Fabrication of titania dense layers by electrophoretic deposition in aqueous media

Fabrication of titania dense layers by electrophoresis in aqueous media has been studied according to the suspension formulation. Stable titania suspensions with negatively charged particles are obtained by adding either the strong basis (C2H5)4NOH, or the Tiron molecule or a salt of polymethacrylic acid. To prevent water electrolysis at the anode which is the collecting electrode, ethanol is added as cosolvent. A concentration of 10 vol% is sufficient to avoid gaseous emission at the anode and to keep a stable suspension suitable for electrophoretic deposition (EPD). The parameters influencing the deposit kinetic of particles are studied, such as the concentration of ethanol, of solid and of dispersant, and the current intensity applied. Finally, it is possible to fabricate layers with a relative density of 60% with a very narrow size distribution of pores.