Hydrophilicity of Silica Nano-Porous Thin Films: Calcination Temperature Effects

In this research work, silica nano-porous thin films were deposited on glass substrates by layer by layer method. The thin films were calcinated at various calcination temperatures (200, 300, 400, and 500 °C). The morphology, surface characteristics, surface roughness and hydrophilic properties of the thin films were investigated by field emission scanning electron microscopy, attenuated total reflectance fourier transform infrared spectroscopy, atomic force microscopy and water contact angle analyzer. The surface characteristic showed that silica nano-porous thin film had an amorphous structure. The hydrophilic results indicated that the water contact angle of the glass coated silica nano-porous surface is decreased by increasing the calcinations temperatures to 300 °C and at higher temperature, it is increased. The deposition of silica nano-porous thin film on the glass surface at the optimum calcination temperature (300 °C) decreased water contact angle of the glass surface from 67° to 3°. Therefore, silica nanoporous thin film calcinated at 300 °C showed superhydrophilicity which greatly encourages the antifogging functions of the thin film.