Schiele S A, Haider T, Briesen H
Chair of Process Systems Engineering, Technical University of Munich, Gregor-Mendel-Str. 4, 85354, Freising, Germany.
Sci Rep. 2024 Sep 23;14(1):21999. doi: 10.1038/s41598-024-73127-y.
Crystallization is a commonly used unit operation for separation and purification. During processing, crystals may break due to mechanical stress, e.g., intentionally by milling or unintentionally through collision with stirrers. This study investigates the growth of broken crystals in three dimensions using X-ray micro-computed tomography. The results show that damaged regions of crystals grow faster than faceted regions, and crystals become faceted through growth. Initially, this happens on a microscale, producing faceted but concave regions on the crystal surface. Eventually, crystals become convex. Shape-healing through growth incorporates inclusions in the crystals. These findings have important implications for designing and optimizing crystallization processes in the pharmaceutical, food, and chemical industries, as purity is often a critical quality criterion adversely affected by inclusions. In addition, the kinetics in crystallization processes are likely to be strongly affected by the growth of non-faceted and concave crystals.
结晶是一种常用的分离和提纯单元操作。在加工过程中，晶体可能会因机械应力而破碎，例如通过研磨有意造成，或因与搅拌器碰撞无意导致。本研究使用X射线显微计算机断层扫描技术研究了破碎晶体的三维生长情况。结果表明，晶体的受损区域比刻面区域生长得更快，并且晶体通过生长变得有刻面。最初，这发生在微观尺度上，在晶体表面产生有刻面但凹陷的区域。最终，晶体变得凸起。通过生长实现的形状修复会将杂质纳入晶体中。这些发现对于制药、食品和化工行业中结晶过程的设计和优化具有重要意义，因为纯度通常是受杂质不利影响的关键质量标准。此外，结晶过程中的动力学可能会受到无刻面和凹陷晶体生长的强烈影响。
