Ceramic interface properties evaluation based on contact angle measurement

The ceramic interface properties and morphology were estimated based on contact angle measurements. The contact angle, θ, was measured using different liquids (glycerol, NaCl 3.5% solution, oleic acid and ultra pure water) with known surface tensions. Correlations of the contact angle with the chemical bonds and morphology of thin films are presented. The thin films, deposited via Spray Pyrolysis Deposition (SPD) are TiO₂ (dense, porous) and WO₃ (dense, porous) films.The interface properties of the ceramic layers were explained using the topography images obtained with Atomic Force Microscopy (AFM), and by measuring the contact angles and surface tensions.The contact angles method is sensitive at high θ values. The experiments indicated that the recommended testing liquid is pure water, both for TiO₂ and WO₃ thin films, allowing a clear difference between dense and porous surfaces. The measurements were done at the initial moment of the contact drop-sample and with 1 s step up to 30 min. The presented results can be further used in optimizing the layer-by-layer deposition of thin films.