Top-level performance

Photocatalytic paints can damage the underlying substrate if photocatalysis occurs in contact with this surface. Based on this background, efforts have been made to develop a single-layer-type of photocatalytic paint that does not require the prior application of a protective layer. The single-coat photocatalytic paints so far proposed are those in which titanium dioxide particles are located only near to the surface of the coating, due to phase separation in the drying process. When the particles have some repulsive force in relation to the matrix polymer, they float up to the air-liquid interface and remain there. The white- colored acrylic board shown on the left side presented dirt stripes caused by rain. On the other hand, no stripes of dirt were observed on the test plate coated with the floating particle paint. This clearly indicated that the painting with photocatalytic floating particles showed excellent antifouling characteristics.