Sol-gel coating of self celaning glass surfaces and their characterization


Thesis Type: Postgraduate

Institution Of The Thesis: Gazi Üniversitesi, Fen Bilimleri Enstitüsü, Turkey

Approval Date: 2013

Student: TARIK BAZU

Supervisor: UĞUR ARABACI

Abstract:

In this study, glass surface is coated with thin films of TiO2 by using sol-gel route. TiO2 chemicals were used as precursors at the solutions prepared for film coating, and also methanol and acetyl acetone were used as solvent and chelating agent respectively. After the glass samples were dipped in to prepared solutions by using a special apparatus, they were taken into the preheated (500 °C) vertical furnace to dry, and then they were annealed at the same temperature. The thin films formed on the glass surface were characterized through the instrument of X-ray diffraction (XRD), X-ray photoelectron spectrometer (XPS), thermogravimetric and differential thermal analysis (TG-DTA), Ellipsometer, Spectrometer and anti-bacterial test devices. TiO2 peak was observed at XPS analysis though it was not seen in the result of XRD output. From the TG-DTA characterization, annealed glass temperature was determined within the interval between 400-500 °C. By means of ellipsometer analysis thickness of layers was measured and it was observed that the thickness of glass samples altered between 42 to 250 nm in accordance with the number of dipping into the solution. Spectrometer analysis indicated that the optical transparency of thin films decreased as the number of dipping increased. Dip the glass samples of different thicknesses were coated with TiO2 thin films. Different crystallization temperatures, the glass samples were coated with TiO2 thin films. Coating different points 1 microliter volume of sample surfaces made of glass distilled water (UP_ ultra-pure) were dropped. The water contact angle between the droplet and the surface of the sample was measured. Immersion did not interfere with the number of the received data. However, the angle of contact with the effect of the temperature of crystallization was observed. 300 ° C for 2 dip-coated TiO2 thin film of the sample surface has been transformed into super-hydrophilic surface structure. Finally, the TiO2 thin film coated glass samples and the samples were subjected to soot dirty in the light of the candle with a special apparatus. And the surface of the TiO2-coated glass samples soot dirty 8 Watt under UV light were subjected to hours of 24-48-72-96-120. changes that may occur in samples that are self-cleaning feature, and to observe the pictures were taken every 24 hours. The images of the samples after 120 hours when viewed under UV light, TiO2 thin film coatings and glass samples soot dirty cleaned surfaces have been identified in a visible way.