초록 |
It is well known that TiO2 photocatalyst can destroy organic pollutants as well as harmful microorganisms. Recently, especially in Japan, lots of TiO2 coated materials have been commercialized in environmental and sanitary fields such as the removal of indoor air pollutants and prevention of kitchen and bathroom from harmful microorganisms. For these applications, thin film TiO2 photocatalyst coated on suitable substrates should have not only good physical properties such as cohesiveness but also photocatalytic activity. In particular, if TiO2 film can be strongly fixed on the substrate without high temperature heat treatment, more wide applications can be expected. We developed TiO2 sols that can be coated on construction materials under room temperature drying without any heat treatment. Physical and photochemical properties such as cohesiveness, hydrophilicity, photocatalytic degradation of VOC, and the bactericidal efficiencies of the coated construction materials were examined. In this study, 12 different kinds of TiO2 sol depending on binders and solvents were prepared and dip coated on three kinds of construction materials: glass, steel and tile. It was found that the optimal TiO2 sol was a different kind for each substrate. Binding hardness was strong enough for practical applications and the hydrophilicity of the UV-illuminated film surface was also good enough to have anti-fogging effect. VOC removal and bactericidal efficiencies of materials coated by our TiO2 sol were also better than those of other commercialized TiO2 sols. |