Effective Air-Spray Deposition of Thin Films Obtained by Sol-Gel Process onto Complex Pieces of Sanitary Ware

A deposition mechanism by air‐spray technique is carried out for depositing silica‐based thin films obtained by the sol–gel process. The air‐spray deposition is very useful to coat large and complex surfaces with different morphologies and roughnesses which favors the technology scale‐up, contrary to the most used deposition methods in the sol–gel process (dip and spin coating). To establish the adequate conditions of these techniques, a complete study of the sol properties (rheology, FT‐IR, roughness, thickness) is attempted, which has allowed determining the parameters for the effective air‐spray deposition of homogeneous thin films. By means of an experimental design, it has been possible to validate the selected parameters. Finally, a scheme of an effective spray deposition model is proposed for a better understanding of the deposition mechanisms.