Morphology control and characteristic parameter R of molten-salt-synthesized K₂Ti₆O₁₃ whiskers

The influence of reaction conditions including reaction temperature, reaction duration, and molar ratio of reactants on the morphology of products was systematically investigated, in order to prepare potassium hexatitanate (K₂Ti₆O₁₃) whiskers with uniform morphology and high crystallinity by molten salt synthesis toward industrial applications. Three typical types of K₂Ti₆O₁₃ whiskers including short, long, and thick K₂Ti₆O₁₃ whiskers with the length and diameter ranges falling in 0–20 and 0.5–2 μm, 10–50 and 0.5–1 μm, and 10–50 and 2–10 μm, respectively, are presented in particular. After surface modification with silane coupling agent A-172, all the three K₂Ti₆O₁₃ whisker samples can evenly disperse in butyl acetate forming parallel arrays along the preferential growth direction [010] and exhibit predominated peaks of crystallographic planes of (200) and (20\( \bar{1} \)) in X-ray diffraction patterns. A characteristic parameter R which is sensitive to the reaction conditions and directly relates to the size and crystallinity of K₂Ti₆O₁₃ whiskers was developed from the intensity ratio of (200)/(20\( \bar{1} \)) in order to quickly evaluate the feature of K₂Ti₆O₁₃ whiskers.