Morphology and orientation of curling of kaolinite layer in hydrate

Abstract

In order to determine if there are curlings along other directions than [100] and [010] in kaolinite (Kaol) layer, 1nm Kaol hydrate with 85% yield was synthesized by the fluorine-free method. Its structure and morphology were investigated by X-ray diffraction (XRD), field emission transmission electron microscopy (FETEM) and selected area electron diffraction (SAED). The results show that: (1) there are not only single curling and two opposite parallel curlings, but also two adjacent curlings with about 120° angle in one single layer; (2) there are four new orientations of curlings [11¯0], [110], [310] and [31¯0] in Kaol hydrate. The reasons that Kaol layers can curl along multiple directions may be that: first, two types of incompatible matchings between tetrahedrons and octahedrons; second, the hexagonal distribution and the zigzag distribution of two types of matchings.