R S Subramanya
Articles written in Proceedings – Section A
Volume 25 Issue 2 February 1947 pp 186-189
The effect of variation of activation temperature on the hysteresis effect has been studied for titania gel. Sorption and desorption of water vapour at 30°C. on titania gels activated at 30°C., 97°C., 214°C, 400°C., 600°C. and 1000°C. have been measured.
At different temperatures of activation, permanent and reproducible hysteresis loops have been obtained. There is however, a marked variation in the total sorptive capacity, the area of the hysteresis loops and the relative vapour pressures corresponding to the tail end of the hysteresis loops.
The results indicate that with an increase in the temperature of activation from 30°C. to 97°C., there is a small increase in the total capillary space and in the total cavity volume. Above 97°C., the gel suffers a structural change with a diminution in capillary space and in cavity volume. There is also a collapse of the smaller cavity necks. At 1000°C., there is a breakdown of the gel structure and a complete collapse of the capillary space.