Cashmore Andrew, Miller Russell, Jolliffe Hikaru, Brown Cameron J, Lee Mei, Haw Mark D, Sefcik Jan
Department of Chemical and Process Engineering, University of Strathclyde, 75 Montrose Street, Glasgow G1 1XJ, U.K.
CMAC Future Manufacturing Research Hub, Technology and Innovation Centre, 99 George Street, Glasgow G1 1RD, U.K.
Cryst Growth Des. 2023 Jun 20;23(7):4779-4790. doi: 10.1021/acs.cgd.2c01406. eCollection 2023 Jul 5.
In this work, we outlined an experimental workflow enabling the rapid assessment of primary and secondary nucleation and crystal growth kinetics. We used small-scale experiments in agitated vials with in situ imaging for crystal counting and sizing to quantify nucleation and growth kinetics of α-glycine in aqueous solutions as a function of supersaturation at isothermal conditions. Seeded experiments were required to assess crystallization kinetics when primary nucleation is too slow, especially at lower supersaturations often encountered in continuous crystallization processes. At higher supersaturations, we compared results from seeded and unseeded experiments and carefully analyzed interdependencies of primary and secondary nucleation and growth kinetics. This approach allows for the rapid estimation of absolute values of primary and secondary nucleation and growth rates without relying on any specific assumptions about functional forms of corresponding rate expressions used for estimation approaches based on fitting population balance models. Quantitative relationships between nucleation and growth rates at given conditions provide useful insights into crystallization behavior and can be explored to rationally manipulate crystallization conditions for achieving desirable outcomes in batch or continuous crystallization processes.
在这项工作中，我们概述了一种实验工作流程，可实现对初级和次级成核以及晶体生长动力学的快速评估。我们在搅拌小瓶中进行小规模实验，并采用原位成像进行晶体计数和尺寸测量，以量化α-甘氨酸在水溶液中的成核和生长动力学，作为等温条件下过饱和度的函数。当初级成核太慢时，尤其是在连续结晶过程中经常遇到的较低过饱和度下，需要进行接种实验来评估结晶动力学。在较高过饱和度下，我们比较了接种和未接种实验的结果，并仔细分析了初级和次级成核以及生长动力学之间的相互依存关系。这种方法无需依赖基于拟合群体平衡模型的估计方法所使用的相应速率表达式的函数形式的任何特定假设，即可快速估计初级和次级成核以及生长速率的绝对值。给定条件下成核速率与生长速率之间的定量关系为结晶行为提供了有用的见解，并且可以通过探索来合理地控制结晶条件，以在间歇或连续结晶过程中实现理想的结果。
