Fabrication of a pure TiO2 thin film using a self-polymeric titania nano-sol and its properties.
A pure TiO2 thin film without adding any organic binder was fabricated by using a self-polymeric titania nano-sol (14 mass%), which was prepared by the acid peptization method. The particle size distribution in the 14 mass% TiO2 sol, in which almost of particles had a size below 10.2 nm and the crystal phase confirmed by X-ray diffraction analysis was anatase. The diluted nano-sol had a capability to form a thin film at a low temperature (100-400 degrees C) on the slide glass by dipping method. The average thickness of a coating film was measured to be about 0.25-0.30 microm. A coated film had a high refractive index over 1.88 at least irrespective of the heat-treatment even at room temperature drying and showed a super-hydrophilicity (< 5 degrees) after 20 minutes under Ultra Violet light irradiation, and it sustained in the darkness during a long period over 7 days depending on the heat-treatment conditions. Atomic Force Microscopic observation shows that the morphology of a heat-treated film had a relationship with the long-term hydrophilicity in the darkness.
Department of Material Engineering, Graduate School of Paichai University, 439-6, Doma-2 Dong, Seo-Gu, Daejeon, Korea.
Won-Kyu
WK
Park
Jeong-Hwan
JH
Song
Soo-Ryong
SR
Kim
Tae-Hyun
TH
Kim
Mitusnobo
M
Iwasaki