Fabrication of a PVP (Polyvinylpyrrolidone)-assisted TiO2 film using a high-concentrated TiO2 nano sol and its optical properties

摘要

A PVP (Polyvinylpyrrolidone)-assisted TiO₂ film with thickness over 100 nm by one step dip coating was prepared by adding polyvinylpyrrolidone (PVP) to TiO₂ nano sol and heat-treatment at the relative low temperature (450°C). The maximum refractive index of PVP-assisted TiO₂ film was measured to be 1.8764 after 5th dip coating and heat-treatment in this work. As the amount of TiO₂ sol increased, it increased, while it decreased as the quantity of PVP increased. The crystalline phase by X-ray diffraction was identified to be anatase and the intensity increased with film thickness’s increase. The maximum thickness of pure TiO₂ film prepared without crack was 1.89 μm and U.V. absorption of PVP–TiO₂ nano hybrid film before heat-treatment was measured to be over 98% at 340 nm wavelength.