J. Phys. IV France 125 (2005) 583-585
Photoacoustic monitoring of dehydration in sol-gel titania emulsionsT. Lopez1, M. Picquart1, D.H. Aguilar2, P. Quintana2, J.J. Alvarado-Gil2 and J. Pacheco3
1 Universidad Autonoma Metropolitana-Iztapalapa, A.P. 55-534, 09340 Mexico, DF, Mexico
2 Cinvestav del IPN-Unidad Merida, Departamento de Fisica Aplicada, A.P. 73, 97310 Merida, Yucatan, Mexico
3 Facultad de Ingenieria, UADY, A.P. 150, 97111 Merida, Yucatan, Mexico
The dehydration process at ambient conditions (25°C and 70% relative humidity) of titania aqueous emulsions, was monitored using the photoacoustic technique. Titania was obtained by the sol-gel method, the powders were thermally treated from ambient temperature up to 700ºC and dispersed in water to form an emulsion. The photoacoustic signal as a function of time, shows two dehydration stages which were parametrized as a sigmoidal curve. The mechanisms inducing the increase in the dehydration rate with the temperature pretreatment are discussed.
© EDP Sciences 2005