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

Abstract

Hexatitanate (K 2Ti 6O 13) and titanium dioxide (TiO 2) fibers were synthesized by ion-exchange method using fibrous potassium titanate (K 4Ti 3O 8) as initial material. Fibrous K 4Ti 3O 8 was prepared by treating TiO 2 with 80 wt.% concentrated KOH solution at 220 °C for 2 h under atmospheric pressure. Then, high qualities of K 2Ti 6O 13 and TiO 2 fibers were formed by a thermal treatment of the hydrolytic intermediates K 4− b H b Ti 3O 8 (1.2 ≤ b ≤ 3.0) and H 4Ti 3O 8, 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 K 4Ti 3O 8, respectively. Based on the experimental results, the possible ion-exchange and phase transformation mechanisms in the reaction process were discussed.