Chemical resistance and cleaning properties of coated glazed surfaces

The effects of sol–gel-derived ceramic titania and zirconia coatings on staining resistance and cleanability of two matt and one glossy glazed tile were characterized. The surfaces were soaked in a weakly alkaline detergent solution in order to imitate the influence of normal household detergents on the surface properties. The soaking caused the water contact angle of the surfaces to decrease and also changes were observed in the average surface roughness. The surfaces were soiled with one color marked and two radiochemically labeled soil mixtures of oils and inorganic or organic particles. Under normal laboratory illumination conditions, the soils consisting of oil and inorganic particles were more easily cleaned from the surfaces than the soil with oil and organic particles. All surfaces soiled with the color marked mixture were also studied under exposure to UV light. The titania coating increased the cleanability and also showed self-cleaning capability after exposure to UV light, whereas exposure to UV increased the soil adherence to the zirconia-coated surfaces.