MECHANOCHEMICAL ADSORPTION OF PHENOL BY TOT SWELLING CLAY-MINERALS II- SIMULTANEOUS DTA AND TG STUDY

The mechanochemical adsorption of phenol by laponite, saponite, montmo rillonite, beidellite and vermiculite was studied by simultaneous DTA and TG analysis. Fitting of the DTA curves showed four endothermic pea ks in the r.t. -250 degrees C temperature range. The first peak repres ents the melting of the excess crystalline phenol. The second peak rep resents the evolution of water. The third peak represents the boiling of the free phenol. The fourth peak represents the evolution of adsorb ed phenol. In the DTA curves of montmorillonite the fourth peak is not observed as a separate peak but as part of the third peak. Laponite, saponite and montmorillonite show a very small exothermic effect which follows the endothermic events. Iaponite adsorbs the greatest amounts of phenol and shows a strong exothermic peak at 390 degrees C. None o f the other clays show this exothermic effect at this temperature.