Products with self-cleaning and/or antibacterial surfaces include self-cleaning windows, hydrophilic ceramic tiles and antibacterial refrigerators. Recent research at Tampere University of Technology has lead to a process for production of surfaces, where self-cleaning photocatalytic and antibacterial properties are combined, and can be manufactured in a single-step process.
The goal of the project was to coat ceramic tiles with titanium oxide- silver nanoparticles, to achieve a smooth thin coating with a functional performance, with both photocatalytic and antibacterial properties. A fine quality multicomponent nanocoating was fabricated on the tiles, and a vast amount of scientific analysis of the nanoparticles from the process and of the particles on the coating were performed. The surfaces were hydrophobic, and became hydrophilic with UVillumination.
The coatings were photocatalytic, but the obtained photocatalytic reaction rate coefficients were smaller than originally expected. Also, biofilm removal was achieved but remained lower than expected. The lower efficiencies were due to thinness of the coating, i.e. the small amount of material on the surface. The surfaces were functional, but for commercial breakthrough, increasing the thickness of the film without losing the transparency requires research and development.
Project presentation: Kick-Off in May 2006 (ppt)
Project duration: May 2006 - March 2009