Toward the control of thickness and uniformity in the coating of TiO 2 -P25 on glass

Abstract : tel: +33 (0)4 72 43 17 55 ­ Fax: +33 (0)4 72 43 16 73 The deposition of TiO 2 ­P25 on Pyrex glass is studied in order to propose a procedure for obtaining uniform and adherent thin films with a controlled thickness in the range between fractions of micrometer to a few tens of micrometers. Different deposition methods such as spray­coating, dip­coating and drop­coating of liquid suspensions of TiO 2 ­P25 powder are considered. The effect of pretreatment of the glass support, as well as post­deposition steps such as drying condition and thermal treatment are also reported. A basic glass pretreatment and an acidic TiO 2 suspension are chosen for an optimized adherence of the film. Drop­coating, associated with a slow drying under 55% relative humidity and a high temperature thermal treatment is the method of choice to prepare coated glass slides in a large range of film thicknesses.