The Surface Properties of Rutile Prepared by the Hydrolysis of Titanium Tetrachloride. I. The Heat of Immersion in Water

The surface properties of rutile prepared by hydrolyzing titanium tetrachloride have been studied by measuring the heat of immersion in water as a function of the outgassing temperature. The heat of immersion showed an extremely large value at outgassing temperatures between 300 and 400°C. However, when the rutile was calcined at 800°C, it showed a heat-of-immersion curve similar to those hitherto reported. In order to examine the phenomenon found on uncalcined rutile, the amounts of water physically and chemically adsorbed on the surface were estimated by measuring the water-vapor adsorption. We found that hydroxyl groups were formed in bulk as well as on the surface by means of the chemisorption, resulting in the formation of a hydrous structure because of the low crystallinity of the sample at temperatures below 400°C.