J. Phys. IV France
Volume 125, June 2005
Page(s) 649 - 652

J. Phys. IV France 125 (2005) 649-652

DOI: 10.1051/jp4:2005125148

Adsorption and desorption kinetics in ZrO2 - TiO2 by photoacoustic techniques

A. Pinto Neto1, D. Moura2, C. Kuranaga3, M.D. Silva3 and L.C.M. Miranda3

1  Universidade Federal do Maranhão, UFMA, Brazil
2  Universidade de Taubaté, UNITAU, Brazil
3  Instituto Nacional de Pesquisas Espaciais, INPE, Brazil

In this paper we report on the photoacoustic (PA) characterization of ZrO2-TiO2 ceramic wafers as a sensing element for solvent adulteration evaluation. The experiments consisted of photoacoustic time dependent monitoring of the sorption and desorption of a droplet of a solvent deposited on the outer face of a ceramic wafer. The used solvents were isopropanol and chloroform. For the polar isopropanol molecule the results shown diffusion into the sample, with a characteristic diffusion time $\tau_1$, accompanied by the evaporation at a rate with a time constant $\tau_2$. Indeed, for the non polar chloroform, wetting-drying kinetics is adequately described by a simple diffusion-evaporation.

© EDP Sciences 2005