Self-propagating high-temperature synthesis of potassium hexatitanate whiskers

Abstract Potassium hexatitanate (K 2 Ti 6 O 13 ) whiskers with high thermal insulating capacity, good mechanical properties, and excellent chemical stability are promising functional materials. In this study, K 2 Ti 6 O 13 whiskers were successfully prepared by one-step self-propagating high-temperature synthesis (SHS) method for the first time. Titanium dioxide (TiO 2 ), potassium carbonate (K 2 CO 3 ) and combustion accelerant with different molar ratios were mixed, and the combustion synthesis was performed using the oxygen bomb calorimeter. The effects of molar ratio TiO 2 to K 2 CO 3 , the type and the amount of combustion accelerant on the purity and morphology of products were investigated by SEM and XRD. The results showed that uniformly distributed K 2 Ti 6 O 13 whiskers with high purity, good crystallinity, and morphology were obtained when the molar ratio of TiO 2 to K 2 CO 3 and the mass ratio of benzoic acid to (TiO 2 +K 2 CO 3 ) were 4 and 2, respectively. K 2 Ti 6 O 13 whiskers of length 10 µm and 1 µm in diameter were obtained within 15 min. In addition, the benzoic acid was a better combustion accelerant than the starch and acetylene black.