TiO2TiO2 mesoporous thin films studied by Atmospheric Ellipsometric Porosimetry: A case of contamination

Anatase mesoporous TiO2TiO2 thin films are frequently prepared by surfactant templating to control porosity development and Atmospheric Ellipsometric Porosimetry is a reliable and fast technique allowing the determination of the porosity of such films. After prolonged exposition to high-vacuum (6.4×10-6mbar), the films porosity exhibits a degraded behavior during porosimetric measurements, indicating a vacuum-induced modification. The main effect resulting from such exposition to high-vacuum is a wettability modification of the films, resulting in an increase of the hydrophobic character of the TiO2TiO2 surface. This evolution induces non-correct results in porosimetric measurements due to the fact that the contact angle parameter needed to calculate the pore size distribution is highly different from the reference films. A surface contamination explains such modifications and a restoration of the films is obtained by using ultraviolet treatment.

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► Anatase Titania mesoporous thin films studied by AEP.
► Mesoporous thin films sensitive to vacuum-induced modifications.
► Vacuum-induced surface contamination, properties restoration using UV irradiations.
► Uncommon porosimetric results explained by properties of Titania and AEP technique.