Optimal Control of Crystal Shapes in Batch Crystallization Experiments by Growth-Dissolution Cycles
Optimal Control of Crystal Shapes in Batch Crystallization Experiments by Growth-Dissolution Cycles
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DOI：
10.1021/acs.cgd.6b00288
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发表时间：
2016-06-01
影响因子：
3.8
通讯作者：
Sundmacher, Kai
中科院分区：
文献类型：
--
作者：
Eisenschmidt, Holger;Bajcinca, Naim;Sundmacher, Kai
控制结晶过程中晶体尺寸和形状分布（CSSD）的演变是结晶过程中的一项重要任务，因为最终的CSSD决定性地影响结晶材料的物理和固态性质。这项工作利用连续的生长和溶解循环，这导致在一个基本上扩大的区域可达到的晶体尺寸和形状。使用磷酸二氢钾作为模型物质，这样的循环结晶过程以舱口规模和新颖的、全自动的和受控的方式实现。为此，提出了一种新的观察者设置，这是基于视频显微镜，便于实时监测的晶体尺寸和形状分布的演变。鉴于此信息，最佳策略的控制过饱和曲线，以及CSSD实验成功实施，证明了一个可靠的和高精度的通用控制方案的晶体形状操纵。所提出的理论和实验研究结果有望在化学和制药工业中用于定向晶体尺寸和形状操纵。
The control of the evolution of the crystal size and shape distribution (CSSD) during crystallization processes is an important task in crystallization, as the final CSSD decisively influences the physical and solid state properties of crystalline material. This work utilizes sequential growth and dissolution cycles, which turn out to result in an essentially enlarged region of attainable crystal sizes and shapes. Using potassium dihydrogen phosphate as a model substance, such a cyclic crystallization process is realized in a hatch scale and in a novel, fully automated, and controlled manner. TO this end, a novel observer setup is presented; which is based on video microscopy, and facilitates the real-time monitoring of the evolution of the crystal size and shape distribution. Given this information, optimal strategies for the control of supersaturation profiles as well CSSD are experimentally successfully implemented, proving a reliable and high-precision generic control scheme for crystal shape manipulation. The proposed theoretical and experimental research results are expected to be of use in targeted crystal size and shape manipulation in chemical and pharmaceutical industries.