Synthesis of hexatitanate and titanium dioxide fibers by ion-exchange approach

Hexatitanate (K2Ti6O13) and titanium dioxide (TiO2) fibers were synthesized by ion-exchange method using fibrous potassium titanate (K4Ti3O8) as initial material. Fibrous K4Ti3O8 was prepared by treating TiO2 with 80 wt.% concentrated KOH solution at 220 °C for 2 h under atmospheric pressure. Then, high qualities of K2Ti6O13 and TiO2 fibers were formed by a thermal treatment of the hydrolytic intermediates K4−bHbTi3O8 (1.2 ≤ b ≤ 3.0) and H4Ti3O8, which were quantitatively obtained by controlling the pH value ranging from 10.9 to 12.0 and from 2.0 to 5.0 in the hydrolytic process of K4Ti3O8, respectively. Based on the experimental results, the possible ion-exchange and phase transformation mechanisms in the reaction process were discussed.