Processing and Characterization of ZrO₂-TiO₂ Porous Films by Dip Coating for Application as Environmental Sensors

Abstract

The main objective of this work is to study and characterize porous ZrO2-TiO2 films on alumina substrates that will be used for the production of porous ceramic sensors for the monitoring of air humidity in environments subject to the incidence of solar radiation. For the production of the films the dip coating technique was adopted. A viscosity study was performed to obtain stable suspensions of ZrO2-TiO2 in isopropyl alcohol with the para-aminobenzoic acid deflocculant (PABA), at concentrations of 10, 12.5 and 15% by weight of solids. X-ray diffraction (XRD) characterizations were performed for the identification of crystalline phases, morphological analyzes by scanning electron microscopy (SEM) and chemical analyzes by energy dispersive X-ray spectroscopy (EDS). The results allowed to determine the minimum value of viscosity and amount of deflocculant to stabilize the suspension. The sensor elements in the form of 1:1 (weight) ZrO2 - TiO2 porous films showed great potential to be used as sensors for the measurement of relative humidity the size and distribution of desirable pores in the porous film for application as moisture sensors was obtained with 12.5 and 15 % by weight ZrO2-TiO2