More about PHOTOCATALYTIC SELF-CLEANING COATING:
Dirt collection (accumulation) in building exteriors have poised considerable problems for building maintenance. Cleaning such building surface is generally done by using detergents accompanied with scrubbing, wiping and high-pressure water jet. These processes have several shortcomings such as use of chemical detergents, high consumption of energy and labour cost. These naturally lead to high maintenance cost; therefore, an effective self-cleaning coating is desirable.
In recent years, "self-cleaning" coating using photocatalytic Titanium Dioxide (TiO2) has gained considerable industry attention. With assistance of little UV light from fluorescence source or sunlight, TiO2 offers two unique properties: (a) strong oxidation power, and (b) super-hydrophilicity.
Strong oxidation power can be used to kill bacteria attached on the wall, or oxide/remove foul smell from stains in toilet (e.g., TiO2-coated tile and TiO2-coated glass are commercially available). Super-hydrophilic property can allow dirt and stains to be easily washed away with water or by rainfall when such coating is applied to exterior surfaces. However, due to its strong photoreactivity, TiO2 coating cannot be coated directly onto an organic paint surface because this will attack the paint surface, causing the so- called paint-chalking phenomenon. This factor has limited the applications of TiO2 coatings.
The present invention provides a highly novel and effective technique for providing an inorganic-organic layer to serve in between a painted surface and TiO2 coating to avoid the effect of paint-chalking. This interlayer functions as a binder TiO2 particles and as well as a barrier to prevent substrate-damage from the photocatalytic reaction. Using this approach, continuous and sustained self-cleaning effects can be realized on t
|Contact: Cathy Yarbrough|
Agency for Science, Technology and Research (A*STAR), Singapore