ترجمه مقاله خواص خود تمیز شوندگی و قدرت چسبندگی پوشش شفاف فتوکاتالیستی TiO2-ZnO بر روی پلی کربنات - نشریه ACS

Transparent layers containing TiO2 have been intensively studied based upon their interesting application potential including photocatalytically active and self-cleaning surfaces. In the present work, transparent TiO2-ZnO thin films on a SiO2 interlayer have been successfully deposited on the surface of polycarbonate to provide polymeric sheets with a self-cleaning, superhydrophilic, and photocatalytically active surface layer. To ensure a good adhesion of the SiO2 interlayer, the polycarbonate sheets have been firstly modified by irradiation with UV(C) light. The prepared films were characterized by UV/Vis spectrophotometry, SEM, XRD, Raman spectroscopy, ellipsometry, and water contact angle measurements. All prepared films are transparent with thicknesses in the range between 120 and 250 nm and possess superhydrophilic properties. Moreover, they exhibit good adhesion qualities as defined quantitatively by cross-cut tests. On the other hand, their mechanical strengths, checked by felt-abrasion tests, differ by changing the molar TiO2-ZnO ratio. The photocatalytic activity, expressed as photonic efficiency, of the coated surfaces was estimated from the kinetics of the photocatalytic degradation of methylene blue and methyl stearate. The combination between superhydrophilic properties and photocatalytic activity was determined by studying the change of water contact angle during the storage of the prepared films in the dark under ambient atmosphere and under an atmosphere containing either acetone or isopropanol followed by UV(A) irradiation. In addition, self-cleaning properties were examined by determining the changes of contact angle during the irradiation time after applying oleic acid to the surface. The results show that increasing the molar ratio of ZnO in TiO2 coatings up to 5% yields maximum photonic efficiency values of 0.023% as assessed by the photocatalytic degradation of methylene blue. Moreover, the superhydrophilic coating with a molar TiO2-ZnO ratio of 1: 0.05 exhibits the best self-cleaning properties combined with a good mechanical stability and a very good stability against UV irradiation.