Introducing Self-cleaning Property to Acrylic Coatings using Fluorosilane Treated TiO2 Nanoparticles

In this research, Aeroxide P25 as a commercial TiO2 nanoparticle was treated with Flouroalkyltriethoxysilane (FTS) in an alkaline condition. Surface treatment of nanoparticles was characterized using FTIR and TEM analyses. Adsorption mechanism of FTS on the surface of TiO2 nanoparticles was investigated using ATR-FTIR technique. pH of the treatment reaction media and the turbidity of FTS alcoholic solution were measured during the first step of the treatment. The treated nanoparticles were then added into an acrylic coating to provide self-cleaning property. Degradation of Rhodamine B (Rh.B) dyestuff as a colorant model on the surface of coatings was investigated by means of colorimetric measurements, while the coating samples were exposed to UVA irradiation. The results confirmed the presence of fluorosilane compound on the surface of TiO2 nanoparticles and therefore, increasing nanoparticles hydrophobicity. ATR-FTIR spectra revealed FTS hydrolysis and turbidity of FTS in alkaline solution showing gradual polymerization of FTS in the media. Because of negative charge of fluoro atom on the polymerized FTS and the positively charged TiO2 nanoparticles in the treatment process, hydrogen bonding found out to be as the dominant mechanism of adsorption. The colorimetric measurements results showed that the addition of the treated nanoparticles into an acrylic polymer provides self-cleaning property to the coatings in a controlled manner.