Plain Table Salt Structure is Out-of-date----Hefei Institutes of Physical Science, The Chinese Academy of Sciences

Supported by the National Natural Science Foundation of China and the National Basic Research Program of China, recently, researchers led by Prof. Dr. Zhongping Zhang and Suhua Wang of the Chinese Academy of Sciences’ Institute of Intelligent Machines, discovered the hopper-like single crystals of table salt and their assemblies of hollow spheres when the crystals were grown at the interface of metastable water microdroplets. The research findings have just been published in the famous international journal Angew. Chem. Int. Ed. (DOI: 10.1002/anie.201101704).
Sodium chloride, also known as table salt that is daily used as an additive in our foods, has always been dedicated in the most classical topic of crystallization chemistry as the representative of perfect cubic crystals that always appear in the form of highly regular cubes in both natural and artificial environments. With the advance in nanotechnology, researchers have succeeded in the controls of crystallographic morphology and assembly of various water-insoluble compounds, and thus found many unique physical/chemical properties based on nanometer-scaled structures. On the contrary, water-soluble salts as a large family of inorganic compounds have also been explored for the production of heterogeneous crystalline shape and structures, but their intrinsic crystal habits have not yet been prodigiously changed. Just recently, the Zhang and Wang’ group have successfully constructed the hopper-like single crystals of sodium chloride and potassium chloride and their uniform arrangement in the form of hollow microspheres at the interface of metastable water microdroplets. The discovery shed bright insights into the crystal growth mechanism, and can be extended to the controls of crystallization and assembly of other water-soluble species such as inorganic, organic and biological materials. The Editor, Angew. Chem. Int. Ed., thought this work is a very interesting and should be highlighted in the frontispieces. The referee pointed that the discovery not only enriches the content of textbooks, but also attracts a number of chemists and material scientists to deeply explore the promising fields.