Morphology and Growth of Methyl Stearate as a Function of Crystallization Environment
Morphology and Growth of Methyl Stearate as a Function of Crystallization Environment
复制标题
DOI：
10.1021/acs.cgd.6b01436
复制
发表时间：
2017-02-01
影响因子：
3.8
通讯作者：
Lewtas, Ken
中科院分区：
文献类型：
--
作者：
Camacho, Diana M.;Roberts, Kevin J.;Lewtas, Ken
硬脂酸甲酯从过饱和正十二烷，煤油和甲苯溶液中生长的原位研究揭示了强有力的证据，溶剂的选择影响晶体形态和晶体生长动力学。在所有溶剂中观察到具有类似习性的晶体，除了在煤油中较低的过饱和度，其中观察到不太对称的形态。基于硬脂酸甲酯的单斜C2晶体结构的BFDH分析得出，对于观察到的主要习性，形态指数为（1-10）、（1-10）、（-1-10）和（-1-10），对于在煤油溶剂中观察到的较不对称习性，形态指数为（1-10）（1- 10）（-1-10）（-240）（-3-10）。对于范围为0.02 - 1.13 μ m/s的所有溶液，（1-10）和（1-10）面的生长速率的测量结果是相似的，在甲苯的情况下，过饱和值明显较低。生长速率对σ的依赖趋势与正十二烷中的Burton Cabrera-Frank（BCF）生长机制、煤油中的出生和扩散（B&S）机制和甲苯溶剂中的扩散控制机制一致。
In situ studies of methyl stearate growing from supersaturated n-dodecane, kerosene, and toluene solutions reveal strong evidence that solvent choice influences the crystal morphology and crystal growth kinetics. Crystals with similar habit are observed in all solvents, with the exception of lower supersaturations in kerosene, where a less symmetric morphology was observed. BFDH analysis based on the monoclinic C2 crystal structure of methyl stearate yielded the morphological indexation to be (110), (1-10), (-110), and (-1-10) for the dominant observed habit and (110) (1-10) (-1-10) (-240) (-3-10) for the less symmetric habit observed in kerosene solvent. Measurements of the growth rate for the (110) and (1-10) faces are similar for all solutions ranging from 0.02 to 1.13 mu m/s, for significantly lower values of supersaturation in the case of toluene. The tendency of the growth rate dependence on sigma was consistent with the Burton Cabrera-Frank (BCF) growth mechanism in n-dodecane, the Birth and Spread (B&S) mechanism in kerosene and diffusion controlled in toluene solvent.