Effects of Air Exposure Time and Annealing Temperature on Superhydrophobic Surface of Titanium Dioxide Films

Abstract:

TiO₂ thin films coated on glass substrates for self-cleaning applications were prepared by sol-gel dip-coating technique. The influence of annealing temperature and air exposure time on wettability was investigated by a water contact-angle measurement. Thermal annealing at temperatures of 100, 200 and 300 °C in air were conducted to the films. Surface morphology of the films was observed by FE-SEM. Elemental distribution and optical properties were examined by EDX mapping and UV-Vis transmission spectroscopy, respectively. Atomic bonding was confirmed by FTIR. The contact angle reached a maximum when the films were annealed at 200 °C. The contact angles of the as-synthesized films were 61.4±2.7°. During storage in air for 20 days, the contact angles increased to 143.1±2.1°. The films were further reannealed with 100 °C for 20 min, the contact angles were enhanced to 153.1±1.3°. The association of contact angle among the surface morphology, elemental distribution and atomic bonding of the films will be discussed.

• Periodical: Key Engineering Materials (Volume 751)
• Pages: 137-142
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.751.137
• Online since: August 2017
• Authors: S.Tipawan Khlayboonme*, Warawoot Thowladda
• Keywords: Hydroxyl Groups, Superhydrophobic Surface, TiO₂ Thin Films, Water Contact Angle

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