Nano-scale mixing of TiO₂·nH₂O and potassium carbonate

The mixing mode of K₂CO₃ with anatase and hydrous titanium dioxide (TiO₂·nH₂O) was studied using thermoanalytical methods, XRD and TEM characterization. XRD results revealed a rather poor inter-contact in the anatase-K₂CO₃ system since there were no peaks attributed to potassic salts. On the contrary, the counterpart of the TiO₂·nH₂O-K₂CO ₃ system demonstrated the well-defined peaks ascribed to KHCO ₃ and K₂CO₃·1.5H₂O, at 25 and 300 °C, respectively. TEM characterization showed that TiO₂ crystallites in the latter tended to disperse in a favourable way and the crystallite sizes were conspicuously smaller. These results suggested that the potassic salts could enter into the framework of TiO₂·nH ₂O and restricted the further crystallite growth. Furthermore, the thermogravimetric analyses demonstrated the preferable nano-scale mixing status resulting from the reaction of K₂CO₃ with hydroxyl in the framework of TiO₂·nH₂O.