common irrespective of the local environment of a crystallizing urea. This finding implies that the additive’s effect on the crystal growth can be predicted by treating the flat surface, which is a convenient system for detailed analyses at atomic resolution. The correspondence to the free energy of adsorption of the additive was then examined for the additive-induced modulation of the growth rate. It was seen that the adsorption free energy correlates to the extent of modulation of the growth rate, and the interaction components that govern the adsorption propensity were identified.