Photocatalytic gradient coatings on plastics by spray techniques

Transport coating systems applicable on plastics surfaces by a spray technique are presented. The coatings are based on highly photocatalytically active nanoscaled titania powders, surface modified with silanes containing organic or fluoro-organic side chains. The modification allows for the introduction of the particles in organic inorganic hybrid NANOMER coating systems. In the wet film - due to the evaporation of the solvents - a decompatibilisation of the coated particles to the matrix results in a self organising gradient layer formation with an up-concentration of the active particles at the interface layer between coating and air. After activation by irradiation with artificial or natural UV-light, highly active transparent photocatalysis coatings for a great variety of materials are obtained