FLAME AEROSOL SYNTHESIS OF TIO2 NANOPARTICLE COATINGS WITH ADVANCED ANTIBACTERIAL AND HYDROPHILIC PROPERTIES

In this work, the production of thin coating layers of TiO2 nanoparticles by aerosol flame synthesis and direct thermophoretic deposition is reported. Three different flame reactor configurations were designed in order to study the effect of particle size on the performances of coating layers. The wetting behavior was investigated by water contact angle analysis, showing that titania coating layers are characterized by a high photoinduced hydrophilicity. Measurements of the inhibition of Staphylococcus aureus biofilm formation revealed a high antibacterial activity from TiO2 nanoparticle films. Hydrophilic character and bactericidal effect are found to be mainly dependent on the dimension of primary particles composing the coating layers. The optimal synthesis conditions have been identified to produce a self-cleaning and self-disinfecting coating layer material, with a nearly superhydrophilicity and a high antibacterial activity, both activated by normal ordinary solar light radiation in standard room illumination conditions.