Self Katherine, Telfer Michael, Greer Heather F, Zhou Wuzong
EaStCHEM, School of Chemistry, University of St Andrews, St Andrews KY16 9ST (UK), Fax: (+44) 1334-468308.
Chemistry. 2015 Dec 21;21(52):19090-5. doi: 10.1002/chem.201503437. Epub 2015 Nov 18.
RHO zeolitic imidazolate framework (ZIF), Zn1.33 (O.OH)0.33 (nim)1.167 (pur), crystals with a rhombic dodecahedral morphology were synthesized by a solvothermal process. The growth of the crystals was studied over time using scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (PXRD) and Brunauer-Emmett-Teller (BET) analyses, and a reversed crystal growth mechanism was revealed. Initially, precursor materials joined together to form disordered aggregates, which then underwent surface recrystallization forming a core-shell structure, in which a disordered core is encased in a layer of denser, less porous crystal. When the growth continued, the shell became less and less porous, until it was a layer of true single crystal. The crystallization then extended from the surface to the core over a six-week period until, eventually, true single crystals were formed.
通过溶剂热法合成了具有菱形十二面体形态的RHO型沸石咪唑框架（ZIF），即Zn1.33（O.OH）0.33（nim）1.167（pur）晶体。利用扫描电子显微镜（SEM）、透射电子显微镜（TEM）、粉末X射线衍射（PXRD）和布鲁诺尔-埃米特-泰勒（BET）分析，对晶体随时间的生长过程进行了研究，并揭示了一种反向晶体生长机制。最初，前驱体材料结合在一起形成无序聚集体，然后进行表面重结晶形成核壳结构，其中无序的核被一层密度更大、孔隙率更小的晶体包裹。当生长继续时，壳层的孔隙率越来越小，直到成为一层真正的单晶。然后，结晶在六周内从表面扩展到核心，最终形成真正的单晶。
