Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou, 215006, China.
Chem Soc Rev. 2014 Apr 7;43(7):2324-47. doi: 10.1039/c3cs60398a. Epub 2014 Jan 17.
In the last few decades, the controlled colloidal assembly was adopted as a new modelling technology for the study of the crystallization mechanism. In colloidal systems, the movement of particles is slow enough to follow and the particle dynamics can be monitored at the single-particle level using normal optical microscopes. So far, the studies of colloidal crystallization have produced a number of insights, which have significantly improved our understanding of crystallization. In this review, we summarize the recent advances in understanding the mechanism of crystallization, which were achieved using colloidal model systems, i.e., the kinetics of nucleation, growth and defect formation. Such model systems allow us to not only visualize some "atomic" details of nucleation and surface processes of crystallization, but also quantify previous models to such an extent that has never been achieved before by other approaches. In the case of nucleation, the quantitative observation of the kinetic process was made at the single-particle level; the results include the ideal case and the deviations from classical theories. The deviations include multi-step crystallization, supersaturation-driven structural mismatch nucleation, defect creation and migration kinetics, surface roughening, etc. It can be foreseen that this approach will become a powerful tool to study the fundamental process of crystallization and other phase transitions.
在过去的几十年中，胶体的受控组装已被采用作为研究结晶机制的新模型技术。在胶体体系中，颗粒的运动速度足够慢，可以使用普通光学显微镜在单粒子水平上跟踪和监测颗粒动力学。到目前为止，胶体结晶的研究已经产生了许多新的认识，这些认识极大地提高了我们对结晶的理解。在这篇综述中，我们总结了使用胶体模型系统（即成核、生长和缺陷形成的动力学）来理解结晶机制的最新进展。这样的模型系统不仅可以使我们直观地看到成核的一些“原子”细节和结晶的表面过程，而且还可以在以前从未通过其他方法实现的程度上对这些模型进行量化。在成核的情况下，在单粒子水平上对动力学过程进行了定量观察；结果包括理想情况和偏离经典理论的情况。这些偏离包括多步结晶、过饱和度驱动的结构失配成核、缺陷形成和迁移动力学、表面粗化等。可以预见，这种方法将成为研究结晶和其他相变的基本过程的有力工具。
