General Strategy for Fine Manipulating Crystal Growth of Water-Soluble Salts

Abstract

In this work, a general strategy was proposed for fine manipulating intrinsic growth of water-soluble salts belonging to different crystal systems. Various hollow microsphere hierarchical architectures assembled with hopperlike single crystal blocks of cubic KBr, orthorhombic (NH₄)₂SO₄, or hexagonal Na₂SO₃ have been designed and prepared via microemulsions. Intrinsic growth manipulations of different water-soluble salts has been successfully achieved by preventing growth of the outside surface of each single crystal block via a diffusion-limit effect of the interfaces between the oil phase and aqueous droplets. As a result, hopperlike single crystals of water-soluble salts belonging to different crystal systems were formed. Furthermore, octahedral NaCl hopperlike single crystal, rather than their typical cubic shape, has also been fabricated by manipulating their growth rates along different lattice directions in combination with urea as additives. The large amount of fine manipulation of intrinsic growth of water-soluble salts will provide us with a deep understanding of crystallography of inorganic salts, as well as facilitate design and production of water-soluble salts architectures with corresponding shapes, according to the different requirements