Preparation, morphology, and structure of kaolinites with various aspect ratios

Abstract A series of four kaolinite (Kaol) samples with various aspect ratios were prepared via a multi-step treatment consisting of intercalating Kaol by potassium acetate, ball-milling, de-intercalation, and classification. The morphology and structure of the samples were characterized by particle size analysis, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-Ray diffraction (XRD). Compared with intercalation by potassium acetate only or ball-milling only, intercalation followed by ball-milling was proved to be a much more effective method to delaminate Kaol to generate high aspect ratio samples. The results showed that the grade of structural order increased with an increase of Kaol aspect ratio, which was supported by an increase of Hinckley index calculated from their XRD patterns. This method offers a facile and scalable production of Kaol with various aspect ratios for different applications.