Predicting crystal growth via a unified kinetic three-dimensional partition model

Abstract

2017) 'Predicting crystal growth via a uni ed kinetic three-dimensional partition model. ', Nature., 544 (7651). pp. 456-459. Further information on publisher's website:https://doi.org/10.1038/nature21684Publisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Understanding and predicting the course of crystal growth is fundamental to the control of functionality in modern materials. Despite investigations for over one hundred years 1-5 it is only recently that the molecular intricacies of these processes have been revealed by scanning probe microscopies 6-8 . In order to bring some order and understanding to this vast amount of new information requires new rules to be developed and tested. To date, because of the complexity and variety of different crystal systems, this has relied on developing models that are usually constrained to one system only 9-11 . Such work is painstakingly slow and will not be able to achieve the wide scope of understanding in order to create a unified model across crystal types and crystal structures. Here we describe a new approach to understand and, in theory, predict the growth of crystals, including the incorporation of defect structures, by simultaneous molecular-scale simulation of crystal habit and surface topology using a unified kinetic 3-D partition model. We exemplify our approach by predicting the crystal growth of a diverse set of crystal types including zeolites, metal-organic frameworks, calcite, urea and L-cystine.By understanding crystal growth at the molecular scale we have the possibility to control crystal habit, crystal size, the elimination or incorporation of defects and the development of intergrowth structures. As crystals are used in technologies from pharmaceuticals to gas storage and separation materials, from optoelectronic devices to heterogeneous catalysts, such understanding is vital. If we take an example of a very complex and yet very important crystal type, that of zeolites 12 which form the backbone of the heterogeneous catalysis industry, then many of the problems that must be addressed in crystal growth can be illustrated. Zeolites are nanoporous materials were the framework of the material is constructed from a strong covalently bonded network of Si -O and Al -O bonds. The pores of the material are filled with water and cations that balance the negative charge on the framework. Crystals of zeolites grow from aqueous solutions at temperatures up to about 230 o C and it is well known from NMR spectroscopy that...

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