Splitting behavior and structural transformation process of K ₂Ti₆O₁₃ whiskers under hydrothermal conditions

The splitting behavior and structural transformation process of K ₂Ti₆O₁₃ whiskers in various hydrothermal solutions were investigated by the X-ray diffraction technique, scanning electron microscopy, transmission electron microscopy, and atomic force microscopy. TiO₂ (B) particle aggregates and rutile twinned crystals were produced respectively in diluted and concentrated HCl solutions via "dissolution-precipitation" mechanism, while no changes were observed in deionized water. In contrary to the chemical inertia of K₂Ti ₆O₁₃ whiskers in KOH solution, trititanate nanowires were synthesized by splitting the bulk K₂Ti₆O₁₃ whiskers in NaOH solution. The driving force for the formation of nanowires originated from the intrinsic strain induced by the phase transition from K ₂Ti₆O₁₃ with a tunnel structure to layered trititanate.